Study of W boson production in pPb collisions at \sqrt{s_{{}_{\mathrm{NN}}}}=5.02\TeV

Study of W boson production in pPb collisions at \TeV


The first study of W boson production in pPb collisions is presented, for bosons decaying to a muon or electron, and a neutrino. The measurements are based on a data sample corresponding to an integrated luminosity of 34.6\nbinvat a nucleon-nucleon centre-of-mass energy of \TeV, collected by the CMS experiment. The W boson differential cross sections, lepton charge asymmetry, and forward-backward asymmetries are measured for leptons of transverse momentum exceeding 25\GeVc, and as a function of the lepton pseudorapidity in the range. Deviations from the expectations based on currently available parton distribution functions are observed, showing the need for including W boson data in nuclear parton distribution global fits.




\RCS \RCS \cmsNoteHeaderHIN-13-007

1 Introduction

Electroweak boson production in proton-nucleus and nucleus-nucleus collisions at the CERN LHC offers a unique opportunity to probe nuclear parton distribution functions (nPDFs) [1, 2, 3, 4]. Leptonic decays of electroweak bosons are of particular interest since leptons do not interact strongly with the medium produced in these collisions [5, 6]. As compared to those in a proton, the nPDFs are expected to be depleted (shadowing) for partons carrying small momentum fractions , and enhanced (anti-shadowing) in the range [7]. However, because of the lack of available data, parton densities are less precisely known for nuclei than for nucleons. As a consequence, precise calculations describing hard processes in high-energy heavy ion collisions are limited by uncertainties in the nPDFs. For \PW boson production, the dominant processes at LHC energies are and , principally reflecting interactions that take place between valence quarks and sea antiquarks. According to Ref. [4], PDF nuclear modifications could affect the yield of \PW bosons in pPb collisions at the LHC by as much as 15% in certain kinematic regions. Therefore, precise measurements of \PW boson production in heavy ion collisions might lead to an improved determination of the nPDFs. Moreover, asymmetries in the individual yields of \PWp and \PWm should permit the flavour decomposition of \cPqu and \cPqd quark distributions in nuclei.

The ATLAS [8, 9] and CMS [10, 11] collaborations reported the observations of \cPZ bosons in heavy ion interactions, at a centre-of-mass energy of 2.76\TeVper nucleon pair. These data showed that the Z boson yields per nucleon–nucleon (NN) collision are essentially unmodified by the medium produced in the collisions. Although \PW bosons decaying to a lepton and a neutrino are more difficult to detect, their rate is about ten times larger than that of \cPZ bosons decaying to leptonic final states. The production of \PW bosons in PbPb collisions was reported by CMS [12] and ATLAS [13], using data corresponding to an integrated luminosity of 7.3 b and 150 b, collected in 2010 and 2011, respectively. The W boson yield per NN collision was shown to be compatible with the one measured in pp collisions, when taking into account isospin effects arising from the mixture of protons and neutrons in the colliding nuclei. However, the presence of 10–20% nPDF effects on \cPZ and \PW boson production could not be excluded due to the relatively large experimental and theoretical uncertainties of these results.

The 2013 pPb LHC run provides the best currently available data sample to look for initial-state effects (such as PDF modifications) using electroweak bosons. The NN-equivalent luminosity is of the same order of magnitude as for the 2011 PbPb run, and the production cross sections are approximately a factor of two greater owing to the increased energy, 5.02\TeVper nucleon pair. Furthermore, the asymmetry of the pPb collision system allows for the measurement of other observables such as forward-backward pseudorapidity asymmetries. This Letter reports a study of \PW boson production in a sample of pPb collisions corresponding to an integrated luminosity of  [14], collected by the CMS experiment.

2 Experimental methods

The direction of the proton beam was initially opposite to the positive direction of the CMS longitudinal axis [15], and was reversed after 60% of the data were taken. The beam energies were 4\TeVfor protons and 1.58\TeVper nucleon for lead nuclei, resulting in a centre-of-mass energy per nucleon pair of \TeV. As a result of the energy difference of the colliding beams, the NN centre-of-mass frame in pPb collisions was not at rest with respect to the laboratory frame. Massless particles emitted at pseudorapidity in the NN centre-of-mass frame are detected at (first proton beam orientation) and (second proton beam orientation) in the CMS coordinate system, as defined in Ref. [15]. The results presented hereafter are expressed in the usual convention of the proton-going side defining the positive pseudorapidity. It coincides with the CMS convention in the second period of data taking, the first one being reversed before summing yields from the two beam configurations.

A detailed description of the CMS detector can be found elsewhere [15]. Its central feature is a superconducting solenoid of 6\unitm internal diameter, providing a magnetic field of 3.8\unitT. Within the field volume are the silicon pixel-and-strip tracker, a lead tungstate crystal electromagnetic calorimeter (ECAL), and a brass and scintillator hadron calorimeter (HCAL), each composed of a barrel and two endcap sections. The silicon tracker consists of 66\unitM pixel and 10\unitM strip sensor elements, and measures charged-particle trajectories in the pseudorapidity range . Outside of the solenoid, muons are detected in the range, with gas-ionization detector planes based on three technologies: drift tubes, cathode strip chambers, and resistive-plate chambers. Electrons are identified in the ECAL, which is made of 75 848 lead tungstate crystals and covers in the barrel and in the two endcap regions. The CMS apparatus also has extensive forward calorimetry, including two steel/quartz-fiber Cherenkov hadron forward (HF) calorimeters, which cover the range. For online event selection, CMS uses a two-level trigger system.

Selection criteria similar to the ones developed in Ref. [16] are applied to the pPb sample to remove events with electromagnetic, beam-gas, or multiple collisions (pileup). The W boson yields are corrected for the induced signal loss.

The primary signature of a boson is a high transverse momentum (\pt) lepton. The current analysis is restricted to leptons of \ptgreater than 25\GeVc. The muon analysis is based on a sample triggered by requiring a single muon with \ptabove 12\GeVc, while the electron analysis uses an ECAL-triggered sample with a transverse energy threshold of 15\GeV. Leptons are reconstructed with the same algorithms as in proton-proton collisions [17, 18], and standard selection criteria are applied, as in Refs. [12, 19]. A special electron charge determination, as described in Ref. [20], is used in order to reduce the electron charge misidentification to a sub-percent level. Events are reconstructed using particle-flow (PF) techniques [21, 22], which reconstruct and classify individual particles with an optimised combination of all subdetector information.

Two criteria are used to remove specific background sources. First, events with two oppositely charged leptons, with the second lepton \ptgreater than 15 (10)\GeVcfor muons (electrons) are removed, since they correspond to well-identified processes like Drell–Yan, \cPZ boson or high-\ptquarkonium production. Second, the leptons are required to be isolated, in order to reduce the contamination coming from jet fragmentation. The energies of all PF candidates are summed within a cone centred around the lepton, with the exception of the lepton itself. The lepton is considered isolated if the total transverse energy in the cone is small compared to its transverse momentum. For muons, a cone of radius is used, where and are the pseudorapidity and azimuthal distances to the lepton. The candidate is rejected if the in-cone transverse energy is greater than 10% of the muon \pt. For electrons, a cone of is used, and only particles with \ptgreater than 1\GeVcare summed, to reduce the underlying-event enhanced contribution. The electron candidate is rejected if the resulting transverse energy is greater than 11.5% (9.5%) of the electron \pt, for the ECAL barrel (endcaps).

An important characteristic of events containing a decay is the missing transverse energy (\ETslash) associated with the undetected neutrino. It is computed as the magnitude of the vectorial sum of transverse momenta of all the PF candidates in the event. The analysis is performed using ten lepton pseudorapidity bins, each 0.5 wide except for the most forward and backward regions (). After having applied the lepton selection criteria, examples of the resulting \ETslashdistributions are shown in Fig. 1 for and , in the most central () and furthest forward () ranges. The distributions for other bins and for the negative leptons are similar.

Figure 1: Missing transverse energy distribution for (left) and (right) events within the (top) and (bottom) ranges. Binned fits to the data (red points) are performed with four contributions, stacked from bottom to top: multijet (QCD, blue), (brown), (white) and (yellow). The regions are defined such that the proton is moving towards positive values. Error bars represent statistical uncertainties. The lower panels display the data divided by the result of the fit, with the band representing the statistical uncertainties on the sum of the fit components, for each \ETslashbin.

To extract the number of events with a lepton coming from a boson, binned fits of these distributions are performed, including the signal and main background contributions, in each bin. The \ETslashshapes assumed for the electroweak processes, namely the signal as well as background from and , are determined by the simulations described hereafter, taking into account the acceptance and efficiency. Their relative normalization is given by the unmodified theoretical cross sections (as computed in Ref. [23]). A maximal 20% variation of the normalization ratio is taken into account, due to potentially different nuclear modifications of the \cPZ and \PW bosons, and resulting in a 1–3% systematic uncertainty in the extracted \PW yields. The noticeable difference between the \ETslashdistributions for the and processes in the forward region (bottom plots of Fig. 1) results from the greater ECAL coverage allowing missed electrons with to be accounted for in the \ETslashcalculation. The shape of the QCD multijet background is modelled by the functional form . It is shown to reproduce the \ETslashshape of data events containing non-isolated leptons, with the , , and parameters, which are observed to depend mildly and linearly on the cone/lepton transverse energy ratio. These fitted parameters are then extrapolated to the isolated lepton signal regime and the resulting function is used as the QCD background shape. The multijet background contribution is larger in the electron channel because the misidentified lepton rate is higher, particularly due to a contribution from photon-jet events. Contributions from other sources, such as production and high-\ptquarkonia, were found to be negligible.

A small charge misidentification correction (less than 0.2%) is applied to the electron yields; this correction is negligible for muons. All fits are of good quality, as illustrated by the bottom panels of Fig. 1 that show the ratio of the data to the fit outcome. The observed numbers of leptons coming from \PW boson decays over the entire pseudorapidity range are:  ,  ,  , and  , where the uncertainty is statistical, determined by the fit procedure.

In order to correct for inefficiencies in the lepton trigger, reconstruction, and selection, the electroweak processes have been simulated using the \PYTHIA6.424 generator [24] with a mixture of pp and pn interactions corresponding to pPb collisions. The detector response to each \PYTHIAsignal event is simulated with \GEANTfour [25] and then embedded in a minimum bias pPb background event. These background events are produced with the hijing event generator [26] and passed through \GEANTfouras well. Each simulation is done twice, once for each proton beam direction, and includes a boost to reproduce the 0.465 rapidity shift. The embedding is done at the level of detector hits, and the signal and background events share the same generated vertex location. The embedded event is then processed through the trigger emulation and the full event reconstruction chain. The resulting reconstructed events are then reweighted to match the distributions observed in data of the event vertex and activity (as measured in the HF calorimeters). The obtained efficiencies vary with (with higher efficiencies at mid-rapidity), from 59% to 89% for muons, and from 51% to 84% for electrons.

The various components of the single-lepton efficiency are also directly computed from pPb data, using samples, and techniques described in Ref. [23]. These efficiencies are then compared to the corresponding efficiencies computed from simulations. In the case of trigger and reconstruction efficiencies, they are found to be consistent. The isolation criterion rejects more leptons in data, because the local activity of the underlying event is greater than in the simulation. To account for such discrepancies, the efficiency from simulation is multiplied by correction factors, which are determined as the ratio of the single-lepton efficiencies measured in data to those estimated in simulations. The so-called “tag-and-probe” method used for this estimation is described in Ref. [27]. These correction factors are computed in bins of and for positively and negatively charged muons separately. In the electron case, the low statistical precision motivates a correction factor estimated for electrons and positrons combined.

The total systematic uncertainty in the lepton yields is estimated by adding the different contributions in quadrature. The -dependent sources of systematic uncertainty arise from the method used for the estimation of multijet background (0.1–2.0% for muons, 0.5–3.8% for electrons), the normalization of the electroweak background (1–3% for muons and electrons), the efficiency correction factors (2.2–7.5% for muons, 2.6–7.4% for electrons), and the energy scale of electrons (0.1–2.0%). The uncertainty in the momentum scale of muons is found to be negligible. The integrated luminosity measurement uncertainty (3.5% [14]) affects only the W boson production cross sections and cancels in the asymmetry measurements, as does the additional global uncertainty arising from the efficiency of the filter rejecting pileup events (0.5% for both channels). Though the common electron/positron correction factors cancel, a residual systematic uncertainty of 3% is assigned to the charge asymmetry, based on simulation studies and -integrated efficiencies determined from data. No other systematic uncertainty cancellations are assumed for the asymmetry results.

3 Results

Figure 2 shows the production cross sections for as a function of the charged lepton pseudorapidity in the laboratory frame, with the lepton having \GeVc. The cross sections are determined by dividing the efficiency-corrected lepton yields by the integrated luminosity.

Figure 2: Production cross sections for (left) and (right), as a function of the lepton pseudorapidity. Error bars represent the statistical uncertainties, while brackets show statistical and systematic uncertainties summed in quadrature. The global luminosity uncertainty of 3.5% is not included. To improve visibility, the muon (electron) measurements, in red circles (blue squares), have been shifted by () in pseudorapidity.

Since the cross sections measured in the electron and muon channels are found to be in good agreement with each other, they are combined using the BLUE method [28]. Figure 3 compares the combined cross sections with next-to-leading-order (NLO) perturbative QCD predictions provided by the authors of Ref. [4] using CT10 [29] proton parton distribution functions (PDF) without or with EPS09 [30] nPDF corrections, termed CT10 and CT10+EPS09, respectively. Their uncertainties are estimated as prescribed in Refs. [29, 30]. Table 3 gives the measured cross sections for each channel separately and combined, as a function of the lepton pseudorapidity, for positive and negative leptons. The theoretical predictions and their uncertainties (coming from the PDF set and from the renormalisation and factorisation scales) are also given. The agreement between the data and both theoretical predictions is within the uncertainties, although a small excess of candidates appears at negative , \iein the Pb ion beam direction.

The comparison between the CT10 and CT10+EPS09 calculations shows that the predicted modifications of the PDFs are of the same order as the theoretical uncertainties. This indicates that cross sections alone lack discriminating power, and motivates the study of various asymmetries of the and cross sections. The interest in such asymmetries is twofold. First, some of the experimental (e.g. integrated luminosity) and theoretical (e.g. scale dependence) uncertainties cancel in such asymmetries. Second, the various asymmetries exhibit different sensitivities to the nuclear modifications of the PDFs, as discussed below.

Figure 3: Production cross sections for (left) and (right), as a function of the lepton pseudorapidity. Error bars represent the statistical uncertainties, while brackets show statistical and systematic uncertainties summed in quadrature. The global luminosity uncertainty of 3.5% is not displayed. Theoretical predictions with (CT10+EPS09, dashed green line) and without (CT10, solid red line) PDF nuclear modifications are also shown, with the uncertainty bands. The bottom panels show the ratio of the data (black points) and CT10+EPS09 (dashed green line) to the CT10 baseline. All theory uncertainty bands include scale and PDF uncertainties, except the EPS09 of the bottom panels which only includes the EPS09 PDF uncertainties.

Production cross section for for positively (top) and negatively (bottom) charged leptons of \ptlarger than 25\GeVc, in nanobarns, as a function of the lepton pseudorapidity. Values are given first for muons and electrons separately, then combined. Quoted uncertainties are first statistical, then systematic. Theoretical predictions with (CT10+EPS09) and without (CT10) PDF nuclear modifications are also given, with their uncertainties. The global normalization uncertainty of 3.5% is not included in the listed uncertainties. (nb) [ bin] CT10+EPS09 CT10 (nb) [ bin] CT10+EPS09 CT10  (nb) [ bin] CT10+EPS09 CT10  (nb) [ bin] CT10+EPS09 CT10

The lepton charge asymmetry, defined as with being the efficiency-corrected lepton yields, is shown in Fig. 4, as a function of , and compared to the theoretical predictions. For , both calculations reproduce the present measurements. For , however, the two calculations overpredict the asymmetry values. A possible physical origin of this disagreement could be a different modification of \cPqu and \cPqd quark distributions in nuclei. In proton-(anti)proton collisions, the W-boson charge asymmetry is known to be a sensitive probe of the down-to-up quark PDF ratio in a proton,  [31, 32, 20]. Similarly, this asymmetry in pPb collisions measured in the lead fragmentation region (\ie) probes these quark densities in a nucleon inside the lead nucleus. Assuming the standard isospin symmetry (, ), one can define a similar ratio, , where are the nPDF ratios, and . The typical quark momentum fraction probed in the Pb nucleus is given by (assuming that the \PW boson rapidity is similar to that of the lepton), therefore in the range . In most global fit analyses of the nPDFs (as in the case of EPS09), it is assumed that the nuclear ratios respect the isospin symmetry, namely , essentially to minimise the number of free parameters in the fits. However, no physical reason prevents nuclear modifications to be different for up and down quark PDFs. For example, it is known that the shapes of the up and down quark distributions in protons are different [33]. Furthermore, the present disparity between data and theory is unlikely to come from the proton PDF assumption, given the excellent agreement of lepton charge asymmetry measured in pp collisions by CMS [32] and ATLAS [34] with NLO calculations using CT10 parton densities.

Figure 4: Lepton charge asymmetry, , as a function of the lepton pseudorapidity. Error bars represent the statistical uncertainties, while brackets show statistical and systematic uncertainties summed in quadrature. Theoretical predictions with (CT10+EPS09, dashed green line) and without (CT10, solid red line) PDF nuclear modifications are also shown, with their uncertainty bands.

A traditional way to probe nuclear parton densities is to compare the forward and backward W yields, that are respectively sensitive to the nPDFs at small and large . The forward-backward asymmetries are shown in Fig. 5, separately for the positively and negatively charged leptons, and compared to the same predictions as mentioned above. Given the experimental accuracy and the magnitude of the differences between the two sets of predictions, the measurements have a potential to discriminate between them. However, although the negative lepton decay channel appears to slightly favour the CT10+EPS09 prediction over the CT10 calculation, the positive lepton channel does not, thus no firm conclusion can be drawn.

Figure 5: Forward-backward asymmetries, , for the positive (left) and negative (right) leptons. Error bars represent the statistical uncertainties, while brackets show statistical and systematic uncertainties summed in quadrature. Theoretical predictions with (CT10+EPS09, dashed green line) and without (CT10, solid red line) PDF nuclear modifications are also shown, with their uncertainty bands.

Another asymmetry variable, , was proposed in Ref. [4] to reach maximum sensitivity to nuclear modifications of PDFs. However, this asymmetry probability distribution shows a very non-Gaussian behaviour, when its denominator approaches zero, and its sign can be flipped within the uncertainty. A different asymmetry is proposed here, , a forward-backward asymmetry of the charge-summed W bosons, which achieves a similar sensitivity. As in the case of the charge asymmetry, this asymmetry can be related to the nuclear modifications of the PDFs within the lead nucleus. Here, forward (backward) W boson production is sensitive to the PDFs of the sea quark at (valence quark at ) in the lead nucleus. Therefore, the forward-backward ratio probes the small- modification of the lead nucleus PDF (shadowing) over the large- modifications (anti-shadowing). This asymmetry is shown in Fig. 6, and deviates from unmodified PDFs, more clearly favouring CT10+EPS09 over CT10.

Figure 6: The forward-backward asymmetry of charge-summed \PW bosons, as a function of the lepton pseudorapidity. Error bars represent the statistical uncertainties, while brackets show statistical and systematic uncertainties summed in quadrature. Theoretical predictions with (CT10+EPS09, dashed green line) and without (CT10, solid red line) PDF nuclear modifications are also shown, with their uncertainty bands.

In order to quantify the agreement between the data and the expectation from the CT10 and CT10+EPS09 calculations, a test is performed for each of the above (correlated) variables. The few correlations in experimental uncertainties described above, only relevant for boson cross sections but not for asymmetries, are taken into account, as well as the correlations in theoretical uncertainties. The resulting values and probabilities are given in Table 3. The CT10+EPS09 calculations provide a better description of the data, with still a relatively low probability for the lepton charge asymmetry, because of the backward region.


Values of the test between the measurements and the theoretical predictions, with (CT10+EPS09) or without (CT10) nuclear modifications of the PDFs. The probability (Prob.) to measure a value greater to that measured in data is also given for ten degrees of freedom in the case of the first three observables and five degrees of freedom for the three others observables. Observable CT10 CT10+EPS09 Prob.(%) Prob.(%) 13 25 8.6 57 15 14 8.2 60 15 12 11 35 3.1 68 3.2 68 9.7 8.4 3.5 63 6.2 29 2.1 83

4 Summary

The first measurement of W boson production in pPb collisions has been reported, using the electron and muon decay modes for leptons of \ptabove 25\GeVcand . The differential cross sections as a function of the lepton pseudorapidity agree with theoretical predictions assuming both unmodified (CT10) and modified (CT10+EPS09) nPDFs, except in the most backward region (Pb ion beam direction), where a hint of an enhancement is seen for the \PWm bosons. In the same region, the related lepton charge asymmetry deviates slightly from the predictions, something that could potentially arise from different nuclear modifications of the up and down quark PDFs. In a related observation, forward-backward asymmetries show a deviation from unmodified PDFs. Taken together, these measurements show the need for including W boson data in nuclear parton distribution global fits.

We congratulate our colleagues in the CERN accelerator departments for the excellent performance of the LHC and thank the technical and administrative staffs at CERN and at other CMS institutes for their contributions to the success of the CMS effort. In addition, we gratefully acknowledge the computing centres and personnel of the Worldwide LHC Computing Grid for delivering so effectively 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); 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); CINVESTAV, CONACYT, 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 (USA). Individuals have received support from the Marie-Curie programme 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 Office; the Fonds pour la Formation à 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 programme of the Foundation for Polish Science, cofinanced from European Union, Regional Development Fund; the Compagnia di San Paolo (Torino); the Consorzio per la Fisica (Trieste); MIUR project 20108T4XTM (Italy); the Thalis and Aristeia programmes cofinanced by EU-ESF and the Greek NSRF; and the National Priorities Research Program by Qatar National Research Fund.

Appendix A The CMS Collaboration

Yerevan Physics Institute, Yerevan, Armenia
V. Khachatryan, A.M. Sirunyan, A. Tumasyan \cmsinstskipInstitut für Hochenergiephysik der OeAW, Wien, Austria
W. Adam, T. Bergauer, M. Dragicevic, J. Erö, M. Friedl, R. Frühwirth\cmsAuthorMark1, V.M. Ghete, C. Hartl, N. Hörmann, J. Hrubec, M. Jeitler\cmsAuthorMark1, W. Kiesenhofer, V. Knünz, M. Krammer\cmsAuthorMark1, I. Krätschmer, D. Liko, I. Mikulec, D. Rabady\cmsAuthorMark2, B. Rahbaran, H. Rohringer, R. Schöfbeck, J. Strauss, W. Treberer-Treberspurg, W. Waltenberger, C.-E. Wulz\cmsAuthorMark1 \cmsinstskipNational Centre for Particle and High Energy Physics, Minsk, Belarus
V. Mossolov, N. Shumeiko, J. Suarez Gonzalez \cmsinstskipUniversiteit Antwerpen, Antwerpen, Belgium
S. Alderweireldt, S. Bansal, T. Cornelis, E.A. De Wolf, X. Janssen, A. Knutsson, J. Lauwers, S. Luyckx, S. Ochesanu, R. Rougny, M. Van De Klundert, H. Van Haevermaet, P. Van Mechelen, N. Van Remortel, A. Van Spilbeeck \cmsinstskipVrije Universiteit Brussel, Brussel, Belgium
F. Blekman, S. Blyweert, J. D’Hondt, N. Daci, N. Heracleous, J. Keaveney, S. Lowette, M. Maes, A. Olbrechts, Q. Python, D. Strom, S. Tavernier, W. Van Doninck, P. Van Mulders, G.P. Van Onsem, I. Villella \cmsinstskipUniversité Libre de Bruxelles, Bruxelles, Belgium
C. Caillol, B. Clerbaux, G. De Lentdecker, D. Dobur, L. Favart, A.P.R. Gay, A. Grebenyuk, A. Léonard, A. Mohammadi, L. Perniè\cmsAuthorMark2, A. Randle-conde, T. Reis, T. Seva, L. Thomas, C. Vander Velde, P. Vanlaer, J. Wang, F. Zenoni \cmsinstskipGhent University, Ghent, Belgium
V. Adler, K. Beernaert, L. Benucci, A. Cimmino, S. Costantini, S. Crucy, S. Dildick, A. Fagot, G. Garcia, J. Mccartin, A.A. Ocampo Rios, D. Poyraz, D. Ryckbosch, S. Salva Diblen, M. Sigamani, N. Strobbe, F. Thyssen, M. Tytgat, E. Yazgan, N. Zaganidis \cmsinstskipUniversité Catholique de Louvain, Louvain-la-Neuve, Belgium
S. Basegmez, C. Beluffi\cmsAuthorMark3, G. Bruno, R. Castello, A. Caudron, L. Ceard, G.G. Da Silveira, C. Delaere, T. du Pree, D. Favart, L. Forthomme, A. Giammanco\cmsAuthorMark4, J. Hollar, A. Jafari, P. Jez, M. Komm, V. Lemaitre, C. Nuttens, L. Perrini, A. Pin, K. Piotrzkowski, A. Popov\cmsAuthorMark5, L. Quertenmont, M. Selvaggi, M. Vidal Marono, J.M. Vizan Garcia \cmsinstskipUniversité de Mons, Mons, Belgium
N. Beliy, T. Caebergs, E. Daubie, G.H. Hammad \cmsinstskipCentro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil
W.L. Aldá Júnior, G.A. Alves, L. Brito, M. Correa Martins Junior, T. Dos Reis Martins, J. Molina, C. Mora Herrera, M.E. Pol, P. Rebello Teles \cmsinstskipUniversidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
W. Carvalho, J. Chinellato\cmsAuthorMark6, A. Custódio, E.M. Da Costa, D. De Jesus Damiao, C. De Oliveira Martins, S. Fonseca De Souza, H. Malbouisson, D. Matos Figueiredo, L. Mundim, H. Nogima, W.L. Prado Da Silva, J. Santaolalla, A. Santoro, A. Sznajder, E.J. Tonelli Manganote\cmsAuthorMark6, A. Vilela Pereira \cmsinstskipUniversidade Estadual Paulista ,  Universidade Federal do ABC ,  São Paulo, Brazil
C.A. Bernardes, S. Dogra, T.R. Fernandez Perez Tomei, E.M. Gregores, P.G. Mercadante, S.F. Novaes, Sandra S. Padula \cmsinstskipInstitute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria
A. Aleksandrov, V. Genchev\cmsAuthorMark2, R. Hadjiiska, P. Iaydjiev, A. Marinov, S. Piperov, M. Rodozov, S. Stoykova, G. Sultanov, M. Vutova \cmsinstskipUniversity of Sofia, Sofia, Bulgaria
A. Dimitrov, I. Glushkov, L. Litov, B. Pavlov, P. Petkov \cmsinstskipInstitute of High Energy Physics, Beijing, China
J.G. Bian, G.M. Chen, H.S. Chen, M. Chen, T. Cheng, R. Du, C.H. Jiang, R. Plestina\cmsAuthorMark7, F. Romeo, J. Tao, Z. Wang \cmsinstskipState Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, China
C. Asawatangtrakuldee, Y. Ban, S. Liu, Y. Mao, S.J. Qian, D. Wang, Z. Xu, L. Zhang, W. Zou \cmsinstskipUniversidad de Los Andes, Bogota, Colombia
C. Avila, A. Cabrera, L.F. Chaparro Sierra, C. Florez, J.P. Gomez, B. Gomez Moreno, J.C. Sanabria \cmsinstskipUniversity of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, Split, Croatia
N. Godinovic, D. Lelas, D. Polic, I. Puljak \cmsinstskipUniversity of Split, Faculty of Science, Split, Croatia
Z. Antunovic, M. Kovac \cmsinstskipInstitute Rudjer Boskovic, Zagreb, Croatia
V. Brigljevic, K. Kadija, J. Luetic, D. Mekterovic, L. Sudic \cmsinstskipUniversity of Cyprus, Nicosia, Cyprus
A. Attikis, G. Mavromanolakis, J. Mousa, C. Nicolaou, F. Ptochos, P.A. Razis \cmsinstskipCharles University, Prague, Czech Republic
M. Bodlak, M. Finger, M. Finger Jr.\cmsAuthorMark8 \cmsinstskipAcademy of Scientific Research and Technology of the Arab Republic of Egypt, Egyptian Network of High Energy Physics, Cairo, Egypt
Y. Assran\cmsAuthorMark9, A. Ellithi Kamel\cmsAuthorMark10, M.A. Mahmoud\cmsAuthorMark11, A. Radi\cmsAuthorMark12\cmsAuthorMark13 \cmsinstskipNational Institute of Chemical Physics and Biophysics, Tallinn, Estonia
M. Kadastik, M. Murumaa, M. Raidal, A. Tiko \cmsinstskipDepartment of Physics, University of Helsinki, Helsinki, Finland
P. Eerola, M. Voutilainen \cmsinstskipHelsinki Institute of Physics, Helsinki, Finland
J. Härkönen, V. Karimäki, R. Kinnunen, M.J. Kortelainen, T. Lampén, K. Lassila-Perini, S. Lehti, T. Lindén, P. Luukka, T. Mäenpää, T. Peltola, E. Tuominen, J. Tuominiemi, E. Tuovinen, L. Wendland \cmsinstskipLappeenranta University of Technology, Lappeenranta, Finland
J. Talvitie, T. Tuuva \cmsinstskipDSM/IRFU, CEA/Saclay, Gif-sur-Yvette, France
M. Besancon, F. Couderc, M. Dejardin, D. Denegri, B. Fabbro, J.L. Faure, C. Favaro, F. Ferri, S. Ganjour, A. Givernaud, P. Gras, G. Hamel de Monchenault, P. Jarry, E. Locci, J. Malcles, J. Rander, A. Rosowsky, M. Titov \cmsinstskipLaboratoire Leprince-Ringuet, Ecole Polytechnique, IN2P3-CNRS, Palaiseau, France
F. Arleo, S. Baffioni, F. Beaudette, P. Busson, E. Chapon, C. Charlot, T. Dahms, M. Dalchenko, L. Dobrzynski, N. Filipovic, A. Florent, R. Granier de Cassagnac, L. Mastrolorenzo, P. Miné, I.N. Naranjo, M. Nguyen, C. Ochando, G. Ortona, P. Paganini, S. Regnard, R. Salerno, J.B. Sauvan, Y. Sirois, C. Veelken, Y. Yilmaz, A. Zabi \cmsinstskipInstitut Pluridisciplinaire Hubert Curien, Université de Strasbourg, Université de Haute Alsace Mulhouse, CNRS/IN2P3, Strasbourg, France
J.-L. Agram\cmsAuthorMark14, J. Andrea, A. Aubin, D. Bloch, J.-M. Brom, E.C. Chabert, C. Collard, E. Conte\cmsAuthorMark14, J.-C. Fontaine\cmsAuthorMark14, D. Gelé, U. Goerlach, C. Goetzmann, A.-C. Le Bihan, K. Skovpen, P. Van Hove \cmsinstskipCentre de Calcul de l’Institut National de Physique Nucleaire et de Physique des Particules, CNRS/IN2P3, Villeurbanne, France
S. Gadrat \cmsinstskipUniversité de Lyon, Université Claude Bernard Lyon 1,  CNRS-IN2P3, Institut de Physique Nucléaire de Lyon, Villeurbanne, France
S. Beauceron, N. Beaupere, C. Bernet\cmsAuthorMark7, G. Boudoul\cmsAuthorMark2, E. Bouvier, S. Brochet, C.A. Carrillo Montoya, J. Chasserat, R. Chierici, D. Contardo\cmsAuthorMark2, P. Depasse, H. El Mamouni, J. Fan, J. Fay, S. Gascon, M. Gouzevitch, B. Ille, T. Kurca, M. Lethuillier, L. Mirabito, S. Perries, J.D. Ruiz Alvarez, D. Sabes, L. Sgandurra, V. Sordini, M. Vander Donckt, P. Verdier, S. Viret, H. Xiao \cmsinstskipInstitute of High Energy Physics and Informatization, Tbilisi State University, Tbilisi, Georgia
Z. Tsamalaidze\cmsAuthorMark8 \cmsinstskipRWTH Aachen University, I. Physikalisches Institut, Aachen, Germany
C. Autermann, S. Beranek, M. Bontenackels, M. Edelhoff, L. Feld, A. Heister, K. Klein, M. Lipinski, A. Ostapchuk, M. Preuten, F. Raupach, J. Sammet, S. Schael, J.F. Schulte, H. Weber, B. Wittmer, V. Zhukov\cmsAuthorMark5 \cmsinstskipRWTH Aachen University, III. Physikalisches Institut A,  Aachen, Germany
M. Ata, M. Brodski, E. Dietz-Laursonn, D. Duchardt, M. Erdmann, R. Fischer, A. Güth, T. Hebbeker, C. Heidemann, K. Hoepfner, D. Klingebiel, S. Knutzen, P. Kreuzer, M. Merschmeyer, A. Meyer, P. Millet, M. Olschewski, K. Padeken, P. Papacz, H. Reithler, S.A. Schmitz, L. Sonnenschein, D. Teyssier, S. Thüer, M. Weber \cmsinstskipRWTH Aachen University, III. Physikalisches Institut B,  Aachen, Germany
V. Cherepanov, Y. Erdogan, G. Flügge, H. Geenen, M. Geisler, W. Haj Ahmad, F. Hoehle, B. Kargoll, T. Kress, Y. Kuessel, A. Künsken, J. Lingemann\cmsAuthorMark2, A. Nowack, I.M. Nugent, O. Pooth, A. Stahl \cmsinstskipDeutsches Elektronen-Synchrotron, Hamburg, Germany
M. Aldaya Martin, I. Asin, N. Bartosik, J. Behr, U. Behrens, A.J. Bell, A. Bethani, K. Borras, A. Burgmeier, A. Cakir, L. Calligaris, A. Campbell, S. Choudhury, F. Costanza, C. Diez Pardos, G. Dolinska, S. Dooling, T. Dorland, G. Eckerlin, D. Eckstein, T. Eichhorn, G. Flucke, J. Garay Garcia, A. Geiser, A. Gizhko, P. Gunnellini, J. Hauk, M. Hempel\cmsAuthorMark15, H. Jung, A. Kalogeropoulos, M. Kasemann, P. Katsas, J. Kieseler, C. Kleinwort, I. Korol, D. Krücker, W. Lange, J. Leonard, K. Lipka, A. Lobanov, W. Lohmann\cmsAuthorMark15, B. Lutz, R. Mankel, I. Marfin\cmsAuthorMark15, I.-A. Melzer-Pellmann, A.B. Meyer, G. Mittag, J. Mnich, A. Mussgiller, S. Naumann-Emme, A. Nayak, E. Ntomari, H. Perrey, D. Pitzl, R. Placakyte, A. Raspereza, P.M. Ribeiro Cipriano, B. Roland, E. Ron, M.Ö. Sahin, J. Salfeld-Nebgen, P. Saxena, T. Schoerner-Sadenius, M. Schröder, C. Seitz, S. Spannagel, A.D.R. Vargas Trevino, R. Walsh, C. Wissing \cmsinstskipUniversity of Hamburg, Hamburg, Germany
V. Blobel, M. Centis Vignali, A.R. Draeger, J. Erfle, E. Garutti, K. Goebel, M. Görner, J. Haller, M. Hoffmann, R.S. Höing, A. Junkes, H. Kirschenmann, R. Klanner, R. Kogler, J. Lange, T. Lapsien, T. Lenz, I. Marchesini, J. Ott, T. Peiffer, A. Perieanu, N. Pietsch, J. Poehlsen, T. Poehlsen, D. Rathjens, C. Sander, H. Schettler, P. Schleper, E. Schlieckau, A. Schmidt, M. Seidel, V. Sola, H. Stadie, G. Steinbrück, D. Troendle, E. Usai, L. Vanelderen, A. Vanhoefer \cmsinstskipInstitut für Experimentelle Kernphysik, Karlsruhe, Germany
C. Barth, C. Baus, J. Berger, C. Böser, E. Butz, T. Chwalek, W. De Boer, A. Descroix, A. Dierlamm, M. Feindt, F. Frensch, M. Giffels, A. Gilbert, F. Hartmann\cmsAuthorMark2, T. Hauth, U. Husemann, I. Katkov\cmsAuthorMark5, A. Kornmayer\cmsAuthorMark2, P. Lobelle Pardo, M.U. Mozer, T. Müller, Th. Müller, A. Nürnberg, G. Quast, K. Rabbertz, S. Röcker, H.J. Simonis, F.M. Stober, R. Ulrich, J. Wagner-Kuhr, S. Wayand, T. Weiler, R. Wolf \cmsinstskipInstitute of Nuclear and Particle Physics (INPP),  NCSR Demokritos, Aghia Paraskevi, Greece
G. Anagnostou, G. Daskalakis, T. Geralis, V.A. Giakoumopoulou, A. Kyriakis, D. Loukas, A. Markou, C. Markou, A. Psallidas, I. Topsis-Giotis \cmsinstskipUniversity of Athens, Athens, Greece
A. Agapitos, S. Kesisoglou, A. Panagiotou, N. Saoulidou, E. Stiliaris \cmsinstskipUniversity of Ioánnina, Ioánnina, Greece
X. Aslanoglou, I. Evangelou, G. Flouris, C. Foudas, P. Kokkas, N. Manthos, I. Papadopoulos, E. Paradas, J. Strologas \cmsinstskipWigner Research Centre for Physics, Budapest, Hungary
G. Bencze, C. Hajdu, P. Hidas, D. Horvath\cmsAuthorMark16, F. Sikler, V. Veszpremi, G. Vesztergombi\cmsAuthorMark17, A.J. Zsigmond \cmsinstskipInstitute of Nuclear Research ATOMKI, Debrecen, Hungary
N. Beni, S. Czellar, J. Karancsi\cmsAuthorMark18, J. Molnar, J. Palinkas, Z. Szillasi \cmsinstskipUniversity of Debrecen, Debrecen, Hungary
A. Makovec, P. Raics, Z.L. Trocsanyi, B. Ujvari \cmsinstskipNational Institute of Science Education and Research, Bhubaneswar, India
S.K. Swain \cmsinstskipPanjab University, Chandigarh, India
S.B. Beri, V. Bhatnagar, R. Gupta, U.Bhawandeep, A.K. Kalsi, M. Kaur, R. Kumar, M. Mittal, N. Nishu, J.B. Singh \cmsinstskipUniversity of Delhi, Delhi, India
Ashok Kumar, Arun Kumar, S. Ahuja, A. Bhardwaj, B.C. Choudhary, A. Kumar, S. Malhotra, M. Naimuddin, K. Ranjan, V. Sharma \cmsinstskipSaha Institute of Nuclear Physics, Kolkata, India
S. Banerjee, S. Bhattacharya, K. Chatterjee, S. Dutta, B. Gomber, Sa. Jain, Sh. Jain, R. Khurana, A. Modak, S. Mukherjee, D. Roy, S. Sarkar, M. Sharan \cmsinstskipBhabha Atomic Research Centre, Mumbai, India
A. Abdulsalam, D. Dutta, V. Kumar, A.K. Mohanty\cmsAuthorMark2, L.M. Pant, P. Shukla, A. Topkar \cmsinstskipTata Institute of Fundamental Research, Mumbai, India
T. Aziz, S. Banerjee, S. Bhowmik\cmsAuthorMark19, R.M. Chatterjee, R.K. Dewanjee, S. Dugad, S. Ganguly, S. Ghosh, M. Guchait, A. Gurtu\cmsAuthorMark20, G. Kole, S. Kumar, M. Maity\cmsAuthorMark19, G. Majumder, K. Mazumdar, G.B. Mohanty, B. Parida, K. Sudhakar, N. Wickramage\cmsAuthorMark21 \cmsinstskipInstitute for Research in Fundamental Sciences (IPM),  Tehran, Iran
H. Bakhshiansohi, H. Behnamian, S.M. Etesami\cmsAuthorMark22, A. Fahim\cmsAuthorMark23, R. Goldouzian, M. Khakzad, M. Mohammadi Najafabadi, M. Naseri, S. Paktinat Mehdiabadi, F. Rezaei Hosseinabadi, B. Safarzadeh\cmsAuthorMark24, M. Zeinali \cmsinstskipUniversity College Dublin, Dublin, Ireland
M. Felcini, M. Grunewald \cmsinstskipINFN Sezione di Bari , Università di Bari , Politecnico di Bari ,  Bari, Italy
M. Abbrescia, C. Calabria, S.S. Chhibra, A. Colaleo, D. Creanza, L. Cristella, N. De Filippis, M. De Palma, L. Fiore, G. Iaselli, G. Maggi, M. Maggi, S. My, S. Nuzzo, A. Pompili, G. Pugliese, R. Radogna\cmsAuthorMark2, G. Selvaggi, A. Sharma, L. Silvestris\cmsAuthorMark2, R. Venditti, P. Verwilligen \cmsinstskipINFN Sezione di Bologna , Università di Bologna ,  Bologna, Italy
G. Abbiendi, A.C. Benvenuti, D. Bonacorsi, S. Braibant-Giacomelli, L. Brigliadori, R. Campanini, P. Capiluppi, A. Castro, F.R. Cavallo, G. Codispoti, M. Cuffiani, G.M. Dallavalle, F. Fabbri, A. Fanfani, D. Fasanella, P. Giacomelli, C. Grandi, L. Guiducci, S. Marcellini, G. Masetti, A. Montanari, F.L. Navarria, A. Perrotta, A.M. Rossi, T. Rovelli, G.P. Siroli, N. Tosi, R. Travaglini \cmsinstskipINFN Sezione di Catania , Università di Catania , CSFNSM ,  Catania, Italy
S. Albergo, G. Cappello, M. Chiorboli, S. Costa, F. Giordano\cmsAuthorMark2, R. Potenza, A. Tricomi, C. Tuve \cmsinstskipINFN Sezione di Firenze , Università di Firenze ,  Firenze, Italy
G. Barbagli, V. Ciulli, C. Civinini, R. D’Alessandro, E. Focardi, E. Gallo, S. Gonzi, V. Gori, P. Lenzi, M. Meschini, S. Paoletti, G. Sguazzoni, A. Tropiano \cmsinstskipINFN Laboratori Nazionali di Frascati, Frascati, Italy
L. Benussi, S. Bianco, F. Fabbri, D. Piccolo \cmsinstskipINFN Sezione di Genova , Università di Genova ,  Genova, Italy
R. Ferretti, F. Ferro, M. Lo Vetere, E. Robutti, S. Tosi \cmsinstskipINFN Sezione di Milano-Bicocca , Università di Milano-Bicocca ,  Milano, Italy
M.E. Dinardo, S. Fiorendi, S. Gennai\cmsAuthorMark2, R. Gerosa\cmsAuthorMark2, A. Ghezzi, P. Govoni, M.T. Lucchini\cmsAuthorMark2, S. Malvezzi, R.A. Manzoni, A. Martelli, B. Marzocchi\cmsAuthorMark2, D. Menasce, L. Moroni, M. Paganoni, D. Pedrini, S. Ragazzi, N. Redaelli, T. Tabarelli de Fatis \cmsinstskipINFN Sezione di Napoli , Università di Napoli ’Federico II’ , Napoli, Italy, Università della Basilicata , Potenza, Italy, Università G. Marconi , Roma, Italy
S. Buontempo, N. Cavallo, S. Di Guida\cmsAuthorMark2, F. Fabozzi, A.O.M. Iorio, L. Lista, S. Meola\cmsAuthorMark2, M. Merola, P. Paolucci\cmsAuthorMark2 \cmsinstskipINFN Sezione di Padova , Università di Padova , Padova, Italy, Università di Trento , Trento, Italy
P. Azzi, N. Bacchetta, D. Bisello, A. Branca, R. Carlin, P. Checchia, M. Dall’Osso, T. Dorigo, U. Gasparini, A. Gozzelino, K. Kanishchev, S. Lacaprara, M. Margoni, A.T. Meneguzzo, J. Pazzini, N. Pozzobon, P. Ronchese, F. Simonetto, E. Torassa, M. Tosi, S. Vanini, S. Ventura, P. Zotto, A. Zucchetta, G. Zumerle \cmsinstskipINFN Sezione di Pavia , Università di Pavia ,  Pavia, Italy
M. Gabusi, S.P. Ratti, V. Re, C. Riccardi, P. Salvini, P. Vitulo \cmsinstskipINFN Sezione di Perugia , Università di Perugia ,  Perugia, Italy
M. Biasini, G.M. Bilei, D. Ciangottini\cmsAuthorMark2, L. Fanò, P. Lariccia, G. Mantovani, M. Menichelli, A. Saha, A. Santocchia, A. Spiezia\cmsAuthorMark2 \cmsinstskipINFN Sezione di Pisa , Università di Pisa , Scuola Normale Superiore di Pisa ,  Pisa, Italy
K. Androsov\cmsAuthorMark25, P. Azzurri, G. Bagliesi, J. Bernardini, T. Boccali, G. Broccolo, R. Castaldi, M.A. Ciocci\cmsAuthorMark25, R. Dell’Orso, S. Donato\cmsAuthorMark2, G. Fedi, F. Fiori, L. Foà, A. Giassi, M.T. Grippo\cmsAuthorMark25, F. Ligabue, T. Lomtadze, L. Martini, A. Messineo, C.S. Moon\cmsAuthorMark26, F. Palla\cmsAuthorMark2, A. Rizzi, A. Savoy-Navarro\cmsAuthorMark27, A.T. Serban, P. Spagnolo, P. Squillacioti\cmsAuthorMark25, R. Tenchini, G. Tonelli, A. Venturi, P.G. Verdini, C. Vernieri \cmsinstskipINFN Sezione di Roma , Università di Roma ,  Roma, Italy
L. Barone, F. Cavallari, G. D’imperio, D. Del Re, M. Diemoz, C. Jorda, E. Longo, F. Margaroli, P. Meridiani, F. Micheli\cmsAuthorMark2, G. Organtini, R. Paramatti, S. Rahatlou, C. Rovelli, F. Santanastasio, L. Soffi, P. Traczyk\cmsAuthorMark2 \cmsinstskipINFN Sezione di Torino , Università di Torino , Torino, Italy, Università del Piemonte Orientale , Novara, Italy
N. Amapane, R. Arcidiacono, S. Argiro, M. Arneodo, R. Bellan, C. Biino, N. Cartiglia, S. Casasso\cmsAuthorMark2, M. Costa, R. Covarelli, A. Degano, N. Demaria, L. Finco\cmsAuthorMark2, C. Mariotti, S. Maselli, G. Mazza, E. Migliore, V. Monaco, M. Musich, M.M. Obertino, L. Pacher, N. Pastrone, M. Pelliccioni, G.L. Pinna Angioni, A. Romero, M. Ruspa, R. Sacchi, A. Solano, A. Staiano, U. Tamponi \cmsinstskipINFN Sezione di Trieste , Università di Trieste ,  Trieste, Italy
S. Belforte, V. Candelise\cmsAuthorMark2, M. Casarsa, F. Cossutti, G. Della Ricca, B. Gobbo, C. La Licata, M. Marone, A. Schizzi, T. Umer, A. Zanetti \cmsinstskipKangwon National University, Chunchon, Korea
S. Chang, A. Kropivnitskaya, S.K. Nam \cmsinstskipKyungpook National University, Daegu, Korea
D.H. Kim, G.N. Kim, M.S. Kim, D.J. Kong, S. Lee, Y.D. Oh, H. Park, A. Sakharov, D.C. Son \cmsinstskipChonbuk National University, Jeonju, Korea
T.J. Kim, M.S. Ryu \cmsinstskipChonnam National University, Institute for Universe and Elementary Particles, Kwangju, Korea
J.Y. Kim, D.H. Moon, S. Song \cmsinstskipKorea University, Seoul, Korea
S. Choi, D. Gyun, B. Hong, M. Jo, H. Kim, Y. Kim, B. Lee, K.S. Lee, S.K. Park, Y. Roh \cmsinstskipSeoul National University, Seoul, Korea
H.D. Yoo \cmsinstskipUniversity of Seoul, Seoul, Korea
M. Choi, J.H. Kim, I.C. Park, G. Ryu \cmsinstskipSungkyunkwan University, Suwon, Korea
Y. Choi, Y.K. Choi, J. Goh, D. Kim, E. Kwon, J. Lee, I. Yu \cmsinstskipVilnius University, Vilnius, Lithuania
A. Juodagalvis \cmsinstskipNational Centre for Particle Physics, Universiti Malaya, Kuala Lumpur, Malaysia
J.R. Komaragiri, M.A.B. Md Ali \cmsinstskipCentro de Investigacion y de Estudios Avanzados del IPN, Mexico City, Mexico
E. Casimiro Linares, H. Castilla-Valdez, E. De La Cruz-Burelo, I. Heredia-de La Cruz, A. Hernandez-Almada, R. Lopez-Fernandez, A. Sanchez-Hernandez \cmsinstskipUniversidad Iberoamericana, Mexico City, Mexico
S. Carrillo Moreno, F. Vazquez Valencia \cmsinstskipBenemerita Universidad Autonoma de Puebla, Puebla, Mexico
I. Pedraza, H.A. Salazar Ibarguen \cmsinstskipUniversidad Autónoma de San Luis Potosí,  San Luis Potosí,  Mexico
A. Morelos Pineda \cmsinstskipUniversity of Auckland, Auckland, New Zealand
D. Krofcheck \cmsinstskipUniversity of Canterbury, Christchurch, New Zealand
P.H. Butler, S. Reucroft \cmsinstskipNational Centre for Physics, Quaid-I-Azam University, Islamabad, Pakistan
A. Ahmad, M. Ahmad, Q. Hassan, H.R. Hoorani, W.A. Khan, T. Khurshid, M. Shoaib \cmsinstskipNational Centre for Nuclear Research, Swierk, Poland
H. Bialkowska, M. Bluj, B. Boimska, T. Frueboes, M. Górski, M. Kazana, K. Nawrocki, K. Romanowska-Rybinska, M. Szleper, P. Zalewski \cmsinstskipInstitute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland
G. Brona, K. Bunkowski, M. Cwiok, W. Dominik, K. Doroba, A. Kalinowski, M. Konecki, J. Krolikowski, M. Misiura, M. Olszewski \cmsinstskipLaboratório de Instrumentação e Física Experimental de Partículas, Lisboa, Portugal
P. Bargassa, C. Beirão Da Cruz E Silva, P. Faccioli, P.G. Ferreira Parracho, M. Gallinaro, L. Lloret Iglesias, F. Nguyen, J. Rodrigues Antunes, J. Seixas, J. Varela, P. Vischia \cmsinstskipJoint Institute for Nuclear Research, Dubna, Russia
S. Afanasiev, P. Bunin, M. Gavrilenko, I. Golutvin, I. Gorbunov, A. Kamenev, V. Karjavin, V. Konoplyanikov, A. Lanev, A. Malakhov, V. Matveev\cmsAuthorMark28, P. Moisenz, V. Palichik, V. Perelygin, S. Shmatov, N. Skatchkov, V. Smirnov, A. Zarubin \cmsinstskipPetersburg Nuclear Physics Institute, Gatchina (St. Petersburg),  Russia
V. Golovtsov, Y. Ivanov, V. Kim\cmsAuthorMark29, E. Kuznetsova, P. Levchenko, V. Murzin, V. Oreshkin, I. Smirnov, V. Sulimov, L. Uvarov, S. Vavilov, A. Vorobyev, An. Vorobyev \cmsinstskipInstitute for Nuclear Research, Moscow, Russia
Yu. Andreev, A. Dermenev, S. Gninenko, N. Golubev, M. Kirsanov, N. Krasnikov, A. Pashenkov, D. Tlisov, A. Toropin \cmsinstskipInstitute for Theoretical and Experimental Physics, Moscow, Russia
V. Epshteyn, V. Gavrilov, N. Lychkovskaya, V. Popov, I. Pozdnyakov, G. Safronov, S. Semenov, A. Spiridonov, V. Stolin, E. Vlasov, A. Zhokin \cmsinstskipP.N. Lebedev Physical Institute, Moscow, Russia
V. Andreev, M. Azarkin\cmsAuthorMark30, I. Dremin\cmsAuthorMark30, M. Kirakosyan, A. Leonidov\cmsAuthorMark30, G. Mesyats, S.V. Rusakov, A. Vinogradov \cmsinstskipSkobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia
A. Belyaev, E. Boos, A. Demiyanov, A. Ershov, A. Gribushin, O. Kodolova, V. Korotkikh, I. Lokhtin, S. Obraztsov, S. Petrushanko, V. Savrin, A. Snigirev, I. Vardanyan \cmsinstskipState Research Center of Russian Federation, Institute for High Energy Physics, Protvino, Russia
I. Azhgirey, I. Bayshev, S. Bitioukov, V. Kachanov, A. Kalinin, D. Konstantinov, V. Krychkine, V. Petrov, R. Ryutin, A. Sobol, L. Tourtchanovitch, S. Troshin, N. Tyurin, A. Uzunian, A. Volkov \cmsinstskipUniversity of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences, Belgrade, Serbia
P. Adzic\cmsAuthorMark31, M. Ekmedzic, J. Milosevic, V. Rekovic \cmsinstskipCentro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT),  Madrid, Spain
J. Alcaraz Maestre, C. Battilana, E. Calvo, M. Cerrada, M. Chamizo Llatas, N. Colino, B. De La Cruz, A. Delgado Peris, D. Domínguez Vázquez, A. Escalante Del Valle, C. Fernandez Bedoya, J.P. Fernández 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. Pérez-Calero Yzquierdo, J. Puerta Pelayo, A. Quintario Olmeda, I. Redondo, L. Romero, M.S. Soares \cmsinstskipUniversidad Autónoma de Madrid, Madrid, Spain
C. Albajar, J.F. de Trocóniz, M. Missiroli, D. Moran \cmsinstskipUniversidad de Oviedo, Oviedo, Spain
H. Brun, J. Cuevas, J. Fernandez Menendez, S. Folgueras, I. Gonzalez Caballero \cmsinstskipInstituto de Física de Cantabria (IFCA),  CSIC-Universidad de Cantabria, Santander, Spain
J.A. Brochero Cifuentes, I.J. Cabrillo, A. Calderon, J. Duarte Campderros, M. Fernandez, G. Gomez, A. Graziano, A. Lopez Virto, J. Marco, R. Marco, C. Martinez Rivero, F. Matorras, F.J. Munoz Sanchez, J. Piedra Gomez, T. Rodrigo, A.Y. Rodríguez-Marrero, A. Ruiz-Jimeno, L. Scodellaro, I. Vila, R. Vilar Cortabitarte \cmsinstskipCERN, European Organization for Nuclear Research, Geneva, Switzerland
D. Abbaneo, E. Auffray, G. Auzinger, M. Bachtis, P. Baillon, A.H. Ball, D. Barney, A. Benaglia, J. Bendavid, L. Benhabib, J.F. Benitez, P. Bloch, A. Bocci, A. Bonato, O. Bondu, C. Botta, H. Breuker, T. Camporesi, G. Cerminara, S. Colafranceschi\cmsAuthorMark32, M. D’Alfonso, D. d’Enterria, A. Dabrowski, A. David, F. De Guio, A. De Roeck, S. De Visscher, E. Di Marco, M. Dobson, M. Dordevic, B. Dorney, N. Dupont-Sagorin, A. Elliott-Peisert, G. Franzoni, W. Funk, D. Gigi, K. Gill, D. Giordano, M. Girone, F. Glege, R. Guida, S. Gundacker, M. Guthoff, J. Hammer, M. Hansen, P. Harris, J. Hegeman, V. Innocente, P. Janot, K. Kousouris, K. Krajczar, P. Lecoq, C. Lourenço, N. Magini, L. Malgeri, M. Mannelli, J. Marrouche, L. Masetti, F. Meijers, S. Mersi, E. Meschi, F. Moortgat, S. Morovic, M. Mulders, L. Orsini, L. Pape, E. Perez, A. Petrilli, G. Petrucciani, A. Pfeiffer, M. Pimiä, D. Piparo, M. Plagge, A. Racz, G. Rolandi\cmsAuthorMark33, M. Rovere, H. Sakulin, C. Schäfer, C. Schwick, A. Sharma, P. Siegrist, P. Silva, M. Simon, P. Sphicas\cmsAuthorMark34, D. Spiga, J. Steggemann, B. Stieger, M. Stoye, Y. Takahashi, D. Treille, A. Tsirou, G.I. Veres\cmsAuthorMark17, N. Wardle, H.K. Wöhri, H. Wollny, W.D. Zeuner \cmsinstskipPaul Scherrer Institut, Villigen, Switzerland
W. Bertl, K. Deiters, W. Erdmann, R. Horisberger, Q. Ingram, H.C. Kaestli, D. Kotlinski, U. Langenegger, D. Renker, T. Rohe \cmsinstskipInstitute for Particle Physics, ETH Zurich, Zurich, Switzerland
F. Bachmair, L. Bäni, L. Bianchini, M.A. Buchmann, B. Casal, N. Chanon, G. Dissertori, M. Dittmar, M. Donegà, M. Dünser, P. Eller, C. Grab, D. Hits, J. Hoss, W. Lustermann, B. Mangano, A.C. Marini, M. Marionneau, P. Martinez Ruiz del Arbol, M. Masciovecchio, D. Meister, N. Mohr, P. Musella, C. Nägeli\cmsAuthorMark35, F. Nessi-Tedaldi, F. Pandolfi, F. Pauss, L. Perrozzi, M. Peruzzi, M. Quittnat, L. Rebane, M. Rossini, A. Starodumov\cmsAuthorMark36, M. Takahashi, K. Theofilatos, R. Wallny, H.A. Weber \cmsinstskipUniversität Zürich, Zurich, Switzerland
C. Amsler\cmsAuthorMark37, M.F. Canelli, V. Chiochia, A. De Cosa, A. Hinzmann, T. Hreus, B. Kilminster, C. Lange, J. Ngadiuba, D. Pinna, P. Robmann, F.J. Ronga, S. Taroni, M. Verzetti, Y. Yang \cmsinstskipNational Central University, Chung-Li, Taiwan
M. Cardaci, K.H. Chen, T.H. Doan, C. Ferro, C.M. Kuo, W. Lin, Y.J. Lu, S.Y. Tseng, R. Volpe, S.S. Yu \cmsinstskipNational Taiwan University (NTU),  Taipei, Taiwan
P. Chang, Y.H. Chang, Y. Chao, K.F. Chen, P.H. Chen, C. Dietz, U. Grundler, W.-S. Hou, Y.F. Liu, R.-S. Lu, E. Petrakou, Y.M. Tzeng, R. Wilken \cmsinstskipChulalongkorn University, Faculty of Science, Department of Physics, Bangkok, Thailand
B. Asavapibhop, G. Singh, N. Srimanobhas, N. Suwonjandee \cmsinstskipCukurova University, Adana, Turkey
A. Adiguzel, M.N. Bakirci\cmsAuthorMark38, S. Cerci\cmsAuthorMark39, C. Dozen, I. Dumanoglu, E. Eskut, S. Girgis, G. Gokbulut, Y. Guler, E. Gurpinar, I. Hos, E.E. Kangal, A. Kayis Topaksu, G. Onengut\cmsAuthorMark40, K. Ozdemir, S. Ozturk\cmsAuthorMark38, A. Polatoz, D. Sunar Cerci\cmsAuthorMark39, B. Tali\cmsAuthorMark39, H. Topakli\cmsAuthorMark38, M. Vergili, C. Zorbilmez \cmsinstskipMiddle East Technical University, Physics Department, Ankara, Turkey
I.V. Akin, B. Bilin, S. Bilmis, H. Gamsizkan\cmsAuthorMark41, B. Isildak\cmsAuthorMark42, G. Karapinar\cmsAuthorMark43, K. Ocalan\cmsAuthorMark44, S. Sekmen, U.E. Surat, M. Yalvac, M. Zeyrek \cmsinstskipBogazici University, Istanbul, Turkey
E.A. Albayrak\cmsAuthorMark45, E. Gülmez, M. Kaya\cmsAuthorMark46, O. Kaya\cmsAuthorMark47, T. Yetkin\cmsAuthorMark48 \cmsinstskipIstanbul Technical University, Istanbul, Turkey
K. Cankocak, F.I. Vardarlı\cmsinstskipNational Scientific Center, Kharkov Institute of Physics and Technology, Kharkov, Ukraine
L. Levchuk, P. Sorokin \cmsinstskipUniversity of Bristol, Bristol, United Kingdom
J.J. Brooke, E. Clement, D. Cussans, H. Flacher, J. Goldstein, M. Grimes, G.P. Heath, H.F. Heath, J. Jacob, L. Kreczko, C. Lucas, Z. Meng, D.M. Newbold\cmsAuthorMark49, S. Paramesvaran, A. Poll, T. Sakuma, S. Seif El Nasr-storey, S. Senkin, V.J. Smith \cmsinstskipRutherford Appleton Laboratory, Didcot, United Kingdom
A. Belyaev\cmsAuthorMark50, C. Brew, R.M. Brown, 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, W.J. Womersley, S.D. Worm \cmsinstskipImperial College, London, United Kingdom
M. Baber, R. Bainbridge, O. Buchmuller, D. Burton, D. Colling, N. Cripps, P. Dauncey, G. Davies, M. Della Negra, P. Dunne, A. Elwood, W. Ferguson, J. Fulcher, D. Futyan, G. Hall, G. Iles, M. Jarvis, G. Karapostoli, M. Kenzie, R. Lane, R. Lucas\cmsAuthorMark49, L. Lyons, A.-M. Magnan, S. Malik, B. Mathias, J. Nash, A. Nikitenko\cmsAuthorMark36, J. Pela, M. Pesaresi, K. Petridis, D.M. Raymond, S. Rogerson, A. Rose, C. Seez, P. Sharp, A. Tapper, M. Vazquez Acosta, T. Virdee, S.C. Zenz \cmsinstskipBrunel University, Uxbridge, United Kingdom
J.E. Cole, P.R. Hobson, A. Khan, P. Kyberd, D. Leggat, D. Leslie, I.D. Reid, P. Symonds, L. Teodorescu, M. Turner \cmsinstskipBaylor University, Waco, USA
J. Dittmann, K. Hatakeyama, A. Kasmi, H. Liu, T. Scarborough, Z. Wu \cmsinstskipThe University of Alabama, Tuscaloosa, USA
O. Charaf, S.I. Cooper, C. Henderson, P. Rumerio \cmsinstskipBoston University, Boston, USA
A. Avetisyan, T. Bose, C. Fantasia, P. Lawson, C. Richardson, J. Rohlf, J. St. John, L. Sulak \cmsinstskipBrown University, Providence, USA
J. Alimena, E. Berry, S. Bhattacharya, G. Christopher, D. Cutts, Z. Demiragli, N. Dhingra, A. Ferapontov, A. Garabedian, U. Heintz, G. Kukartsev, E. Laird, G. Landsberg, M. Luk, M. Narain, M. Segala, T. Sinthuprasith, T. Speer, J. Swanson \cmsinstskipUniversity of California, Davis, Davis, USA
R. Breedon, G. Breto, M. Calderon De La Barca Sanchez, S. Chauhan, M. Chertok, J. Conway, R. Conway, P.T. Cox, R. Erbacher, M. Gardner, W. Ko, R. Lander, M. Mulhearn, D. Pellett, J. Pilot, F. Ricci-Tam, S. Shalhout, J. Smith, M. Squires, D. Stolp, M. Tripathi, S. Wilbur, R. Yohay \cmsinstskipUniversity of California, Los Angeles, USA
R. Cousins, P. Everaerts, C. Farrell, J. Hauser, M. Ignatenko, G. Rakness, E. Takasugi, V. Valuev, M. Weber \cmsinstskipUniversity of California, Riverside, Riverside, USA
K. Burt, R. Clare, J. Ellison, J.W. Gary, G. Hanson, J. Heilman, M. Ivova Rikova, P. Jandir, E. Kennedy, F. Lacroix, O.R. Long, A. Luthra, M. Malberti, M. Olmedo Negrete, A. Shrinivas, S. Sumowidagdo, S. Wimpenny \cmsinstskipUniversity of California, San Diego, La Jolla, USA
J.G. Branson, G.B. Cerati, S. Cittolin, R.T. D’Agnolo, A. Holzner, R. Kelley, D. Klein, J. Letts, I. Macneill, D. Olivito, S. Padhi, C. Palmer, M. Pieri, M. Sani, V. Sharma, S. Simon, M. Tadel, Y. Tu, A. Vartak, C. Welke, F. Würthwein, A. Yagil, G. Zevi Della Porta \cmsinstskipUniversity of California, Santa Barbara, Santa Barbara, USA
D. Barge, J. Bradmiller-Feld, C. Campagnari, T. Danielson, A. Dishaw, V. Dutta, K. Flowers, M. Franco Sevilla, P. Geffert, C. George, F. Golf, L. Gouskos, J. Incandela, C. Justus, N. Mccoll, S.D. Mullin, J. Richman, D. Stuart, W. To, C. West, J. Yoo \cmsinstskipCalifornia Institute of Technology, Pasadena, USA
A. Apresyan, A. Bornheim, J. Bunn, Y. Chen, J. Duarte, A. Mott, H.B. Newman, C. Pena, M. Pierini, M. Spiropulu, J.R. Vlimant, R. Wilkinson, S. Xie, R.Y. Zhu \cmsinstskipCarnegie Mellon University, Pittsburgh, USA
V. Azzolini, A. Calamba, B. Carlson, T. Ferguson, Y. Iiyama, M. Paulini, J. Russ, H. Vogel, I. Vorobiev \cmsinstskipUniversity of Colorado at Boulder, Boulder, USA
J.P. Cumalat, W.T. Ford, A. Gaz, M. Krohn, E. Luiggi Lopez, U. Nauenberg, J.G. Smith, K. Stenson, S.R. Wagner \cmsinstskipCornell University, Ithaca, USA
J. Alexander, A. Chatterjee, J. Chaves, J. Chu, S. Dittmer, N. Eggert, N. Mirman, G. Nicolas Kaufman, J.R. Patterson, A. Ryd, E. Salvati, L. Skinnari, W. Sun, W.D. Teo, J. Thom, J. Thompson, J. Tucker, Y. Weng, L. Winstrom, P. Wittich \cmsinstskipFairfield University, Fairfield, USA
D. Winn \cmsinstskipFermi National Accelerator Laboratory, Batavia, USA
S. Abdullin, M. Albrow, J. Anderson, G. Apollinari, 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. Cihangir, V.D. Elvira, I. Fisk, J. Freeman, E. Gottschalk, L. Gray, D. Green, S. Grünendahl, O. Gutsche, J. Hanlon, D. Hare, R.M. Harris, J. Hirschauer, B. Hooberman, S. Jindariani, M. Johnson, U. Joshi, B. Klima, B. Kreis, S. Kwan, J. Linacre, D. Lincoln, R. Lipton, T. Liu, J. Lykken, K. Maeshima, J.M. Marraffino, V.I. Martinez Outschoorn, S. Maruyama, D. Mason, P. McBride, P. Merkel, K. Mishra, S. Mrenna, S. Nahn, C. Newman-Holmes, V. O’Dell, O. Prokofyev, E. Sexton-Kennedy, S. Sharma, A. Soha, W.J. Spalding, L. Spiegel, L. Taylor, S. Tkaczyk, N.V. Tran, L. Uplegger, E.W. Vaandering, R. Vidal, A. Whitbeck, J. Whitmore, F. Yang \cmsinstskipUniversity of Florida, Gainesville, USA
D. Acosta, P. Avery, P. Bortignon, D. Bourilkov, M. Carver, D. Curry, S. Das, M. De Gruttola, G.P. Di Giovanni, R.D. Field, M. Fisher, I.K. Furic, J. Hugon, J. Konigsberg, A. Korytov, T. Kypreos, J.F. Low, K. Matchev, H. Mei, P. Milenovic\cmsAuthorMark51, G. Mitselmakher, L. Muniz, A. Rinkevicius, L. Shchutska, M. Snowball, D. Sperka, J. Yelton, M. Zakaria \cmsinstskipFlorida International University, Miami, USA
S. Hewamanage, S. Linn, P. Markowitz, G. Martinez, J.L. Rodriguez \cmsinstskipFlorida State University, Tallahassee, USA
T. Adams, A. Askew, J. Bochenek, B. Diamond, J. Haas, S. Hagopian, V. Hagopian, K.F. Johnson, H. Prosper, V. Veeraraghavan, M. Weinberg \cmsinstskipFlorida Institute of Technology, Melbourne, USA
M.M. Baarmand, M. Hohlmann, H. Kalakhety, F. Yumiceva \cmsinstskipUniversity of Illinois at Chicago (UIC),  Chicago, USA
M.R. Adams, L. Apanasevich, D. Berry, R.R. Betts, I. Bucinskaite, R. Cavanaugh, O. Evdokimov, L. Gauthier, C.E. Gerber, D.J. Hofman, P. Kurt, C. O’Brien, I.D. Sandoval Gonzalez, C. Silkworth, P. Turner, N. Varelas \cmsinstskipThe University of Iowa, Iowa City, USA
B. Bilki\cmsAuthorMark52, W. Clarida, K. Dilsiz, M. Haytmyradov, J.-P. Merlo, H. Mermerkaya\cmsAuthorMark53, A. Mestvirishvili, A. Moeller, J. Nachtman, H. Ogul, Y. Onel, F. Ozok\cmsAuthorMark45, A. Penzo, R. Rahmat, S. Sen, P. Tan, E. Tiras, J. Wetzel, K. Yi \cmsinstskipJohns Hopkins University, Baltimore, USA
I. Anderson, B.A. Barnett, B. Blumenfeld, S. Bolognesi, D. Fehling, A.V. Gritsan, P. Maksimovic, C. Martin, M. Swartz, M. Xiao \cmsinstskipThe University of Kansas, Lawrence, USA
P. Baringer, A. Bean, G. Benelli, C. Bruner, J. Gray, R.P. Kenny III, D. Majumder, M. Malek, M. Murray, D. Noonan, S. Sanders, J. Sekaric, R. Stringer, Q. Wang, J.S. Wood \cmsinstskipKansas State University, Manhattan, USA
I. Chakaberia, A. Ivanov, K. Kaadze, S. Khalil, M. Makouski, Y. Maravin, L.K. Saini, N. Skhirtladze, I. Svintradze \cmsinstskipLawrence Livermore National Laboratory, Livermore, USA
J. Gronberg, D. Lange, F. Rebassoo, D. Wright \cmsinstskipUniversity of Maryland, College Park, USA
A. Baden, A. Belloni, B. Calvert, S.C. Eno, J.A. Gomez, N.J. Hadley, S. Jabeen, R.G. Kellogg, T. Kolberg, Y. Lu, A.C. Mignerey, K. Pedro, A. Skuja, M.B. Tonjes, S.C. Tonwar \cmsinstskipMassachusetts Institute of Technology, Cambridge, USA
A. Apyan, R. Barbieri, K. Bierwagen, W. Busza, I.A. Cali, L. Di Matteo, G. Gomez Ceballos, M. Goncharov, D. Gulhan, M. Klute, Y.S. Lai, Y.-J. Lee, A. Levin, P.D. Luckey, C. Paus, D. Ralph, C. Roland, G. Roland, G.S.F. Stephans, K. Sumorok, D. Velicanu, J. Veverka, B. Wyslouch, M. Yang, M. Zanetti, V. Zhukova \cmsinstskipUniversity of Minnesota, Minneapolis, USA
B. Dahmes, A. Gude, S.C. Kao, K. Klapoetke, Y. Kubota, J. Mans, S. Nourbakhsh, N. Pastika, R. Rusack, A. Singovsky, N. Tambe, J. Turkewitz \cmsinstskipUniversity of Mississippi, Oxford, USA
J.G. Acosta, S. Oliveros \cmsinstskipUniversity of Nebraska-Lincoln, Lincoln, USA
E. Avdeeva, K. Bloom, S. Bose, D.R. Claes, A. Dominguez, R. Gonzalez Suarez, J. Keller, D. Knowlton, I. Kravchenko, J. Lazo-Flores, F. Meier, F. Ratnikov, G.R. Snow, M. Zvada \cmsinstskipState University of New York at Buffalo, Buffalo, USA
J. Dolen, A. Godshalk, I. Iashvili, A. Kharchilava, A. Kumar, S. Rappoccio \cmsinstskipNortheastern University, Boston, USA
G. Alverson, E. Barberis, D. Baumgartel, M. Chasco, A. Massironi, D.M. Morse, D. Nash, T. Orimoto, D. Trocino, R.-J. Wang, D. Wood, J. Zhang \cmsinstskipNorthwestern University, Evanston, USA
K.A. Hahn, A. Kubik, N. Mucia, N. Odell, B. Pollack, A. Pozdnyakov, M. Schmitt, S. Stoynev, K. Sung, M. Velasco, S. Won \cmsinstskipUniversity of Notre Dame, Notre Dame, USA
A. Brinkerhoff, K.M. Chan, A. Drozdetskiy, M. Hildreth, C. Jessop, D.J. Karmgard, N. Kellams, K. Lannon, S. Lynch, N. Marinelli, Y. Musienko\cmsAuthorMark28, T. Pearson, M. Planer, R. Ruchti, G. Smith, N. Valls, M. Wayne, M. Wolf, A. Woodard \cmsinstskipThe Ohio State University, Columbus, USA
L. Antonelli, J. Brinson, B. Bylsma, L.S. Durkin, S. Flowers, A. Hart, C. Hill, R. Hughes, K. Kotov, T.Y. Ling, W. Luo, D. Puigh, M. Rodenburg, B.L. Winer, H. Wolfe, H.W. Wulsin \cmsinstskipPrinceton University, Princeton, USA
O. Driga, P. Elmer, J. Hardenbrook, P. Hebda, S.A. Koay, P. Lujan, D. Marlow, T. Medvedeva, M. Mooney, J. Olsen, P. Piroué, X. Quan, H. Saka, D. Stickland\cmsAuthorMark2, C. Tully, J.S. Werner, A. Zuranski \cmsinstskipUniversity of Puerto Rico, Mayaguez, USA
E. Brownson, S. Malik, H. Mendez, J.E. Ramirez Vargas \cmsinstskipPurdue University, West Lafayette, USA
V.E. Barnes, D. Benedetti, D. Bortoletto, M. De Mattia, L. Gutay, Z. Hu, M.K. Jha, M. Jones, K. Jung, M. Kress, N. Leonardo, D.H. Miller, N. Neumeister, F. Primavera, B.C. Radburn-Smith, X. Shi, I. Shipsey, D. Silvers, A. Svyatkovskiy, F. Wang, W. Xie, L. Xu, J. Zablocki \cmsinstskipPurdue University Calumet, Hammond, USA
N. Parashar, J. Stupak \cmsinstskipRice University, Houston, USA
A. Adair, B. Akgun, K.M. Ecklund, F.J.M. Geurts, W. Li, B. Michlin, B.P. Padley, R. Redjimi, J. Roberts, J. Zabel \cmsinstskipUniversity of Rochester, Rochester, USA
B. Betchart, A. Bodek, P. de Barbaro, R. Demina, Y. Eshaq, T. Ferbel, M. Galanti, A. Garcia-Bellido, P. Goldenzweig, J. Han, A. Harel, O. Hindrichs, A. Khukhunaishvili, S. Korjenevski, G. Petrillo, D. Vishnevskiy \cmsinstskipThe Rockefeller University, New York, USA
R. Ciesielski, L. Demortier, K. Goulianos, C. Mesropian \cmsinstskipRutgers, The State University of New Jersey, Piscataway, USA
S. Arora, A. Barker, J.P. Chou, C. Contreras-Campana, E. Contreras-Campana, D. Duggan, D. Ferencek, Y. Gershtein, R. Gray, E. Halkiadakis, D. Hidas, S. Kaplan, A. Lath, S. Panwalkar, M. Park, R. Patel, S. Salur, S. Schnetzer, D. Sheffield, S. Somalwar, R. Stone, S. Thomas, P. Thomassen, M. Walker \cmsinstskipUniversity of Tennessee, Knoxville, USA
K. Rose, S. Spanier, A. York \cmsinstskipTexas A&M University, College Station, USA
O. Bouhali\cmsAuthorMark54, A. Castaneda Hernandez, R. Eusebi, W. Flanagan, J. Gilmore, T. Kamon\cmsAuthorMark55, V. Khotilovich, V. Krutelyov, R. Montalvo, I. Osipenkov, Y. Pakhotin, A. Perloff, J. Roe, A. Rose, A. Safonov, I. Suarez, A. Tatarinov, K.A. Ulmer \cmsinstskipTexas Tech University, Lubbock, USA
N. Akchurin, C. Cowden, J. Damgov, C. Dragoiu, P.R. Dudero, J. Faulkner, K. Kovitanggoon, S. Kunori, S.W. Lee, T. Libeiro, I. Volobouev \cmsinstskipVanderbilt University, Nashville, USA
E. Appelt, A.G. Delannoy, S. Greene, A. Gurrola, W. Johns, C. Maguire, Y. Mao, A. Melo, M. Sharma, P. Sheldon, B. Snook, S. Tuo, J. Velkovska \cmsinstskipUniversity of Virginia, Charlottesville, USA
M.W. Arenton, S. Boutle, B. Cox, B. Francis, J. Goodell, R. Hirosky, A. Ledovskoy, H. Li, C. Lin, C. Neu, J. Wood \cmsinstskipWayne State University, Detroit, USA
C. Clarke, R. Harr, P.E. Karchin, C. Kottachchi Kankanamge Don, P. Lamichhane, J. Sturdy \cmsinstskipUniversity of Wisconsin, Madison, USA
D.A. Belknap, D. Carlsmith, M. Cepeda, S. Dasu, L. Dodd, S. Duric, E. Friis, R. Hall-Wilton, M. Herndon, A. Hervé, P. Klabbers, A. Lanaro, C. Lazaridis, A. Levine, R. Loveless, A. Mohapatra, I. Ojalvo, T. Perry, G.A. Pierro, G. Polese, I. Ross, T. Sarangi, A. Savin, W.H. Smith, D. Taylor, C. Vuosalo, N. Woods \cmsinstskip†: Deceased
1:  Also at Vienna University of Technology, Vienna, Austria
2:  Also at CERN, European Organization for Nuclear Research, Geneva, Switzerland
3:  Also at Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg, Université de Haute Alsace Mulhouse, CNRS/IN2P3, Strasbourg, France
4:  Also at National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
5:  Also at Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia
6:  Also at Universidade Estadual de Campinas, Campinas, Brazil
7:  Also at Laboratoire Leprince-Ringuet, Ecole Polytechnique, IN2P3-CNRS, Palaiseau, France
8:  Also at Joint Institute for Nuclear Research, Dubna, Russia
9:  Also at Suez University, Suez, Egypt
10: Also at Cairo University, Cairo, Egypt
11: Also at Fayoum University, El-Fayoum, Egypt
12: Also at British University in Egypt, Cairo, Egypt
13: Now at Ain Shams University, Cairo, Egypt
14: Also at Université de Haute Alsace, Mulhouse, France
15: Also at Brandenburg University of Technology, Cottbus, Germany
16: Also at Institute of Nuclear Research ATOMKI, Debrecen, Hungary
17: Also at Eötvös Loránd University, Budapest, Hungary
18: Also at University of Debrecen, Debrecen, Hungary
19: Also at University of Visva-Bharati, Santiniketan, India
20: Now at King Abdulaziz University, Jeddah, Saudi Arabia
21: Also at University of Ruhuna, Matara, Sri Lanka
22: Also at Isfahan University of Technology, Isfahan, Iran
23: Also at University of Tehran, Department of Engineering Science, Tehran, Iran
24: Also at Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran, Iran
25: Also at Università degli Studi di Siena, Siena, Italy
26: Also at Centre National de la Recherche Scientifique (CNRS) - IN2P3, Paris, France
27: Also at Purdue University, West Lafayette, USA
28: Also at Institute for Nuclear Research, Moscow, Russia
29: Also at St. Petersburg State Polytechnical University, St. Petersburg, Russia
30: Also at National Research Nuclear University ’Moscow Engineering Physics Institute’ (MEPhI), Moscow, Russia
31: Also at Faculty of Physics, University of Belgrade, Belgrade, Serbia
32: Also at Facoltà Ingegneria, Università di Roma, Roma, Italy
33: Also at Scuola Normale e Sezione dell’INFN, Pisa, Italy
34: Also at University of Athens, Athens, Greece
35: Also at Paul Scherrer Institut, Villigen, Switzerland
36: Also at Institute for Theoretical and Experimental Physics, Moscow, Russia
37: Also at Albert Einstein Center for Fundamental Physics, Bern, Switzerland
38: Also at Gaziosmanpasa University, Tokat, Turkey
39: Also at Adiyaman University, Adiyaman, Turkey
40: Also at Cag University, Mersin, Turkey
41: Also at Anadolu University, Eskisehir, Turkey
42: Also at Ozyegin University, Istanbul, Turkey
43: Also at Izmir Institute of Technology, Izmir, Turkey
44: Also at Necmettin Erbakan University, Konya, Turkey
45: Also at Mimar Sinan University, Istanbul, Istanbul, Turkey
46: Also at Marmara University, Istanbul, Turkey
47: Also at Kafkas University, Kars, Turkey
48: Also at Yildiz Technical University, Istanbul, Turkey
49: Also at Rutherford Appleton Laboratory, Didcot, United Kingdom
50: Also at School of Physics and Astronomy, University of Southampton, Southampton, United Kingdom
51: Also at University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences, Belgrade, Serbia
52: Also at Argonne National Laboratory, Argonne, USA
53: Also at Erzincan University, Erzincan, Turkey
54: Also at Texas A&M University at Qatar, Doha, Qatar
55: Also at Kyungpook National University, Daegu, Korea


  1. V. Kartvelishvili, R. Kvatadze, and R. Shanidze, “On Z and Z + jet production in heavy ion collisions”, Phys. Lett. B 356 (1995) 589, doi:10.1016/0370-2693(95)00865-I, arXiv:hep-ph/9505418.
  2. R. Vogt, “Shadowing effects on vector boson production”, Phys. Rev. C 64 (2001) 044901, doi:10.1103/PhysRevC.64.044901, arXiv:hep-ph/0011242.
  3. X.-F. Zhang and G. I. Fai, “ production as a test of nuclear effects at the LHC”, Phys. Lett. B 545 (2002) 91, doi:10.1016/S0370-2693(02)02558-3, arXiv:hep-ph/0205155.
  4. H. Paukkunen and C. A. Salgado, “Constraints for the nuclear parton distributions from Z and W production at the LHC”, JHEP 03 (2011) 071, doi:10.1007/JHEP03(2011)071, arXiv:1010.5392.
  5. Z. Conesa del Valle et al., “Effect of heavy-quark energy loss on the muon differential production cross-section in Pb-Pb collisions at  TeV”, Phys. Lett. B 663 (2008) 202, doi:10.1016/j.physletb.2008.03.073, arXiv:0712.0051.
  6. Z. Conesa del Valle, “Vector bosons in heavy-ion collisions at the LHC”, Eur. Phys. J. C 61 (2009) 729, doi:10.1140/epjc/s10052-009-0980-8, arXiv:0903.1432.
  7. N. Armesto, “Nuclear shadowing”, J. Phys. G 32 (2006) R367, doi:10.1088/0954-3899/32/11/R01, arXiv:hep-ph/0604108.
  8. ATLAS Collaboration, “Measurement of the centrality dependence of J/ yields and observation of Z production in lead-lead collisions with the ATLAS detector at the LHC”, Phys. Lett. B 697 (2011) 294, doi:10.1016/j.physletb.2011.02.006, arXiv:1012.5419.
  9. ATLAS Collaboration, “Measurement of boson Production in PbPb Collisions at TeV with the ATLAS Detector”, Phys. Rev. Lett. 110 (2013) 022301, doi:10.1103/PhysRevLett.110.022301, arXiv:1210.6486.
  10. CMS Collaboration, “Study of Z boson production in PbPb collisions at nucleon-nucleon centre of mass energy = 2.76 TeV”, Phys. Rev. Lett. 106 (2011) 212301, doi:10.1103/PhysRevLett.106.212301, arXiv:1102.5435.
  11. CMS Collaboration, “Study of Z production in PbPb and pp collisions at = 2.76 TeV in the dimuon and dielectron decay channels”, JHEP 03 (2015) 022, doi:10.1007/JHEP03(2015)022, arXiv:1410.4825.
  12. CMS Collaboration, “Study of boson production in PbPb and pp collisions at TeV”, Phys. Lett. B 715 (2012) 66, doi:10.1016/j.physletb.2012.07.025, arXiv:1205.6334.
  13. ATLAS Collaboration, “Measurement of the production and lepton charge asymmetry of bosons in PbPb collisions at with the ATLAS detector”, Eur. Phys. J. C 75 (2015), no. 1, 23, doi:10.1140/epjc/s10052-014-3231-6, arXiv:1408.4674.
  14. CMS Collaboration, “Luminosity Calibration for the 2013 Proton-Lead and Proton-Proton Data Taking”, CMS Physics Analysis Summary CMS-PAS-LUM-13-002, 2013.
  15. CMS Collaboration, “The CMS experiment at the CERN LHC”, JINST 3 (2008) S08004, doi:10.1088/1748-0221/3/08/S08004.
  16. CMS Collaboration, “Multiplicity and transverse momentum dependence of two- and four-particle correlations in pPb and PbPb collisions”, Phys. Lett. B 724 (2013) 213, doi:10.1016/j.physletb.2013.06.028, arXiv:1305.0609.
  17. CMS Collaboration, “Performance of CMS muon reconstruction in pp collision events at \TeV”, JINST 7 (2012) P10002, doi:10.1088/1748-0221/7/10/P10002.
  18. CMS Collaboration, “Energy calibration and resolution of the CMS electromagnetic calorimeter in pp collisions at  TeV”, JINST 8 (2013) P09009, doi:10.1088/1748-0221/8/09/P09009, arXiv:1306.2016.
  19. CMS Collaboration, “Performance of Electron Reconstruction and Selection with the CMS Detector in Proton-Proton Collisions at √s = 8 TeV”, JINST 10 (2015), no. 06, P06005, doi:10.1088/1748-0221/10/06/P06005, arXiv:1502.02701.
  20. CMS Collaboration, “Measurement of the electron charge asymmetry in inclusive production in pp collisions at  TeV”, Phys. Rev. Lett. 109 (2012) 111806, doi:10.1103/PhysRevLett.109.111806, arXiv:1206.2598.
  21. CMS Collaboration, “Particle–Flow Event Reconstruction in CMS and Performance for Jets, Taus, and \MET”, CMS Physics Analysis Summary CMS-PAS-PFT-09-001, 2009.
  22. CMS Collaboration, “Commissioning of the Particle-flow Event Reconstruction with the first LHC collisions recorded in the CMS detector”, CMS Physics Analysis Summary CMS-PAS-PFT-10-001, 2010.
  23. CMS Collaboration, “Measurement of the Inclusive and Production Cross Sections in pp Collisions at  TeV”, JHEP 10 (2011) 132, doi:10.1007/JHEP10(2011)132, arXiv:1107.4789.
  24. T. Sjöstrand, S. Mrenna, and P. Skands, “PYTHIA 6.4 physics and manual”, JHEP 05 (2006) 026, doi:10.1088/1126-6708/2006/05/026, arXiv:hep-ph/0603175.
  25. GEANT Collaboration, “GEANT4 — A simulation toolkit”, Nucl. Instrum. Meth. A 506 (2003) 250, doi:10.1016/S0168-9002(03)01368-8.
  26. M. Gyulassy and X.-N. Wang, “HIJING 1.0: A Monte Carlo program for parton and particle production in high-energy hadronic and nuclear collisions”, Comput. Phys. Commun. 83 (1994) 307, doi:10.1016/0010-4655(94)90057-4, arXiv:nucl-th/9502021.
  27. CMS Collaboration, “Measurements of Inclusive and Cross Sections in pp Collisions at  TeV”, JHEP 01 (2011) 080, doi:10.1007/JHEP01(2011)080, arXiv:1012.2466.
  28. L. Lyons, D. Gibaut, and P. Clifford, “How to Combine Correlated Estimates of a Single Physical Quantity”, Nucl. Instrum. Meth. A 270 (1988) 110, doi:10.1016/0168-9002(88)90018-6.
  29. H.-L. Lai et al., “New parton distributions for collider physics”, Phys. Rev. D 82 (2010) 074024, doi:10.1103/PhysRevD.82.074024, arXiv:1007.2241.
  30. K. J. Eskola, H. Paukkunen, and C. A. Salgado, “EPS09: A new generation of NLO and LO nuclear parton distribution functions”, JHEP 04 (2009) 065, doi:10.1088/1126-6708/2009/04/065, arXiv:0902.4154.
  31. CDF Collaboration, “Direct Measurement of the Production Charge Asymmetry in Collisions at TeV”, Phys. Rev. Lett. 102 (2009) 181801, doi:10.1103/PhysRevLett.102.181801, arXiv:0901.2169.
  32. CMS Collaboration, “Measurement of the muon charge asymmetry in inclusive pp  production at 7 TeV and an improved determination of light parton distribution functions”, Phys. Rev. D 90 (2014) 032004, doi:10.1103/PhysRevD.90.032004, arXiv:1312.6283.
  33. A. D. Martin, W. J. Stirling, R. S. Thorne, and G. Watt, “Parton distributions for the LHC”, Eur. Phys. J. C 63 (2009) 189, doi:10.1140/epjc/s10052-009-1072-5, arXiv:0901.0002.
  34. ATLAS Collaboration, “Measurement of the Muon Charge Asymmetry from W Bosons Produced in pp Collisions at TeV with the ATLAS detector”, Phys. Lett. B 701 (2011) 31, doi:10.1016/j.physletb.2011.05.024, arXiv:1103.2929.
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