Search for CP violation in \( t\overline{t} \) production and decay in proton-proton collisions at \( \sqrt{s}=8 \) TeV

Journal of High Energy Physics, Mar 2017

The results of a first search for CP violation in the production and decay of top quark-antiquark (\( t\overline{t} \)) pairs are presented. The search is based on asymmetries in T-odd, triple-product correlation observables, where T is the time-reversal operator. The analysis uses a sample of proton-proton collisions at \( \sqrt{s}=8 \) TeV collected by the CMS experiment, corresponding to an integrated luminosity of 19.7 fb−1. Events are selected having one electron or muon and at least four jets. The T-odd observables are measured using four-momentum vectors associated with \( t\overline{t} \) production and decay. The measured asymmetries exhibit no evidence for CP-violating effects, consistent with the expectation from the standard model.

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Search for CP violation in \( t\overline{t} \) production and decay in proton-proton collisions at \( \sqrt{s}=8 \) TeV

Received: November violation in tt production and decay in Search for CP 0 1 2 3 4 0 . Events are selected 1 [25] R. Gavin, Y. Li , F. Petriello and S. Quackenbush, FEWZ 2.0: A code for hadronic Z 2 tute' (MEPhI) , Moscow , Russia 3 University , Budapest , Hungary 4 46: Also at University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences The results of a rst search for CP violation in the production and decay of top quark-antiquark (tt) pairs are presented. The search is based on asymmetries in T-odd, triple-product correlation observables, where T is the time-reversal operator. The analysis uses a sample of proton-proton collisions at p s = 8 TeV collected by the CMS experiment, corresponding to an integrated luminosity of 19.7 fb 1 having one electron or muon and at least four jets. The T-odd observables are measured using four-momentum vectors associated with tt production and decay. The measured asymmetries exhibit no evidence for CP-violating e ects, consistent with the expectation from the standard model. p; CP violation; Hadron-Hadron scattering (experiments); Top physics 8 TeV 1 Introduction 2 3 4 The CMS detector Data and simulated samples Object de nition and event selection Background control sample and check for asymmetry bias Fit procedure and A0CP determination Systematic uncertainties Experimental sensitivity study Asymmetry measurements The CMS collaboration Violation of the combined operation of charge conjugation and parity (CP) is introduced in the standard model (SM) via an irreducible phase in the Cabibbo-Kobayashi-Maskawa quark-mixing matrix [1]. Detailed experimental investigation of CP violation (CPV) in the strange and bottom quark sectors has been conducted over the past few decades [2]. The measured asymmetries are well described by the SM, but are too small to explain the observed matter-antimatter asymmetry of the universe [3]. In contrast to the strange and bottom quark sectors, CPV in the top quark sector is relatively unexplored. In the SM, CPV in the production and decay of top quark-antiquark (tt) pairs is predicted to be very small [4]. However, in many theories of physics beyond the SM (see, for example, refs. [5, 6] and references therein) sizable CP-violating e ects could be observed, which have the potential to shed light on the matter-antimatter asymmetry of the universe. In this paper, the rst measurements of CP-violating asymmetries in tt production and decay are presented. One of the top quarks is presumed to decay to a bottom (b) quark and a hadronically decaying W boson. The other top quark is required to decay to a b quark and a W boson that decays leptonically to an electron or muon and its associated neutrino. The analysis exploits T-odd, triple-product correlations, where T is the time-reversal operator. Several observables are measured, as proposed in refs. [5{7], that take the form ~v1 (~v2 ~v3), where ~vi (i = 1; 2; 3) are spin or momentum vectors. These triple-product observables are odd under the T transformation, and are thus also Oi are the proposed observables. The presence of CPV would be manifested by a nonzero value of the asymmetry ACP(Oi) = Nevents(Oi > 0) Nevents(Oi < 0) Nevents(Oi > 0) + Nevents(Oi < 0) The measurements of the asymmetry corrected for the e ects of the detector (ACP) and also without these corrections (A0CP) are presented. The reason to present both ACP and A0CP values is that the corrections, called dilution factors (section 8.1), could themselves be a ected by physics beyond the SM [7]; no particular such new-physics process is considered Four observables that can be measured in the single-lepton + jets nal state of tt production and decay in proton-proton (pp) collisions are de ned as: O2 = (P; pb + pb; p`; pj1 ) lab !/ (p~b + p~b) (p~` O3 = Q` (pb; pb; p`; pj1 ) bb CM !/ Q` p~b (p~` O4 = Q` (P; pb O7 = q (pb The symbol ! indicates the spatial frame chosen to simplify the triple product. The observables O2, O4, and O7 are calculated in the laboratory (lab) frame, and O3 in the bb centre-of-mass frame (bb CM), where b and b indicate the bottom quark and antiquark jets from the t and t decays, respectively. The symbol / indicates proportionality. The symbol b, c, and d, i.e. (a; b; c; d) a b c d . In these expressions, P is the sum of, and q the di erence between, the four-momenta of the two initial-state protons; p and p~ are the four- and three-momenta, respectively, of the nal-state particles; the subscript z indicates a projection along the direction of the counterclockwise rotating proton beam, de ned to be the +z direction in the CMS coordinate system; ` refers to the electron or muon from the leptonically decaying W boson; j1 refers to the non-b quark jet originating from the hadronically decaying W boson with the highest transverse momentum (pT); and Q` is the electric charge of `. Note that the sign of the observable is the only information needed to measure ACP. The asymmetries ACP computed from the above observables are predicted to be zero in the SM [5, 6]. However, in some new-physics scenarios [7], the e ects of CPV can be sizable: ACP(O3) and ACP(O4) could be as large as 8%, while ACP(O2) and ACP(O7) are less sensitive to new physics and can reach 0.4% [7]. The sensitivity of the observables to CPV depends on whether distinguishable nal-state objects are involved in their de nition. For instance, the b quark jet charges need to be distinguished for O3 and O4, but not for 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, each composed of a barrel and two endcap sections. Forward calorimeters extend the pseudorapidity ( ) coverage provided by the barrel and endcap detectors. Muons are measured in gas-ionization detectors embedded in the steel ux-return yoke outside the solenoid. A more detailed description of the CMS detector, together with a de nition of the coordinate system and relevant kinematic variables, is given in ref. [8]. Data and simulated samples This analysis uses data from p 2012, corresponding to an integrated luminosity of 19.7 fb 1. Monte Carlo (MC) simulations are used to model the SM processes of relevance for this analysis. Top quark-antiquark events are generated at leading order using the MadGraph (v5.1.3.30) program [9] with the CT10 [10] parton distribution functions (PDFs). The MadGraph generator accounts for the spin correlations between the top quark and MadGraph generator is interfaced with the pythia (v6.426) generator [11] with Tune Z2* [12] to simulate parton showering and hadronization. The tt production cross section is calculated with the Top++ 2.0 package [13] and estimated up to next-to-next-to-leading order (NNLO). It has been observed in CMS measurements [14, 15] that MadGraph exhibits a mismodelling of the top quark pT in tt events. To rectify this de ciency, an additional top quark pT reweighting is applied at generator level to obtain agreement in the pT spectra between data and simulation. The weighting factors are derived from the results of ref. [14]. Several background processes are considered in the analysis. Single top quark production is the main background, and is simulated with the powheg (v1.0) program [16{21]. The cross section is calculated with the Hathor (v2.1) program [22, 23] at next-to-leading order (NLO). Drell-Yan (DY) and W + jets processes are generated with MadGraph, and diboson events (WW, WZ, and ZZ) with pythia. The cross sections of W + jet and DY production are calculated with the fewz (v3.1) [24, 25] program at NNLO, while the mcfm (v6.6) [26] program is used for the cross sections of diboson productions at NLO. The quantum chromodynamic (QCD) background is suppressed by the selection requirements (section 4) and is negligible in the signal region. All generated events are subjected to a Geant4-based [27] simulation of the detector response. Additional pp interactions occurring in the same or nearby bunch crossing (pileup) are included in the simulation. The number of pileup events in simulation is corrected to agree with data. The average number of interactions per event in data is 21. The event selection is based on the signature of the single-lepton + jets decay channel of the tt process. Events containing one isolated electron or muon and at least four jets, including exactly two jets identi ed as originating from the hadronization of b quarks (b quark jets), are selected. Events with electrons and muons coming from the decay of leptons are included in the sample. Electrons, muons, photons, and neutral and charged hadrons are reconstructed and identi ed with the CMS particle- ow (PF) algorithm [28, 29]. The energy of electrons is determined from a combination of the track momentum at the primary collision vertex, the corresponding cluster of energy deposits in the ECAL, and the energy sum of all bremsstrahlung photons associated with the track [30]. The momentum of muons is obtained from a global t to signals registered by the silicon tracker and muon detectors [31]. The trigger requires at least one electron candidate with pT > 27 GeV and j j < 2:5, or at least one muon candidate with pT > 24 GeV and j j < 2:1. The primary event vertex is the reconstructed vertex with the largest p In the subsequent o ine selection, electrons are identi ed using a combination of the ECAL shower shape information, and the geometric matching between the track and the ECAL energy cluster [30]. The electron candidates are required to have pT > 30 GeV and j j < 2:1, excluding the transition region (1:44 < j j < 1:56) between the barrel and endcap sections of the ECAL, where the acceptance is di cult to accurately model. Electrons from identi ed photon conversions are rejected. Muon candidates must be associated with a good-quality track [31] with pT > 26 GeV and j j < 2:1. The trigger and lepton identi cation e ciencies are determined from data and simulation [32] as functions of the lepton pT and . The electron (muon) identi cation e ciency ranges from 55 to 85% (93 to 97%). The lepton from the W boson decay is expected to be isolated from other activity in the event. A relative isolation parameter [30, 31] is de ned as the scalar pT sum of the particles reconstructed by the PF algorithm within a cone of angular radius R = divided by the pT of the lepton candidate, where are the relative di erences in pseudorapidity and azimuthal angle (in radians), respectively, between the directions of the lepton and other particle. The sum includes pileup corrections and excludes the lepton candidate under consideration. The relative isolation parameter is required to be less than 0.10 for electrons and 0.12 for muons. Events with additional loosely de ned leptons (satisfying a lower-pT threshold and a less stringent isolation requirement) are rejected in order to reduce the contributions from Z boson or tt decays into dileptons. Jets are reconstructed by clustering charged and neutral PF particles, using the anti-kT jet algorithm [33] with a distance parameter of 0.5, implemented in the FastJet package [34]. Jet energies are corrected for the nonlinear response of the calorimeters and for the di erences between the measured and simulated responses [35]. Charged hadrons that are not associated with the primary vertex are removed, and the jet energy is corrected to account for the expected contributions of neutral particles from pileup interactions [28, 36]. An event is discarded if the lepton candidate lies within R = 0:5 of any selected jet. At least four jets with pT > 30 GeV and j j < 2:4 are required, two of which must be identi ed as b quark jets. The b tagging is performed with the combined secondary vertex (CSV) algorithm at the medium working point [37], corresponding to an e ciency of about 1% for light-quark and gluon jets (mistag rate) and 60{70% for b quark jets, depending on the jet pT and . The MC simulation is corrected with scale factors to account for di erences with respect to the data for the b tagging e ciency [38]. One of the b quark jets is combined with two non-b quark jets in the event through a 2-sorting algorithm [37, 39] that makes use of top quark and W boson mass constraints to de ne the hadronically decaying top quark candidate. The other b quark jet is then associated with the semileptonically decaying top quark candidate. The purity of the selected tt candidates is 92% after the 2 selection, while single top quark production contributes with only 3% of the total number of events. The charge of the isolated lepton is used to distinguish between the b and b quark jets. The b quark jet charges are correctly assigned in 60% of the tt events. For the semileptonically decaying top quark, the analysis uses the mass variable M`b, which is the invariant mass of the isolated lepton and the associated b quark jet. For the hadronically decaying top quark, the mass variable Mjjb is used, which is the invariant mass of the two non-b quark jets and the associated b quark jet. As shown in gure 1, although the analysis does not depend on the simulated background events, there is reasonable agreement in the two mass-variable distributions between the data and the simulation. The distributions of the two mass variables for data events with positive and negative Oi values are consistent with each other in both the electron and muon channels. Background control sample and check for asymmetry bias Detector and reconstruction e ects may induce spurious results for the asymmetries. A data-control sample (CS) enriched in random combinations of leptons and jets (combinatorial background) from non-tt events is used to check for these spurious e ects and to evaluate possible bias, i.e. a nonzero measured value for A0CP. The combinatorial background is assumed to possess no intrinsic CPV because of its random nature. To enhance the fraction of background events and minimize the contribution from tt signal events, the CS is selected by requiring no b-tagged jets de ned according to the loose working point of CSV [37], which is 80% e cient in identifying b jets with a mistag rate for lighter jets of 10%. The event is rejected if there are additional nonisolated electron or muon candidates. All other event selection requirements are equivalent to the signal region. The CS is expected to be dominated by non-tt processes 90%), with the major contribution from the W + jets process. The CS contains a su ciently large number of events to perform statistically signi cant cross-checks. The kinematic distributions from data in the CS are in agreement with those of the background simulation in the signal region, and thus the CS can be used to represent the signal-region background. Since the CS does not contain any events with a tagged b quark jet, the two jets with the highest CSV discriminator values are used to play the role of the b quark jets. Using the same procedure as for the signal region, i.e. the 2-sorting algorithm, the required 0 50 100 150 200 250 300 350 400 450 500 0 50 100 150 200 250 300 350 400 450 500 1 e + ≥ 4 jets (2 b jets) 1 e + ≥ 4 jets (2 b jets) 0 50 100 150 200 250 300 350 400 450 500 0 50 100 150 200 250 300 350 400 450 500 and (lower) semileptonically decaying top quark candidates in the (left) electron and (right) muon channels, compared to the predictions for the signal and various backgrounds from simulation ( lled histograms). The QCD background is found to be negligible. The over ow events are collected in the last bins. The vertical bars on the data points and the hatched bands indicate the statistical uncertainties in the data and simulation, respectively. objects are found and the A0CP values are determined. The CS asymmetry measurements are consistent with zero within about two standard deviations of the statistical uncertainty in both the electron and muon channels, as shown in table 1. The combined electron and muon A0CP results are determined by summing the distributions in the electron and muon channels after applying the background normalization from the t described in section 6. The systematic uncertainties given in table 1 are derived from the t results described in section 7. The distributions of the observables of interest measured in the CS are used for background subtraction in the signal region. Fit procedure and A0CP determination The yields of signal and background events are extracted by maximizing an extended likelihood function from the data, using the M`b distribution. The expected signal distribution is obtained from simulation, while the background distribution is obtained from the CS. Figure 2 shows the measured M`b distributions compared to the results of the t. The t is seen to provide a good representation of the data for both the electron and muon channels. For the nal measurement, only events with M`b < 200 GeV are considered A0CP(CS) (%) sample as described in the text for each of the four observables. Results are given for the electron and muon channels separately and for their combination. For the separate electron and muon channels, the uncertainties are statistical. For the combined results, the rst uncertainty is statistical and the second systematic. P−2 P−2 0 50 100 150 200 250 300 350 400 450 500 0 50 100 150 200 250 300 350 400 450 500 candidates for the (left) electron and (right) muon channels, in comparison to the results of the t described in the text. Over ow events are collected in the last bins. The vertical bars on the data points indicate the statistical uncertainties. The hatched bands shows the combined statistical and systematic uncertainties in the t results added in quadrature. The di erence between the observed tted events, divided by the total statistical and systematic uncertainty (pull), is shown for each bin in the lower panels. because events with large M`b su er from a high rate of incorrect lepton and b quark jet assignments, as determined from simulation. Imposing this requirement increases the sensitivity of nal measurements to CPV. The nal results for the number of events in the electron and muon channels, and the corresponding tt event purities, are presented in under the variations described in section 7. The shape of the background distribution is obtained from the CS, while its yield is estimated from the t to the M`b distribution. The A0CP results are then computed using an analogous equation to eq. (1.1), after subtracting the estimated background contribution from the measured observables. Fitted tt fraction (%) tted number of events in the electron and muon channels as well as the tted tt fraction (purity) in percent. While the t is performed over the full mass range, the tted and observed results are for M`b < 200 GeV. The rst uncertainty is statistical and the Systematic uncertainties Several sources of systematic uncertainty can a ect the measurement of A0CP. The largest uncertainty comes from possible intrinsic detector bias. As shown in section 5, the CS results are compatible with no asymmetry. The statistical uncertainties in the asymmetries measured from the CS are 0.59%, 0.65%, and 0.44% for the electron, muon, and combined channels, respectively, as indicated in table 1. These uncertainties are taken as the systematic uncertainty from possible detector bias. Other systematic uncertainties, described below, associated with the signal and background yields are evaluated by repeating the M`b t described in section 6 under di erent conditions in correction and modelling. The uncertainty related to pileup modelling is estimated by varying the inelastic pp cross section in the simulation by 5% [40]. The uncertainties from the lepton identi cation and isolation e ciencies are determined by varying the data-to-simulation scale factors according to their uncertainties. The jet energy scale and resolution are varied according to their - and pT-dependent uncertainties [28, 36]. The scale factors used to correct the b tagging identi cation probabilities are varied according to their uncertainties [37]. E ects related to the modelling of the PDFs of the initial-state protons are estimated by varying the CT10 nominal prediction by its eigen-uncertainty sources. Each source is used to derive event-by-event weights, which are then applied to obtain a variation of the signal shape. The envelope of the variations is normalized to re ect a 68% con dence level [41]. The uncertainties related to the tt simulation are evaluated by varying the matrix-element-to-parton-shower matching thresholds and the factorization and renormalization scales by factors of 2.0 and 0.5 with respect to their nominal values in the simulation. A modelling uncertainty is determined through comparison to a tt sample generated with powheg. The uncertainty related to the modelling of the top quark pT spectrum in MadGraph is assessed by varying the weight applied by a factor of two. The uncertainty associated with the top quark mass is estimated by repeating the M`b t using di erent top quark masses. The observed di erence is scaled to re ect an uncertainty of 1 GeV in the mass [42]. These systematic uncertainties contribute to the intermediate stages of the analysis but are observed to largely cancel in the measurements of the CP asymmetry. Thus, the dominant systematic uncertainty arises from the statistical uncertainty in the measurements of possible detector bias (table 1). sy 0 a −20 sy 0 a −20 8 TeV −20 −10 −20 −10 8 TeV sy 0 a −20 sy 0 a −20 −20 −10 −20 −10 for the four di erent CPV observables. The circular markers show the output A0CP measurements for each generated ACP value. The dashed lines are the result of linear ts to the A0CP points. The triangular markers give the corrected ACP values, obtained after applying the dilution factor. The solid lines are the result of linear ts to the corrected ACP points. The statistical uncertainties in both sets of asymmetries are smaller than the markers. Results Experimental sensitivity study To evaluate the sensitivity of the analysis to CPV, simulated events are reweighted at the generator level to produce hypothetical ACP asymmetries in the observables. As shown in gure 3, the resulting values of A0CP (circular points), extracted by treating the simulated events as data, exhibit a linear dependence on the generated ACP values (dashed line). The A0CP values are related to the generated ACP values through dilution factors D, applied factors applied (triangular points) are in agreement with the generator-level asymmetries, as shown by solid lines in gure 3, which are the results of ts to the corrected asymmetry values. The slopes of the lines are consistent with 1.0 and their y intercepts consistent As mentioned in the introduction, the dilution factors can be a ected by new-physics processes. The reason for this is that the processes can alter the kinematic distributions of tt events. For this reason, we consider the measurements of the uncorrected asymmetries A0CP to be our primary result. It is nonetheless of interest to examine the overall size of the dilution factors, using the tt simulation, for the cases when no new physics is present or when it is present to only a small degree. Wrong-sign fraction k (%) Dilution factor D associated dilution factor D computed from k, determined from simulated tt events. The rst uncertainty is statistical and the second is systematic. the four CPV observables. Results for A0CP are given for the electron and muon channels separately and for their combination. For the A0CP results, the rst uncertainty is statistical and the second systematic. The ACP values assume the dilution factors found from the SM simulation. The uncertainties in the ACP results are the combined statistical and systematic terms added in quadrature. The results for the dilution factors of the four observables are summarized in table 3. If the sign of an observable at the generator level is the same as (di erent from) its sign in the reconstructed event, the event is classi ed as having the correct (wrong) sign. The 2k. The value of k for the four CPV observables are given in table 3, along with their statistical and systematic uncertainties. The systematic uncertainties are estimated from the di erent conditions of correction and modeling, as mentioned in section 7. Studies reveal the following sources contribute to the value of k: misidenti cation of the b quark jet charge, 10.5%; mistagging of b quark jets, 7.5%; misassignment of the highest-pT jet from W boson decay, 6.5%; jet energy resolution, 2.5% per jet. The e ect of lepton charge misidenti cation is negligible. The observables O3 and O4 depend on similar quantities, including the charges of the b quark jets, and exhibit similar values of k. The observables O2 and O7 have lower k values since fewer objects are used in their calculation. Asymmetry measurements The measured distributions of the four observables are presented in gure 4. The corresponding A0CP values, determined after subtraction of the background contributions, are shown in table 4 and displayed in gure 5. No signi cant nonzero asymmetry is observed in any of the separate electron or muon channels. Assuming that any new-physics process has at most a small e ect on the tt kinematic distributions, the dilution factors given in 10 25 .(1 20 /s 15 t ven 10 llu 02 P−2 10 25 .(1 20 /s 15 t ven 10 llu 02 P−2 CMS −1 −0.5 −1 −0.5 10 25 .(1 20 /s 15 t ven 10 llu 02 P−2 10 25 .(1 20 /s 15 t ven 10 llu 02 P−2 −1 −0.5 −1 −0.5 combined electron and muon channels from data (points) and simulated signal and background ( lled histograms). The simulated tt and background samples are normalized to the tted yields. The over ow events are collected in the rst and last bins. Each observable is given in units of mt3, hatched bands give the combined statistical and systematic uncertainties added in quadrature. The di erence between the observed and expected events, divided by the total statistical and systematic uncertainty (pull), is shown for each bin in the lower panels. table 3 are applied to the combined sample to obtain the corrected ACP values presented in table 4 and shown in gure 5. Summary The rst search for CP-violating e ects in top quark-antiquark events has been presented. The search is performed in the electron + jets and muon + jets nal states, with one based on a sample of proton-proton collision data collected at p top quark assumed to decay hadronically and the other semileptonically. The search is s = 8 TeV with the CMS detector in 2012, corresponding to an integrated luminosity of 19.7 fb 1. The CP-violating asymmetries are measured using four T-odd, triple-product observables, where T is the time-reversal operator. A data control sample is used to verify that no signi cant spurious CP asymmetry is introduced by background processes, and to model the shape of the background in the asymmetry observables. The normalization of the background contribution in the signal region is determined from a t to the mass distribution M`b associated with y 2 r A'CP in lepton + jets ACP (SM correction) de ned in eq. (1.2). The results for A0CP are shown for the electron and muon channels separately and for their combination. The results for ACP are shown for the combined electron and muon channels, using the dilution factors from SM simulation of tt production. The inner bars represent the statistical uncertainties, and the outer bars the combined statistical and systematic uncertainties added in quadrature. the semileptonically decaying top quarks. The background-subtracted distributions of the observables are used to compute the uncorrected asymmetries. The corrected asymmetries are obtained by using a multiplicative dilution factor derived from simulation. Both the uncorrected and corrected asymmetries are consistent with zero, in agreement with the expectation from the standard model. 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 (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, 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. 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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, D. Vannerom, 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, G. Krintiras, 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, M. VuUniversity of So a, So a, Bulgaria A. Dimitrov, I. Glushkov, L. Litov, B. Pavlov, P. Petkov Beihang University, Beijing, China 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, H. Zhang, J. Zhao 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, B. Mesic, 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 Y. Assran9;10, T. Elkafrawy11, A. Mahrous12 National Institute of Chemical Physics and Biophysics, Tallinn, Estonia M. Kadastik, 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. Agram13, J. Andrea, A. Aubin, D. Bloch, J.-M. Brom, M. Buttignol, E.C. Chabert, N. Chanon, C. Collard, E. Conte13, X. Coubez, J.-C. Fontaine13, 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. Popov14, D. Sabes, V. Sordini, M. Vander Donckt, P. Verdier, T. Toriashvili15 Z. Tsamalaidze8 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. Zhukov14 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, B. Kargoll, T. Kress, A. Kunsken, J. Lingemann, T. Muller, A. Nehrkorn, A. Nowack, C. Pistone, O. Pooth, A. Stahl16 Deutsches Elektronen-Synchrotron, Hamburg, Germany M. Aldaya Martin, T. Arndt, C. Asawatangtrakuldee, K. Beernaert, O. Behnke, U. Behrens, A.A. Bin Anuar, K. Borras17, A. Campbell, P. Connor, C. Contreras-Campana, F. Costanza, C. Diez Pardos, G. Dolinska, G. Eckerlin, D. Eckstein, T. Eichhorn, E. Eren, E. Gallo18, J. Garay Garcia, A. Geiser, A. Gizhko, J.M. Grados Luyando, P. Gunnellini, A. Harb, J. Hauk, M. Hempel19, H. Jung, A. Kalogeropoulos, O. Karacheban19, M. Kase mann, J. Keaveney, C. Kleinwort, I. Korol, D. Krucker, W. Lange, A. Lelek, J. Leonard, K. Lipka, A. Lobanov, W. Lohmann19, 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. Pantaleo16, 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, Institute of Nuclear and Particle Physics (INPP), NCSR Demokritos, Aghia I. Topsis-Giotis 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, D. Horvath20, F. Sikler, V. Veszpremi, G. Vesztergombi21, A.J. Zsig Institute of Nuclear Research ATOMKI, Debrecen, Hungary N. Beni, S. Czellar, J. Karancsi22, A. Makovec, J. Molnar, Z. Szillasi Institute of Physics, University of Debrecen M. Bartok21, P. Raics, Z.L. Trocsanyi, B. Ujvari National Institute of Science Education and Research, Bhubaneswar, India S. Bahinipati, S. Choudhury23, P. Mal, K. Mandal, A. Nayak24, 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. Mohanty16, 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. Bhowmik25, R.K. Dewanjee, S. Ganguly, M. Guchait, Sa. Jain, S. Kumar, M. Maity25, G. Majumder, K. Mazumdar, T. Sarkar25, N. Wickramage26 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. Chenarani27, E. Eskandari Tadavani, S.M. Etesami27, A. Fahim28, M. Khakzad, M. Mohammadi Najafabadi, M. Naseri, S. Paktinat Mehdiabadi29, F. Rezaei Hosseinabadi, B. Safarzadeh30, M. 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Iorioa;b, G. Lanzaa, L. Listaa, S. Meolaa;d;16, P. Paoluccia;16, C. Sciaccaa;b, F. Thyssen INFN Sezione di Padova a, Universita di Padova b, Padova, Italy, Universita di Trento c, Trento, Italy P. Azzia;16, N. Bacchettaa, L. Benatoa;b, D. Biselloa;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, M. Margonia;b, A.T. Meneguzzoa;b, J. Pazzinia;b, N. Pozzobona;b, P. Ronchesea;b, F. Simonettoa;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. 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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. 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, 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 S. Afanasiev, P. Bunin, M. Gavrilenko, I. Golutvin, I. Gorbunov, A. Kamenev, V. Karjavin, A. Lanev, A. Malakhov, V. Matveev37;38, V. Palichik, V. Perelygin, S. Shmatov, S. Shulha, N. Skatchkov, V. Smirnov, N. Voytishin, 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 tute' (MEPhI), Moscow, Russia M. Chadeeva41, V. Rusinov, E. Zhemchugov National Research Nuclear University 'Moscow Engineering Physics InstiP.N. Lebedev Physical Institute, Moscow, Russia V. Andreev, M. Azarkin38, I. Dremin38, M. Kirakosyan, A. Leonidov38, A. Terkulov Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, S. Petrushanko, V. Savrin A. Baskakov, A. Belyaev, E. Boos, V. Bunichev, M. Dubinin42, L. Dudko, A. Gribushin, V. Klyukhin, N. Korneeva, I. Lokhtin, I. Miagkov, S. Obraztsov, M. Per lov, 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 nologicas (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. Kornmayer16, 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. Veres21, M. Verweij, 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, C. Dietz, F. Fiori, W.-S. Hou, Y. Hsiung, Y.F. Liu, R.-S. Lu, M. Min~ano Moya, E. Paganis, 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. Cerci52, S. Damarseckin, Z.S. Demiroglu, C. Dozen, I. Dumanoglu, I.S. Zorbakir, C. Zorbilmez Middle East Technical University, Physics Department, Ankara, Turkey B. Bilin, S. Bilmis, B. Isildak58, G. Karapinar59, M. Yalvac, M. Zeyrek Bogazici University, Istanbul, Turkey E. Gulmez, M. Kaya60, O. Kaya61, E.A. Yetkin62, T. Yetkin63 Istanbul Technical University, Istanbul, Turkey A. Cakir, K. Cankocak, S. Sen64 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. Newbold65, S. Paramesvaran, A. Poll, T. Sakuma, S. Seif El Nasr-storey, D. Smith, Rutherford Appleton Laboratory, Didcot, United Kingdom K.W. Bell, A. Belyaev66, 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. Lucas65, 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 Acosta67, T. Virdee16, 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. 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 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. Wasserbaech68, 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, 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, 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. M.B. Andrews, V. Azzolini, T. Ferguson, M. Paulini, J. Russ, M. Sun, H. Vogel, I. Vorobiev, 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, 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, H. Prosper, A. Santra, R. Yohay Florida Institute of Technology, Melbourne, U.S.A. M.M. Baarmand, V. Bhopatkar, S. Colafranceschi, 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. Bartek72, K. Bloom, D.R. Claes, A. Dominguez72, C. Fangmeier, R. Gon zalez 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, O. Charaf, 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, 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, A. Khatiwada, D.H. Miller, N. Neumeister, J.F. Schulte, X. Shi, J. Sun, F. Wang, W. Xie 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. 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 M.W. Arenton, P. Barria, B. Cox, J. Goodell, R. Hirosky, A. Ledovskoy, H. Li, C. Neu, University of Wisconsin - Madison, Madison, WI, U.S.A. D.A. Belknap, J. Buchanan, 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, 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: Also at Suez University, Suez, Egypt 10: Now at British University in Egypt, Cairo, Egypt 11: Also at Ain Shams University, Cairo, Egypt 12: Now at Helwan University, Cairo, Egypt 13: Also at Universite de Haute Alsace, Mulhouse, France 14: Also at Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 15: Also at Tbilisi State University, Tbilisi, Georgia 16: Also at CERN, European Organization for Nuclear Research, Geneva, Switzerland 17: Also at RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany 18: Also at University of Hamburg, Hamburg, Germany 19: Also at Brandenburg University of Technology, Cottbus, Germany 20: Also at Institute of Nuclear Research ATOMKI, Debrecen, Hungary 21: Also at MTA-ELTE Lendulet CMS Particle and Nuclear Physics Group, Eotvos Lorand 22: Also at Institute of Physics, University of Debrecen, Debrecen, Hungary 23: Also at Indian Institute of Science Education and Research, Bhopal, India 24: Also at Institute of Physics, Bhubaneswar, India 25: Also at University of Visva-Bharati, Santiniketan, India 26: Also at University of Ruhuna, Matara, Sri Lanka 27: Also at Isfahan University of Technology, Isfahan, Iran 28: Also at University of Tehran, Department of Engineering Science, Tehran, 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 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 at National Research Nuclear University 'Moscow Engineering Physics Insti39: 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 Adiyaman University, Adiyaman, Turkey 53: Also at Istanbul Aydin University, Istanbul, Turkey 54: Also at Mersin University, Mersin, Turkey 55: Also at Cag University, Mersin, Turkey 56: Also at Piri Reis University, Istanbul, Turkey 57: Also at Gaziosmanpasa University, Tokat, Turkey 58: Also at Ozyegin University, Istanbul, Turkey 59: Also at Izmir Institute of Technology, Izmir, 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 Yildiz Technical University, Istanbul, Turkey 64: Also at Hacettepe University, Ankara, Turkey 65: Also at Rutherford Appleton Laboratory, Didcot, United Kingdom 66: Also at School of Physics and Astronomy, University of Southampton, Southampton, United 68: Also at Utah Valley University, Orem, U.S.A. 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 [8] CMS collaboration, The CMS Experiment at the CERN LHC, 2008 JINST 3 S08004 [9] J. 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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. Hartmann16, S.M. Heindl, U. Husemann, I. Katkov14, S. Kudella, 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, S. Wayand, M. Weber, T. Weiler, S. Williamson, C. Wohrmann, R. Wolf Italy Italy L. Brianzaa;b;16, F. Brivioa;b, M.E. Dinardoa;b, S. Fiorendia;b;16, S. Gennaia, A. Ghezzia;b, P. Govonia;b, M. Malbertia;b, S. Malvezzia, R.A. Manzonia;b, D. Menascea, L. Moronia, M. Paganonia;b, D. Pedrinia, S. Pigazzinia;b, S. Ragazzia;b, T. Tabarelli de Fatisa;b 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, 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, B. Calpas, 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, Thailand S. Girgis, G. Gokbulut, Y. Guler, I. Hos53, E.E. Kangal54, O. Kara, U. Kiminsu, M. Oglakci, G. Onengut55, K. Ozdemir56, D. 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Search for CP violation in \( t\overline{t} \) production and decay in proton-proton collisions at \( \sqrt{s}=8 \) TeV, Journal of High Energy Physics, 2017, DOI: 10.1007/JHEP03(2017)101