Search for heavy resonances decaying to tau lepton pairs in proton-proton collisions at \( \sqrt{s}=13 \) TeV

Journal of High Energy Physics, Feb 2017

A search for heavy resonances that decay to tau lepton pairs is performed using proton-proton collisions at \( \sqrt{s}=13 \) TeV. The data were collected with the CMS detector at the CERN LHC and correspond to an integrated luminosity of 2.2 fb−1. The observations are in agreement with standard model predictions. An upper limit at 95% confidence level on the product of the production cross section and branching fraction into tau lepton pairs is calculated as a function of the resonance mass. For the sequential standard model, the presence of Z′ bosons decaying into tau lepton pairs is excluded for Z′ masses below 2.1 TeV, extending previous limits for this final state. For the topcolor-assisted technicolor model, which predicts Z′ bosons that preferentially couple to third-generation fermions, Z′ masses below 1.7 TeV are excluded, representing the most stringent limit to date.

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:

http://link.springer.com/content/pdf/10.1007%2FJHEP02%282017%29048.pdf

Search for heavy resonances decaying to tau lepton pairs in proton-proton collisions at \( \sqrt{s}=13 \) TeV

Received: November pairs in proton-proton collisions at s M. Gouzevitch 0 2 3 G. Grenier 0 2 3 B. Ille 0 2 3 F. Lagarde 0 2 3 I.B. Laktineh 0 2 3 M. Lethuillier 0 2 3 L. Mirabito 0 2 3 0 [29] T. Melia , P. Nason, R. Rontsch and G. Zanderighi, W 1 W , WZ and ZZ production in the 2 University , Budapest , Hungary 3 46: Also at University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences A search for heavy resonances that decay to tau lepton pairs is performed using the CERN LHC and correspond to an integrated luminosity of 2.2 fb 1. The observations are in agreement with standard model predictions. An upper limit at 95% con dence level on the product of the production cross section and branching fraction into tau lepton pairs is calculated as a function of the resonance mass. For the sequential standard model, the presence of Z0 bosons decaying into tau lepton pairs is excluded for Z0 masses below 2.1 TeV, extending previous limits for this nal state. For the topcolor-assisted technicolor model, which predicts Z0 bosons that preferentially couple to third-generation fermions, Z0 masses below 1.7 TeV are excluded, representing the most stringent limit to date. p; Beyond Standard Model; Hadron-Hadron scattering (experiments); Particle - proton-proton collisions at p 1 Introduction 2 The CMS experiment 3 Object reconstruction and identi cation 4 Signal and background Monte Carlo samples 5 Event selection 6 Background estimation 7 Systematic uncertainties 8 Results 9 Summary The CMS collaboration The standard model (SM) of particle physics is a successful theory that can explain many experimental observations involving weak, electromagnetic, and strong interactions. Nevertheless, it cannot be an ultimate theory of nature since it fails, for instance, to provide an explanation for the mass of neutrinos and lacks a particle candidate for dark matter. Many models of physics beyond the SM have therefore been proposed. Such models often predict new heavy particles that could be observed at the CERN LHC. A straightforward way to extend the SM gauge structure is to include an additional U(1) group with an associated neutral gauge boson, denoted Z0. The universality of couplings is not necessary for new gauge bosons. Indeed, models exist that incorporate generation-dependent couplings, resulting in Z0 bosons that preferentially decay into fermions of the third generation [1, 2]. Such models motivate a search for Z0 resonances that decay to a pair of In particular, extensions to the SM proposed as an explanation for the high mass of the top quark predict Z0 bosons that typically couple to third-generation fermions [2]. Examples are the topcolor-assisted technicolor (TAT) models [3, 4]. A widely used benchmark model in searches for Z0 bosons is the sequential standard model (SSM) [5], which predicts a neutral spin-1 Z0 boson, denoted Z0SSM, with the same couplings to quarks and leptons as the SM Z boson. Results of direct searches for heavy resonances in proton-proton (pp) collisions and exclude Z0SSM masses below 2.0 TeV [6{8]. The most stringent mass limits on Z0SSM production, set by ATLAS and CMS in searches for a narrow resonance decaying into an pair, are 3.4 [9] and 3.2 [10] TeV, respectively. In this paper we report on a search for physics beyond the SM in events containing a pair of high transverse momentum (pT) oppositely charged hadronic decay modes of the lepton, respectively. The study is based on a data sample corresponds to an integrated luminosity of 2.2 fb 1. The CMS experiment The central feature of the CMS apparatus is a superconducting solenoid, of 6 m internal diameter, providing a eld of 3.8 T. Within the eld volume are the inner tracker, the crystal electromagnetic calorimeter (ECAL), and the brass and scintillator hadron calorimeter (HCAL). The inner tracker is composed of a pixel detector and a silicon strip tracker, and measures charged-particle trajectories in the pseudorapidity range j j < 2:5. The segmented ECAL consists of nearly 76 000 lead-tungstate crystals that provide coverage layers of brass as an absorber and plastic scintillator as an active material, covering the range j j < 3, and is extended to j j < 5 by a forward hadron calorimeter. The muon system covers j j < 2:4 and consists of four stations of gas-ionization muon detectors installed outside the solenoid and sandwiched between the layers of the steel return yoke. A detailed description of the CMS detector, together with a de nition of the coordinate system and relevant kinematic variables, is given elsewhere [11]. Events of interest are selected using a two-tiered trigger system [12]. 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 less than 1 kHz before data storage. Object reconstruction and identi cation A particle- ow (PF) algorithm [13, 14] is used to combine information from all CMS subdetectors in order to reconstruct and identify individual particles in the event: muons, electrons, photons, and charged and neutral hadrons. The resulting set of particles is used to reconstruct the h candidates, jets, missing transverse momentum, and the isolation variables described below. The primary vertex of an event is chosen to be the reconstructed vertex with the largest p2T sum of associated tracks. are reconstructed and identi ed with the usual techniques for electrons and muons. Electrons are reconstructed as energy deposits in the ECAL associated with tracks in the tracking detector [10, 15]. Requirements on energy deposits in the calorimeter and on the number of hits in the inner tracker are imposed to distinguish electrons produced in hard scattering processes from charged pions and from electrons produced through photon conversions. Muons are reconstructed using the inner tracker and the muon detectors [16, 17]. Quality requirements, based on the minimum number of hits in the inner tracker and muon detectors, are applied to suppress backgrounds from the decays-in- ight of lightavor hadrons, and from hadron shower remnants that reach the muon system. R = p Both the electron and muon selections impose an isolation requirement to suppress both jets erroneously identi ed as leptons and genuine leptons from hadron decays. The isolation criterion for light leptons is based on the variable I`, which is the scalar pT sum, divided by the lepton pT, of charged and neutral PF candidates within a cone of radius )2 = 0:3 around the lepton direction at the interaction vertex, where is the azimuthal angle. The sum excludes the lepton under consideration as well as charged particles from additional pp interactions within the same or a nearby bunch crossing (\pileup"). The contribution of neutral particles from pileup is accounted for by subtracting from the isolation sum a term given by the scalar pT sum of charged hadrons from pileup vertices that appear within the isolation cone, multiplied by a factor of 0.5 to account for the ratio of neutral to charged hadron production. The isolation criterion is I` < 0:15. The h candidates are reconstructed using the hadrons-plus-strips algorithm [18, 19], which is designed to optimize the performance of h reconstruction and identi cation by considering speci c lepton decay modes. Individual hadronic decay modes are reconstructed separately. The signatures distinguished by the algorithm are: a single charged hadron, a charged hadron plus up to two neutral pions, and three charged hadrons. Reconstructed h leptons are required to be isolated to reduce background from misidenti ed light-quark or gluon jets. The isolation criterion for h leptons is based on the scalar pT sum S of charged and neutral PF candidates within a cone of radius R = 0:5 around the h direction, excluding the h candidate and charged tracks from pileup. The contribution of neutral particles from pileup is accounted for by subtracting from S the scalar pT sum of charged particles from pileup interactions that appear within a cone of radius R = 0:8 around the h candidate, multiplied by a factor of 0.2 [19]. The factor of 0.2 is chosen to render the h identi cation e ciency insensitive to the level of pileup. The isolation < 0:8 GeV. The h candidates are further distinguished from electrons and muons using dedicated algorithms, referred to as discriminators. The algorithm to discriminate a h lepton from an electron utilizes observables that quantify the compactness and shape of energy deposits in the ECAL, to distinguish electromagnetic from hadronic showers, in combination with observables that are sensitive to the amount of bremsstrahlung radiation emitted along the highest pT track of the h candidate, and observables that are sensitive to the overall particle multiplicity. The discriminator against muons requires that no hits in the muon system be matched to the h candidate. For a h with pT > 20 GeV and j j < 2:1, the identi cation e ciency is approximately 55%. The probability for a light-quark or gluon jet, electron, and muon to be misidenti ed as a h is approximately 1%, 0.2%, and 0.03%. The jets are reconstructed using the anti-kT jet algorithm [20, 21] with a distance parameter of 0.4. In order to tag jets from b quark decays, the combined secondary vertex (CSVv2) algorithm at the loose working point is used [22, 23]. This algorithm is based on the reconstruction of secondary vertices, together with track-based lifetime information. For b quark jets with pT > 30 GeV and j j < 2:4, the identi cation e ciency is approximately 85%, while the probability for a light-quark or gluon (charm quark) jet to be misidenti ed as a b quark jet is approximately 10% (20%). The missing transverse momentum vector p~ miss is de ned as the negative of the vector sum of transverse momenta of all PF candidates reconstructed in the event. The magnitude of this vector is referred to as ETmiss. The raw ETmiss value is modi ed to account for corrections to the energy scale of all the reconstructed jets in the event [24]. Events that contain large values of ETmiss as a consequence of instrumental e ects, such as calorimeter noise, beam halo, or jets near nonfunctioning channels in the calorimeters, are removed from the analysis. Signal and background Monte Carlo samples The most important sources of background arise from the production of Drell-Yan events ), W bosons in association with one or more jets (W+jets), top quark pairs (tt), quantum chromodynamics (QCD) multijet events, and diboson events (WW, WZ, ZZ). Although the Drell-Yan background peaks around the Z pole mass, its tail extends into the high-mass region where a signal might be present. The W+jets events are characterized by an isolated lepton from the decay of the W boson and an uncorrelated jet misidenti ed as a light lepton or h lepton. Background from tt events contains one or two b quark jets, in addition to isolated ` or h candidates. Background from diboson events produces isolated leptons if the gauge bosons decay leptonically. Should the gauge bosons decay hadronically, one of the jets may be misidenti ed as a h lepton. Finally, QCD multijet background is characterized by jets with low charged-track multiplicity that can be misidenti ed as ` or h candidates. Monte Carlo (MC) event generators are used to simulate the signal and SM back The Drell-Yan, W+jets, and tt processes are generated with the MadGraph5 amc@nlo program [25]. The pythia 8.2 program is used to generate the diboson and signal events [26]. The signal events are generated with Z0 masses ranging from 0.5 to 3.0 TeV, with a step size of 0.5 TeV. The expected signal yields are rescaled to next-to-leading order (NLO) accuracy using a K-factor of 1.3 [10]. The electroweak NLO corrections are small in the range of masses considered. The SM samples are normalized using the most accurate cross section calculations currently available [25, 27{37], generally with NLO or next-to-next-leading order (NNLO) accuracy. The NNPDF 3.0 [38] parton distribution functions (PDF) are used, and all simulated samples use the pythia program with the CUETP8M1 tune [39] to describe parton showering and hadronization. The simulation of pileup is performed by superimposing minimum bias interactions onto the hard scattering process, matching the pileup pro le in data. The mean number of interactions in a single bunch crossing in the analysed data set is approximately 14. The MC-generated events are propagated through a Geant4-based simulation [40] of the CMS apparatus. Event selection The requirements described below de ne the signal region. A new heavy neutral gauge boson decaying into a lepton pair would be characterized by an excess above the SM expectation for the rate of events with two high-pT, oppositely charged, isolated candidates. Single-lepton triggers are used to select e , e h, and h events, while a trigger requiring at least two h candidates at the L1 and HLT levels is used to select h h events. The triggers are designed to allow the use of the background estimation methods outlined in section 6. Electrons (muons) are required to have pT > 35 (30) GeV. The h candidates are required to have pT > 20 and 60 GeV in the ` h and h h channels, respectively. lepton candidate pT is de ned by the vector pT sum of its visible decay products. Both ` and h candidates must have j j < 2:1 and satisfy isolation requirements to mitigate background from misidenti ed jets. The pT thresholds on the e, , and h candidates are chosen such that the trigger e ciency is about 90% or higher in each channel considered. pairs are formed from oppositely charged candidates with The h charge is reconstructed from the sum of the charges of the associated tracks used to reconstruct the decay mode and is required to be 1. Owing to the large invariant mass resonances assumed for this study, the two candidates are expected to be backto-back. Events are therefore required to satisfy cos 0:95. An additional requirement of ETmiss > 30 GeV is applied to preferentially select events with neutrinos from the lepton decays rather than apparent ETmiss due to mismeasurement of jet pT. The signal e ciency of this requirement is 85% e ciency or more, depending on the Z0 boson mass. The direction of p~ miss is required to be consistent with the expectation for a pair of lepton decays, to reduce the background from events with W bosons (primarily W+jets and tt events). This requirement is implemented through a variable known as \CDF- " [41], referred to below as the variable. This variable is de ned by considering a unit vector, denoted the ^ axis, along the bisector between the pT directions of the two lepton candidates. Two projection variables for the visible lepton decay products and p~ miss are then constructed: pvis. = (p~T1 + p~T2 ) T = (p~T1 + p~T2 + p~Tmiss) contrast to signal events in which pvis. and p are strongly correlated, these two variables are nearly independent in events with a W boson because in this case the direction and magnitude of p~Tmiss are correlated with those of the lepton, but not with those of the jet. Events are selected by requiring = p 50 GeV. Residual contributions from tt events are reduced by selecting events without a tagged b jet. To distinguish more e ectively between signal and background events, the visible reconstruct a mass value m, de ned as m( 1; 2; p~Tmiss) = We do not apply a selection requirement on the mass variable of eq. (5.1), but instead utilize it to search for a broad enhancement in the m( 1; 2; p~Tmiss) distribution consistent with new physics. boson mass. The e ciency, while the e The product of signal acceptance and e ciency for Z0 ! events varies with the Z0 h and h h channels provide the largest product of acceptance and channel has the lowest. For the combination of all four channels the product of acceptance and e ciency amounts to 6.3, 13, and 14%, respectively, for m (Z0SSM) = 0.5, 1.5, and 3.0 TeV. Background estimation To estimate the background contributions in the signal region, techniques based on data control regions are employed wherever possible. The strategy when using such a technique is to modify the standard event selection requirements in order to de ne samples enriched with events from speci c sources of background. These control regions are used to model the m( 1; 2; p~Tmiss) shape of the backgrounds and to measure the probability for an event to satisfy the selection requirements. Contributions from additional background sources in a given control region are subtracted using their predictions from simulation. background estimation methods based on data control regions are validated by determining the ability of the method, applied to simulated samples, to predict correctly the true number of background events and the shape of the m( 1; 2; p~Tmiss) distribution. In some cases, for backgrounds with misidenti ed leptons, the background estimation methods are also validated with the data. In such tests, the agreement between the relevant quantities is always within the statistical uncertainties, and is at the level of 20% or better, depending on the channel. In cases where an approach based on a data control region is not possible, or for backgrounds with small expected contributions, we rely on simulation. For the most relevant SM contributions evaluated from simulation, we verify that the MC prediction is in agreement with the data in background-enhanced regions. The QCD multijet background is relevant for both the h h and ` h channels, where it represents more than 80% or 20% of the total background, respectively. The contribution from QCD multijet events in the e m( 1; 2; p~Tmiss) > 85 (300) GeV. In the h h channel is approximately 5% (< 1%) for nal state, this background is evaluated from the like-sign mass distribution (> 98% purity of QCD multijet events), which is scaled using the opposite-sign-to-like-sign ratio measured in a control region where the ETmiss requirement is inverted (ETmiss < 30 GeV). In the e h nal state, the QCD multijet background is evaluated using the mass shape reconstructed from a data sample with a . This mass shape is weighted by the probability for a jet to satisfy the h isolation criterion, which is measured from a sample of like-sign candidates. The systematic uncertainties in these estimates are discussed in section 7. Background from W+jets events is important in the ` h channels, representing about 40 (45)% of the total background when ` is an electron (muon). The contribution from W+jets events in the e and h h channels is <1% for m( 1; 2; p~Tmiss) > 300 GeV. To estimate this background, we take the mass distribution of events selected in data with one nonisolated h, subtract the QCD multijet background as determined from a data control region, subtract other backgrounds as determined from simulation, and weight the distribution by the probability for a jet to satisfy the h isolation criterion. This probability is measured in a data control region for which the ( 1; 2) requirements are 50 GeV or cos 0:95). The sample used to determine the QCD multijet contribution to the W+jets control region contains a small expected contribution from W+jets events, which is subtracted using simulation. The systematic uncertainties in these estimates are discussed in section 7. The tt background is relevant for the e channel, where it represents more than 30% (70%) of the total background for m( 1; 2; p~Tmiss) > 85 (300) GeV. Its contribution to the other channels is <2% (< 15%) for m( 1; 2; p~Tmiss) > 85 (300) GeV. High-purity samples of tt events are obtained by requiring the presence of at least one b-tagged jet with pT > 20 GeV. The tt prediction from simulation agrees with the observed yield and mass shape in the control sample, with a statistical uncertainty of 8% in the ratio of the simulated to the observed yield. Thus the tt prediction in the signal region is based on simulation with an additional systematic uncertainty of 8%. The SM Drell-Yan background contributes to all nal states, ranging from about 10% of the total background in the h h channel to 40% in the other channels. It is estimated from simulation, after comparing the expectations from simulation with data in low-mass control regions where no signal is expected [6], speci cally regions where ETmiss < 30 GeV, and either m( 1; 2) < 100 GeV ( h h channel) or m( 1; 2; p~Tmiss) < 200 GeV (the other channels). The data and simulation are found to be in agreement within the systematic uncertainties discussed in section 7. The remaining backgrounds described in section 4 are estimated using simulation. Systematic uncertainties The main source of systematic uncertainty is the uncertainty in the estimation of the background, due to the limited number of events in the data control regions. This results in uncertainties ranging from 8% for the contribution from dominant backgrounds such as that from W+jets events in the ` h channels, to 68% for the small contribution of QCD multijet h channel. Nondominant backgrounds in the control regions, including the resulting uncertainties in the control sample purities, make a minor contribution to the overall systematic uncertainty. The e ciencies for electron and muon reconstruction, identi cation, and triggering have an uncertainty of approximately 2%, measured using Z ! `+` events [15, 17]. For the uncertainty in the description by the simulation of the identi cation e ciency for high-pT electrons (muons), an uncertainty of 6% (7%), independent of pT, is assigned, as described in ref. [10]. The systematic uncertainty on h trigger e ciency is 5% per h candidate, as measured with Z ! h events triggered by single-muon triggers. Systematic e ects associated with h identi cation are measured using the visible around the Z boson peak as well as o -mass-shell virtual W bosons selected with a single h candidate and large ETmiss [19]. The resulting uncertainty is 6% per h candidate. An additional systematic uncertainty, which dominates for high-pT h candidates, is related to the con dence that the MC simulation correctly models the identi cation e ciency, and is validated with high-pT jet and electron candidates that produce h-like signatures in the detector. This additional uncertainty increases linearly with pT and amounts to 20% resulting in an uncertainty of 4% (10%) for a reconstructed mass of 0.5 TeV in the ` h ( h h) channel, and 12% (25%) for a mass of 2 TeV. The uncertainty in the integrated luminosity measurement is 2.7% [42]. Uncertainties that a ect the m( 1; 2; p~Tmiss) mass shape include the electron, muon, and h energy scales, and the jet and ETmiss energy scales and resolutions. The uncertainty in the probability for a light quark or gluon jet to be misidenti ed as a b quark jet (20%) is also considered, and has a 3% e ect on the signal acceptance and a negligible e ect on the m( 1; 2; p~Tmiss) mass shape. The uncertainty in the signal acceptance associated with the PDFs is evaluated in accordance with the PDF4LHC recommendations [43] and amounts to a few percent. The systematic uncertainties in the W+jets, Drell-Yan, QCD multijet, and tt background normalizations are approximately 9% (9%), 10% (19%), 68% (20%), and 8% (8%), respectively, in the ` h ( h h) channel. The total systematic uncertainty in the SM background yield ranges from <10% at low mass in the ` h channels to 100% at high mass in the h h channel. The normalization uncertainties have a fully correlated e ect across all mass bins, while the shape uncertainties account for systematic migrations of expected yields among neighboring bins in m( 1; 2; p~Tmiss). The upper section of table 1 lists the estimated background yields and the total number of observed events for each channel, integrated over all values of reconstructed mass. The lower section of table 1 lists the results for m( 1; 2; p~Tmiss) > 300 GeV, where the signal is primarily expected. The distributions of m( 1; 2; p~Tmiss) are shown in gure 1 for all The observed mass spectra shown in gure 1 do not reveal evidence for new particles lepton pairs. We proceed to set upper limits on the product of the signal cross section and the branching fraction for a Z0 boson decaying to a lepton pair. The modi ed frequentist construction CLs [44{46] is used to determine these upper limits at 95% con dence level (CL) as a function of the Z0 mass for each nal state. For each decay channel, and for each bin of reconstructed mass above 85 GeV, the observed number of events is tted by a Poisson distribution whose mean is the sum of the total SM expectation, determined as described in section 6, and a potential signal contribution determined from simulation. Systematic uncertainties are implemented as nuisance parameters, which are pro led, and modeled with gamma or log-normal priors for normalization parameters and Gaussian priors for shape uncertainties. Figure 2 shows the observed and expected limits on the product of the cross section and the branching fraction for the decays into lepton pairs as functions of the Z0 mass, together with the theoretical predictions from the SSM and TAT models. The shaded bands represent one and two standard deviation uncertainty intervals in the expected Z0SSM (1.0 TeV) Z0SSM (1.5 TeV) Z0SSM (2.0 TeV) Z0SSM (1.0 TeV) Z0SSM (1.5 TeV) Z0SSM (2.0 TeV) the predicted numbers of signal events for Z0SSM masses of 1.0, 1.5, and 2.0 TeV. The upper section of the table presents the inclusive yields. The lower section presents the yields after the requirement m( 1; 2; p~Tmiss) > 300 GeV. The uncertainties quoted in the background yields represent the combined statistical and systematic uncertainties. limits obtained using a large sample of pseudo-experiments where the pseudodata are generated from distributions corresponding to the background-only hypothesis. The upper limit on the cross section times branching fraction to the point where the observed limit crosses the theory curve. In the TAT model the gauge group structure is characterized by a reduced coupling to light fermions (1st and 2nd generations) and an enhanced coupling to heavy fermions (3rd generation). Because light quark annihilation (e.g. uu ! Z0) is the dominant Z0 production mechanism at the LHC, the cross section (pp ! Z0) in the TAT model is suppressed (relative to that in the SSM model) because of the reduced coupling to light quarks. On the other hand, the vE 1 /s 1 / ts10 vE 1 vE 1 /s 1 /ts10 vE 1 Figure 1. Observed m( 1; 2; p~Tmiss) distribution in the signal region compared to the expected SM backgrounds for the (top left) e , (top right) e h, (bottom left) h, and (bottom right) The dashed histogram shows the distribution expected for a Z0SSM boson with mass 1500 GeV. The rightmost bins also include events with m( 1; 2; p~Tmiss) > 900 GeV, and are normalized to the displayed bin width. The lower panel shows the ratio of the observed number of events to the total background prediction. The shaded bands represent the total uncertainty in the branching fraction B(Z0 ! ) in the TAT model is enhanced as a result of the stronger leptons. With the TAT parameters in refs. [3, 4], the suppression in the cross section outweighs the increase of the branching fraction. Overall, the product of the cross section and branching fraction (pp ! Z0) B(Z0 ! ) in the TAT model is approximately one-third of the value in the SSM model. Combining the four nal states, we exclude Z0SSM and Z0TAT models with masses less than 2.1 TeV (1.9 TeV expected) and 1.7 TeV (1.5 TeV expected), respectively, at 95% CL. ')x 1 10−2 ')x 1 10−2 500 1000 1500 2000 2500 500 1000 1500 2000 2500 ')x 1 10−2 ')x 1 10−2 500 1000 1500 2000 2500 500 1000 1500 2000 2500 ')x 1 10−2 500 1000 1500 2000 2500 lepton pairs as a function of the Z0 mass m(Z0) (solid black lines), for the (top left) e , (top right) e h, (middle left) h, and (middle right) h h nal states, and (bottom) for the combination of the four channels. The expected limits (dash-dotted lines) with one and two standard deviation (s.d.) uncertainty bands are also shown. The predictions of the NLO theory cross sections in the SSM and TAT models are represented by the red (lighter) and blue (darker) solid curves, respectively. CMS experiment, using a data sample of proton-proton collisions at p A search for heavy resonances decaying to a tau lepton pair has been performed by the s = 13 TeV collected in 2015, corresponding to an integrated luminosity of 2.2 fb 1. The tau leptons are reconstructed in their decays to an electron ( e) and muon ( ), and in their hadronic decays ( h). The observed invariant mass spectra in the are measured and are found to be consistent with expectations from the standard model. Upper limits at 95% con dence level are derived for the product of the cross section and branching fraction for a Z0 boson decaying to a tau lepton pair, as a function of the Z0 mass. The presence of Z0 bosons decaying to a tau lepton pair is excluded for Z0 masses below decaying to a tau lepton pair using events from proton-proton collisions at p 2.1 TeV in the sequential standard model. This is the rst search for heavy resonances s = 13 TeV, already extending previous limits [6{8] for this nal state using the data sample collected in 2015. In the topcolor-assisted technicolor model, which predicts Z0 bosons that exhibit enhanced couplings to third-generation fermions, the presence of Z0 bosons decaying to a tau lepton pair is excluded for Z0 masses below 1.7 TeV, resulting in the most stringent 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, and RFBR (Russia); MESTD (Serbia); SEIDI and CPAN (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 EPLANET (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 (IWTBelgium); 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 2013/11/B/ST2/04202, 2014/13/B/ST2/02543 and 2014/15/B/ST2/03998, Sonatabis 2012/07/E/ST2/01406; the Thalis and Aristeia programs co nanced by EU-ESF and the Greek NSRF; the National Priorities Research Program by Qatar National Research Fund; the Programa Clar n-COFUND del Principado de Asturias; the Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University and the Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand); and the Welch Foundation, contract C-1845. This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited. [arXiv:0801.1345] [INSPIRE]. [hep-ph/0007286] [INSPIRE]. [hep-ph/9805254] [INSPIRE]. proton-proton collisions at p 372 [arXiv:1607.03669] [INSPIRE]. [5] G. Altarelli, B. Mele and M. Ruiz-Altaba, Searching for New Heavy Vector Bosons in pp Colliders, Z. Phys. C 45 (1989) 109 [Erratum ibid. C 47 (1990) 676] [INSPIRE]. [6] CMS collaboration, Search for high-mass resonances decaying into -lepton pairs in pp [7] ATLAS collaboration, A search for high-mass resonances decaying to + [8] ATLAS collaboration, A search for high-mass resonances decaying to + [9] ATLAS collaboration, Search for high-mass new phenomena in the dilepton nal state using (2016) [arXiv:1609.05391] [INSPIRE]. [10] CMS collaboration, Search for narrow resonances in dilepton mass spectra in proton-proton Detector in Proton-Proton Collisions at p [arXiv:1502.02701] [INSPIRE]. s = 8 TeV, 2015 JINST 10 P06005 [14] CMS collaboration, Commissioning of the Particle- ow Event Reconstruction with the rst LHC collisions recorded in the CMS detector, CMS-PAS-PFT-10-001 (2010). [15] CMS collaboration, Performance of Electron Reconstruction and Selection with the CMS [16] CMS collaboration, Performance of CMS muon reconstruction in pp collision events at [17] CMS collaboration, Muon Reconstruction and Identi cation Improvements for Run-2 and First Results with 2015 Run Data, CMS-DP-2015-015 (2015). [18] CMS collaboration, Reconstruction and identi cation of lepton decays to hadrons and at CMS, 2016 JINST 11 P01019 [arXiv:1510.07488] [INSPIRE]. [19] CMS collaboration, Performance of reconstruction and identi cation of tau leptons in their decays to hadrons and tau neutrino in LHC Run-2, CMS-PAS-TAU-16-002 (2016). 063 [arXiv:0802.1189] [INSPIRE]. 1896 [arXiv:1111.6097] [INSPIRE]. P04013 [arXiv:1211.4462] [INSPIRE]. CMS-PAS-BTV-15-001 (2016). [24] CMS collaboration, Performance of the CMS missing transverse momentum reconstruction [25] 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) 079 [arXiv:1405.0301] [INSPIRE]. 159 [arXiv:1410.3012] [INSPIRE]. 011] [arXiv:0907.4076] [INSPIRE]. POWHEG: s- and t-channel contributions, JHEP 09 (2009) 111 [Erratum ibid. 02 (2010) [28] E. Re, Single-top Wt-channel production matched with parton showers using the POWHEG method, Eur. Phys. J. C 71 (2011) 1547 [arXiv:1009.2450] [INSPIRE]. POWHEG BOX, JHEP 11 (2011) 078 [arXiv:1107.5051] [INSPIRE]. NNLL threshold resummation, Nucl. Phys. B 855 (2012) 695 [arXiv:1109.1536] [INSPIRE]. hadron colliders with next-to-next-to-leading logarithmic soft-gluon resummation, Phys. Lett. B 710 (2012) 612 [arXiv:1111.5869] [INSPIRE]. First Genuine NNLO QCD Corrections to qq ! tt + X, Phys. Rev. Lett. 109 (2012) 132001 [arXiv:1204.5201] [INSPIRE]. all-fermionic scattering channels, JHEP 12 (2012) 054 [arXiv:1207.0236] [INSPIRE]. [34] M. Czakon and A. Mitov, NNLO corrections to top pair production at hadron colliders: the quark-gluon reaction, JHEP 01 (2013) 080 [arXiv:1210.6832] [INSPIRE]. Hadron Colliders Through O( S4), Phys. Rev. Lett. 110 (2013) 252004 [arXiv:1303.6254] Comput. Phys. Commun. 184 (2013) 208 [arXiv:1201.5896] [INSPIRE]. [arXiv:1011.3540] [INSPIRE]. (2015) 040 [arXiv:1410.8849] [INSPIRE]. [39] CMS collaboration, Event generator tunes obtained from underlying event and multiparton scattering measurements, Eur. Phys. J. C 76 (2016) 155 [arXiv:1512.00815] [INSPIRE]. Meth. A 506 (2003) 250 [INSPIRE]. tau pairs in pp collisions at p [hep-ex/0508051] [INSPIRE]. CMS-PAS-LUM-15-001 (2015). 023001 [arXiv:1510.03865] [INSPIRE]. [42] CMS collaboration, CMS Luminosity Measurement for the 2015 Data Taking Period, [44] T. Junk, Con dence level computation for combining searches with small statistics, Nucl. Instrum. Meth. A 434 (1999) 435 [hep-ex/9902006] [INSPIRE]. Higgs boson search combination in Summer 2011, CMS-NOTE-2011-005, ATL-PHYS-PUB-2011-11 (2011). [46] ATLAS, CMS collaborations, the LHC Higgs Combination Group, Procedure for the LHC Yerevan Physics Institute, Yerevan, Armenia V. Khachatryan, A.M. Sirunyan, A. Tumasyan Institut fur Hochenergiephysik, Wien, Austria W. Adam, E. Asilar, T. Bergauer, J. Brandstetter, E. Brondolin, M. Dragicevic, J. Ero, M. Flechl, M. Friedl, R. Fruhwirth1, V.M. Ghete, C. Hartl, N. Hormann, J. Hrubec, M. Jeitler1, A. Konig, I. Kratschmer, D. Liko, T. Matsushita, I. Mikulec, D. Rabady, N. Rad, B. Rahbaran, H. Rohringer, J. Schieck1, J. Strauss, W. Waltenberger, C.-E. Wulz1 Institute for Nuclear Problems, Minsk, Belarus O. Dvornikov, V. Makarenko, V. Zykunov National Centre for Particle and High Energy Physics, Minsk, Belarus V. Mossolov, N. Shumeiko, J. Suarez Gonzalez Universiteit Antwerpen, Antwerpen, Belgium S. Alderweireldt, E.A. De Wolf, X. Janssen, J. Lauwers, M. Van De Klundert, H. Van Haevermaet, P. Van Mechelen, N. Van Remortel, A. Van Spilbeeck Vrije Universiteit Brussel, Brussel, Belgium S. Abu Zeid, F. Blekman, J. D'Hondt, N. Daci, I. De Bruyn, K. Deroover, S. Lowette, S. Moortgat, L. Moreels, A. Olbrechts, Q. Python, S. Tavernier, W. Van Doninck, P. Van Mulders, I. Van Parijs Universite Libre de Bruxelles, Bruxelles, Belgium H. Brun, B. Clerbaux, G. De Lentdecker, H. Delannoy, G. Fasanella, L. Favart, R. Goldouzian, A. Grebenyuk, G. Karapostoli, T. Lenzi, A. Leonard, J. Luetic, T. Maerschalk, A. Marinov, A. Randle-conde, T. Seva, C. Vander Velde, P. Vanlaer, R. Yonamine, F. Zenoni, F. Zhang2 Ghent University, Ghent, Belgium A. Cimmino, T. Cornelis, D. Dobur, A. Fagot, G. Garcia, M. Gul, I. Khvastunov, D. Poyraz, S. Salva, R. Schofbeck, A. Sharma, M. Tytgat, W. Van Driessche, E. Yazgan, N. Zaganidis Universite Catholique de Louvain, Louvain-la-Neuve, Belgium H. Bakhshiansohi, C. Belu 3, O. Bondu, S. Brochet, G. Bruno, A. Caudron, S. De Visscher, C. Delaere, M. Delcourt, B. Francois, A. Giammanco, A. Jafari, P. Jez, M. Komm, V. Lemaitre, A. Magitteri, A. Mertens, M. Musich, C. Nuttens, K. Piotrzkowski, L. Quertenmont, M. Selvaggi, M. Vidal Marono, S. Wertz Universite de Mons, Mons, Belgium Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil W.L. Alda Junior, F.L. Alves, G.A. Alves, L. Brito, C. Hensel, A. Moraes, M.E. Pol, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil E. Belchior Batista Das Chagas, W. Carvalho, J. Chinellato4, A. Custodio, E.M. Da Costa, G.G. Da Silveira5, D. De Jesus Damiao, C. De Oliveira Martins, S. Fonseca De Souza, L.M. Huertas Guativa, H. Malbouisson, D. Matos Figueiredo, C. Mora Herrera, L. Mundim, H. Nogima, W.L. Prado Da Silva, A. Santoro, A. Sznajder, E.J. Tonelli Manganote4, A. Vilela Pereira J.C. Ruiz Vargas Universidade Estadual Paulista a, Universidade Federal do ABC b, S~ao Paulo, S. Ahujaa, C.A. Bernardesb, S. Dograa, T.R. Fernandez Perez Tomeia, E.M. Gregoresb, P.G. Mercadanteb, C.S. Moona, S.F. Novaesa, Sandra S. Padulaa, D. Romero Abadb, Institute for Nuclear Research and Nuclear Energy, So a, Bulgaria A. Aleksandrov, R. Hadjiiska, P. Iaydjiev, M. Rodozov, S. Stoykova, G. Sultanov, University of So a, So a, Bulgaria A. Dimitrov, I. Glushkov, L. Litov, B. Pavlov, P. Petkov Beihang University, Beijing, China H. Zhang, J. Zhao Institute of High Energy Physics, Beijing, China M. Ahmad, J.G. Bian, G.M. Chen, H.S. Chen, M. Chen, Y. Chen7, T. Cheng, C.H. Jiang, D. Leggat, Z. Liu, F. Romeo, S.M. Shaheen, A. Spiezia, J. Tao, C. Wang, Z. Wang, State Key Laboratory of Nuclear Physics and Technology, Peking University, 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, J.P. Gomez, C.F. Gonzalez Hernandez, J.D. Ruiz Alvarez, J.C. Sanabria University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, Split, Croatia 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, S. Micanovic, L. Sudic, T. Susa University of Cyprus, Nicosia, Cyprus A. Attikis, G. Mavromanolakis, J. Mousa, C. Nicolaou, F. Ptochos, P.A. Razis, H. Rykaczewski, D. Tsiakkouri 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 E. El-khateeb9, S. Elgammal10, A. Mohamed11 National Institute of Chemical Physics and Biophysics, Tallinn, Estonia B. Calpas, M. Kadastik, M. Murumaa, L. Perrini, M. Raidal, A. Tiko, C. Veelken Department of Physics, University of Helsinki, Helsinki, Finland P. Eerola, J. Pekkanen, M. Voutilainen Helsinki Institute of Physics, Helsinki, Finland J. Harkonen, T. Jarvinen, V. Karimaki, R. Kinnunen, T. Lampen, K. Lassila-Perini, S. Lehti, T. Linden, P. Luukka, J. Tuominiemi, E. Tuovinen, L. Wendland 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, B. Fabbro, J.L. Faure, C. Favaro, F. Ferri, S. Ganjour, S. Ghosh, A. Givernaud, P. Gras, G. Hamel de Monchenault, P. Jarry, I. Kucher, E. Locci, M. Machet, J. Malcles, J. Rander, A. Rosowsky, M. Titov, A. Zghiche Laboratoire Leprince-Ringuet, Ecole Polytechnique, IN2P3-CNRS, Palaiseau, Institut Pluridisciplinaire Hubert Curien, Universite de Strasbourg, Universite de Haute Alsace Mulhouse, CNRS/IN2P3, Strasbourg, France J.-L. Agram12, J. Andrea, A. Aubin, D. Bloch, J.-M. Brom, M. Buttignol, E.C. Chabert, N. Chanon, C. Collard, E. Conte12, X. Coubez, J.-C. Fontaine12, D. Gele, U. Goerlach, A.-C. Le Bihan, K. Skovpen, 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, E. Bouvier, C.A. Carrillo Montoya, R. Chierici, D. Contardo, B. Courbon, P. Depasse, H. El Mamouni, J. Fan, J. Fay, S. Gascon, A.L. Pequegnot, S. Perries, A. Popov13, D. Sabes, V. Sordini, M. Vander Donckt, P. Verdier, T. Toriashvili14 Georgian Technical University, Tbilisi, Georgia Tbilisi State University, Tbilisi, Georgia RWTH Aachen University, I. Physikalisches Institut, Aachen, Germany C. Autermann, S. Beranek, L. Feld, A. Heister, M.K. Kiesel, K. Klein, M. Lipinski, A. Ostapchuk, M. Preuten, F. Raupach, S. Schael, C. Schomakers, J. Schulz, T. Verlage, H. Weber, V. Zhukov13 RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany A. Albert, M. Brodski, 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, M. Olschewski, K. Padeken, T. Pook, M. Radziej, H. Reithler, M. Rieger, F. Scheuch, L. Sonnenschein, D. Teyssier, S. Thuer RWTH Aachen University, III. Physikalisches Institut B, Aachen, Germany V. Cherepanov, G. Flugge, F. Hoehle, B. Kargoll, T. Kress, A. Kunsken, J. Lingemann, T. Muller, A. Nehrkorn, A. Nowack, I.M. Nugent, C. Pistone, O. Pooth, A. Stahl15 Deutsches Elektronen-Synchrotron, Hamburg, Germany M. Aldaya Martin, T. Arndt, C. Asawatangtrakuldee, K. Beernaert, O. Behnke, U. Behrens, A.A. Bin Anuar, K. Borras16, A. Campbell, P. Connor, C. Contreras-Campana, F. Costanza, C. Diez Pardos, G. Dolinska, G. Eckerlin, D. Eckstein, T. Eichhorn, E. Eren, E. Gallo17, J. Garay Garcia, A. Geiser, A. Gizhko, J.M. Grados Luyando, P. Gunnellini, A. Harb, J. Hauk, M. Hempel18, H. Jung, A. Kalogeropoulos, O. Karacheban18, M. Kase mann, J. Keaveney, C. Kleinwort, I. Korol, D. Krucker, W. Lange, A. Lelek, J. Leonard, K. Lipka, A. Lobanov, W. Lohmann18, R. Mankel, I.-A. Melzer-Pellmann, A.B. Meyer, G. Mittag, J. Mnich, A. Mussgiller, E. Ntomari, D. Pitzl, R. Placakyte, A. Raspereza, B. Roland, M.O . Sahin, P. Saxena, T. Schoerner-Sadenius, C. Seitz, S. Spannagel, N. Stefaniuk, G.P. Van Onsem, R. Walsh, C. Wissing University of Hamburg, Hamburg, Germany V. Blobel, M. Centis Vignali, A.R. Draeger, T. Dreyer, E. Garutti, D. Gonzalez, J. Haller, M. Ho mann, A. Junkes, R. Klanner, R. Kogler, N. Kovalchuk, T. Lapsien, T. Lenz, I. Marchesini, D. Marconi, M. Meyer, M. Niedziela, D. Nowatschin, F. Pantaleo15, T. Pei er, A. Perieanu, J. Poehlsen, C. Sander, C. Scharf, P. Schleper, A. Schmidt, S. Schumann, J. Schwandt, 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, C. Baus, J. Berger, E. Butz, R. Caspart, T. Chwalek, I. Topsis-Giotis Institute of Nuclear and Particle Physics (INPP), NCSR Demokritos, Aghia G. Anagnostou, G. Daskalakis, T. Geralis, V.A. Giakoumopoulou, A. Kyriakis, D. Loukas, National and Kapodistrian University of Athens, Athens, Greece S. Kesisoglou, A. Panagiotou, N. Saoulidou, E. Tziaferi University of Ioannina, Ioannina, Greece I. Evangelou, G. Flouris, C. Foudas, P. Kokkas, N. Loukas, N. Manthos, I. Papadopoulos, MTA-ELTE Lendulet CMS Particle and Nuclear Physics Group, Eotvos Lorand University, Budapest, Hungary Wigner Research Centre for Physics, Budapest, Hungary G. Bencze, C. Hajdu, P. Hidas, D. Horvath19, F. Sikler, V. Veszpremi, G. Vesztergombi20, Institute of Nuclear Research ATOMKI, Debrecen, Hungary N. Beni, S. Czellar, J. Karancsi21, A. Makovec, J. Molnar, Z. Szillasi Institute of Physics, University of Debrecen M. Bartok20, P. Raics, Z.L. Trocsanyi, B. Ujvari National Institute of Science Education and Research, Bhubaneswar, India S. Bahinipati, S. Choudhury22, P. Mal, K. Mandal, A. Nayak23, D.K. Sahoo, N. Sahoo, Panjab University, Chandigarh, India S. Bansal, S.B. Beri, V. Bhatnagar, R. Chawla, U.Bhawandeep, A.K. Kalsi, A. Kaur, M. Kaur, R. Kumar, P. Kumari, A. Mehta, M. Mittal, J.B. Singh, G. Walia University of Delhi, Delhi, India Ashok Kumar, A. Bhardwaj, B.C. Choudhary, R.B. Garg, S. Keshri, S. Malhotra, M. Naimuddin, N. Nishu, K. Ranjan, R. Sharma, V. Sharma Saha Institute of Nuclear Physics, Kolkata, India R. Bhattacharya, S. Bhattacharya, K. Chatterjee, 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 Indian Institute of Technology Madras, Madras, India Bhabha Atomic Research Centre, Mumbai, India R. Chudasama, D. Dutta, V. Jha, V. Kumar, A.K. Mohanty15, P.K. Netrakanti, L.M. Pant, P. Shukla, A. Topkar Tata Institute of Fundamental Research-A, Mumbai, India T. Aziz, S. Dugad, G. Kole, B. Mahakud, S. Mitra, G.B. Mohanty, B. Parida, N. Sur, Tata Institute of Fundamental Research-B, Mumbai, India S. Banerjee, S. Bhowmik24, R.K. Dewanjee, S. Ganguly, M. Guchait, Sa. Jain, S. Kumar, M. Maity24, G. Majumder, K. Mazumdar, T. Sarkar24, N. Wickramage25 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 H. Behnamian, S. Chenarani26, E. Eskandari Tadavani, S.M. Etesami26, A. Fahim27, M. Khakzad, M. Mohammadi Najafabadi, M. Naseri, S. Paktinat Mehdiabadi28, F. Rezaei Hosseinabadi, B. Safarzadeh29, 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, C. Caputoa;b, A. Colaleoa, D. Creanzaa;c, L. Cristellaa;b, N. De Filippisa;c, M. De Palmaa;b, L. Fiorea, G. Iasellia;c, G. Maggia;c, M. Maggia, G. Minielloa;b, S. Mya;b, S. Nuzzoa;b, A. Pompilia;b, G. Pugliesea;c, R. Radognaa;b, A. Ranieria, G. Selvaggia;b, L. Silvestrisa;15, R. Vendittia;b, P. Verwilligena INFN Sezione di Bologna a, Universita di Bologna b, Bologna, Italy G. Abbiendia, C. Battilana, D. Bonacorsia;b, S. Braibant-Giacomellia;b, L. Brigliadoria;b, R. Campaninia;b, P. Capiluppia;b, A. Castroa;b, F.R. Cavalloa, S.S. Chhibraa;b, 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;b;15 INFN Sezione di Catania a, Universita di Catania b, Catania, Italy S. Albergoa;b, M. Chiorbolia;b, S. Costaa;b, A. Di Mattiaa, F. Giordanoa;b, R. Potenzaa;b, A. Tricomia;b, C. Tuvea;b INFN Sezione di Firenze a, Universita di Firenze b, Firenze, Italy G. Barbaglia, V. Ciullia;b, C. Civininia, R. D'Alessandroa;b, E. Focardia;b, V. Goria;b, P. Lenzia;b, M. Meschinia, S. Paolettia, G. Sguazzonia, L. Viliania;b;15 INFN Laboratori Nazionali di Frascati, Frascati, Italy L. Benussi, S. Bianco, F. Fabbri, D. Piccolo, F. Primavera15 INFN Sezione di Genova a, Universita di Genova b, Genova, Italy V. Calvellia;b, F. Ferroa, M. Lo Veterea;b, M.R. Mongea;b, E. Robuttia, S. Tosia;b INFN Sezione di Milano-Bicocca a, Universita di Milano-Bicocca b, Milano, INFN Sezione di Napoli a, Universita di Napoli 'Federico II' b, Napoli, Italy, Universita della Basilicata c, Potenza, Italy, Universita G. Marconi d, Roma, S. Buontempoa, N. Cavalloa;c, G. De Nardo, S. Di Guidaa;d;15, M. Espositoa;b, F. Fabozzia;c, F. Fiengaa;b, A.O.M. Iorioa;b, G. Lanzaa, L. Listaa, S. Meolaa;d;15, P. Paoluccia;15, C. Sciaccaa;b, F. Thyssen INFN Sezione di Padova a, Universita di Padova b, Padova, Italy, Universita di Trento c, Trento, Italy P. Azzia;15, N. Bacchettaa, M. Bellatoa, L. Benatoa;b, M. Biasottoa;30, D. Biselloa;b, A. Bolettia;b, R. Carlina;b, P. Checchiaa, M. Dall'Ossoa;b, P. De Castro Manzanoa, T. Dorigoa, S. Fantinela, F. Gasparinia;b, U. Gasparinia;b, A. Gozzelinoa, S. Lacapraraa, M. Margonia;b, A.T. Meneguzzoa;b, J. Pazzinia;b, N. Pozzobona;b, P. Ronchesea;b, E. Torassaa, M. Zanetti, P. Zottoa;b, G. Zumerlea;b INFN Sezione di Pavia a, Universita di Pavia b, Pavia, Italy A. Braghieria, A. Magnania;b, P. Montagnaa;b, S.P. Rattia;b, V. Rea, 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, G.M. Bileia, D. Ciangottinia;b, L. Fanoa;b, P. Laricciaa;b, R. Leonardia;b, G. Mantovania;b, M. Menichellia, A. Sahaa, A. Santocchiaa;b INFN Sezione di Pisa a, Universita di Pisa b, Scuola Normale Superiore di Pisa c, Pisa, Italy K. Androsova;31, P. Azzurria;15, G. Bagliesia, J. Bernardinia, T. Boccalia, R. Castaldia, M.A. Cioccia;31, R. Dell'Orsoa, S. Donatoa;c, G. Fedi, A. Giassia, M.T. Grippoa;31, F. Ligabuea;c, T. Lomtadzea, L. Martinia;b, A. Messineoa;b, F. Pallaa, A. Rizzia;b, A. SavoyNavarroa;32, P. Spagnoloa, R. Tenchinia, G. Tonellia;b, A. Venturia, P.G. Verdinia INFN Sezione di Roma a, Universita di Roma b, Roma, Italy L. Baronea;b, F. Cavallaria, M. Cipriania;b, D. Del Rea;b;15, M. Diemoza, S. Gellia;b, E. Longoa;b, F. Margarolia;b, Marzocchia;b, G. Organtinia;b, R. Paramattia, F. Preiatoa;b, S. Rahatloua;b, C. Rovellia, 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;15, 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, L. Fincoa;b, B. Kiania;b, C. Mariottia, S. Masellia, E. Migliorea;b, V. Monacoa;b, E. Monteila;b, 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, S. Lee, S.W. Lee, Y.D. Oh, S. Sekmen, D.C. Son, A. Lee Chonbuk National University, Jeonju, Korea Chonnam National University, Institute for Universe and Elementary Particles, Hanyang University, Seoul, Korea J.A. Brochero Cifuentes, T.J. Kim Korea University, Seoul, Korea S. Lee, J. Lim, S.K. Park, Y. Roh Seoul National University, Seoul, Korea University of Seoul, Seoul, Korea M. Choi, H. Kim, J.H. Kim, J.S.H. Lee, I.C. Park, G. Ryu, M.S. Ryu Sungkyunkwan University, Suwon, Korea Y. Choi, J. Goh, 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, B. Lee, K. Lee, K.S. Lee, J. Almond, J. Kim, H. Lee, S.B. Oh, B.C. Radburn-Smith, S.h. Seo, U.K. Yang, H.D. Yoo, { 23 { National Centre for Particle Physics, Universiti Malaya, Kuala Lumpur, Centro de Investigacion y de Estudios Avanzados del IPN, Mexico City, Mexico H. Castilla-Valdez, E. De La Cruz-Burelo, I. Heredia-De La Cruz35, A. Hernandez-Almada, R. Lopez-Fernandez, R. Magan~a Villalba, 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 S. Carpinteyro, 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, W.A. Khan, A. Saddique, M.A. Shah, M. Shoaib, M. Waqas National Centre for Nuclear Research, Swierk, Poland H. Bialkowska, M. Bluj, B. Boimska, T. Frueboes, M. Gorski, M. Kazana, K. Nawrocki, K. Romanowska-Rybinska, M. Szleper, P. Zalewski Institute of Experimental Physics, Faculty of Physics, University of Warsaw, K. Bunkowski, A. Byszuk36, K. Doroba, A. Kalinowski, M. Konecki, J. Krolikowski, M. Misiura, M. Olszewski, M. Walczak Laboratorio de Instrumentac~ao e F sica Experimental de Part culas, Lisboa, Joint Institute for Nuclear Research, Dubna, Russia V. Alexakhin, P. Bunin, M. Gavrilenko, I. Golutvin, I. Gorbunov, V. Karjavin, G. Kozlov, A. Lanev, A. Malakhov, V. Matveev37;38, V. Palichik, V. Perelygin, M. Savina, S. Shmatov, S. Shulha, N. Skatchkov, V. Smirnov, A. Zarubin Petersburg Nuclear Physics Institute, Gatchina (St. Petersburg), Russia L. Chtchipounov, V. Golovtsov, Y. Ivanov, V. Kim39, E. Kuznetsova40, V. Murzin, V. Oreshkin, V. Sulimov, 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, M. Toms, E. Vlasov, A. Zhokin Moscow Institute of Physics and Technology A. Bylinkin38 National Research Nuclear University 'Moscow Engineering Physics Institute' (MEPhI), Moscow, Russia R. Chistov41, M. Danilov41, V. Rusinov P.N. Lebedev Physical Institute, Moscow, Russia V. Andreev, M. Azarkin38, I. Dremin38, M. Kirakosyan, A. Leonidov38, S.V. Rusakov, Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, A. Baskakov, A. Belyaev, E. Boos, V. Bunichev, M. Dubinin42, L. Dudko, A. Ershov, A. Gribushin, V. Klyukhin, O. Kodolova, I. Lokhtin, I. Miagkov, S. Obraztsov, V. Savrin, Novosibirsk State University (NSU), Novosibirsk, Russia V. Blinov43, Y.Skovpen43, D. Shtol43 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, V. Krychkine, V. Petrov, R. Ryutin, A. Sobol, S. Troshin, N. Tyurin, A. Uzunian, University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences, Belgrade, Serbia P. Adzic44, 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, E. Calvo, M. Cerrada, M. Chamizo Llatas, 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, P. Garcia-Abia, O. Gonzalez Lopez, S. Goy Lopez, J.M. Hernandez, M.I. Josa, E. Navarro De Martino, A. Perez-Calero Yzquierdo, J. Puerta Pelayo, A. Quintario Olmeda, I. Redondo, L. Romero, M.S. Soares Universidad Autonoma de Madrid, Madrid, Spain J.F. de Troconiz, M. Missiroli, D. Moran Universidad de Oviedo, Oviedo, Spain J. Cuevas, J. Fernandez Menendez, I. Gonzalez Caballero, J.R. Gonzalez Fernandez, E. Palencia Cortezon, S. Sanchez Cruz, I. Suarez Andres, J.M. Vizan Garcia Instituto de F sica de Cantabria (IFCA), CSIC-Universidad de Cantabria, Gomez, T. Rodrigo, A. Ruiz-Jimeno, L. Scodellaro, N. Trevisani, I. Vila, R. Vilar CERN, European Organization for Nuclear Research, Geneva, Switzerland D. Abbaneo, E. Au ray, G. Auzinger, M. Bachtis, P. Baillon, A.H. Ball, D. Barney, P. Bloch, A. Bocci, A. Bonato, C. Botta, T. Camporesi, R. Castello, M. Cepeda, G. Cerminara, M. D'Alfonso, D. d'Enterria, A. Dabrowski, V. Daponte, A. David, M. De Gruttola, A. De Roeck, E. Di Marco45, M. Dobson, B. Dorney, T. du Pree, D. Duggan, M. Dunser, N. Dupont, A. Elliott-Peisert, S. Fartoukh, G. Franzoni, J. Fulcher, W. Funk, D. Gigi, K. Gill, M. Girone, F. Glege, D. Gulhan, S. Gundacker, M. Gutho , J. Hammer, P. Harris, J. Hegeman, V. Innocente, P. Janot, J. Kieseler, H. Kirschenmann, V. Knunz, A. Kornmayer15, M.J. Kortelainen, K. Kousouris, 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, S. Morovic, M. Mulders, H. Neugebauer, M. Stoye, Y. Takahashi, M. Tosi, D. Treille, A. Triossi, A. Tsirou, V. Veckalns49, G.I. Veres20, N. Wardle, H.K. Wohri, A. Zagozdzinska36, W.D. Zeuner Paul Scherrer Institut, Villigen, Switzerland W. Bertl, K. Deiters, W. Erdmann, R. Horisberger, Q. Ingram, H.C. Kaestli, D. Kotlinski, U. Langenegger, T. Rohe Institute for Particle Physics, ETH Zurich, Zurich, Switzerland F. Bachmair, L. Bani, L. Bianchini, B. Casal, G. Dissertori, M. Dittmar, M. Donega, C. Grab, C. Heidegger, D. Hits, J. Hoss, G. Kasieczka, P. Lecomtey, W. Lustermann, B. Mangano, M. Marionneau, P. Martinez Ruiz del Arbol, M. Masciovecchio, 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. Rossini, M. Schonenberger, A. Starodumov50, V.R. Tavolaro, K. Theo latos, R. Wallny Universitat Zurich, Zurich, Switzerland T.K. Aarrestad, C. Amsler51, L. Caminada, M.F. Canelli, A. De Cosa, C. Galloni, A. Hinzmann, T. Hreus, B. Kilminster, J. Ngadiuba, D. Pinna, G. Rauco, P. Robmann, D. Salerno, Y. Yang, A. Zucchetta National Central University, Chung-Li, Taiwan V. Candelise, T.H. Doan, Sh. Jain, R. Khurana, M. Konyushikhin, C.M. Kuo, W. Lin, Y.J. Lu, A. Pozdnyakov, S.S. Yu National Taiwan University (NTU), Taipei, Taiwan Arun Kumar, P. Chang, Y.H. Chang, Y.W. Chang, Y. Chao, K.F. Chen, P.H. Chen, A. Psallidas, J.f. Tsai, Y.M. Tzeng Chulalongkorn University, Faculty of Science, Department of Physics, Bangkok, B. Asavapibhop, G. Singh, N. Srimanobhas, N. Suwonjandee Cukurova University - Physics Department Science and Art Faculty A. Adiguzel, S. Damarseckin, Z.S. Demiroglu, C. Dozen, E. Eskut, S. Girgis, G. Gokbulut, Y. Guler, I. Hos, E.E. Kangal52, O. Kara, A. Kayis Topaksu, U. Kiminsu, M. Oglakci, G. Onengut53, K. Ozdemir54, S. Ozturk55, A. Polatoz, B. Tali56, S. Turkcapar, I.S. Zor bakir, C. Zorbilmez Middle East Technical University, Physics Department, Ankara, Turkey B. Bilin, S. Bilmis, B. Isildak57, G. Karapinar58, M. Yalvac, M. Zeyrek Bogazici University, Istanbul, Turkey E. Gulmez, M. Kaya59, O. Kaya60, E.A. Yetkin61, T. Yetkin62 Istanbul Technical University, Istanbul, Turkey A. Cakir, K. Cankocak, S. Sen63 Institute for Scintillation Materials of National Academy of Science of Ukraine, L. Levchuk, P. Sorokin National Scienti c Center, Kharkov Institute of Physics and Technology, University of Bristol, Bristol, United Kingdom R. Aggleton, F. Ball, L. Beck, J.J. Brooke, D. Burns, E. Clement, D. Cussans, H. Flacher, J. Goldstein, M. Grimes, G.P. Heath, H.F. Heath, J. Jacob, L. Kreczko, C. Lucas, D.M. Newbold64, S. Paramesvaran, A. Poll, T. Sakuma, S. Seif El Nasr-storey, D. Smith, Rutherford Appleton Laboratory, Didcot, United Kingdom K.W. Bell, A. Belyaev65, 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 M. Baber, R. Bainbridge, O. Buchmuller, A. Bundock, D. Burton, S. Casasso, M. Citron, D. Colling, L. Corpe, P. Dauncey, G. Davies, A. De Wit, M. Della Negra, R. Di Maria, P. Dunne, A. Elwood, D. Futyan, Y. Haddad, G. Hall, G. Iles, T. James, R. Lane, C. Laner, R. Lucas64, L. Lyons, A.-M. Magnan, S. Malik, L. Mastrolorenzo, J. Nash, A. Nikitenko50, J. Pela, B. Penning, M. Pesaresi, D.M. Raymond, A. Richards, A. Rose, C. Seez, S. Summers, A. Tapper, K. Uchida, M. Vazquez Acosta66, T. Virdee15, J. Wright, Brunel University, Uxbridge, United Kingdom J.E. Cole, P.R. Hobson, A. Khan, P. Kyberd, D. Leslie, I.D. Reid, P. Symonds, L. TeodorBaylor University, Waco, U.S.A. A. Borzou, K. Call, J. Dittmann, K. Hatakeyama, H. Liu, N. Pastika The University of Alabama, Tuscaloosa, U.S.A. O. Charaf, S.I. Cooper, C. Henderson, P. Rumerio, C. West Boston University, Boston, U.S.A. Brown University, Providence, U.S.A. G. Benelli, E. Berry, D. Cutts, A. Garabedian, J. Hakala, U. Heintz, J.M. Hogan, O. Jesus, K.H.M. Kwok, E. Laird, G. Landsberg, Z. Mao, M. Narain, S. Piperov, S. Sagir, E. Spencer, University of California, Davis, Davis, U.S.A. R. Breedon, G. Breto, D. Burns, M. Calderon De La Barca Sanchez, S. Chauhan, 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, J. Smith, M. Squires, D. Stolp, M. Tripathi, S. Wilbur, R. Yohay University of California, Los Angeles, U.S.A. C. Bravo, R. Cousins, A. Dasgupta, P. Everaerts, A. Florent, J. Hauser, M. Ignatenko, N. Mccoll, D. Saltzberg, C. Schnaible, E. Takasugi, V. Valuev, M. Weber University of California, Riverside, Riverside, U.S.A. K. Burt, R. Clare, J. Ellison, J.W. Gary, S.M.A. Ghiasi Shirazi, G. Hanson, J. Heilman, P. Jandir, E. Kennedy, F. Lacroix, O.R. Long, M. Olmedo Negrete, M.I. Paneva, A. Shrinivas, W. Si, H. Wei, S. Wimpenny, B. R. Yates University of California, San Diego, La Jolla, U.S.A. J.G. Branson, G.B. Cerati, S. Cittolin, M. Derdzinski, R. Gerosa, A. Holzner, D. Klein, V. Krutelyov, J. Letts, I. Macneill, D. Olivito, S. Padhi, M. Pieri, M. Sani, V. Sharma, S. Simon, M. Tadel, A. Vartak, S. Wasserbaech67, C. Welke, J. Wood, F. Wurthwein, A. Yagil, G. Zevi Della Porta University of California, Santa Barbara - Department of Physics, Santa Bar N. Amin, R. Bhandari, J. Bradmiller-Feld, C. Campagnari, A. Dishaw, V. Dutta, K. Flowers, M. Franco Sevilla, P. Ge ert, C. George, F. Golf, L. Gouskos, J. Gran, R. Heller, J. Incandela, S.D. Mullin, A. Ovcharova, J. Richman, D. Stuart, I. Suarez, J. Yoo California Institute of Technology, Pasadena, U.S.A. D. Anderson, A. Apresyan, J. Bendavid, A. Bornheim, J. Bunn, Y. Chen, J. Duarte, J.M. Lawhorn, A. Mott, H.B. Newman, C. Pena, M. Spiropulu, J.R. Vlimant, S. Xie, Carnegie Mellon University, Pittsburgh, U.S.A. University of Colorado Boulder, Boulder, U.S.A. J.P. Cumalat, W.T. Ford, F. Jensen, A. Johnson, M. Krohn, T. Mulholland, K. Stenson, Cornell University, Ithaca, U.S.A. J. Alexander, J. Chaves, J. Chu, S. Dittmer, K. Mcdermott, N. Mirman, G. Nicolas Kaufman, J.R. Patterson, A. Rinkevicius, A. Ryd, L. Skinnari, L. So , S.M. Tan, Z. Tao, J. Thom, J. Tucker, P. Wittich, M. Zientek Fair eld University, Fair eld, U.S.A. Fermi National Accelerator Laboratory, Batavia, U.S.A. S. Abdullin, M. Albrow, G. Apollinari, S. Banerjee, L.A.T. Bauerdick, A. Beretvas, J. Berryhill, P.C. Bhat, G. Bolla, K. Burkett, J.N. Butler, H.W.K. Cheung, F. Chlebana, S. Cihangiry, M. Cremonesi, V.D. Elvira, I. Fisk, J. Freeman, E. Gottschalk, L. Gray, D. Green, S. Grunendahl, O. Gutsche, D. Hare, R.M. Harris, S. Hasegawa, J. Hirschauer, Z. Hu, B. Jayatilaka, S. Jindariani, M. Johnson, U. Joshi, B. Klima, B. Kreis, S. Lammel, J. Linacre, D. Lincoln, R. Lipton, M. Liu, T. Liu, R. Lopes De Sa, J. Lykken, K. Maeshima, N. Magini, J.M. Marra no, S. Maruyama, D. Mason, P. McBride, P. Merkel, S. Mrenna, S. Nahn, C. Newman-Holmesy, V. O'Dell, K. Pedro, O. Prokofyev, G. Rakness, L. Ristori, 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, Y. Wu University of Florida, Gainesville, U.S.A. D. Acosta, P. Avery, P. Bortignon, D. Bourilkov, A. Brinkerho , A. Carnes, M. Carver, D. Curry, S. Das, R.D. Field, I.K. Furic, J. Konigsberg, A. Korytov, J.F. Low, P. Ma, K. Matchev, H. Mei, G. Mitselmakher, D. Rank, L. Shchutska, D. Sperka, L. Thomas, J. Wang, S. Wang, J. Yelton Florida International University, Miami, U.S.A. S. Linn, P. Markowitz, G. Martinez, J.L. Rodriguez A. Ackert, J.R. Adams, T. Adams, A. Askew, S. Bein, B. Diamond, S. Hagopian, V. Hagopian, K.F. Johnson, A. Khatiwada, H. Prosper, A. Santra Florida Institute of Technology, Melbourne, U.S.A. M.M. Baarmand, V. Bhopatkar, S. Colafranceschi68, M. Hohlmann, D. Noonan, T. Roy, University of Illinois at Chicago (UIC), Chicago, U.S.A. M.R. Adams, L. Apanasevich, D. Berry, R.R. Betts, I. Bucinskaite, R. Cavanaugh, O. Evdokimov, L. Gauthier, C.E. Gerber, D.J. Hofman, K. Jung, P. Kurt, C. O'Brien, I.D. Sandoval Gonzalez, P. Turner, N. Varelas, H. Wang, Z. Wu, M. Zakaria, J. Zhang The University of Iowa, Iowa City, U.S.A. B. Bilki69, W. Clarida, K. Dilsiz, S. Durgut, R.P. Gandrajula, M. Haytmyradov, V. Khristenko, J.-P. Merlo, H. Mermerkaya70, A. Mestvirishvili, A. Moeller, J. Nachtman, H. Ogul, Y. Onel, F. Ozok71, A. Penzo, C. Snyder, E. Tiras, J. Wetzel, K. Yi Johns Hopkins University, Baltimore, U.S.A. I. Anderson, B. Blumenfeld, A. Cocoros, N. Eminizer, D. Fehling, L. Feng, A.V. Gritsan, P. Maksimovic, C. Martin, M. Osherson, J. Roskes, U. Sarica, M. Swartz, M. Xiao, Y. Xin, The University of Kansas, Lawrence, U.S.A. A. Al-bataineh, P. Baringer, A. Bean, S. Boren, J. Bowen, C. Bruner, J. Castle, L. Forthomme, R.P. Kenny III, S. Khalil, A. Kropivnitskaya, D. Majumder, W. Mcbrayer, M. Murray, S. Sanders, R. Stringer, 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, C. Ferraioli, J.A. Gomez, N.J. Hadley, S. Jabeen, R.G. Kellogg, T. Kolberg, J. Kunkle, Y. Lu, A.C. Mignerey, F. Ricci-Tam, Y.H. Shin, A. Skuja, M.B. Tonjes, S.C. Tonwar Massachusetts Institute of Technology, Cambridge, U.S.A. D. Abercrombie, B. Allen, A. Apyan, R. Barbieri, A. Baty, R. Bi, K. Bierwagen, S. Brandt, W. Busza, I.A. Cali, Z. Demiragli, L. Di Matteo, G. Gomez Ceballos, M. Goncharov, D. Hsu, Y. Iiyama, G.M. Innocenti, M. Klute, D. Kovalskyi, K. Krajczar, 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. Sumorok, K. Tatar, M. Varma, D. Velicanu, J. Veverka, J. Wang, T.W. Wang, B. Wyslouch, M. Yang, V. Zhukova { 30 { A.C. Benvenuti, R.M. Chatterjee, A. Evans, A. Finkel, A. Gude, P. Hansen, S. Kalafut, S.C. Kao, Y. Kubota, Z. Lesko, J. Mans, S. Nourbakhsh, N. Ruckstuhl, R. Rusack, N. Tambe, J. Turkewitz University of Mississippi, Oxford, U.S.A. J.G. Acosta, S. Oliveros University of Nebraska-Lincoln, Lincoln, U.S.A. E. Avdeeva, R. Bartek, K. Bloom, D.R. Claes, A. Dominguez72, C. Fangmeier, R. Gonzalez Suarez, R. Kamalieddin, I. Kravchenko, A. Malta Rodrigues, F. Meier, J. Monroy, J.E. Siado, G.R. Snow, B. Stieger State University of New York at Bu alo, Bu alo, U.S.A. M. Alyari, J. Dolen, J. George, A. Godshalk, C. Harrington, I. Iashvili, J. Kaisen, A. Kharchilava, A. Kumar, A. Parker, S. Rappoccio, B. Roozbahani Northeastern University, Boston, U.S.A. G. Alverson, E. Barberis, A. Hortiangtham, A. Massironi, D.M. Morse, D. Nash, T. Orimoto, R. Teixeira De Lima, D. Trocino, R.-J. Wang, D. Wood Northwestern University, Evanston, U.S.A. S. Bhattacharya, K.A. Hahn, A. Kubik, A. Kumar, 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. Marinelli, F. Meng, C. Mueller, Y. Musienko37, 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, J. Brinson, B. Bylsma, L.S. Durkin, S. Flowers, B. Francis, A. Hart, C. Hill, R. Hughes, 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, D. Lange, J. Luo, D. Marlow, J. Mc Donald, T. Medvedeva, K. Mei, M. Mooney, J. Olsen, C. Palmer, P. Piroue, D. Stickland, A. Svyatkovskiy, C. Tully, A. Zuranski University of Puerto Rico, Mayaguez, U.S.A. Purdue University, West Lafayette, U.S.A. A. Barker, V.E. Barnes, S. Folgueras, L. Gutay, M.K. Jha, M. Jones, A.W. Jung, D.H. Miller, N. Neumeister, J.F. Schulte, X. Shi, J. Sun, F. Wang, W. Xie, L. Xu Purdue University Calumet, Hammond, U.S.A. N. Parashar, J. Stupak A. Adair, B. Akgun, Z. Chen, K.M. Ecklund, F.J.M. Geurts, M. Guilbaud, W. Li, B. Michlin, M. Northup, B.P. Padley, R. Redjimi, J. Roberts, J. Rorie, Z. Tu, J. Zabel University of Rochester, Rochester, U.S.A. B. Betchart, 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 Rutgers, The State University of New Jersey, Piscataway, U.S.A. A. Agapitos, J.P. Chou, E. Contreras-Campana, Y. Gershtein, T.A. Gomez Espinosa, E. Halkiadakis, M. Heindl, D. Hidas, E. Hughes, S. Kaplan, R. Kunnawalkam Elayavalli, S. Kyriacou, A. Lath, K. Nash, 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. Bouhali73, A. Celik, M. Dalchenko, M. De Mattia, A. Delgado, S. Dildick, R. Eusebi, J. Gilmore, T. Huang, E. Juska, T. Kamon74, R. Mueller, Y. Pakhotin, R. Patel, A. Perlo , L. Pernie, D. Rathjens, A. Rose, A. Safonov, A. Tatarinov, K.A. Ulmer Texas Tech University, Lubbock, U.S.A. N. Akchurin, C. Cowden, J. Damgov, F. De Guio, C. Dragoiu, 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, P. Sheldon, S. Tuo, J. Velkovska, Q. Xu University of Virginia, Charlottesville, U.S.A. M.W. Arenton, P. Barria, B. Cox, J. Goodell, R. Hirosky, A. Ledovskoy, H. Li, C. Neu, T. Sinthuprasith, X. Sun, Y. Wang, E. Wolfe, F. Xia Wayne State University, Detroit, U.S.A. C. Clarke, R. Harr, P.E. Karchin, J. Sturdy University of Wisconsin - Madison, Madison, WI, U.S.A. D.A. Belknap, C. Caillol, S. Dasu, L. Dodd, S. Duric, B. Gomber, M. Grothe, M. Herndon, A. Herve, P. Klabbers, A. Lanaro, A. Levine, K. Long, R. Loveless, I. Ojalvo, T. Perry, G.A. Pierro, G. Polese, T. Ruggles, A. Savin, N. Smith, W.H. Smith, D. Taylor, N. Woods 1: Also at Vienna University of Technology, Vienna, Austria 2: Also at State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, Haute Alsace Mulhouse, CNRS/IN2P3, Strasbourg, 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 Deutsches Elektronen-Synchrotron, Hamburg, Germany 8: Also at Joint Institute for Nuclear Research, Dubna, Russia 9: Now at Ain Shams University, Cairo, Egypt 10: Now at British University in Egypt, Cairo, Egypt 11: Also at Zewail City of Science and Technology, Zewail, Egypt 12: Also at Universite de Haute Alsace, Mulhouse, France 13: Also at Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 14: Also at Tbilisi State University, Tbilisi, Georgia 15: Also at CERN, European Organization for Nuclear Research, Geneva, Switzerland 16: Also at RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany 17: Also at University of Hamburg, Hamburg, Germany 18: Also at Brandenburg University of Technology, Cottbus, Germany 19: Also at Institute of Nuclear Research ATOMKI, Debrecen, Hungary 20: Also at MTA-ELTE Lendulet CMS Particle and Nuclear Physics Group, Eotvos Lorand 21: Also at Institute of Physics, University of Debrecen, Debrecen, Hungary 22: Also at Indian Institute of Science Education and Research, Bhopal, India 23: Also at Institute of Physics, Bhubaneswar, India 24: Also at University of Visva-Bharati, Santiniketan, India 25: Also at University of Ruhuna, Matara, Sri Lanka 26: Also at Isfahan University of Technology, Isfahan, Iran 27: Also at University of Tehran, Department of Engineering Science, Tehran, Iran 28: Also at Yazd University, Yazd, Iran 29: Also at Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran, Iran 30: Also at Laboratori Nazionali di Legnaro dell'INFN, Legnaro, Italy 31: Also at Universita degli Studi di Siena, Siena, Italy 32: Also at Purdue University, West Lafayette, U.S.A. 33: Also at International Islamic University of Malaysia, Kuala Lumpur, Malaysia 34: Also at Malaysian Nuclear Agency, MOSTI, Kajang, Malaysia 35: Also at Consejo Nacional de Ciencia y Tecnolog a, Mexico city, Mexico 36: Also at Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland 37: Also at Institute for Nuclear Research, Moscow, Russia 38: Now at National Research Nuclear University 'Moscow Engineering Physics Institute' (MEPhI), Moscow, Russia 39: Also at St. Petersburg State Polytechnical University, St. Petersburg, Russia 40: Also at University of Florida, Gainesville, U.S.A. 41: Also at P.N. Lebedev Physical Institute, Moscow, Russia 42: Also at California Institute of Technology, Pasadena, U.S.A. 43: Also at Budker Institute of Nuclear Physics, Novosibirsk, Russia 44: Also at Faculty of Physics, University of Belgrade, Belgrade, Serbia 45: Also at INFN Sezione di Roma; Universita di Roma, Roma, Italy 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 Institute for Theoretical and Experimental Physics, Moscow, Russia 51: Also at Albert Einstein Center for Fundamental Physics, Bern, Switzerland 52: Also at Mersin University, Mersin, Turkey 53: Also at Cag University, Mersin, Turkey 54: Also at Piri Reis University, Istanbul, Turkey 55: Also at Gaziosmanpasa University, Tokat, Turkey 56: Also at Adiyaman University, Adiyaman, Turkey 57: Also at Ozyegin University, Istanbul, Turkey 58: Also at Izmir Institute of Technology, Izmir, Turkey 59: Also at Marmara University, Istanbul, Turkey 60: Also at Kafkas University, Kars, Turkey 61: Also at Istanbul Bilgi University, Istanbul, Turkey 62: Also at Yildiz Technical University, Istanbul, Turkey 63: Also at Hacettepe University, Ankara, Turkey 64: Also at Rutherford Appleton Laboratory, Didcot, United Kingdom 65: Also at School of Physics and Astronomy, University of Southampton, Southampton, United 67: Also at Utah Valley University, Orem, U.S.A. 68: Also at Facolta Ingegneria, Universita di Roma, Roma, Italy 69: Also at Argonne National Laboratory, Argonne, U.S.A. 70: Also at Erzincan University, Erzincan, Turkey 71: Also at Mimar Sinan University, Istanbul, Istanbul, Turkey 72: Now at The Catholic University of America, Washington, U.S.A. 73: Also at Texas A&M University at Qatar, Doha, Qatar 74: Also at Kyungpook National University, Daegu, Korea [1] P. Langacker , The Physics of Heavy Z0 Gauge Bosons, Rev. Mod. Phys . 81 ( 2009 ) 1199 [2] K.R. Lynch , E.H. Simmons , M. Narain and S. Mrenna , Finding Z0 bosons coupled preferentially to the third family at LEP and the Tevatron , Phys. Rev. D 63 (2001) 035006 [3] C.T. Hill , Topcolor assisted technicolor , Phys. Lett . B 345 ( 1995 ) 483 [hep-ph/9411426] [4] K.D. Lane , A new model of topcolor assisted technicolor , Phys. Lett . B 433 ( 1998 ) 96 [11] CMS collaboration, The CMS experiment at the CERN LHC, 2008 JINST 3 S08004 [12] CMS collaboration, The CMS trigger system, 2016 JINST 12 P01020 [arXiv:1609 .02366] [13] CMS collaboration, Particle-Flow Event Reconstruction in CMS and Performance for Jets, Taus and MET, CMS-PAS-PFT-09- 001 ( 2009 ). [20] M. Cacciari , G.P. Salam and G. Soyez , The anti-kt jet clustering algorithm , JHEP 04 ( 2008 ) [21] M. Cacciari , G.P. Salam and G. Soyez , FastJet User Manual , Eur. Phys. J. C 72 ( 2012 ) [22] CMS collaboration, Identi cation of b-quark jets with the CMS experiment, 2013 JINST 8 [23] CMS collaboration, Identi cation of b quark jets at the CMS Experiment in the LHC Run 2 , [26] T. Sj ostrand et al., An introduction to PYTHIA 8 . 2 , Comput . Phys. Commun . 191 ( 2015 ) [27] S. Alioli , P. Nason , C. Oleari and E. Re , NLO single-top production matched with shower in [32] P. Barnreuther, M. Czakon and A. Mitov , Percent Level Precision Physics at the Tevatron : [36] R. Gavin , Y. Li , F. Petriello and S. Quackenbush , W Physics at the LHC with FEWZ 2 . 1 , [37] 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 [38] NNPDF collaboration , R.D. Ball et al., Parton distributions for the LHC Run II , JHEP 04 [40] GEANT4 collaboration , S. Agostinelli et al., GEANT4: A simulation toolkit, Nucl . Instrum. [41] CDF collaboration, A. Abulencia et al., Search for neutral MSSM Higgs bosons decaying to s = 1:96 TeV, Phys. Rev. Lett. 96 (2006) 011802 [43] J. Butterworth et al., PDF4LHC recommendations for LHC Run II, J. Phys. G 43 (2016) [45] A.L. Read, Presentation of search results: The CLs technique, J. Phys. G 28 (2002) 2693 Brazil France A. Abdulsalam, I. Antropov, S. Ba oni, F. Beaudette, P. Busson, L. Cadamuro, E. Chapon, C. Charlot, O. Davignon, R. Granier de Cassagnac, M. Jo, S. Lisniak, P. Mine, M. Nguyen, C. Ochando, G. Ortona, P. Paganini, P. Pigard, S. Regnard, R. Salerno, Y. Sirois, T. Strebler, Y. Yilmaz, A. Zabi F. Colombo, W. De Boer, A. Dierlamm, S. Fink, B. Freund, R. Friese, M. Gi els, A. Gilbert, P. Goldenzweig, D. Haitz, F. Hartmann15, S.M. Heindl, U. Husemann, I. Katkov13, S. Kudella, P. Lobelle Pardo, H. Mildner, M.U. Mozer, Th. Muller, M. Plagge, G. Quast, K. Rabbertz, S. Rocker, F. Roscher, M. Schroder, I. Shvetsov, G. Sieber, H.J. Simonis, R. Ulrich, J. Wagner-Kuhr, S. Wayand, M. Weber, T. Weiler, S. Williamson, C. Wohrmann, Italy Italy L. Brianza15, M.E. Dinardoa;b, S. Fiorendia;b, S. Gennaia, A. Ghezzia;b, P. Govonia;b, M. Malberti, S. Malvezzia, R.A. Manzonia;b;15, D. Menascea, L. Moronia, M. Paganonia;b, D. Pedrinia, S. Pigazzini, S. Ragazzia;b, T. Tabarelli de Fatisa;b Malaysia I. Ahmed, Z.A. Ibrahim, J.R. Komaragiri, M.A.B. Md Ali33, F. Mohamad Idris34, W.A.T. Wan Abdullah, M.N. Yusli, Z. Zolkapli Portugal P. Bargassa, C. Beir~ao Da Cruz E Silva, A. Di Francesco, P. Faccioli, P.G. Ferreira Parracho, M. Gallinaro, J. Hollar, N. Leonardo, L. Lloret Iglesias, M.V. Nemallapudi, J. Rodrigues Antunes, J. Seixas, O. Toldaiev, D. Vadruccio, J. Varela, P. Vischia Cortabitarte I.J. Cabrillo, A. Calderon, J.R. Castin~eiras De Saa, E. Curras, M. Fernandez, J. GarciaFerrero, G. Gomez, A. Lopez Virto, J. Marco, C. Martinez Rivero, F. Matorras, J. Piedra S. Orfanelli, L. Orsini, L. Pape, E. Perez, M. Peruzzi, A. Petrilli, G. Petrucciani, A. Pfei er, M. Pierini, A. Racz, T. Reis, G. Rolandi47, M. Rovere, M. Ruan, H. Sakulin, J.B. Sauvan, C. Schafer, C. Schwick, M. Seidel, A. Sharma, P. Silva, P. Sphicas48, J. Steggemann, C. Dietz, F. Fiori, W.-S. Hou, Y. Hsiung, Y.F. Liu, R.-S. Lu, M. Min~ano Moya, E. Paganis, Thailand D. Arcaro, A. Avetisyan, T. Bose, D. Gastler, D. Rankin, C. Richardson, J. Rohlf, L. Sulak, M.B. Andrews, V. Azzolini, T. Ferguson, M. Paulini, J. Russ, M. Sun, H. Vogel, I. Vorobiev, China 3: Also at Institut Pluridisciplinaire Hubert Curien, Universite de Strasbourg, Universite de Kingdom 66: Also at Instituto de Astrof sica de Canarias, La Laguna, Spain


This is a preview of a remote PDF: http://link.springer.com/content/pdf/10.1007%2FJHEP02%282017%29048.pdf

Search for heavy resonances decaying to tau lepton pairs in proton-proton collisions at \( \sqrt{s}=13 \) TeV, Journal of High Energy Physics, 2017, DOI: 10.1007/JHEP02(2017)048