Measurement of differential cross sections in the kinematic angular variable ϕ* for inclusive Z boson production in pp collisions at $$ \sqrt{s}=8 $$ TeV

Journal of High Energy Physics, Mar 2018

Abstract Measurements of differential cross sections dσ/dϕ* and double-differential cross sections d2σ/dϕ*d|y| for inclusive Z boson production are presented using the dielectron and dimuon final states. The kinematic observable ϕ* correlates with the dilepton transverse momentum but has better resolution, and y is the dilepton rapidity. The analysis is based on data collected with the CMS experiment at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 19.7 fb−1. The normalised cross section (1/σ) dσ/dϕ*, within the fiducial kinematic region, is measured with a precision of better than 0.5% for ϕ* < 1. The measurements are compared to theoretical predictions and they agree, typically, within few percent. Open image in new window

A PDF file should load here. If you do not see its contents the file may be temporarily unavailable at the journal website or you do not have a PDF plug-in installed and enabled in your browser.

Alternatively, you can download the file locally and open with any standalone PDF reader:

https://link.springer.com/content/pdf/10.1007%2FJHEP03%282018%29172.pdf

Measurement of differential cross sections in the kinematic angular variable ϕ* for inclusive Z boson production in pp collisions at $$ \sqrt{s}=8 $$ TeV

HJE Measurement of di erential cross sections in the Measurements of di erential cross sections d =d sections d2 =d djyj for inclusive Z boson production are presented using the dielectron and dimuon nal states. The kinematic observable momentum but has better resolution, and y is the dilepton rapidity. The analysis is based on data collected with the CMS experiment at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 19.7 fb 1 . The normalised cross section (1= ) d =d , within the ducial kinematic region, is measured with a precision of better than 0.5% Hadron-Hadron scattering (experiments); Particle correlations and uctua- - boson 8 TeV p The CMS collaboration for < 1. The measurements are compared to theoretical predictions and they agree, typically, within few percent. 1 Introduction 2 3 4 5 6 7 8 9 The CMS detector Event reconstruction and selection Monte Carlo simulation Analysis method Background estimation Unfolding Systematic uncertainties Theoretical predictions 10 Results 11 Summary The CMS collaboration 1 Introduction The neutral current Drell-Yan (DY) process, qq ! Z= ! `+` , where ` is either an electron or a muon, is one of the best studied physics processes at the CERN LHC. The total and di erential cross sections have been calculated theoretically at next-to-next-toleading order (NNLO) accuracy in the strong coupling S [1{4]. The di erential cross section as a function of dilepton invariant mass d =dm`` has been measured by the LHC experiments at di erent centre-of-mass energies [5{8]. Theoretical calculations reproduce the measurements over nine orders of magnitude at the level of a few percent. The large production cross section and the experimentally clean nal state of the DY process allow for detailed studies of kinematic distributions that serve as stringent tests of the perturbative calculations. One of the most interesting observables is the transverse momentum qT of the Z boson, which is related to its production mechanism. The lower range of qT values are caused by multiple soft-gluon emissions, whereas high qT values result from the emission of one or more hard partons in association with the Z boson. Another interesting observable is the rapidity y of the Z boson which depends on the di erence in { 1 { p momentum between the parent partons in the colliding protons; therefore, the cross section as a function of y depends on the parton distribution functions (PDF). The qT spectrum of the Z boson has been measured by the ATLAS, CMS and LHCb Collaborations at s = 7 TeV [9{11]. Recently, both the CMS and ATLAS Collaborations have extended the study at 8 TeV by performing double-di erential measurements as functions of qT and y [12, 13]. Calculations based on xed-order perturbative quantum chromodynamics (QCD) [14] describe these measurements fairly well. A thorough understanding of the qT spectra of the electroweak vector bosons is essential for high-precision measurements at the LHC, in particular that of the mass of the W boson. Furthermore, the theoretical calculation of the transverse momentum distriform factors [15], which are closely related to those appearing in the calculations for qT. Thus precise measurements of vector boson production are important for validating the theoretical calculations of Higgs boson production at the LHC. An important issue in the accurate measurement of the di erential cross section d =dqT is the experimental resolution of qT, which is dominated by the uncertainties in the magnitude of the transverse momenta of the leptons from the decay of the Z boson. The angles subtended by the leptons, however, are measured more precisely due to the excellent spatial resolution of the CMS tracking system. A kinematic quantity [16{18], derived from these angles, is de ned by the expression = tan 2 sin( ): (1.1) section d 2 =d integrated luminosity of L = 19:7 djyj in CMS at p 0:5 fb 1 . The variable is the opening angle between the leptons in the plane transverse to the beam axis. The variable indicates the scattering angle of the dileptons with respect to the beam in the boosted frame where the leptons are aligned. It is related to the pseudorapidities of the oppositely charged leptons by the relation cos( ) = tanh[ =2], where is the di erence in pseudorapidity between the two leptons. By construction, is greater than zero. Since depends on angular variables, the resolution of is signi cantly better than that of qT, especially at low qT values. Since qT=m``, the range 1 corresponds to qT up to about 100 GeV for a dilepton mass close to the nominal Z boson mass. The cross sections for the DY process as a function of the D0 Collaboration at the Tevatron for pp collisions at p have been measured by s = 1:96 TeV [19] and at the LHC by the ATLAS Collaboration for pp collisions at 7 and 8 TeV [13, 20]. In this paper, the measurements of the di erential cross section d =d and the double-di erential cross s = 8 TeV are presented using data corresponding to an The paper is organized as follows. A brief description of the CMS detector is presented in section 2. The general features of event reconstruction and selection for the analysis are discussed in section 3. The details of simulated samples used to guide and validate the measurements are given in section 4. Section 5 states the precise de nitions of the ducial region and the di erential cross sections. Section 6 describes the background subtraction, and section 7 describes how the signal distributions are unfolded to remove the impact { 2 { of resolution in the experimental measurement. Section 8 provides a discussion of the systematic uncertainties. Section 9 discusses the theoretical predictions that are compared to the measured cross sections. Finally the results are reported and discussed in section 10, with a summary presented in section 11. 2 The CMS detector The central feature of the CMS apparatus is a superconducting solenoid of 6 m internal diameter, providing a magnetic eld of 3.8 T. Within the solenoid volume are a silicon pixel and strip tracker, a lead tungstate crystal electromagnetic calorimeter (ECAL), and a brass and scintillator hadron calorimeter (HCAL), each composed of a barrel and two endcap sections. The steel and quartz- bre Cherenkov hadron forward calorimeters extend the pseudorapidity coverage provided by the barrel and endcap detectors. Muons are measured in the gas-ionization detectors embedded in the steel ux-return yoke outside the solenoid, with detection planes made using three technologies: drift tubes, cathode strip chambers, and resistive-plate chambers. A more detailed description of the CMS detector, together with a de nition of the coordinate system used and the relevant kinematic variables, can be found in ref. [21]. 3 Event reconstruction and selection Events of interest are selected using a two-tiered trigger system [22]. The rst level (L1), composed of custom hardware processors, uses information from the calorimeters and muon detectors to select events at a rate of around 100 kHz within a time interval of less than 4 s. The second level, known as the high-level trigger (HLT), consists of a farm of processors running a version of the full event reconstruction software optimized for fast processing, and reduces the event rate to around 1 kHz before data storage. The events for this analysis are triggered by the presence of at least one electron with transverse momentum pT > 27 GeV and j j < 2:5, or at least one muon with pT > 24 GeV and j j < 2:1. Both electrons and muons must satisfy relatively loose isolation and identi cation requirements compared to the o -line selection. For this analysis, the overall performance of this trigger is found to be better than the inclusive dilepton trigger. Because of the high instantaneous luminosity, there are multiple pp collisions within the same bunch crossing leading to event pileup in the detector. The average number of pileup in a triggered event during the 2012 data taking period is about 21. The reconstructed vertex with the largest value of summed physics-object p2T is taken to be the primary pp interaction vertex. The physics objects are the objects returned by a jet nding algorithm [23, 24] applied to all charged tracks associated with the vertex, plus the corresponding associated missing transverse momentum. The o -line particle- ow event algorithm [25] reconstructs and identi es individual particles with an optimised combination of information from the various elements of the CMS detector. The photon energy is obtained directly from the ECAL measurement, corrected for zero-suppression e ects. Electron identi cation relies on the electromagnetic { 3 { shower shape and other observables based on tracker and calorimeter information [26]. The barrel-endcap transition regions of the ECAL (1:444 < j j < 1:566) are excluded from the acceptance. The energy of electrons is inferred from a combination of the electron momentum at the primary vertex as determined by the tracker, the energy of the corresponding ECAL cluster, and the energy sum of all the bremsstrahlung photons spatially compatible with originating from the electron track. Electrons originating from photon conversions are suppressed by requiring no more than one missing tracker hit and that the nal hit on the reconstructed track matches an electron cluster in the ECAL. Electron candidates are rejected if they form a pair with a nearby track that is consistent with photon conversion. To ensure that the electron is consistent with a particle originating from the primary interaction vertex, the magnitude of the transverse impact parameter of the candidate track must be less than 0.02 cm, and the longitudinal distance from the primary interaction vertex is required to be less than 0:1 cm. The momentum resolution for electrons from Z ! e+e decays ranges from 1.7% for electrons in the barrel region to 4.5% for electrons that begin to shower before the calorimeter in the endcaps [26]. The transverse momentum of muons is obtained from the curvature of the muon tracks in the muon detector combined with matched tracks in the silicon tracker. Muon candidates are selected by applying minimal requirements to the track segments in both muon and inner tracker systems as well as consistent with small energy deposits in the calorimeters. The track associated with each muon candidate is required to have at least one hit in the pixel detector and at least ve hits in di erent layers of the silicon tracker. The muon candidate is required to have hits in at least two di erent muon stations. To reject cosmic ray muons, the magnitude of the transverse impact parameter is required to be less than 0.2 cm and the longitudinal distance from the primary interaction vertex is required to be less than 0.5 cm [27]. Selected muons in the range 20 < pT < 100 GeV have a relative pT resolution of 1.3{2.0% in the barrel (j j < 1:2) and less than 6% in the endcaps (1:2 < j j < 2:4) [27]. The energy of charged hadrons is determined from a combination of their momentum measured in the tracker, and the matched ECAL and HCAL energy deposits. Subsequently, it is corrected for zero-suppression e ects and for the response function of the calorimeters to hadronic showers. Finally, the energy of neutral hadrons is obtained from the corresponding corrected ECAL and HCAL energies. Events containing at least two leptons are selected, in which one lepton, consistent with the trigger, satis es pT > 30 GeV and j j < 2:1, while the other is required to have pT > 20 GeV and j j < 2:4. These two leptons must have the same avour and originate from the same primary vertex. For dimuon events, the leptons must have opposite electric charges. The probability of charge misidenti cation is not negligible for electrons and hence this criteria is not applied to dielectron events. Events are retained if the dilepton invariant mass falls in the range 60 < m`` < 120 GeV. The leptons in the DY process are usually isolated from other particles produced in the event; hence isolation criteria are useful for rejecting non-DY events. The isolation of a lepton, I, is de ned as the ratio of the sum of the transverse momenta of the charged and neutral hadrons as well as photons that fall within a cone of radius R = p ( )2 + ( ) 2 { 4 { is the azimuthal angle in radians) centered on the lepton to its pT. The requirement that the reconstructed charged particle tracks originate from a common primary vertex practically eliminates the pileup contribution from charged hadrons. In the case of electrons the pileup contributions for neutral hadrons and photons are estimated on a statistical basis using the approach of jet area subtraction [28]. For muons the corresponding subtracted quantity is computed by summing up the momenta of the charged tracks not associated with the interaction vertex and multiplying the total contribution by a factor of 0.5 to account for the relative fraction of neutral and charged particles. The values of the cone size and relative isolation optimised for electrons (muons) are R < 0:3(0:4) with I < 0:15(0:12). Applying the full set of selection criteria, the dielectron and dimuon data samples include approximately 4.4 and 6.7 million events, respectively. 4 Monte Carlo simulation Samples of simulated Monte Carlo (MC) events are used for estimating the signal e ciencies and the rates of most of the background processes. An inclusive DY signal sample generated by the MadGraph (v1.3.30) leading order (LO) matrix element generator [29] that includes up to four extra partons in the calculation, is used to estimate the e ciency and to unfold the data. The parton distribution function (PDF) set CTEQ6L1 [30] is used for the generation of this sample. Parton shower and hadronisation e ects are implemented by interfacing the event generator with pythia6 (v6.4.24) [31] along with the kT-MLM matching scheme [32] and using the Z2* tune [33, 34] for the underlying event. The background due to DY ! + production is simulated in the MadGraph sample used for the signal. The decays of leptons are described by the tauola (v1.27) [35] package. The backgrounds due to tt and W+jets events are also generated using MadGraph, while dibosons (WW, WZ and ZZ), single top quarks (tW and tW), and muonenriched QCD multijet samples are generated using pythia6. The cross sections for the simulated processes are normalised to the available state-of-the-art theoretical calculations. For the MadGraph signal as well as W+jets samples, the total inclusive cross sections are normalised to the values obtained from the theoretical predictions, computed using fewz (v2.0) [36] with the NNPDF3.0 set of PDF [37]. fewz includes QCD corrections up to NNLO and electroweak corrections up to next-to-leading order (NLO). The tt rate is normalised to the predicted cross section with NNLO+NNLL (next-to-next-to-leading logarithm) accuracy [38]. The normalisations for single top quark and diboson samples use cross section values available at NLO accuracy [39{42]. For QCD multijet events the simulated sample is normalised to the LO cross section. The generated events are passed through a CMS detector simulation based on Geant4 [43]. Minimum bias events are superposed on each of the simulated samples to account for pileup. The number of superposed events is dictated by the distribution of the number of reconstructed primary vertices in data, which is a function of the instantaneous luminosity. { 5 { HJEP03(218)7 The ducial region is de ned by a common set of kinematic restrictions applied to both the dielectron and the dimuon channels: one lepton with pT > 30 GeV and j j < 2:1, a second lepton with pT > 20 GeV and j j < 2:4, and a dilepton invariant mass 60 < m`` < 120 GeV. The range is restricted to a value less than 3.227 so as to keep the statistical and systematic uncertainties comparable in the relevant bin. Leptons are de ned at Born level, i.e., before bremsstrahlung or nal-state radiation of photon (QED-FSR). Di erential cross sections are de ned within this ducial region. Before the spectra are unfolded (as it will be discussed later), the absolute di erential cross section is de ned by i are the number of selected events, the estimated number of background events, the overall e ciency, and the width of the ith bin of , respectively, and L is the total integrated luminosity. The normalised cross section is de ned as the absolute cross section divided by the integral over all the bins of the di erential distribution: (1= ) d =d . The cancellation of some of the factors leads to a reduction in uncertainty, and hence the normalised cross section is more suitable for a comparison with theoretical predictions. The double-di erential cross section is de ned similarly by taking into account the width of the rapidity bin jyjj , and the e ciency, de ned suitably, d 2 d djyj ij = Nij L ij Bij i jyjj : The normalised double-di erential cross section is given by (1= ) d2 =d The e ciencies for the trigger, reconstruction, identi cation, and isolation requirements on the leptons are obtained in bins of pT and j j using \tag-and-probe" techniques [44]. Scale factors are applied as event weights to the simulated samples to correct for the di erences in the e ciencies measured with the data and the simulation. The scale factors for trigger, reconstruction, identi cation, and isolation e ciencies depend on pT and j j. For the dielectron channel the trigger e ciency scale factors range from 0.92 to 1.03 with an uncertainty in the range 0.1 to 1.9%. The reconstruction e ciency scale factors vary from 0.98 to 1.01 with uncertainties of 0.1 to 1.2% respectively, while the combined identi cation and isolation e ciency scale factors range from 0.91 to 1.02 with uncertainties of 0.1 to 5.7%. For the dimuon channel the scale factor for the trigger e ciency varies from 0.97 to 1.01 with a typical uncertainty of 0.2%, and the combined scale factor for the reconstruction, identi cation, and isolation e ciencies ranges from 0.92 to 1.03 with an uncertainty of about 0.5%. Energy and momentum scale corrections are applied to the electrons and muons, respectively, in both experimental data and simulated events [45, 46]. Thirty-four bins in are de ned [13] with widths that increase with ; the bulk of the distribution falls in the range < 1. When measuring the double-di erential cross section, six bins in jyj of constant width jyj = 0:4 covering the range jyj < 2:4 are used. djyj. { 6 { The background contributions to the selected samples amount only to about 0.6% and 0.5% in the dielectron and dimuon channels, respectively. The components of this background consist of the inclusive production of tt, Z ! + , WW, WZ, ZZ, single top quarks, and, to a lesser extent, W+jets and QCD multijets. The latter two processes contribute when at least one jet is misidenti ed as a lepton or when a lepton produced within a jet passes the isolation requirement. Their contribution in the dimuon channel is negligible. In the dielectron channel the background arising from W+jets and QCD multijet processes is estimated by tting the invariant mass distribution in each nal bin. The t is performed using an analytical shape for the W+jets and QCD multijet backgrounds and a simulation-derived shape for the other backgrounds and the signal events that have wrongly reconstructed same-sign dielectrons. Since the processes which generate dielectron pairs in QCD multijets and W+jets are expected to be charge-symmetric, the analytical t result from the same-sign distribution is used to predict the background in the total sample. This background constitutes approximately 6% of the total background in the dielectron channel. All other backgrounds are estimated using simulated event samples. As indicated in eqs. (5.1) and (5.2), the estimated total background is subtracted bin-by-bin before unfolding the spectra. tributions. Scale factors have been applied to remove any di erences in e ciency between data and simulation as discussed earlier; weights have been applied to match the distribution of pileup vertices in data. The error bars represent the statistical uncertainties for the data and the simulations. The top row displays the qT distribution followed by the and jyj distributions. The data and the expectations in all distributions agree within 10%. 7 Unfolding To compare with the predictions from event generators, the distributions of the observables need to be corrected back to the stable particle level for event selection e ciencies and for detector resolution e ects. The measurement uncertainties for and jyj are small, but not zero. In order to remove the impact of events migrating among bins, the background-subtracted distributions are unfolded. For the double-di erential distribution, the migration of events from one bin to another is at the level of 10 (3) % for the dielectron (dimuon) channel, while for the jyj distribution the corresponding values are smaller, typically less than 2 ( 1 )%, because the jyj bins are large compared to the resolution. In addition to the e ects of measurement uncertainties, the impact of QED-FSR is included in the unfolding. The observed distributions are unfolded to pre-FSR or \Born-level" distributions using the d'Agostini method [47] as implemented in the RooUnfold package [48]. Four iterations have been performed for the unfolding of the distributions. A response matrix correlates the values of the observable with and without the detector e ects. The model for the detector resolution is derived from a simulated signal sample generated with MadGraph interfaced with pythia6. { 7 { Data (ee) tt+tW+tW WZ WW γ*/Z→ee (MG+PY6) ZZ γ*/Z→ττ QCD,W+Jets V V Data (μμ) tt+tW+tW WZ WW γ*/Z→μμ (MG+PY6) ZZ γ*Z→ττ e e e e N N U / the shaded histograms represent the expectations which are based on simulation, except for the contributions from QCD multijet and W+jets events in the dielectron channel, which are obtained from control samples in data. Here \MG+PY6" refers to a sample produced with MadGraph interfaced with pythia6 (Z2* tune). The error bars indicate the statistical uncertainties for data and for simulation only. No unfolding procedure has been applied to these distributions. { 8 { The total systematic uncertainty includes uncertainties in the integrated luminosity, unfolding, lepton e ciencies (trigger, identi cation and isolation), pileup, background estimation, electron energy scale, muon momentum scale and resolution, and modelling of QED-FSR. The impact of these sources of systematic uncertainty varies with , as shown in gure 2, and is di erent for the measurement of absolute and normalised cross sections. As expected, the systematic uncertainties for the normalised cross sections are substantially smaller than those for the absolute cross section. The largest source of uncertainty comes from the measurement of the integrated luminosity and amounts to 2.6% [49]. It is uniform across all only for the absolute cross section measurements. and jyj bins and is relevant The unfolding uncertainty originates from the nite size of the simulated signal sample used for the response matrix and hence the variation of this uncertainty with closely parallels the statistical uncertainty. The model dependence is studied by reweighting the simulated events used for the unfolding to match either the y or m`` distribution in data or to change the qT distribution. The e ect of this reweighting on the unfolded data is less than 0.05% for most of the range and reaches about 0.5% for the highest bin of the jyj distribution. The systematic uncertainty due to the model dependence of the unfolding procedure is of comparable magnitude and both are negligible. Systematic uncertainties for lepton e ciencies include the uncertainties in the scale factors used to correct the identi cation, isolation, and trigger e ciency values from the simulation. and jyj The uncertainty in the background estimates from the simulated samples is assessed by varying the cross sections of the contributing processes by the amount as measured by the CMS Collaboration. The tt background is varied by 10% [50] while WZ and ZZ contributions are varied simultaneously by 20% [51, 52]. In the dielectron channel the contribution due to QCD multijets and W+jets processes is assigned a conservative uncertainty of 100% based on variations observed when the binning is changed. Uncertainties in the other background processes lead to negligible e ects on the measured cross sections, being less than a tenth of the e ect of the major backgrounds. The electron energy scale, known to a precision of 0.1{0.2%, a ects all of the bins almost uniformly at the level of 0.15% for the absolute cross section measurement. The impact on the normalised cross sections is smaller, at the level of 0.06%. The muon momentum scale is corrected for the misalignments in the detector systems and the uncertainty in the knowledge of the magnetic eld. The corresponding cross section uncertainties are below 0.1% level. To account for the uncertainty in QED-FSR, the simulation is weighted to re ect the di erence between a soft-collinear approach and the exact O( ) result as obtained in PHOTOS [53]. This uncertainty is less than 0.08% in the entire phase space considered. To estimate the uncertainty in our measurement due to that in pileup multiplicity, the number of interactions per bunch crossing in the simulation is varied by 5%. This includes the e ects due to the modelling of minimum bias events in simulation, uncertainty { 9 { HJEP03(218)7 in the measurement of the inelastic cross section and the number of interactions per bunch crossing as measured in data. the used PDF sets is negligible. The uncertainty in the cross sections due to variations of the structure functions in Summaries of the uncertainties for the absolute and normalised double-di erential cross section measurements and their variations with in representative jyj bins are displayed in gures 3 and 4, respectively. For the double-di erential cross section, the statistical uncertainty from the data and the MC unfolding statistical uncertainty are larger than in the single-di erential cross section measurement. The statistical uncertainty starts to dominate the total uncertainty in the high and high-jyj regions. Furthermore, the relative contribution of the background processes in the ducial region, and therefore the background uncertainty, increases with rapidity. This is especially true for the QCD multijet and W+jets backgrounds in the dielectron channel, leading to an uncertainty of approximately 5% in the highest ranges of smaller than the statistical uncertainty. and jyj covered, which nonetheless remains 9 Theoretical predictions The measured di erential cross sections are compared with ve theoretical predictions. Apart from the LO predictions of MadGraph described in section 4, the following are also considered: (i) powheg [54{57] with the CT10NLO PDFs [58] interfaced with pythia6 and the Z2* tune; (ii) powheg with the CT10NLO PDF, but interfaced with pythia8 (v8.2) [59] and the CUETP8M1 tune [34] using NNPDF2.3 LO PDF [60, 61]; (iii) ResBos [62{64] with CT10NLO PDF, and (iv) MadGraph5 amc@nlo (henceforth referred to as amc@nlo) [65] with the NNPDF3.0 NLO PDF and pythia8 for the parton shower and FxFx merging scheme [66]. The generators powheg and amc@nlo are both accurate at NLO, while the order for ResBos is resummed NNLL/NLO QCD. Since ResBos uses the resummation method of pT to account for contributions from soft-gluon radiations in the initial state it di ers from xed-order perturbative calculations and MC showering methods. ResBos predictions have been obtained with CP version using general purpose grids. The MadGraph predictions are normalised to the fewz cross section for m`` > 50 GeV [3]. The uncertainties in the total theoretical cross section calculated with fewz include those due to S, neglected higher-order QCD terms beyond NNLO, the choice of heavy-quark masses (bottom and charm), and PDFs, amounting to a total of 3.3%. The theoretical uncertainties for powheg, ResBos, and amc@nlo include statistical, PDF, and scale uncertainties. The PDF uncertainty is calculated using the recommendations of refs. [67, 68], and the scale uncertainties are evaluated by varying the renormalisation and the factorisation scales independently by factors of 2 and 1/2 and taking the largest variations as the uncertainty. 100-3 2 CMS a l eR 1 n i a t 10-3 10-2 φ* 10-1 19.7 fb-1 (8 TeV) Unfolding 1 1 100-3 2 CMS a l eR 1 [%1.5 y t n i a t uncertainty for the normalised cross section. The left plots pertain to the dielectron channel and the right plots pertain to the dimuon channel. The uncertainties from the background, pileup, the electron energy scale or the muon pT resolution, and from QED-FSR modelling are combined under the label \Other". 10 Results The measurements in the dielectron and dimuon channels are consistent within the uncorrelated statistical and systematic uncertainties, and hence they are combined. The best linear unbiased estimator (BLUE) method [69, 70], as implemented in ref. [71] is used. The resulting output is unbiased and has minimal variance. The correlations among bins in one channel as well as between the two channels, including those in the unfolding, are taken into account. The correlation between channels originates from the systematic uncertainties due to background estimates, pileup, QED-FSR, and the integrated luminosity. The correlations within one channel also include uncertainties from the lepton e ciencies. The uncertainty in the integrated luminosity is fully correlated across all bins and both nal states. It is evaluated for the nal result after combining channels with the BLUE method. 19.7 fb-1 (8 TeV) Absolute cross section, ee channel Absolute cross section, μμ channel n i v i 4 a l 2 0 20 15 10 5 0 1.2 ≤ |y| < 1.6 1.2 ≤ |y| < 1.6 2.0 ≤ |y| ≤ 2.4 2.0 ≤ |y| ≤ 2.4 4 3 2 n i v i 4 a l 2 0 20 15 10 5 0 10-3 10-2 djyj measurements, in the dielectron (left) and dimuon (right) channels. The main components are shown individually while uncertainties from the background, pileup, the electron energy scale or the muon pT resolution, and from QED-FSR are combined under the label \Other". 19.7 fb-1 (8 TeV) Normalised cross section, ee channel Normalised cross section, μμ channel 1.2 ≤ |y| < 1.6 1.2 ≤ |y| < 1.6 2.0 ≤ |y| ≤ 2.4 2.0 ≤ |y| ≤ 2.4 3 2 1 n i t0 a r 4 v i l3 a e 2 1 0 20 15 10 5 0 10-3 10-2 di erential cross section measurements, in representative jyj bins, in the dielectron (left) and dimuon (right) channel. The main components are shown individually while uncertainties from the background, pileup, the electron energy scale or the muon pT resolution, and from QED-FSR are combined under the label \Other". 3 2 1 n i v i CMS ee + μμ combined 480.7 ± 0.2 (stat) ± 3.6 (sys) ± 12.5 (lumi) pb FEWZ × Acc(MadGraph + PYTHIA6) aMC@NLO + PYTHIA8 POWHEG + PYTHIA8 ResBos 440 460 480 500 520 Drell-Yan fiducial cross section [pb] The grey error bar represents the total experimental uncertainty for the measured value. The error bars for the theoretical values include the uncertainties due to statistical precision, the PDFs, and the scale choice. The ducial cross section for fewz is obtained by multiplying the total cross section with the acceptance determined from the simulated MadGraph+pythia6 sample; the uncertainty in the prediction corresponds to that in the fewz calculation. The ducial cross section, as de ned in section 5, is obtained by integrating the absolute di erential cross section d =d . After combining dielectron and dimuon channels, the measured value for a single lepton avour is (pp ! Z= ! `+` ) = 480:7 0:2 (stat) 3:6 (syst) 12:5 (lumi) pb; (10.1) where the statistical, systematic, and integrated luminosity uncertainties are indicated separately. As shown in gure 5, this measurement is in agreement with the theoretical predictions which have a typical uncertainty of 3%. The combined absolute and normalised single-di erential cross sections, d =d and (1= ) d =d are presented in gure 6. The lower panels indicate the conformity of theory with data. None of the predictions matches the measurements perfectly for the entire range of covered in this analysis. For the normalised cross section, MadGraph+pythia6 provides the best description with a disagreement of at most 5% over the entire range. ResBos, amc@nlo+pythia8 and powheg+pythia8 predictions are similarly successful at describing the data at low but they disagree with the measurements by as much as 10% for > 0:1. powheg+pythia6 provides the least accurate prediction, with a disagreement up to 11 (15)% for less (greater) than value 0.1. Better models of the hard-scattering process, such as provided by MadGraph+pythia6, lead to an improved agreement with the data. At the same time, the importance of the underlying event model and hadronisation tune for correctly reproducing the distribution is evident from the signi cant di erence (up to 11%) in predicted distributions for a given sample of powheg events hadronised with pythia6 and with pythia8 separately. 1•0-1 σ / 1 10-2 104 ee + μμ combined ee + μμ combined Data 10-3 10-2 bination of dielectron and dimuon channels. The measurement is compared with the predictions from ResBos, MadGraph and powheg interfaced with pythia6 (Z2* tune), and amc@nlo and powheg interfaced with pythia8 (CUETP8M1 tune). In the lower panels, the horizontal bands correspond to the experimental uncertainty, while the error bars correspond to the statistical, PDF, and scale uncertainties in the theoretical predictions from ResBos, powheg and amc@nlo and only the statistical uncertainty for MadGraph. The combined double-di erential cross sections are shown in gure 7 with theoretical predictions from MadGraph+pythia6 with Z2* tune. Comparisons with a variety of theoretical predictions for the normalised cross section are presented in gure 8. The shape of the distribution varies with dilepton rapidity. In order to emphasize this feature, ratios of cross sections as functions of for bins of jyj relative to the central bin jyj < 0:4 are presented in gure 9, where they are compared to predictions from theoretical calculations and models. All of the theoretical predictions provide a fairly good description of the shape of the distribution with jyj. However, the predictions from amc@nlo+pythia8 and Mad Graph+pythia6 overestimate the cross section at high jyj by approximately 2% and 5%, respectively, while powheg+pythia6 and powheg+pythia8 underestimate the cross section by 2%. The prediction from ResBos agrees with the jyj dependence at the level of 1%. Due to di erence in kinematic selections these results cannot be directly compared with similar measurements performed by ATLAS Collaboration [13]. |y| < 0.4 [× 105] 10-3 10-3 φ 1/d02 ee + μμ combined 10-1 106 105 104 1|03 y | 1*d02 φ /d10 2 σ for six ranges of jyj. Experimental data is compared with prediction from MadGraph+pythia6 with Z2* tune. 11 Summary Measurements of the absolute di erential cross sections d =d corresponding normalised di erential cross sections in the combined dielectron and dimuon channels were presented for the dilepton mass range of 60 to 120 GeV. The measurements are based on a sample of proton-proton collision data at a centre-of-mass energy of 8 TeV collected with the CMS detector at the LHC and correspond to an integrated luminosity of 19.7 fb 1. They provide a sensitive test of theoretical predictions. The normalised cross section (1= ) d =d is precise at the level of 0.24{1.2%. Theoretical predictions di er from the measurements at the level of 3% (ResBos), 3% (powheg+pythia8), 4% (MadGraph+pythia6), 6% (amc@nlo+pythia8) and 11% (powheg+pythia6) for . 0:1. For higher values of the di erences are larger: about 9, 8, 5, 10 and 15%, respectively. These observations suggest that more advanced calculations of the hard-scattering process reproduce the data better. At the same time, the large di erence in theoretical predictions from a single powheg sample interfaced with two di erent versions of pythia and underlying event tunes indicates the combined importance of the showering method, nonperturbative e ects and the need for soft-gluon resummation on the predicted values of cross sections reported in this paper. The variation of the cross section with jyj is reproduced by ResBos within 1%, while MadGraph+pythia6 di ers from the data by 5% comparing the most central and most forward rapidity bins. The predictions from amc@nlo+pythia8, powheg+pythia6, and powheg+pythia8 deviate from the measurement by at most 2%. and d2 =d djyj and the 1.2 |y| < 0.4 0.8 1.2 1 1 0.8 10-3 φ* 10-1 1 The ratio of predicted over measured normalised di erential cross sections, djyj, as a function of for six bins in jyj. The theoretical predictions from MadGraph+pythia6, powheg+pythia6, powheg+pythia8, ResBos, and amc@nlo+pythia8 are shown. The horizontal band corresponds to the uncertainty in the experimental measurement. The vertical bars are dominated by the statistical uncertainties in the theoretical predictions. 0.4 -3 -3 -3 -3 0.2 0.1 100-3 φ* 10-1 1 djyj for higher rapidity bins (jyj > 0:4) normalised to the values in the most central bin jyj < 0:4. The theoretical predictions from MadGraph+pythia6, powheg+pythia6, powheg+pythia8, ResBos, and amc@nlo+pythia8 are also shown. The uncertainties in the theoretical predictions at large are dominated by the statistical component. This analysis validates the overall theoretical description of inclusive production of vector bosons at the LHC energies by the perturbative formalism of the standard model. Nevertheless, further tuning of the description of the underlying event is necessary for an accurate prediction of the kinematics of the Drell-Yan production of lepton pairs. Acknowledgments We congratulate our colleagues in the CERN accelerator departments for the excellent performance of the LHC and thank the technical and administrative sta s at CERN and at other CMS institutes for their contributions to the success of the CMS e ort. In addition, we gratefully acknowledge the computing centers and personnel of the Worldwide LHC Computing Grid for delivering so e ectively the computing infrastructure essential to our analyses. Finally, we acknowledge the enduring support for the construction and operation of the LHC and the CMS detector provided by the following funding agencies: BMWFW and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES and CSF (Croatia); RPF (Cyprus); SENESCYT (Ecuador); MoER, ERC IUT, and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NIH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); MSIP and NRF (Republic of Korea); LAS (Lithuania); MOE and UM (Malaysia); BUAP, CINVESTAV, CONACYT, LNS, SEP, and UASLP-FAI (Mexico); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON, RosAtom, RAS, RFBR and RAEP (Russia); MESTD (Serbia); SEIDI, CPAN, PCTI and FEDER (Spain); Swiss Funding Agencies (Switzerland); MST (Taipei); ThEPCenter, IPST, STAR, and NSTDA (Thailand); TUBITAK and TAEK (Turkey); NASU and SFFR (Ukraine); STFC (United Kingdom); DOE and NSF (U.S.A.). Individuals have received support from the Marie-Curie program and the European Research Council and Horizon 2020 Grant, contract No. 675440 (European Union); the Leventis Foundation; the A. P. Sloan Foundation; the Alexander von Humboldt Foundation; the Belgian Federal Science Policy O ce; the Fonds pour la Formation a la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Council of Science and Industrial Research, India; the HOMING PLUS program of the Foundation for Polish Science, co nanced from European Union, Regional Development Fund, the Mobility Plus program of the Ministry of Science and Higher Education, the National Science Center (Poland), contracts Harmonia 2014/14/M/ST2/00428, Opus 2014/13/B/ST2/02543, 2014/15/B/ST2/03998, and 2015/19/B/ST2/02861, Sonata-bis 2012/07/E/ST2/01406; the National Priorities Research Program by Qatar National Research Fund; the Programa Severo Ochoa del Principado de Asturias; the Thalis and Aristeia programs co nanced by EU-ESF and the Greek NSRF; the Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University and the Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand); the Welch Foundation, contract C-1845; and the Weston Havens Foundation (U.S.A.). p [33] CMS collaboration, Study of the underlying event at forward rapidity in pp collisions at s = 0:9, 2:76 and 7 TeV, JHEP 04 (2013) 072 [arXiv:1302.2394] [INSPIRE]. [34] CMS collaboration, Event generator tunes obtained from underlying event and multiparton photos F environment for the TAUOLA and PHOTOS packages: release II, Comput. Phys. Commun. 174 (2006) 818 [hep-ph/0312240] [INSPIRE]. HJEP03(218)7 at hadron colliders, Comput. Phys. Commun. 185 (2014) 2930 [arXiv:1112.5675] [INSPIRE]. HAdronic Top and Heavy quarks crOss section calculatoR, Comput. Phys. Commun. 182 (2011) 1034 [arXiv:1007.1327] [INSPIRE]. [40] P. Kant et al., HatHor for single top-quark production: updated predictions and uncertainty estimates for single top-quark production in hadronic collisions, Comput. Phys. Commun. 191 (2015) 74 [arXiv:1406.4403] [INSPIRE]. 07 (2011) 018 [arXiv:1105.0020] [INSPIRE]. [41] J.M. Campbell, R.K. Ellis and C. Williams, Vector boson pair production at the LHC, JHEP [42] T. Melia, P. Nason, R. Rontsch and G. Zanderighi, W +W , W Z and ZZ production in the POWHEG BOX, JHEP 11 (2011) 078 [arXiv:1107.5051] [INSPIRE]. [43] GEANT4 collaboration, S. Agostinelli et al., GEANT4: a simulation toolkit, Nucl. Instrum. Meth. A 506 (2003) 250 [INSPIRE]. collisions at p s = 7 TeV, JHEP 10 (2011) 132 [arXiv:1107.4789] [INSPIRE]. [44] CMS collaboration, Measurement of the inclusive W and Z production cross sections in pp [45] A. Bodek, A. van Dyne, J.Y. Han, W. Sakumoto and A. Strelnikov, Extracting muon momentum scale corrections for hadron collider experiments, Eur. Phys. J. C 72 (2012) 2194 [arXiv:1208.3710] [INSPIRE]. [46] CMS collaboration, Measurement of the properties of a Higgs boson in the four-lepton nal state, Phys. Rev. D 89 (2014) 092007 [arXiv:1312.5353] [INSPIRE]. [47] G. D'Agostini, A multidimensional unfolding method based on Bayes' theorem, Nucl. Instrum. Meth. A 362 (1995) 487 [INSPIRE]. [48] T. Adye, Unfolding algorithms and tests using RooUnfold, in Proceedings, PHYSTAT 2011 Workshop on Statistical Issues Related to Discovery Claims in Search Experiments and [INSPIRE]. [49] CMS collaboration, CMS luminosity based on pixel cluster counting | Summer 2013 update, CMS-PAS-LUM-13-001, CERN, Geneva Switzerland, (2013). proton-proton collisions at p [50] CMS collaboration, Measurement of the tt production cross section in the e channel in s = 7 and 8 TeV, JHEP 08 (2016) 029 [arXiv:1603.02303] [51] CMS collaboration, Measurement of the W Z production cross section in pp collisions at s = 7 and 8 TeV and search for anomalous triple gauge couplings at p s = 8 TeV, Eur. Phys. J. C 77 (2017) 236 [arXiv:1609.05721] [INSPIRE]. [52] CMS collaboration, Measurement of the pp ! ZZ production cross section and constraints on anomalous triple gauge couplings in four-lepton 740 (2015) 250 [Erratum ibid. B 757 (2016) 569] [arXiv:1406.0113] [INSPIRE]. nal states at p s = 8 TeV, Phys. Lett. B [53] G. Nanava and Z. Was, How to use SANC to improve the PHOTOS Monte Carlo simulation HJEP03(218)7 of bremsstrahlung in leptonic W boson decays, Acta Phys. Polon. B 34 (2003) 4561 [hep-ph/0303260] [INSPIRE]. [54] P. Nason, A new method for combining NLO QCD with shower Monte Carlo algorithms, JHEP 11 (2004) 040 [hep-ph/0409146] [INSPIRE]. [55] S. Alioli, P. Nason, C. Oleari and E. Re, A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX, JHEP 06 (2010) 043 [arXiv:1002.2581] [INSPIRE]. [56] S. Alioli, P. Nason, C. Oleari and E. Re, Vector boson plus one jet production in POWHEG, JHEP 01 (2011) 095 [arXiv:1009.5594] [INSPIRE]. [57] S. Frixione, P. Nason and C. Oleari, Matching NLO QCD computations with parton shower simulations: the POWHEG method, JHEP 11 (2007) 070 [arXiv:0709.2092] [INSPIRE]. [58] J. Gao et al., CT10 next-to-next-to-leading order global analysis of QCD, Phys. Rev. D 89 (2014) 033009 [arXiv:1302.6246] [INSPIRE]. 159 [arXiv:1410.3012] [INSPIRE]. [60] R.D. Ball et al., A rst unbiased global NLO determination of parton distributions and their uncertainties, Nucl. Phys. B 838 (2010) 136 [arXiv:1002.4407] [INSPIRE]. [61] R.D. Ball et al., Impact of heavy quark masses on parton distributions and LHC phenomenology, Nucl. Phys. B 849 (2011) 296 [arXiv:1101.1300] [INSPIRE]. [62] G.A. Ladinsky and C.P. Yuan, The nonperturbative regime in QCD resummation for gauge boson production at hadron colliders, Phys. Rev. D 50 (1994) R4239 [hep-ph/9311341] [63] C. Balazs and C.P. Yuan, Soft gluon e ects on lepton pairs at hadron colliders, Phys. Rev. D [64] F. Landry, R. Brock, P.M. Nadolsky and C.P. Yuan, Fermilab Tevatron run-1 Z boson data and the Collins-Soper-Sterman resummation formalism, Phys. Rev. D 67 (2003) 073016 [65] J. Alwall et al., The automated computation of tree-level and next-to-leading order di erential cross sections and their matching to parton shower simulations, JHEP 07 (2014) [66] R. Frederix and S. Frixione, Merging meets matching in MC@NLO, JHEP 12 (2012) 061 [67] S. Alekhin et al., The PDF4LHC working group interim report, arXiv:1101.0536 [INSPIRE]. [INSPIRE]. C 74 (2014) 3004 [arXiv:1402.4016] [INSPIRE]. HJEP03(218)7 Yerevan Physics Institute, Yerevan, Armenia A.M. Sirunyan, A. Tumasyan Institut fur Hochenergiephysik, Wien, Austria W. Adam, F. Ambrogi, E. Asilar, T. Bergauer, J. Brandstetter, E. Brondolin, M. Dragicevic, J. Ero, M. Flechl, M. Friedl, R. Fruhwirth1, V.M. Ghete, J. Grossmann, J. Hrubec, M. Jeitler1, A. Konig, N. Krammer, I. Kratschmer, D. Liko, T. Madlener, I. Mikulec, E. Pree, N. Rad, H. Rohringer, J. Schieck1, R. Schofbeck, M. Spanring, D. Spitzbart, W. Waltenberger, J. Wittmann, C.-E. Wulz1, M. Zarucki Institute for Nuclear Problems, Minsk, Belarus V. Chekhovsky, V. Mossolov, J. Suarez Gonzalez Universiteit Antwerpen, Antwerpen, Belgium Haevermaet, P. Van Mechelen, N. Van Remortel Vrije Universiteit Brussel, Brussel, Belgium E.A. De Wolf, D. Di Croce, X. Janssen, J. Lauwers, M. Van De Klundert, H. Van S. Abu Zeid, F. Blekman, J. D'Hondt, I. De Bruyn, J. De Clercq, K. Deroover, G. Flouris, D. Lontkovskyi, S. Lowette, S. Moortgat, L. Moreels, Q. Python, K. Skovpen, S. Tavernier, W. Van Doninck, P. Van Mulders, I. Van Parijs Universite Libre de Bruxelles, Bruxelles, Belgium D. Beghin, H. Brun, B. Clerbaux, G. De Lentdecker, H. Delannoy, B. Dorney, G. Fasanella, L. Favart, R. Goldouzian, A. Grebenyuk, G. Karapostoli, T. Lenzi, J. Luetic, T. Maerschalk, A. Marinov, A. Randle-conde, T. Seva, E. Starling, C. Vander Velde, P. Vanlaer, D. Vannerom, R. Yonamine, F. Zenoni, F. Zhang2 Ghent University, Ghent, Belgium A. Cimmino, T. Cornelis, D. Dobur, A. Fagot, M. Gul, I. Khvastunov3, D. Poyraz, C. Roskas, S. Salva, M. Tytgat, W. Verbeke, N. Zaganidis Universite Catholique de Louvain, Louvain-la-Neuve, Belgium H. Bakhshiansohi, O. Bondu, S. Brochet, G. Bruno, C. Caputo, A. Caudron, P. David, S. De Visscher, C. Delaere, M. Delcourt, B. Francois, A. Giammanco, M. Komm, G. Krintiras, V. Lemaitre, A. Magitteri, A. Mertens, M. Musich, K. Piotrzkowski, L. Quertenmont, A. Saggio, M. Vidal Marono, S. Wertz, J. Zobec Universite de Mons, Mons, Belgium N. Beliy Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil W.L. Alda Junior, F.L. Alves, G.A. Alves, L. Brito, M. Correa Martins Junior, C. Hensel, A. Moraes, M.E. Pol, P. Rebello Teles Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil E. Belchior Batista Das Chagas, W. Carvalho, J. Chinellato4, E. Coelho, E.M. Da Costa, G.G. Da Silveira5, D. De Jesus Damiao, S. Fonseca De Souza, L.M. Huertas Guativa, H. Malbouisson, M. Melo De Almeida, C. Mora Herrera, L. Mundim, H. Nogima, L.J. Sanchez Rosas, A. Santoro, A. Sznajder, M. Thiel, E.J. Tonelli Manganote4, F. Torres Da Silva De Araujo, A. Vilela Pereira Universidade Estadual Paulista a, Universidade Federal do ABC b, S~ao Paulo, Brazil S. Ahujaa, Sciences tanov C.A. Bernardesa, T.R. Fernandez Perez Tomeia, E.M. Gregoresb, P.G. Mercadanteb, S.F. Novaesa, Sandra S. Padulaa, D. Romero Abadb, J.C. Ruiz Vargasa Institute for Nuclear Research and Nuclear Energy of Bulgaria Academy of A. Aleksandrov, R. Hadjiiska, P. Iaydjiev, M. Misheva, M. Rodozov, M. Shopova, G. SulUniversity of So a, So a, Bulgaria A. Dimitrov, I. Glushkov, L. Litov, B. Pavlov, P. Petkov Beihang University, Beijing, China W. Fang6, X. Gao6, L. Yuan Institute of High Energy Physics, Beijing, China M. Ahmad, J.G. Bian, G.M. Chen, H.S. Chen, M. Chen, Y. Chen, C.H. Jiang, D. Leggat, H. Liao, Z. Liu, F. Romeo, S.M. Shaheen, A. Spiezia, J. Tao, C. Wang, Z. Wang, E. Yazgan, H. Zhang, S. Zhang, J. Zhao State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, China Y. Ban, G. Chen, Q. Li, S. Liu, Y. Mao, S.J. Qian, D. Wang, Z. Xu Universidad de Los Andes, Bogota, Colombia C. Avila, A. Cabrera, L.F. Chaparro Sierra, C. Florez, C.F. Gonzalez Hernandez, J.D. Ruiz Alvarez University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, Split, Croatia B. Courbon, N. Godinovic, D. Lelas, I. Puljak, P.M. Ribeiro Cipriano, T. Sculac University of Split, Faculty of Science, Split, Croatia Z. Antunovic, M. Kovac Institute Rudjer Boskovic, Zagreb, Croatia V. Brigljevic, D. Ferencek, K. Kadija, B. Mesic, A. Starodumov7, T. Susa University of Cyprus, Nicosia, Cyprus M.W. Ather, A. Attikis, G. Mavromanolakis, J. Mousa, C. Nicolaou, F. Ptochos, P.A. Razis, H. Rykaczewski Charles University, Prague, Czech Republic M. Finger8, M. Finger Jr.8 Universidad San Francisco de Quito, Quito, Ecuador E. Carrera Jarrin Academy of Scienti c Research and Technology of the Arab Republic of Egypt, Egyptian Network of High Energy Physics, Cairo, Egypt A.A. Abdelalim9;10, Y. Mohammed11, E. Salama12;13 National Institute of Chemical Physics and Biophysics, Tallinn, Estonia R.K. Dewanjee, M. Kadastik, L. Perrini, M. Raidal, A. Tiko, C. Veelken Department of Physics, University of Helsinki, Helsinki, Finland P. Eerola, H. Kirschenmann, J. Pekkanen, M. Voutilainen Helsinki Institute of Physics, Helsinki, Finland T. Jarvinen, V. Karimaki, R. Kinnunen, T. Lampen, K. Lassila-Perini, S. Lehti, T. Linden, P. Luukka, E. Tuominen, J. Tuominiemi Lappeenranta University of Technology, Lappeenranta, Finland J. Talvitie, T. Tuuva IRFU, CEA, Universite Paris-Saclay, Gif-sur-Yvette, France M. Besancon, F. Couderc, M. Dejardin, D. Denegri, J.L. Faure, F. Ferri, S. Ganjour, S. Ghosh, A. Givernaud, P. Gras, G. Hamel de Monchenault, P. Jarry, I. Kucher, C. Leloup, E. Locci, M. Machet, J. Malcles, G. Negro, J. Rander, A. Rosowsky, M.O . Sahin, M. Titov Laboratoire Leprince-Ringuet, Ecole polytechnique, CNRS/IN2P3, Universite Paris-Saclay, Palaiseau, France A. Abdulsalam, C. Amendola, I. Antropov, S. Ba oni, F. Beaudette, P. Busson, L. Cadamuro, C. Charlot, R. Granier de Cassagnac, M. Jo, S. Lisniak, A. Lobanov, J. Martin Blanco, M. Nguyen, C. Ochando, G. Ortona, P. Paganini, P. Pigard, R. Salerno, J.B. Sauvan, Y. Sirois, A.G. Stahl Leiton, T. Strebler, Y. Yilmaz, A. Zabi, A. Zghiche Universite de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France S. Gadrat J.-L. Agram14, J. Andrea, D. Bloch, J.-M. Brom, M. Buttignol, E.C. Chabert, N. Chanon, C. Collard, E. Conte14, X. Coubez, J.-C. Fontaine14, D. Gele, U. Goerlach, M. Jansova, A.-C. Le Bihan, N. Tonon, P. Van Hove Centre de Calcul de l'Institut National de Physique Nucleaire et de Physique des Particules, CNRS/IN2P3, Villeurbanne, France Universite de Lyon, Universite Claude Bernard Lyon 1, CNRS-IN2P3, Institut de Physique Nucleaire de Lyon, Villeurbanne, France S. Beauceron, C. Bernet, G. Boudoul, R. Chierici, D. Contardo, P. Depasse, H. El Mamouni, J. Fay, L. Finco, S. Gascon, M. Gouzevitch, G. Grenier, B. Ille, F. Lagarde, I.B. Laktineh, M. Lethuillier, L. Mirabito, A.L. Pequegnot, S. Perries, A. Popov15, V. Sordini, M. Vander Donckt, S. Viret A. Khvedelidze8 I. Bagaturia16 Georgian Technical University, Tbilisi, Georgia Tbilisi State University, Tbilisi, Georgia RWTH Aachen University, I. Physikalisches Institut, Aachen, Germany C. Autermann, L. Feld, M.K. Kiesel, K. Klein, M. Lipinski, M. Preuten, C. Schomakers, J. Schulz, T. Verlage, V. Zhukov15 RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany A. Albert, E. Dietz-Laursonn, D. Duchardt, M. Endres, M. Erdmann, S. Erdweg, T. Esch, R. Fischer, A. Guth, M. Hamer, T. Hebbeker, C. Heidemann, K. Hoepfner, S. Knutzen, M. Merschmeyer, A. Meyer, P. Millet, S. Mukherjee, T. Pook, M. Radziej, H. Reithler, M. Rieger, F. Scheuch, D. Teyssier, S. Thuer RWTH Aachen University, III. Physikalisches Institut B, Aachen, Germany G. Flugge, B. Kargoll, T. Kress, A. Kunsken, J. Lingemann, T. Muller, A. Nehrkorn, A. Nowack, C. Pistone, O. Pooth, A. Stahl17 Deutsches Elektronen-Synchrotron, Hamburg, Germany M. Aldaya Martin, T. Arndt, C. Asawatangtrakuldee, K. Beernaert, O. Behnke, U. Behrens, A. Bermudez Mart nez, A.A. Bin Anuar, K. Borras18, V. Botta, A. Campbell, P. Connor, C. Contreras-Campana, F. Costanza, C. Diez Pardos, G. Eckerlin, D. Eckstein, T. Eichhorn, E. Eren, E. Gallo19, J. Garay Garcia, A. Geiser, A. Gizhko, J.M. Grados Luyando, A. Grohsjean, P. Gunnellini, M. Gutho , A. Harb, J. Hauk, M. Hempel20, H. Jung, A. Kalogeropoulos, M. Kasemann, J. Keaveney, C. Kleinwort, I. Korol, D. Krucker, W. Lange, A. Lelek, T. Lenz, J. Leonard, K. Lipka, W. Lohmann20, R. Mankel, I.-A. Melzer-Pellmann, A.B. Meyer, G. Mittag, J. Mnich, A. Mussgiller, E. Ntomari, D. Pitzl, A. Raspereza, B. Roland, M. Savitskyi, P. Saxena, R. Shevchenko, S. Spannagel, N. Stefaniuk, G.P. Van Onsem, R. Walsh, Y. Wen, K. Wichmann, C. Wissing, O. Zenaiev University of Hamburg, Hamburg, Germany R. Aggleton, S. Bein, V. Blobel, M. Centis Vignali, T. Dreyer, E. Garutti, D. Gonzalez, J. Haller, A. Hinzmann, M. Ho mann, A. Karavdina, R. Klanner, R. Kogler, N. Kovalchuk, S. Kurz, T. Lapsien, I. Marchesini, D. Marconi, M. Meyer, M. Niedziela, D. Nowatschin, F. Pantaleo17, T. Pei er, A. Perieanu, C. Scharf, P. Schleper, A. Schmidt, S. Schumann, J. Schwandt, J. Sonneveld, H. Stadie, G. Steinbruck, F.M. Stober, M. Stover, H. Tholen, D. Troendle, E. Usai, L. Vanelderen, A. Vanhoefer, B. Vormwald Institut fur Experimentelle Kernphysik, Karlsruhe, Germany M. Akbiyik, C. Barth, S. Baur, E. Butz, R. Caspart, T. Chwalek, F. Colombo, W. De Boer, A. Dierlamm, B. Freund, R. Friese, M. Gi els, D. Haitz, M.A. Harrendorf, F. Hartmann17, S.M. Heindl, U. Husemann, F. Kassel17, S. Kudella, H. Mildner, M.U. Mozer, Th. Muller, M. Plagge, G. Quast, K. Rabbertz, M. Schroder, I. Shvetsov, G. Sieber, H.J. Simonis, R. Ulrich, S. Wayand, M. Weber, T. Weiler, S. Williamson, C. Wohrmann, R. Wolf Institute of Nuclear and Particle Physics (INPP), NCSR Demokritos, Aghia Paraskevi, Greece I. Topsis-Giotis G. Anagnostou, G. Daskalakis, T. Geralis, V.A. Giakoumopoulou, A. Kyriakis, D. Loukas, National and Kapodistrian University of Athens, Athens, Greece G. Karathanasis, S. Kesisoglou, A. Panagiotou, N. Saoulidou National Technical University of Athens, Athens, Greece K. Kousouris University of Ioannina, Ioannina, Greece I. Evangelou, C. Foudas, P. Kokkas, S. Mallios, N. Manthos, I. Papadopoulos, E. Paradas, J. Strologas, F.A. Triantis MTA-ELTE Lendulet CMS Particle and Nuclear Physics Group, Eotvos Lorand University, Budapest, Hungary M. Csanad, N. Filipovic, G. Pasztor, O. Suranyi, G.I. Veres21 Wigner Research Centre for Physics, Budapest, Hungary G. Bencze, C. Hajdu, D. Horvath22, A. Hunyadi, F. Sikler, V. Veszpremi, A.J. Zsigmond Institute of Nuclear Research ATOMKI, Debrecen, Hungary N. Beni, S. Czellar, J. Karancsi23, A. Makovec, J. Molnar, Z. Szillasi Institute of Physics, University of Debrecen, Debrecen, Hungary M. Bartok21, P. Raics, Z.L. Trocsanyi, B. Ujvari Indian Institute of Science (IISc), Bangalore, India S. Choudhury, J.R. Komaragiri National Institute of Science Education and Research, Bhubaneswar, India S. Bahinipati24, S. Bhowmik, P. Mal, K. Mandal, A. Nayak25, D.K. Sahoo24, N. Sahoo, S.K. Swain Panjab University, Chandigarh, India S. Bansal, S.B. Beri, V. Bhatnagar, R. Chawla, N. Dhingra, A.K. Kalsi, A. Kaur, M. Kaur, S. Kaur, R. Kumar, P. Kumari, A. Mehta, J.B. Singh, G. Walia University of Delhi, Delhi, India Ashok Kumar, Aashaq Shah, A. Bhardwaj, S. Chauhan, B.C. Choudhary, R.B. Garg, S. Keshri, A. Kumar, S. Malhotra, M. Naimuddin, K. Ranjan, R. Sharma Saha Institute of Nuclear Physics, HBNI, Kolkata, India R. Bhardwaj, R. Bhattacharya, S. Bhattacharya, U. Bhawandeep, S. Dey, S. Dutt, S. Dutta, S. Ghosh, N. Majumdar, A. Modak, K. Mondal, S. Mukhopadhyay, S. Nandan, A. Purohit, A. Roy, D. Roy, S. Roy Chowdhury, S. Sarkar, M. Sharan, S. Thakur HJEP03(218)7 Indian Institute of Technology Madras, Madras, India P.K. Behera Bhabha Atomic Research Centre, Mumbai, India R. Chudasama, D. Dutta, V. Jha, V. Kumar, A.K. Mohanty17, P.K. Netrakanti, L.M. Pant, P. Shukla, A. Topkar Tata Institute of Fundamental Research-A, Mumbai, India T. Aziz, S. Dugad, B. Mahakud, S. Mitra, G.B. Mohanty, N. Sur, B. Sutar Tata Institute of Fundamental Research-B, Mumbai, India S. Banerjee, S. Bhattacharya, S. Chatterjee, P. Das, M. Guchait, Sa. Jain, S. Kumar, M. Maity26, G. Majumder, K. Mazumdar, T. Sarkar26, N. Wickramage27 Indian Institute of Science Education and Research (IISER), Pune, India S. Chauhan, S. Dube, V. Hegde, A. Kapoor, K. Kothekar, S. Pandey, A. Rane, S. Sharma Institute for Research in Fundamental Sciences (IPM), Tehran, Iran S. Chenarani28, E. Eskandari Tadavani, S.M. Etesami28, M. Khakzad, M. Mohammadi Najafabadi, M. Naseri, S. Paktinat Mehdiabadi29, F. Rezaei Hosseinabadi, B. Safarzadeh30, M. Zeinali University College Dublin, Dublin, Ireland M. Felcini, M. Grunewald INFN Sezione di Bari a, Universita di Bari b, Politecnico di Bari c, Bari, Italy M. Abbresciaa;b, C. Calabriaa;b, A. Colaleoa, D. Creanzaa;c, L. Cristellaa;b, N. De Filippisa;c, M. De Palmaa;b, F. Erricoa;b, L. Fiorea, G. Iasellia;c, S. Lezkia;b, G. Maggia;c, M. Maggia, G. Minielloa;b, S. Mya;b, S. Nuzzoa;b, A. Pompilia;b, G. Pugliesea;c, R. Radognaa, A. Ranieria, G. Selvaggia;b, A. Sharmaa, L. Silvestrisa;17, R. Vendittia, P. Verwilligena INFN Sezione di Bologna a, Universita di Bologna b, Bologna, Italy G. Abbiendia, C. Battilanaa;b, D. Bonacorsia;b, L. Borgonovia;b, S. Braibant-Giacomellia;b, R. Campaninia;b, P. Capiluppia;b, A. Castroa;b, F.R. Cavalloa, S.S. Chhibraa, G. Codispotia;b, M. Cu ania;b, G.M. Dallavallea, F. Fabbria, A. Fanfania;b, D. Fasanellaa;b, P. Giacomellia, C. Grandia, L. Guiduccia;b, S. Marcellinia, G. Masettia, A. Montanaria, F.L. Navarriaa;b, A. Perrottaa, A.M. Rossia;b, T. Rovellia;b, G.P. Sirolia;b, N. Tosia INFN Sezione di Catania a, Universita di Catania b, Catania, Italy S. Albergoa;b, S. Costaa;b, A. Di Mattiaa, F. Giordanoa;b, R. Potenzaa;b, A. Tricomia;b, C. Tuvea;b L. Viliania;b;17 INFN Sezione di Firenze a, Universita di Firenze b, Firenze, Italy G. Barbaglia, K. Chatterjeea;b, V. Ciullia;b, C. Civininia, R. D'Alessandroa;b, E. Focardia;b, P. Lenzia;b, M. Meschinia, S. Paolettia, L. Russoa;31, G. Sguazzonia, D. Stroma, INFN Laboratori Nazionali di Frascati, Frascati, Italy L. Benussi, S. Bianco, F. Fabbri, D. Piccolo, F. Primavera17 INFN Sezione di Genova a, Universita di Genova b, Genova, Italy V. Calvellia;b, F. Ferroa, E. Robuttia, S. Tosia;b INFN Sezione di Milano-Bicocca a, Universita di Milano-Bicocca b, Milano, Italy A. Benagliaa, L. Brianzaa;b, F. Brivioa;b, V. Cirioloa;b, M.E. Dinardoa;b, S. Fiorendia;b, S. Gennaia, A. Ghezzia;b, P. Govonia;b, M. Malbertia;b, S. Malvezzia, R.A. Manzonia;b, D. Menascea, L. Moronia, M. Paganonia;b, K. Pauwelsa;b, D. Pedrinia, S. Pigazzinia;b;32, S. Ragazzia;b, N. Redaellia, T. Tabarelli de Fatisa;b INFN Sezione di Napoli a, Universita di Napoli 'Federico II' b, Napoli, Italy, Universita della Basilicata c, Potenza, Italy, Universita G. Marconi d, Roma, Italy F. Thyssena S. Buontempoa, N. Cavalloa;c, S. Di Guidaa;d;17, F. Fabozzia;c, F. Fiengaa;b, A.O.M. Iorioa;b, W.A. Khana, L. Listaa, S. Meolaa;d;17, P. Paoluccia;17, C. Sciaccaa;b, INFN Sezione di Padova a, Universita di Padova b, Padova, Italy, Universita di Trento c, Trento, Italy P. Azzia, N. Bacchettaa, L. Benatoa;b, A. Bolettia;b, R. Carlina;b, A. Carvalho Antunes De Oliveiraa;b, P. Checchiaa, M. Dall'Ossoa;b, P. De Castro Manzanoa, T. Dorigoa, U. Dossellia, F. Gasparinia;b, U. Gasparinia;b, A. Gozzelinoa, S. Lacapraraa, P. Lujan, M. Margonia;b, A.T. Meneguzzoa;b, N. Pozzobona;b, P. Ronchesea;b, R. Rossina;b, F. Simonettoa;b, E. Torassaa, S. Venturaa, M. Zanettia;b, P. Zottoa;b INFN Sezione di Pavia a, Universita di Pavia b, Pavia, Italy A. Braghieria, A. Magnania, P. Montagnaa;b, S.P. Rattia;b, V. Rea, M. Ressegottia;b, C. Riccardia;b, P. Salvinia, I. Vaia;b, P. Vituloa;b INFN Sezione di Perugia a, Universita di Perugia b, Perugia, Italy L. Alunni Solestizia;b, M. Biasinia;b, G.M. Bileia, C. Cecchia;b, D. Ciangottinia;b, L. Fanoa;b, P. Laricciaa;b, R. Leonardia;b, E. Manonia, G. Mantovania;b, V. Mariania;b, M. Menichellia, A. Rossia;b, A. Santocchiaa;b, D. Spigaa INFN Sezione di Pisa a, Universita di Pisa b, Scuola Normale Superiore di Pisa c, Pisa, Italy K. Androsova, P. Azzurria;17, G. Bagliesia, T. Boccalia, L. Borrello, R. Castaldia, M.A. Cioccia;b, R. Dell'Orsoa, G. Fedia, L. Gianninia;c, A. Giassia, M.T. Grippoa;31, F. Ligabuea;c, T. Lomtadzea, E. Mancaa;c, G. Mandorlia;c, L. Martinia;b, A. Messineoa;b, F. Pallaa, A. Rizzia;b, A. Savoy-Navarroa;33, P. Spagnoloa, R. Tenchinia, G. Tonellia;b, A. Venturia, P.G. Verdinia INFN Sezione di Roma a, Sapienza Universita di Roma b, Rome, Italy L. Baronea;b, F. Cavallaria, M. Cipriania;b, N. Dacia, D. Del Rea;b;17, E. Di Marcoa;b, M. Diemoza, S. Gellia;b, E. Longoa;b, F. Margarolia;b, B. Marzocchia;b, HJEP03(218)7 F. Santanastasioa;b INFN Sezione di Torino a, Universita di Torino b, Torino, Italy, Universita del Piemonte Orientale c, Novara, Italy N. Amapanea;b, R. Arcidiaconoa;c, S. Argiroa;b, M. Arneodoa;c, N. Bartosika, R. Bellana;b, C. Biinoa, N. Cartigliaa, F. Cennaa;b, M. Costaa;b, R. Covarellia;b, A. Deganoa;b, N. Demariaa, B. Kiania;b, C. Mariottia, S. Masellia, E. Migliorea;b, V. Monacoa;b, E. Monteila;b, M. Montenoa, M.M. Obertinoa;b, L. Pachera;b, N. Pastronea, M. Pelliccionia, G.L. Pinna Angionia;b, F. Raveraa;b, A. Romeroa;b, M. Ruspaa;c, R. Sacchia;b, K. Shchelinaa;b, V. Solaa, A. Solanoa;b, A. Staianoa, P. Traczyka;b INFN Sezione di Trieste a, Universita di Trieste b, Trieste, Italy S. Belfortea, M. Casarsaa, F. Cossuttia, G. Della Riccaa;b, A. Zanettia Kyungpook National University, Daegu, Korea D.H. Kim, G.N. Kim, M.S. Kim, J. Lee, S. Lee, S.W. Lee, C.S. Moon, Y.D. Oh, S. Sekmen, D.C. Son, Y.C. Yang Chonbuk National University, Jeonju, Korea A. Lee Chonnam National University, Institute for Universe and Elementary Particles, Kwangju, Korea H. Kim, D.H. Moon, G. Oh Hanyang University, Seoul, Korea J.A. Brochero Cifuentes, J. Goh, T.J. Kim Korea University, Seoul, Korea J. Lim, S.K. Park, Y. Roh Seoul National University, Seoul, Korea S.h. Seo, U.K. Yang, H.D. Yoo, G.B. Yu University of Seoul, Seoul, Korea M. Choi, H. Kim, J.H. Kim, J.S.H. Lee, I.C. Park Sungkyunkwan University, Suwon, Korea Y. Choi, C. Hwang, J. Lee, I. Yu Vilnius University, Vilnius, Lithuania V. Dudenas, A. Juodagalvis, J. Vaitkus S. Cho, S. Choi, Y. Go, D. Gyun, S. Ha, B. Hong, Y. Jo, Y. Kim, K. Lee, K.S. Lee, S. Lee, J. Almond, J. Kim, J.S. Kim, H. Lee, K. Lee, K. Nam, S.B. Oh, B.C. Radburn-Smith, National Centre for Particle Physics, Universiti Malaya, Kuala Lumpur, Malaysia M.N. Yusli, Z. Zolkapli I. Ahmed, Z.A. Ibrahim, M.A.B. Md Ali34, F. Mohamad Idris35, W.A.T. Wan Abdullah, HJEP03(218)7 Reyes-Almanza, R, Ramirez-Sanchez, G., Duran-Osuna, M. C., H. Castilla-Valdez, E. De La Cruz-Burelo, I. Heredia-De La Cruz36, Rabadan-Trejo, R. I., R. Lopez-Fernandez, J. Mejia Guisao, A. Sanchez-Hernandez Universidad Iberoamericana, Mexico City, Mexico S. Carrillo Moreno, C. Oropeza Barrera, F. Vazquez Valencia Benemerita Universidad Autonoma de Puebla, Puebla, Mexico I. Pedraza, H.A. Salazar Ibarguen, C. Uribe Estrada Universidad Autonoma de San Luis Potos , San Luis Potos , Mexico A. Morelos Pineda University of Auckland, Auckland, New Zealand University of Canterbury, Christchurch, New Zealand National Centre for Physics, Quaid-I-Azam University, Islamabad, Pakistan A. Ahmad, M. Ahmad, Q. Hassan, H.R. Hoorani, A. Saddique, M.A. Shah, M. Shoaib, National Centre for Nuclear Research, Swierk, Poland H. Bialkowska, M. Bluj, B. Boimska, T. Frueboes, M. Gorski, M. Kazana, K. Nawrocki, M. Szleper, P. Zalewski Warsaw, Poland Institute of Experimental Physics, Faculty of Physics, University of Warsaw, K. Bunkowski, A. Byszuk37, K. Doroba, A. Kalinowski, M. Konecki, J. Krolikowski, M. Misiura, M. Olszewski, A. Pyskir, M. Walczak Laboratorio de Instrumentac~ao e F sica Experimental de Part culas, Lisboa, Portugal P. Bargassa, C. Beir~ao Da Cruz E Silva, A. Di Francesco, P. Faccioli, B. Galinhas, M. Gallinaro, J. Hollar, N. Leonardo, L. Lloret Iglesias, M.V. Nemallapudi, J. Seixas, G. Strong, O. Toldaiev, D. Vadruccio, J. Varela Joint Institute for Nuclear Research, Dubna, Russia S. Afanasiev, P. Bunin, M. Gavrilenko, I. Golutvin, I. Gorbunov, A. Kamenev, V. Karjavin, A. Lanev, A. Malakhov, V. Matveev38;39, V. Palichik, V. Perelygin, S. Shmatov, S. Shulha, N. Skatchkov, V. Smirnov, N. Voytishin, A. Zarubin Petersburg Nuclear Physics Institute, Gatchina (St. Petersburg), Russia Y. Ivanov, V. Kim40, E. Kuznetsova41, P. Levchenko, V. Murzin, V. Oreshkin, I. Smirnov, V. Sulimov, L. Uvarov, S. Vavilov, A. Vorobyev Institute for Nuclear Research, Moscow, Russia Yu. Andreev, A. Dermenev, S. Gninenko, N. Golubev, A. Karneyeu, M. Kirsanov, N. Krasnikov, A. Pashenkov, D. Tlisov, A. Toropin Institute for Theoretical and Experimental Physics, Moscow, Russia V. Epshteyn, V. Gavrilov, N. Lychkovskaya, V. Popov, I. Pozdnyakov, G. Safronov, A. Spiridonov, A. Stepennov, M. Toms, E. Vlasov, A. Zhokin Moscow Institute of Physics and Technology, Moscow, Russia T. Aushev, A. Bylinkin39 National Research Nuclear University 'Moscow Engineering Physics Institute' (MEPhI), Moscow, Russia M. Chadeeva42, P. Parygin, D. Philippov, S. Polikarpov, E. Popova, V. Rusinov P.N. Lebedev Physical Institute, Moscow, Russia V. Andreev, M. Azarkin39, I. Dremin39, M. Kirakosyan39, A. Terkulov Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia A. Snigirev A. Baskakov, A. Belyaev, E. Boos, M. Dubinin43, L. Dudko, A. Ershov, A. Gribushin, V. Klyukhin, O. Kodolova, I. Lokhtin, I. Miagkov, S. Obraztsov, S. Petrushanko, V. Savrin, Novosibirsk State University (NSU), Novosibirsk, Russia V. Blinov44, Y.Skovpen44, D. Shtol44 State Research Center of Russian Federation, Institute for High Energy Physics, Protvino, Russia I. Azhgirey, I. Bayshev, S. Bitioukov, D. Elumakhov, V. Kachanov, A. Kalinin, D. Konstantinov, P. Mandrik, V. Petrov, R. Ryutin, A. Sobol, S. Troshin, N. Tyurin, A. Uzunian, A. Volkov University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences, Belgrade, Serbia P. Adzic45, P. Cirkovic, D. Devetak, M. Dordevic, J. Milosevic, V. Rekovic Centro de Investigaciones Energeticas Medioambientales y Tecnologicas (CIEMAT), Madrid, Spain J. Alcaraz Maestre, M. Barrio Luna, M. Cerrada, N. Colino, B. De La Cruz, A. Delgado Peris, A. Escalante Del Valle, C. Fernandez Bedoya, J.P. Fernandez Ramos, J. Flix, M.C. Fouz, O. Gonzalez Lopez, S. Goy Lopez, J.M. Hernandez, M.I. Josa, D. Moran, A. Perez-Calero Yzquierdo, J. Puerta Pelayo, A. Quintario Olmeda, I. Redondo, L. Romero, M.S. Soares, A. Alvarez Fernandez Universidad Autonoma de Madrid, Madrid, Spain C. Albajar, J.F. de Troconiz, M. Missiroli J. Cuevas, C. Erice, J. Fernandez Menendez, I. Gonzalez Caballero, J.R. Gonzalez Fernandez, E. Palencia Cortezon, S. Sanchez Cruz, P. Vischia, J.M. Vizan Garcia Instituto de F sica de Cantabria (IFCA), CSIC-Universidad de Cantabria, Santander, Spain I.J. Cabrillo, A. Calderon, B. Chazin Quero, E. Curras, J. Duarte Campderros, M. Fernandez, J. Garcia-Ferrero, G. Gomez, A. Lopez Virto, J. Marco, C. Martinez Rivero, P. Martinez Ruiz del Arbol, F. Matorras, J. Piedra Gomez, T. Rodrigo, A. Ruiz-Jimeno, L. Scodellaro, N. Trevisani, I. Vila, R. Vilar Cortabitarte CERN, European Organization for Nuclear Research, Geneva, Switzerland D. Abbaneo, B. Akgun, E. Au ray, P. Baillon, A.H. Ball, D. Barney, M. Bianco, P. Bloch, A. Bocci, C. Botta, T. Camporesi, R. Castello, M. Cepeda, G. Cerminara, E. Chapon, Y. Chen, D. d'Enterria, A. Dabrowski, V. Daponte, A. David, M. De Gruttola, A. De Roeck, N. Deelen, M. Dobson, T. du Pree, M. Dunser, N. Dupont, A. Elliott-Peisert, P. Everaerts, F. Fallavollita, G. Franzoni, J. Fulcher, W. Funk, D. Gigi, A. Gilbert, K. Gill, F. Glege, D. Gulhan, P. Harris, J. Hegeman, V. Innocente, A. Jafari, P. Janot, O. Karacheban20, J. Kieseler, V. Knunz, A. Kornmayer, M.J. Kortelainen, M. Krammer1, C. Lange, P. Lecoq, C. Lourenco, M.T. Lucchini, L. Malgeri, M. Mannelli, A. Martelli, F. Meijers, J.A. Merlin, S. Mersi, E. Meschi, P. Milenovic46, F. Moortgat, M. Mulders, H. Neugebauer, J. Ngadiuba, S. Orfanelli, L. Orsini, L. Pape, E. Perez, M. Peruzzi, A. Petrilli, G. Petrucciani, A. Pfei er, M. Pierini, D. Rabady, A. Racz, T. Reis, G. Rolandi47, M. Rovere, H. Sakulin, C. Schafer, C. Schwick, M. Seidel, M. Selvaggi, A. Sharma, P. Silva, P. Sphicas48, A. Stakia, J. Steggemann, M. Stoye, M. Tosi, D. Treille, A. Triossi, A. Tsirou, V. Veckalns49, M. Verweij, W.D. Zeuner Paul Scherrer Institut, Villigen, Switzerland W. Bertly, L. Caminada50, K. Deiters, W. Erdmann, R. Horisberger, Q. Ingram, H.C. Kaestli, D. Kotlinski, U. Langenegger, T. Rohe, S.A. Wiederkehr ETH Zurich - Institute for Particle Physics and Astrophysics (IPA), Zurich, Switzerland M. Backhaus, L. Bani, P. Berger, L. Bianchini, B. Casal, G. Dissertori, M. Dittmar, M. Donega, C. Dorfer, C. Grab, C. Heidegger, D. Hits, J. Hoss, G. Kasieczka, T. Klijnsma, W. Lustermann, B. Mangano, M. Marionneau, M.T. Meinhard, D. Meister, F. Micheli, P. Musella, F. Nessi-Tedaldi, F. Pandol , J. Pata, F. Pauss, G. Perrin, L. Perrozzi, M. Quittnat, M. Reichmann, D.A. Sanz Becerra, M. Schonenberger, L. Shchutska, V.R. Tavolaro, K. Theo latos, M.L. Vesterbacka Olsson, R. Wallny, D.H. Zhu Universitat Zurich, Zurich, Switzerland T.K. Aarrestad, C. Amsler51, M.F. Canelli, A. De Cosa, R. Del Burgo, S. Donato, C. Galloni, T. Hreus, B. Kilminster, D. Pinna, G. Rauco, P. Robmann, D. Salerno, K. Schweiger, C. Seitz, Y. Takahashi, A. Zucchetta National Central University, Chung-Li, Taiwan V. Candelise, T.H. Doan, Sh. Jain, R. Khurana, C.M. Kuo, W. Lin, A. Pozdnyakov, S.S. Yu National Taiwan University (NTU), Taipei, Taiwan Arun Kumar, P. Chang, Y. Chao, K.F. Chen, P.H. Chen, F. Fiori, W.-S. Hou, Y. Hsiung, Y.F. Liu, R.-S. Lu, E. Paganis, A. Psallidas, A. Steen, J.f. Tsai Chulalongkorn University, Faculty of Science, Department of Physics, Bangkok, Thailand Turkey B. Asavapibhop, K. Kovitanggoon, G. Singh, N. Srimanobhas Cukurova University, Physics Department, Science and Art Faculty, Adana, F. Boran, S. Damarseckin, Z.S. Demiroglu, C. Dozen, E. Eskut, S. Girgis, G. Gokbulut, Y. Guler, I. Hos52, E.E. Kangal53, O. Kara, U. Kiminsu, M. Oglakci, G. Onengut54, K. Ozdemir55, S. Ozturk56, A. Polatoz, D. Sunar Cerci57, H. Topakli56, S. Turkcapar, I.S. Zorbakir, C. Zorbilmez Middle East Technical University, Physics Department, Ankara, Turkey B. Bilin, G. Karapinar58, K. Ocalan59, M. Yalvac, M. Zeyrek Bogazici University, Istanbul, Turkey E. Gulmez, M. Kaya60, O. Kaya61, S. Tekten, E.A. Yetkin62 Istanbul Technical University, Istanbul, Turkey M.N. Agaras, S. Atay, A. Cakir, K. Cankocak Institute for Scintillation Materials of National Academy of Science of Ukraine, Kharkov, Ukraine B. Grynyov Kharkov, Ukraine L. Levchuk National Scienti c Center, Kharkov Institute of Physics and Technology, University of Bristol, Bristol, United Kingdom F. Ball, L. Beck, J.J. Brooke, D. Burns, E. Clement, D. Cussans, O. Davignon, H. Flacher, J. Goldstein, G.P. Heath, H.F. Heath, J. Jacob, L. Kreczko, D.M. Newbold63, S. Paramesvaran, T. Sakuma, S. Seif El Nasr-storey, D. Smith, V.J. Smith Rutherford Appleton Laboratory, Didcot, United Kingdom K.W. Bell, A. Belyaev64, C. Brew, R.M. Brown, L. Calligaris, D. Cieri, D.J.A. Cockerill, J.A. Coughlan, K. Harder, S. Harper, E. Olaiya, D. Petyt, C.H. Shepherd-Themistocleous, A. Thea, I.R. Tomalin, T. Williams Imperial College, London, United Kingdom G. Auzinger, R. Bainbridge, J. Borg, S. Breeze, O. Buchmuller, A. Bundock, S. Casasso, M. Citron, D. Colling, L. Corpe, P. Dauncey, G. Davies, A. De Wit, M. Della Negra, R. Di Maria, A. Elwood, Y. Haddad, G. Hall, G. Iles, T. James, R. Lane, C. Laner, L. Lyons, V. Palladino, M. Pesaresi, D.M. Raymond, A. Richards, A. Rose, E. Scott, C. Seez, A. Shtipliyski, S. Summers, A. Tapper, K. Uchida, M. Vazquez Acosta65, T. Virdee17, N. Wardle, D. Winterbottom, J. Wright, S.C. Zenz Brunel University, Uxbridge, United Kingdom J.E. Cole, P.R. Hobson, A. Khan, P. Kyberd, I.D. Reid, P. Symonds, L. Teodorescu, M. Turner, S. Zahid Baylor University, Waco, U.S.A. A. Borzou, K. Call, J. Dittmann, K. Hatakeyama, H. Liu, N. Pastika, C. Smith Catholic University of America, Washington DC, U.S.A. R. Bartek, A. Dominguez The University of Alabama, Tuscaloosa, U.S.A. A. Buccilli, S.I. Cooper, C. Henderson, P. Rumerio, C. West Boston University, Boston, U.S.A. D. Zou Brown University, Providence, U.S.A. D. Arcaro, A. Avetisyan, T. Bose, D. Gastler, D. Rankin, C. Richardson, J. Rohlf, L. Sulak, G. Benelli, D. Cutts, A. Garabedian, M. Hadley, J. Hakala, U. Heintz, J.M. Hogan, K.H.M. Kwok, E. Laird, G. Landsberg, J. Lee, Z. Mao, M. Narain, J. Pazzini, S. Piperov, S. Sagir, R. Syarif, D. Yu University of California, Davis, Davis, U.S.A. R. Band, C. Brainerd, D. Burns, M. Calderon De La Barca Sanchez, M. Chertok, J. Conway, R. Conway, P.T. Cox, R. Erbacher, C. Flores, G. Funk, M. Gardner, W. Ko, R. Lander, C. Mclean, M. Mulhearn, D. Pellett, J. Pilot, S. Shalhout, M. Shi, J. Smith, D. Stolp, K. Tos, M. Tripathi, Z. Wang University of California, Los Angeles, U.S.A. M. Bachtis, C. Bravo, R. Cousins, A. Dasgupta, A. Florent, J. Hauser, M. Ignatenko, N. Mccoll, S. Regnard, D. Saltzberg, C. Schnaible, V. Valuev University of California, Riverside, Riverside, U.S.A. E. Bouvier, K. Burt, R. Clare, J. Ellison, J.W. Gary, S.M.A. Ghiasi Shirazi, G. Hanson, J. Heilman, E. Kennedy, F. Lacroix, O.R. Long, M. Olmedo Negrete, M.I. Paneva, W. Si, L. Wang, H. Wei, S. Wimpenny, B. R. Yates University of California, San Diego, La Jolla, U.S.A. J.G. Branson, S. Cittolin, M. Derdzinski, R. Gerosa, D. Gilbert, B. Hashemi, A. Holzner, D. Klein, G. Kole, V. Krutelyov, J. Letts, I. Macneill, M. Masciovecchio, D. Olivito, S. Padhi, M. Pieri, M. Sani, V. Sharma, S. Simon, M. Tadel, A. Vartak, S. Wasserbaech66, J. Wood, F. Wurthwein, A. Yagil, G. Zevi Della Porta University of California, Santa Barbara - Department of Physics, Santa Barbara, U.S.A. N. Amin, R. Bhandari, J. Bradmiller-Feld, C. Campagnari, A. Dishaw, V. Dutta, M. Franco Sevilla, C. George, F. Golf, L. Gouskos, J. Gran, R. Heller, J. Incandela, S.D. Mullin, A. Ovcharova, H. Qu, J. Richman, D. Stuart, I. Suarez, J. Yoo California Institute of Technology, Pasadena, U.S.A. D. Anderson, J. Bendavid, A. Bornheim, J.M. Lawhorn, H.B. Newman, T. Nguyen, C. Pena, M. Spiropulu, J.R. Vlimant, S. Xie, Z. Zhang, R.Y. Zhu Carnegie Mellon University, Pittsburgh, U.S.A. M.B. Andrews, T. Ferguson, T. Mudholkar, M. Paulini, J. Russ, M. Sun, H. Vogel, I. Vorobiev, M. Weinberg University of Colorado Boulder, Boulder, U.S.A. J.P. Cumalat, W.T. Ford, F. Jensen, A. Johnson, M. Krohn, S. Leontsinis, T. Mulholland, K. Stenson, S.R. Wagner Cornell University, Ithaca, U.S.A. J. Alexander, J. Chaves, J. Chu, S. Dittmer, K. Mcdermott, N. Mirman, J.R. Patterson, D. Quach, A. Rinkevicius, A. Ryd, L. Skinnari, L. So , S.M. Tan, Z. Tao, J. Thom, J. Tucker, P. Wittich, M. Zientek Fermi National Accelerator Laboratory, Batavia, U.S.A. S. Abdullin, M. Albrow, M. Alyari, G. Apollinari, A. Apresyan, A. Apyan, S. Banerjee, L.A.T. Bauerdick, A. Beretvas, J. Berryhill, P.C. Bhat, G. Bollay, K. Burkett, J.N. Butler, A. Canepa, G.B. Cerati, H.W.K. Cheung, F. Chlebana, M. Cremonesi, J. Duarte, V.D. Elvira, J. Freeman, Z. Gecse, E. Gottschalk, L. Gray, D. Green, S. Grunendahl, O. Gutsche, R.M. Harris, S. Hasegawa, J. Hirschauer, Z. Hu, B. Jayatilaka, S. Jindariani, M. Johnson, U. Joshi, B. Klima, B. Kreis, S. Lammel, D. Lincoln, R. Lipton, M. Liu, T. Liu, R. Lopes De Sa, J. Lykken, K. Maeshima, N. Magini, J.M. Marra no, D. Mason, P. McBride, P. Merkel, S. Mrenna, S. Nahn, V. O'Dell, K. Pedro, O. Prokofyev, G. Rakness, L. Ristori, B. Schneider, E. Sexton-Kennedy, A. Soha, W.J. Spalding, L. Spiegel, S. Stoynev, J. Strait, N. Strobbe, L. Taylor, S. Tkaczyk, N.V. Tran, L. Uplegger, E.W. Vaandering, C. Vernieri, M. Verzocchi, R. Vidal, M. Wang, H.A. Weber, A. Whitbeck University of Florida, Gainesville, U.S.A. D. Acosta, P. Avery, P. Bortignon, D. Bourilkov, A. Brinkerho , A. Carnes, M. Carver, D. Curry, R.D. Field, I.K. Furic, S.V. Gleyzer, B.M. Joshi, J. Konigsberg, A. Korytov, K. Kotov, P. Ma, K. Matchev, H. Mei, G. Mitselmakher, D. Rank, K. Shi, D. Sperka, N. Terentyev, L. Thomas, J. Wang, S. Wang, J. Yelton Florida International University, Miami, U.S.A. Y.R. Joshi, S. Linn, P. Markowitz, J.L. Rodriguez Florida State University, Tallahassee, U.S.A. A. Ackert, T. Adams, A. Askew, S. Hagopian, V. Hagopian, K.F. Johnson, T. Kolberg, G. Martinez, T. Perry, H. Prosper, A. Saha, A. Santra, V. Sharma, R. Yohay Florida Institute of Technology, Melbourne, U.S.A. M.M. Baarmand, V. Bhopatkar, S. Colafranceschi, M. Hohlmann, D. Noonan, T. Roy, F. Yumiceva University of Illinois at Chicago (UIC), Chicago, U.S.A. M.R. Adams, L. Apanasevich, D. Berry, R.R. Betts, R. Cavanaugh, X. Chen, O. Evdokimov, C.E. Gerber, D.A. Hangal, D.J. Hofman, K. Jung, J. Kamin, I.D. Sandoval Gonzalez, M.B. Tonjes, H. Trauger, N. Varelas, H. Wang, Z. Wu, J. Zhang The University of Iowa, Iowa City, U.S.A. B. Bilki67, W. Clarida, K. Dilsiz68, S. Durgut, R.P. Gandrajula, M. Haytmyradov, V. Khristenko, J.-P. Merlo, H. Mermerkaya69, A. Mestvirishvili, A. Moeller, J. Nachtman, H. Ogul70, Y. Onel, F. Ozok71, A. Penzo, C. Snyder, E. Tiras, J. Wetzel, K. Yi Johns Hopkins University, Baltimore, U.S.A. B. Blumenfeld, A. Cocoros, N. Eminizer, D. Fehling, L. Feng, A.V. Gritsan, P. Maksimovic, J. Roskes, U. Sarica, M. Swartz, M. Xiao, C. You The University of Kansas, Lawrence, U.S.A. A. Al-bataineh, P. Baringer, A. Bean, S. Boren, J. Bowen, J. Castle, S. Khalil, A. Kropivnitskaya, D. Majumder, W. Mcbrayer, M. Murray, C. Royon, S. Sanders, E. Schmitz, J.D. Tapia Takaki, Q. Wang Kansas State University, Manhattan, U.S.A. A. Ivanov, K. Kaadze, Y. Maravin, A. Mohammadi, L.K. Saini, N. Skhirtladze, S. Toda Lawrence Livermore National Laboratory, Livermore, U.S.A. F. Rebassoo, D. Wright University of Maryland, College Park, U.S.A. C. Anelli, A. Baden, O. Baron, A. Belloni, B. Calvert, S.C. Eno, Y. Feng, C. Ferraioli, N.J. Hadley, S. Jabeen, G.Y. Jeng, R.G. Kellogg, J. Kunkle, A.C. Mignerey, F. Ricci-Tam, Y.H. Shin, A. Skuja, S.C. Tonwar Massachusetts Institute of Technology, Cambridge, U.S.A. D. Abercrombie, B. Allen, V. Azzolini, R. Barbieri, A. Baty, R. Bi, S. Brandt, W. Busza, I.A. Cali, M. D'Alfonso, Z. Demiragli, G. Gomez Ceballos, M. Goncharov, D. Hsu, M. Hu, Y. Iiyama, G.M. Innocenti, M. Klute, D. Kovalskyi, Y.S. Lai, Y.-J. Lee, A. Levin, P.D. Luckey, B. Maier, A.C. Marini, C. Mcginn, C. Mironov, S. Narayanan, X. Niu, C. Paus, C. Roland, G. Roland, J. Salfeld-Nebgen, G.S.F. Stephans, K. Tatar, D. Velicanu, J. Wang, T.W. Wang, B. Wyslouch University of Minnesota, Minneapolis, U.S.A. A.C. Benvenuti, R.M. Chatterjee, A. Evans, P. Hansen, J. Hiltbrand, S. Kalafut, Y. Kubota, Z. Lesko, J. Mans, S. Nourbakhsh, N. Ruckstuhl, R. Rusack, J. Turkewitz, M.A. Wadud University of Mississippi, Oxford, U.S.A. J.G. Acosta, S. Oliveros E. Avdeeva, K. Bloom, D.R. Claes, C. Fangmeier, R. Gonzalez Suarez, R. Kamalieddin, I. Kravchenko, J. Monroy, J.E. Siado, G.R. Snow, B. Stieger State University of New York at Bu alo, Bu alo, U.S.A. J. Dolen, A. Godshalk, C. Harrington, I. Iashvili, D. Nguyen, A. Parker, S. Rappoccio, B. Roozbahani Northeastern University, Boston, U.S.A. R. Teixeira De Lima, D. Trocino, D. Wood Northwestern University, Evanston, U.S.A. G. Alverson, E. Barberis, A. Hortiangtham, A. Massironi, D.M. Morse, T. Orimoto, S. Bhattacharya, O. Charaf, K.A. Hahn, N. Mucia, N. Odell, B. Pollack, M.H. Schmitt, K. Sung, M. Trovato, M. Velasco University of Notre Dame, Notre Dame, U.S.A. N. Dev, M. Hildreth, K. Hurtado Anampa, C. Jessop, D.J. Karmgard, N. Kellams, K. Lannon, N. Loukas, N. Marinelli, F. Meng, C. Mueller, Y. Musienko38, M. Planer, A. Reinsvold, R. Ruchti, G. Smith, S. Taroni, M. Wayne, M. Wolf, A. Woodard The Ohio State University, Columbus, U.S.A. J. Alimena, L. Antonelli, B. Bylsma, L.S. Durkin, S. Flowers, B. Francis, A. Hart, C. Hill, W. Ji, B. Liu, W. Luo, D. Puigh, B.L. Winer, H.W. Wulsin Princeton University, Princeton, U.S.A. S. Cooperstein, O. Driga, P. Elmer, J. Hardenbrook, P. Hebda, S. Higginbotham, D. Lange, J. Luo, D. Marlow, K. Mei, I. Ojalvo, J. Olsen, C. Palmer, P. Piroue, D. Stickland, C. Tully University of Puerto Rico, Mayaguez, U.S.A. S. Malik, S. Norberg Purdue University, West Lafayette, U.S.A. A. Barker, V.E. Barnes, S. Das, S. Folgueras, L. Gutay, M.K. Jha, M. Jones, A.W. Jung, A. Khatiwada, D.H. Miller, N. Neumeister, C.C. Peng, H. Qiu, J.F. Schulte, J. Sun, F. Wang, W. Xie Purdue University Northwest, Hammond, U.S.A. T. Cheng, N. Parashar, J. Stupak Rice University, Houston, U.S.A. A. Adair, Z. Chen, K.M. Ecklund, S. Freed, F.J.M. Geurts, M. Guilbaud, M. Kilpatrick, W. Li, B. Michlin, M. Northup, B.P. Padley, J. Roberts, J. Rorie, W. Shi, Z. Tu, J. Zabel, A. Zhang University of Rochester, Rochester, U.S.A. A. Bodek, P. de Barbaro, R. Demina, Y.t. Duh, T. Ferbel, M. Galanti, A. Garcia-Bellido, J. Han, O. Hindrichs, A. Khukhunaishvili, K.H. Lo, P. Tan, M. Verzetti The Rockefeller University, New York, U.S.A. R. Ciesielski, K. Goulianos, C. Mesropian Rutgers, The State University of New Jersey, Piscataway, U.S.A. A. Agapitos, J.P. Chou, Y. Gershtein, T.A. Gomez Espinosa, E. Halkiadakis, M. Heindl, E. Hughes, S. Kaplan, R. Kunnawalkam Elayavalli, S. Kyriacou, A. Lath, R. Montalvo, K. Nash, M. Osherson, H. Saka, S. Salur, S. Schnetzer, D. She eld, S. Somalwar, R. Stone, S. Thomas, P. Thomassen, M. Walker University of Tennessee, Knoxville, U.S.A. A.G. Delannoy, M. Foerster, J. Heideman, G. Riley, K. Rose, S. Spanier, K. Thapa Texas A&M University, College Station, U.S.A. O. Bouhali72, A. Castaneda Hernandez72, A. Celik, M. Dalchenko, M. De Mattia, A. Delgado, S. Dildick, R. Eusebi, J. Gilmore, T. Huang, T. Kamon73, R. Mueller, Y. Pakhotin, R. Patel, A. Perlo , L. Pernie, D. Rathjens, A. Safonov, A. Tatarinov, K.A. Ulmer Texas Tech University, Lubbock, U.S.A. N. Akchurin, J. Damgov, F. De Guio, P.R. Dudero, J. Faulkner, E. Gurpinar, S. Kunori, K. Lamichhane, S.W. Lee, T. Libeiro, T. Peltola, S. Undleeb, I. Volobouev, Z. Wang Vanderbilt University, Nashville, U.S.A. S. Greene, A. Gurrola, R. Janjam, W. Johns, C. Maguire, A. Melo, H. Ni, K. Padeken, P. Sheldon, S. Tuo, J. Velkovska, Q. Xu University of Virginia, Charlottesville, U.S.A. M.W. Arenton, P. Barria, B. Cox, R. Hirosky, M. Joyce, A. Ledovskoy, H. Li, C. Neu, T. Sinthuprasith, Y. Wang, E. Wolfe, F. Xia Wayne State University, Detroit, U.S.A. R. Harr, P.E. Karchin, N. Poudyal, J. Sturdy, P. Thapa, S. Zaleski University of Wisconsin - Madison, Madison, WI, U.S.A. M. Brodski, J. Buchanan, C. Caillol, S. Dasu, L. Dodd, S. Duric, B. Gomber, M. Grothe, M. Herndon, A. Herve, U. Hussain, P. Klabbers, A. Lanaro, A. Levine, K. Long, R. Loveless, G. Polese, T. Ruggles, A. Savin, N. Smith, W.H. Smith, D. Taylor, N. Woods y: Deceased China 1: Also at Vienna University of Technology, Vienna, Austria 2: Also at State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, 3: Also at IRFU, CEA, Universite Paris-Saclay, Gif-sur-Yvette, France 4: Also at Universidade Estadual de Campinas, Campinas, Brazil 5: Also at Universidade Federal de Pelotas, Pelotas, Brazil 6: Also at Universite Libre de Bruxelles, Bruxelles, Belgium 7: Also at Institute for Theoretical and Experimental Physics, Moscow, Russia 8: Also at Joint Institute for Nuclear Research, Dubna, Russia 9: Also at Helwan University, Cairo, Egypt 11: Now at Fayoum University, El-Fayoum, Egypt 12: Also at British University in Egypt, Cairo, Egypt 13: Now at Ain Shams University, Cairo, Egypt 14: Also at Universite de Haute Alsace, Mulhouse, France Moscow, Russia 15: Also at Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 16: Also at Ilia State University, Tbilisi, Georgia 17: Also at CERN, European Organization for Nuclear Research, Geneva, Switzerland 18: Also at RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany 19: Also at University of Hamburg, Hamburg, Germany 20: Also at Brandenburg University of Technology, Cottbus, Germany 21: Also at MTA-ELTE Lendulet CMS Particle and Nuclear Physics Group, Eotvos Lorand University, Budapest, Hungary 22: Also at Institute of Nuclear Research ATOMKI, Debrecen, Hungary 23: Also at Institute of Physics, University of Debrecen, Debrecen, Hungary 24: Also at Indian Institute of Technology Bhubaneswar, Bhubaneswar, India 25: Also at Institute of Physics, Bhubaneswar, India 26: Also at University of Visva-Bharati, Santiniketan, India 27: Also at University of Ruhuna, Matara, Sri Lanka 28: Also at Isfahan University of Technology, Isfahan, Iran 29: Also at Yazd University, Yazd, Iran 30: Also at Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran, Iran 31: Also at Universita degli Studi di Siena, Siena, Italy 32: Also at INFN Sezione di Milano-Bicocca; Universita di Milano-Bicocca, Milano, Italy 33: Also at Purdue University, West Lafayette, U.S.A. 34: Also at International Islamic University of Malaysia, Kuala Lumpur, Malaysia 35: Also at Malaysian Nuclear Agency, MOSTI, Kajang, Malaysia 36: Also at Consejo Nacional de Ciencia y Tecnolog a, Mexico city, Mexico 37: Also at Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland 38: Also at Institute for Nuclear Research, Moscow, Russia 39: Now at National Research Nuclear University 'Moscow 40: Also at St. Petersburg State Polytechnical University, St. Petersburg, Russia 41: Also at University of Florida, Gainesville, U.S.A. 42: Also at P.N. Lebedev Physical Institute, Moscow, Russia 43: Also at California Institute of Technology, Pasadena, U.S.A. 44: Also at Budker Institute of Nuclear Physics, Novosibirsk, Russia 45: Also at Faculty of Physics, University of Belgrade, Belgrade, Serbia 46: Also at University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences, Belgrade, Serbia 47: Also at Scuola Normale e Sezione dell'INFN, Pisa, Italy 48: Also at National and Kapodistrian University of Athens, Athens, Greece 49: Also at Riga Technical University, Riga, Latvia 50: Also at Universitat Zurich, Zurich, Switzerland 51: Also at Stefan Meyer Institute for Subatomic Physics (SMI), Vienna, Austria 52: Also at Istanbul Aydin University, Istanbul, Turkey 54: Also at Cag University, Mersin, Turkey 55: Also at Piri Reis University, Istanbul, Turkey 56: Also at Gaziosmanpasa University, Tokat, Turkey 57: Also at Adiyaman University, Adiyaman, Turkey 58: Also at Izmir Institute of Technology, Izmir, Turkey 59: Also at Necmettin Erbakan University, Konya, Turkey 60: Also at Marmara University, Istanbul, Turkey 61: Also at Kafkas University, Kars, Turkey 62: Also at Istanbul Bilgi University, Istanbul, Turkey 63: Also at Rutherford Appleton Laboratory, Didcot, United Kingdom 64: Also at School of Physics and Astronomy, University of Southampton, Southampton, United 65: Also at Instituto de Astrof sica de Canarias, La Laguna, Spain 66: Also at Utah Valley University, Orem, U.S.A. 67: Also at Beykent University, Istanbul, Turkey 68: Also at Bingol University, Bingol, Turkey 69: Also at Erzincan University, Erzincan, Turkey 70: Also at Sinop University, Sinop, Turkey 71: Also at Mimar Sinan University, Istanbul, Istanbul, Turkey 72: Also at Texas A&M University at Qatar, Doha, Qatar 73: Also at Kyungpook National University, Daegu, Korea 1σ0-1 ee + μμ combined • scattering measurements , Eur. Phys. J. C 76 ( 2016 ) 155 [arXiv: 1512 .00815] [INSPIRE]. [35] P. Golonka , B. Kersevan , T. Pierzchala , E. Richter-Was , Z. Was and M. Worek , The Tauola [36] R. Gavin , Y. Li , F. Petriello and S. Quackenbush , FEWZ 2 : 0: a code for hadronic Z production at next-to-next-to-leading order , Comput. Phys. Commun . 182 ( 2011 ) 2388 [39] M. Aliev , H. Lacker , U. Langenfeld , S. Moch , P. Uwer and M. Wiedermann , HATHOR: [59] T. Sj ostrand et al ., An introduction to PYTHIA 8:2, Comput . Phys. Commun . 191 ( 2015 ) [68] M. Botje et al., The PDF4LHC working group interim recommendations , arXiv:1101 .0538 [69] L. Lyons , D. Gibaut and P. Cli ord, How to combine correlated estimates of a single physical quantity , Nucl. Instrum. Meth. A 270 ( 1988 ) 110 [INSPIRE]. Instrum. Meth . A 500 ( 2003 ) 391 [INSPIRE]. [70] A. Valassi , Combining correlated measurements of several di erent physical quantities , Nucl. [71] R. Nisius , On the combination of correlated estimates of a physics observable , Eur. Phys. J.


This is a preview of a remote PDF: https://link.springer.com/content/pdf/10.1007%2FJHEP03%282018%29172.pdf

The CMS collaboration, A. M. Sirunyan, A. Tumasyan, W. Adam, F. Ambrogi, E. Asilar, T. Bergauer, J. Brandstetter, E. Brondolin, M. Dragicevic, J. Erö, M. Flechl, M. Friedl, R. Frühwirth, V. M. Ghete, J. Grossmann, J. Hrubec, M. Jeitler, A. König, N. Krammer, I. Krätschmer, D. Liko, T. Madlener, I. Mikulec, E. Pree, N. Rad, H. Rohringer, J. Schieck, R. Schöfbeck, M. Spanring, D. Spitzbart, W. Waltenberger, J. Wittmann, C.-E. Wulz, M. Zarucki, V. Chekhovsky, V. Mossolov, J. Suarez Gonzalez, E. A. De Wolf, D. Di Croce, X. Janssen, J. Lauwers, M. Van De Klundert, H. Van Haevermaet, P. Van Mechelen, N. Van Remortel, S. Abu Zeid, F. Blekman, J. D’Hondt, I. De Bruyn, J. De Clercq, K. Deroover, G. Flouris, D. Lontkovskyi, S. Lowette, S. Moortgat, L. Moreels, Q. Python, K. Skovpen, S. Tavernier, W. Van Doninck, P. Van Mulders, I. Van Parijs, D. Beghin, H. Brun, B. Clerbaux, G. De Lentdecker, H. Delannoy, B. Dorney, G. Fasanella, L. Favart, R. Goldouzian, A. Grebenyuk, G. Karapostoli, T. Lenzi, J. Luetic, T. Maerschalk, A. Marinov, A. Randle-conde, T. Seva, E. Starling, C. Vander Velde, P. Vanlaer, D. Vannerom, R. Yonamine, F. Zenoni, F. Zhang, A. Cimmino, T. Cornelis, D. Dobur, A. Fagot, M. Gul, I. Khvastunov, D. Poyraz, C. Roskas, S. Salva, M. Tytgat, W. Verbeke, N. Zaganidis, H. Bakhshiansohi, O. Bondu, S. Brochet, G. Bruno, C. Caputo, A. Caudron, P. David, S. De Visscher, C. Delaere, M. Delcourt, B. Francois, A. Giammanco, M. Komm, G. Krintiras, V. Lemaitre, A. Magitteri, A. Mertens, M. Musich, K. Piotrzkowski, L. Quertenmont, A. Saggio, M. Vidal Marono, S. Wertz, J. Zobec, N. Beliy, W. L. Aldá Júnior, F. L. Alves, G. A. Alves, L. Brito, M. Correa Martins Junior, C. Hensel, A. Moraes, M. E. Pol, P. Rebello Teles, E. Belchior Batista Das Chagas, W. Carvalho, J. Chinellato, E. Coelho, E. M. Da Costa, G. G. Da Silveira, D. De Jesus Damiao, S. Fonseca De Souza, L. M. Huertas Guativa, H. Malbouisson, M. Melo De Almeida, C. Mora Herrera, L. Mundim, H. Nogima, L. J. Sanchez Rosas, A. Santoro, A. Sznajder, M. Thiel, E. J. Tonelli Manganote, F. Torres Da Silva De Araujo, A. Vilela Pereira, S. Ahuja, C. A. Bernardes, T. R. Fernandez Perez Tomei, E. M. Gregores, P. G. Mercadante, S. F. Novaes, Sandra S. Padula, D. Romero Abad, J. C. Ruiz Vargas, A. Aleksandrov, R. Hadjiiska, P. Iaydjiev, M. Misheva, M. Rodozov, M. Shopova, G. Sultanov, A. Dimitrov, I. Glushkov, L. Litov, B. Pavlov, P. Petkov, W. Fang, X. Gao, L. Yuan, M. Ahmad, J. G. Bian, G. M. Chen, H. S. Chen, M. Chen, Y. Chen, C. H. Jiang, D. Leggat, H. Liao, Z. Liu, F. Romeo, S. M. Shaheen, A. Spiezia, J. Tao, C. Wang, Z. Wang, E. Yazgan, H. Zhang, S. Zhang, J. Zhao, Y. Ban, G. Chen, Q. Li, S. Liu, Y. Mao, S. J. Qian, D. Wang, Z. Xu, C. Avila, A. Cabrera, L. F. Chaparro Sierra, C. Florez, C. F. González Hernández, J. D. Ruiz Alvarez, B. Courbon, N. Godinovic, D. Lelas, I. Puljak, P. M. Ribeiro Cipriano, T. Sculac, Z. Antunovic, M. Kovac, V. Brigljevic, D. Ferencek, K. Kadija, B. Mesic, A. Starodumov, T. Susa, M. W. Ather, A. Attikis, G. Mavromanolakis, J. Mousa, C. Nicolaou, F. Ptochos, P. A. Razis, H. Rykaczewski, M. Finger, M. Finger, E. Carrera Jarrin, A. A. Abdelalim, Y. Mohammed, E. Salama, R. K. Dewanjee, M. Kadastik, L. Perrini, M. Raidal, A. Tiko, C. Veelken, P. Eerola, H. Kirschenmann, J. Pekkanen, M. Voutilainen, T. Järvinen, V. Karimäki, R. Kinnunen, T. Lampén, K. Lassila-Perini, S. Lehti, T. Lindén, P. Luukka, E. Tuominen, J. Tuominiemi, J. Talvitie, T. Tuuva, M. Besancon, F. Couderc, M. Dejardin, D. Denegri, J. L. Faure, F. Ferri, S. Ganjour, S. Ghosh, A. Givernaud, P. Gras, G. Hamel de Monchenault, P. Jarry, I. Kucher, C. Leloup, E. Locci, M. Machet, J. Malcles, G. Negro, J. Rander, A. Rosowsky, M. Ö. Sahin, M. Titov, A. Abdulsalam, C. Amendola, I. Antropov, S. Baffioni, F. Beaudette, P. Busson, L. Cadamuro, C. Charlot, R. Granier de Cassagnac, M. Jo, S. Lisniak, A. Lobanov, J. Martin Blanco, M. Nguyen, C. Ochando, G. Ortona, P. Paganini, P. Pigard, R. Salerno, J. B. Sauvan, Y. Sirois, A. G. Stahl Leiton, T. Strebler, Y. Yilmaz, A. Zabi, A. Zghiche, J.-L. Agram, J. Andrea, D. Bloch, J.-M. Brom, M. Buttignol, E. C. Chabert, N. Chanon, C. Collard, E. Conte, X. Coubez, J.-C. Fontaine, D. Gelé, U. Goerlach, M. Jansová, A.-C. Le Bihan, N. Tonon, P. Van Hove, S. Gadrat, S. Beauceron, C. Bernet, G. Boudoul, R. Chierici, D. Contardo, P. Depasse, H. El Mamouni, J. Fay, L. Finco, S. Gascon, M. Gouzevitch, G. Grenier, B. Ille, F. Lagarde, I. B. Laktineh, M. Lethuillier, L. Mirabito, A. L. Pequegnot, S. Perries, A. Popov, V. Sordini, M. Vander Donckt, S. Viret, A. Khvedelidze, I. Bagaturia, C. Autermann, L. Feld, M. K. Kiesel, K. Klein, M. Lipinski, M. Preuten, C. Schomakers, J. Schulz, T. Verlage, V. Zhukov, A. Albert, E. Dietz-Laursonn, D. Duchardt, M. Endres, M. Erdmann, S. Erdweg, T. Esch, R. Fischer, A. Güth, M. Hamer, T. Hebbeker, C. Heidemann, K. Hoepfner, S. Knutzen, M. Merschmeyer, A. Meyer, P. Millet, S. Mukherjee, T. Pook, M. Radziej, H. Reithler. Measurement of differential cross sections in the kinematic angular variable ϕ* for inclusive Z boson production in pp collisions at $$ \sqrt{s}=8 $$ TeV, Journal of High Energy Physics, 2018, 172, DOI: 10.1007/JHEP03(2018)172