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Azimuthal anisotropy of charged particles at high

transverse momenta in Pb-Pb collisions at √s NN=2.76TeV

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Chatrchyan, S. et al. “Azimuthal Anisotropy of Charged Particles at

High Transverse Momenta in Pb-Pb Collisions at sqrt[s_{NN}]=2.76�

�TeV.” Physical Review Letters 109.2 (2012): 022301. © 2012

Published by the American Physical Society under the terms of the

Creative Commons Attribution 3.0 License. Further distribution

of this work must maintain attribution to the author(s) and the

published article’s title, journal citation, and DOI.

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http://dx.doi.org/10.1103/PhysRevLett.109.022301

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American Physical Society

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http://hdl.handle.net/1721.1/72206

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Azimuthal Anisotropy of Charged Particles at High Transverse Momenta

in Pb-Pb Collisions at

p

ffiffiffiffiffiffiffiffiffi

s

NN

¼ 2:76 TeV

S. Chatrchyan et al.* (CMS Collaboration)

(Received 9 April 2012; published 10 July 2012)

The azimuthal anisotropy of charged particles in Pb-Pb collisions atpffiffiffiffiffiffiffiffisNN¼ 2:76 TeV is measured

with the CMS detector at the LHC over an extended transverse momentum (pT) range up to approximately

60 GeV=c. The data cover both the low-pTregion associated with hydrodynamic flow phenomena and the

high-pTregion where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0–60% most-central events, the

observed v2values are found to first increase with pT, reaching a maximum around pT¼ 3 GeV=c, and

then to gradually decrease to almost zero, with the decline persisting up to at least pT¼ 40 GeV=c over the full centrality range measured.

DOI:10.1103/PhysRevLett.109.022301 PACS numbers: 25.75.Gz, 25.75.Ag, 25.75.Ld

The experiments at the Relativistic Heavy Ion Collider have provided evidence for the formation of a strongly coupled quantum chromodynamics (QCD) state of matter in ultrarelativistic nucleus-nucleus interactions [1–4]. The opaqueness of this matter to high-energy partons leads to a ‘‘jet-quenching’’ phenomenon where the final-state parti-cle yield at high transverse momentum (pT) is found to be suppressed compared to that expected from the scaling of pp collision yields [1–6]. A large energy loss for partons traversing the dense QCD medium is also suggested by the recent observation of a large momentum imbalance of reconstructed back-to-back jets [7–9] in Pb-Pb collisions at the Large Hadron Collider (LHC).

Despite the progress made on the theoretical description of jet quenching in the past decade [10], some of its key properties, such as the detailed path-length dependence of parton energy loss, remain unknown. In addition to measurements of hadron-yield suppression, observables such as the azimuthal anisotropy of high-pT hadrons are needed to differentiate between the theoretical approaches [11–16]. The anisotropy can be characterized by the second-order Fourier harmonic coefficient (v2) in the azi-muthal angle () distribution of the hadron yield, dN=d / 1 þ 2v2cos½2ð  PPÞ, where PP is the event-by-event azimuthal angle of the ‘‘participant plane.’’ In a noncentral heavy-ion collision, the overlap region of the two colliding nuclei has a lenticular shape, and the interacting nucleons in this region are known as

‘‘participants.’’ The participant plane is defined by the beam direction and the short direction of the lenticular region. In general, the participant plane will not contain the reaction impact parameter vector because of fluctua-tions that arise from having a finite number of nucleons. For high-pT particles, an azimuthal anisotropy can be induced if there is stronger suppression of the hadron yield along the long axis than the short axis of the overlap region. The importance of jet-quenching measurements taking into account the jet orientation relative to the geometry of the interaction region was first demonstrated by the PHENIX experiment [17], where the azimuthal anisotropy of high-pT neutral pions (0) was studied up to pT 18 GeV=c in AuAu collisions at ffiffiffiffiffiffiffiffipsNN ¼ 200 GeV.

This Letter presents a study of the azimuthal anisotropy extended to very high pT (up to pT 60 GeV=c) for Pb-Pb collisions at pffiffiffiffiffiffiffiffisNN ¼ 2:76 TeV at the LHC using the Compact Muon Solenoid (CMS) detector. The v2 coefficient is determined as a function of charged particle pT and overlap of the colliding nuclei (centrality) in the pseudorapidity regions ofjj < 1 and 1 < jj < 2, where  ¼  ln½tanð=2Þ and  is the polar angle relative to the counterclockwise beam direction. In the low momentum region (below a few GeV=c), v2 is generally associated with hydrodynamic flow [18], as distinct from the jet energy-loss mechanism believed to dominate at high pT (e.g., above10 GeV=c). By using a single-track high-level trigger, a significantly larger event sample of high-pT tracks than previously available is obtained, providing the first precise measurement of the v2 coefficient above 20 GeV=c in heavy-ion collisions. Our results may impose quantitative constraints on models of the in-medium en-ergy loss of high-pT partons, particularly the influence of the path length and the shape of the interaction region on the energy loss.

*Full author list given at the end of the article.

Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distri-bution of this work must maintain attridistri-bution to the author(s) and the published article’s title, journal citation, and DOI.

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The data used in this analysis correspond to an inte-grated luminosity of150 b1and were recorded during the 2011 LHC heavy-ion running period. A detailed de-scription of the CMS detector can be found in Ref. [19]. Its central feature is a superconducting solenoid of 6 m inter-nal diameter, providing a magnetic field of 3.8 T. Within the field volume are the silicon pixel and strip tracker, the crystal electromagnetic calorimeter, and the brass and scintillator hadron calorimeter. In Pb-Pb collisions, trajec-tories of charged particles with pT> 200 MeV=c are re-constructed in the silicon tracker covering the pseudorapidity regionjj < 2:5, with a track momentum resolution of about 1% at pT¼ 100 GeV=c. In addition, CMS has extensive forward calorimetry, in particular, two steel and quartz-fiber Cˇ erenkov hadronic forward (HF) calorimeters, which cover the pseudorapidity range 2:9 < jj < 5:2. The HF calorimeters are segmented into towers, each of which is a two-dimensional cell with a granularity of 0.5 unit in  and 0.349 rad in .

Minimum bias Pb-Pb events were triggered by coinci-dent signals from both ends of the detector in either the beam scintillator counters at 3:23 < jj < 4:65 or in the HF calorimeters. Events due to noise, cosmic rays, out-of-time triggers, and beam backgrounds were suppressed by requiring a coincidence of the minimum bias trigger with bunches colliding in the interaction region. The trigger has an acceptance of ð97  3Þ% for hadronic inelastic Pb-Pb collisions. Because of hardware limits on the data acquis-ition rate, only a small fraction of all minimum bias triggered events were recorded. To maximize the event sample with high-pT particles emitted in the Pb-Pb colli-sions, a dedicated high-pTsingle-track trigger was imple-mented by using the CMS level-1 (L1) and high-level trigger system. The trajectories of charged particles from the silicon tracker were found online by using a tracking algorithm identical to those employed in the offline track reconstruction, starting with a candidate from the three-layer silicon pixel tracker having pT> 11 GeV=c. For Pb-Pb events with total transverse energy at L1 (L1_ETT) above 100 GeV, a trigger efficiency of above 95% relative to offline reconstructed tracks was achieved for track pT greater than12 GeV=c. For the events with L1_ETT less than 100 GeV, an additional requirement of a calorimeter jet at L1 with pT> 16 GeV=c [8] was imposed in order to reduce the detector readout rate. This resulted in an effi-ciency of about 75% starting at pT 12 GeV=c but in-creasing to almost 100% above pT 20 GeV=c. In this analysis, the minimum bias data sample is used for the v2 measurement of tracks with 1 < pT< 12 GeV=c (also 12 < pT< 20 GeV=c for cross-check purposes), while the high-pTtrack triggered sample is used in the range of pT> 12 GeV=c.

Events are further selected offline by requiring energy deposits in at least three towers in each of the HF calo-rimeters, with at least 3 GeV of energy in each tower, and

the presence of a reconstructed primary vertex containing at least two tracks. These criteria further reduce the back-ground from single-beam interactions (e.g., beam-gas and beam-halo), cosmic muons, and large impact parameter, ultraperipheral collisions that lead to the electromagnetic breakup of one or both Pb nuclei [20]. The reconstructed primary vertex is required to be located within15 cm of the average vertex position along the beam axis and within a radius of 0.02 cm in the transverse plane. The centrality of the Pb-Pb reaction is determined by taking fractions of the total hadronic inelastic cross section, according to percentiles of the distribution of the total energy deposited in the HF calorimeters [8]. The centrality classes used in this analysis are 0–10% (most central), 10%–20%, 20%–30%, 30%–40%, 40%–50%, and 50%–60%, ordered from the highest to the lowest HF energy deposited.

The reconstruction of the primary event vertex and the trajectories of charged particles in Pb-Pb collisions is based on signals in the silicon pixel and strip detectors and described in detail in Ref. [6]. In selecting the charged primary tracks, a set of tight quality selections were im-posed to minimize the contamination from misidentified tracks. These include requirements of a relative momentum uncertainty of less than 5%, at least 13 hits on the track, a normalized 2 for the track fit of less than 0.15 times the number of hits, and transverse and longitudinal track displacements from the primary vertex position less than 3 times the sum in quadrature of the measurement uncertainties. From studies based on Pb-Pb events simu-lated by using HYDJET [21] (version 1.6), the combined geometrical acceptance and reconstruction efficiency of the primary tracks reaches about 66% (50%) atjj < 1:0 (1:0 < jj < 2:0) for the 5% most-central Pb-Pb events, with little dependence on pT. For the peripheral Pb-Pb events, the efficiency is improved by up to 5%, again largely independent of pT. The fraction of misidentified tracks is kept at the 1%–2% level at pT> 2 GeV=c over almost the entire  and centrality ranges. It increases up to 10% for very low pT( 1 GeV=c) particles in the forward (jj  2) region for the 5% most-central Pb-Pb events.

The analysis follows closely the event-plane method described in Ref. [22]. The observed v2 value for a given centrality and pT range is defined by vobs2 ¼ hcos2ð  2Þi, where the average is taken over all parti-cles in all events within a centrality and pT bin. The second-order ‘‘event-plane’’ angle 2 corresponds to the event-by-event azimuthal angle of maximum particle den-sity in Pb-Pb collisions. It is an approximation of the participant-plane anglePP, which is not directly observ-able. The determination of2uses the energy deposited in the HF calorimeters with2¼12tan1

P

iwisinð2iÞ

P

iwicosð2iÞ

, where the weight factor wifor the ith tower at azimuthal angle i is taken as the corresponding transverse energy. The sums are taken over all the towers within a slightly truncated  range of each HF calorimeter coverage. For the v2study in

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this analysis, charged particles detected in the tracker with  > 0 (<0) are correlated with an event plane found by using energy deposited in a region of the HF spanning 5 <  < 3 (3 <  < 5). In this manner, a minimum  gap of 3 units is guaranteed between particles used in the event-plane determination and those for which the v2value is being measured, thereby significantly reducing the effect of other correlations that might exist, such as that from dijets. This  gap is particularly important for the high-pT particle studies.

The resolution of the event plane depends on the central-ity and is limited by the finite number of particles used in its determination. The final v2 coefficient in the event-plane method is evaluated by dividing the observed value vobs2 by a ‘‘resolution-correction’’ factor R, with v2 ¼ vobs2 =R and where R can range from 0 to 1 [23], with a better resolution corresponding to a larger value of R. An event-averaged resolution-correction factor can be found experimentally by extracting separate event-plane angles using particles emitted into three nonoverlapping  regions. In this ‘‘three-subevent’’ technique, which is de-scribed in more detail in Ref. [23], the resolution-correction factor for a given  region (denoted A, with B and C used for the other two  ranges) is found by using

RA¼ ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi hcos½2ðA 2  B2Þihcos½2ðA2  C2Þi hcos½2ðB 2  C2Þi v u u t :

The averages are over all events corresponding to a given centrality bin. Reconstructed tracks with jj < 0:8 and pT> 1 GeV=c are used for the ‘‘third’’  range (denoted C) introduced to determine the resolution of the event planes found by using the HF detectors at5 <  < 3 (denoted A) and 3 <  < 5 (denoted B). In the calculation ofC2, the weight factor wiof the ith track at angle iis taken as the corresponding transverse momentum. The extracted R values for the HF event planes are found to vary between 0.55 and 0.84, reaching a maximum value for events in the 20%–30% centrality bin. The difference in the resolution-correction factors found for the two HF event planes is less than 1%.

The sensitivity of the deduced v2values to the size of the minimum  gap is explored by defining additional event planes with different pseudorapidity ranges. Varying the gap size from 3 to 4 units, the v2 values are found to be consistent within 2:5% (central) or 10% (peripheral). For all systematic studies, relative uncertainties to v2 are quoted. The influence of misidentified tracks is another source of systematic uncertainty at high pT. The v2 of misidentified tracks in data is estimated by using a very loose track selection. By taking the misidentified-track v2 signal, together with the probability of reconstructing a fake track as determined from simulated events, the sys-tematic uncertainty on the observed v2 values is estimated to be1%–3%, depending on pTand centrality. Potential

biases of the events triggered by the high-pT track algo-rithm are investigated. A comparison of v2 results for 12 < pT< 20 GeV=c obtained from minimum bias and high-pT track triggered samples shows a variation of less than1%. To account for nonuniformities in the detector acceptance that can lead to artificial asymmetries in the event-plane angle distribution and thereby also affect the deduced v2 values, a Fourier-analysis-based ‘‘flattening’’ procedure is used [23] where each calculated event-plane angle is shifted slightly to recover a uniform azimuthal distribution of angles [22]. Monte Carlo studies have shown that this flattening procedure fully corrects for non-uniformities in the CMS detector response. The overall systematic uncertainties associated with the event-plane flattening procedure and the resolution-correction determi-nation are found to be less than 1%. Additional uncer-tainties due to track-quality requirements are examined by loosening or tightening the selection criteria described previously and are found to be less than 0:5%. The different systematic sources are added in quadrature to obtain the overall systematic uncertainty in v2.

The results of v2, as a function of pT from 1 to 60 GeV=c for events with centralities ranging from 0–10% (central) to 50%–60% (peripheral), are presented in Fig. 1for jj < 1. The highest pT bin covers a range from 48.0 to 60:8 GeV=c. The new CMS results in this Letter significantly extend the pT reach of v2 measure-ments previously achieved by the ALICE [24], ATLAS [25], and CMS [22] Collaborations. The CMS and ATLAS results based on event-plane analyses using forward calo-rimeters for the event-plane determination show agreement within 2%–3% up to pT 20 GeV=c.

The pT dependence of v2 shows a trend of rapid rise, reaching a maximum at  3 GeV=c, followed by a dra-matic decrease for pT values up to about 10 GeV=c. Beyond pT 10 GeV=c, the v2 values show a much weaker dependence on pT and gradually decrease but remain larger than zero up to at least pT 40 GeV=c. The magnitude of v2at high pTcan probe the path-length (l) dependence of parton energy loss (E), E  l [11–16]. At Relativistic Heavy Ion Collider energies, the 0 v2 data for pT 6–10 GeV=c support a scenario of  ¼ 3 based on AdS/CFT gravity-gauge dual modeling, while the perturbative QCD calculations ( ¼ 1 for colli-sional energy loss and  ¼ 2 for radiative energy loss) seem to underpredict the data [17]. The v2results reported in this Letter extend to a significantly wider pT regime, where particle production is unambiguously dominated by parton fragmentation and energy-loss models are expected to be more applicable. The clear pT dependence of v2 observed at the LHC energy suggests that additional dy-namical modeling of parton modification, particularly by incorporating the proper initial parton energy dependence, is required in order to further examine the path-length dependence of energy loss (i.e.,  parameter).

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Figure2 shows the v2 dependences on the number of participant nucleons (Npart) associated with each centrality bin through a Glauber model calculation. The correspond-ing participant eccentricities of the overlap region vary from 0.46 to 0.093. Different pT bins are shown for two pseudorapidity ranges: jj < 1 and 1 < jj < 2. The re-sults appear to be independent of  in all pTbins within the statistical uncertainties. Also, the v2 values tend to de-crease with increasing collision centrality (i.e., larger Npart) over a wide pT range (although this trend appears to be reversed for 3:2 < pT< 4:0 GeV=c toward very peripheral events). This behavior is expected for low-pT (below a fewGeV=c) particles in the context of the rela-tionship between hydrodynamic flow phenomena and the eccentricity of the initial-state collision geometry. The similar trend observed for very high-pT particles, at least up to pT 48 GeV=c, reflects how the v2 results at high pTare also sensitive to the initial geometry. This indicates that the initial conditions of the hot QCD medium can be further constrained by simultaneously comparing data with

theoretical calculations from both hydrodynamics at low pTand in-medium parton energy loss at high pT.

In summary, the azimuthal anisotropy of charged parti-cles with respect to the event plane has been studied in Pb-Pb collisions atpffiffiffiffiffiffiffiffisNN ¼ 2:76 TeV using the CMS detector. The v2coefficient was determined over a wide range in pT up to approximately60 GeV=c, as a function of collision centrality. The results reported in this Letter significantly improve the statistical precision of previous v2 measure-ments for 12 < pT< 20 GeV=c and explore for the first time the very high-pT region beyond 20 GeV=c. The v2ðpTÞ behavior shows a trend of rapid rise to a maximum at pT 3 GeV=c and a subsequent fall for all centrality andjj ranges. Beyond pT 10 GeV=c, the observed v2 values still show a clear pT dependence but with a more moderate decrease with pT, remaining finite up to at least pT 40 GeV=c. A common trend in the centrality depen-dence of v2is observed for particles over a wide range of pTup to approximately48 GeV=c, suggesting a potential connection to the initial-state geometry. The precision data over a wide kinematic range presented here will provide important constraints on models of parton energy loss,

0.0 0.1 0.2 -1 b µ = 150 int CMS L = 2.76 TeV NN s PbPb |<1 η | |<2 η 1<| < 1.1 GeV/c T 1.0 < p 0.0 0.1 0.2 < 16 GeV/c T 14 < p 100 200 300 0.0 0.1 0.2 < 48 GeV/c T 35.2 < p < 4.0 GeV/c T 3.2 < p < 35.2 GeV/c T 28.8 < p 100 200 300 < 60.8 GeV/c T 48 < p 2 v 2 v 2 v part N Npart

FIG. 2 (color online). The single-particle azimuthal anisotropy

v2 as a function of the number of participating nucleons with

jj < 1 (solid circles) and 1 < jj < 2 (open squares) for six selected pT ranges in Pb-Pb collisions at pffiffiffiffiffiffiffiffisNN¼ 2:76 TeV, measured by the CMS experiment. Error bars denote the statis-tical uncertainties, while the gray bands correspond to the systematic uncertainties. 0.0 0.1 0.2 CMS 2011 |<0.8 η CMS 2010, | ATLAS -1 b µ = 150 int CMS L = 2.76 TeV NN s PbPb |<1 η | 0-10% 0.0 0.1 0.2 20-30% 20 40 0.0 0.1 0.2 40-50% 10-20% 30-40% 20 40 50-60% 2 v 2 v 2 v (GeV/c) T p (GeV/c) T p

FIG. 1 (color online). The single-particle azimuthal anisotropy

v2 as a function of the charged particle transverse momentum

from 1 to60 GeV=c with jj < 1 for six centrality ranges in

Pb-Pb collisions at pffiffiffiffiffiffiffiffisNN¼ 2:76 TeV, measured by the CMS experiment (solid markers). Error bars denote the statistical uncertainties, while the gray bands correspond to the small systematic uncertainties. Comparison to results from the ATLAS (open squares) and CMS (open circles) experiments using data collected in 2010 is also shown.

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particularly in terms of its dependence on the initial con-ditions, parton energy, and path length through the medium.

We congratulate our colleagues in the CERN accelerator departments for the excellent performance of the LHC machine. We thank the technical and administrative staff at CERN and other CMS institutes and acknowledge sup-port from FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); MSI (New Zealand); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MON, RosAtom, RAS, and RFBR (Russia); MSTD (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA).

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W. Carvalho,11A. Custo´dio,11E. M. Da Costa,11C. De Oliveira Martins,11S. Fonseca De Souza,11 D. Matos Figueiredo,11L. Mundim,11H. Nogima,11V. Oguri,11W. L. Prado Da Silva,11A. Santoro,11 S. M. Silva Do Amaral,11L. Soares Jorge,11A. Sznajder,11T. S. Anjos,12,dC. A. Bernardes,12,dF. A. Dias,12,e T. R. Fernandez Perez Tomei,12E. M. Gregores,12,dC. Lagana,12F. Marinho,12P. G. Mercadante,12,dS. F. Novaes,12

Sandra S. Padula,12V. Genchev,13,bP. Iaydjiev,13,bS. Piperov,13M. Rodozov,13S. Stoykova,13G. Sultanov,13 V. Tcholakov,13R. Trayanov,13M. Vutova,13A. Dimitrov,14R. Hadjiiska,14V. Kozhuharov,14L. Litov,14B. Pavlov,14

P. Petkov,14J. G. Bian,15G. M. Chen,15H. S. Chen,15C. H. Jiang,15D. Liang,15S. Liang,15X. Meng,15J. Tao,15 J. Wang,15J. Wang,15X. Wang,15Z. Wang,15H. Xiao,15M. Xu,15J. Zang,15Z. Zhang,15C. Asawatangtrakuldee,16 Y. Ban,16S. Guo,16Y. Guo,16W. Li,16S. Liu,16Y. Mao,16S. J. Qian,16H. Teng,16S. Wang,16B. Zhu,16W. Zou,16 C. Avila,17B. Gomez Moreno,17A. F. Osorio Oliveros,17J. C. Sanabria,17N. Godinovic,18D. Lelas,18R. Plestina,18,f

D. Polic,18I. Puljak,18,bZ. Antunovic,19M. Dzelalija,19M. Kovac,19V. Brigljevic,20S. Duric,20K. Kadija,20 J. Luetic,20S. Morovic,20A. Attikis,21M. Galanti,21G. Mavromanolakis,21J. Mousa,21C. Nicolaou,21F. Ptochos,21

P. A. Razis,21M. Finger,22M. Finger, Jr.,22Y. Assran,23,gS. Elgammal,23A. Ellithi Kamel,23,hS. Khalil,23,i M. A. Mahmoud,23,jA. Radi,23M. Kadastik,24M. Mu¨ntel,24M. Raidal,24L. Rebane,24A. Tiko,24V. Azzolini,25

P. Eerola,25G. Fedi,25M. Voutilainen,25J. Ha¨rko¨nen,26A. Heikkinen,26V. Karima¨ki,26R. Kinnunen,26 M. J. Kortelainen,26T. Lampe´n,26K. Lassila-Perini,26S. Lehti,26T. Linde´n,26P. Luukka,26T. Ma¨enpa¨a¨,26 T. Peltola,26E. Tuominen,26J. Tuominiemi,26E. Tuovinen,26D. Ungaro,26L. Wendland,26K. Banzuzi,27 A. Korpela,27T. Tuuva,27M. Besancon,28S. Choudhury,28M. Dejardin,28D. Denegri,28B. Fabbro,28J. L. Faure,28 F. Ferri,28S. Ganjour,28A. Givernaud,28P. Gras,28G. Hamel de Monchenault,28P. Jarry,28E. Locci,28J. Malcles,28 L. Millischer,28A. Nayak,28J. Rander,28A. Rosowsky,28I. Shreyber,28M. Titov,28S. Baffioni,29F. Beaudette,29

L. Benhabib,29L. Bianchini,29M. Bluj,29,kC. Broutin,29P. Busson,29C. Charlot,29N. Daci,29T. Dahms,29 L. Dobrzynski,29R. Granier de Cassagnac,29M. Haguenauer,29P. Mine´,29C. Mironov,29C. Ochando,29 P. Paganini,29D. Sabes,29R. Salerno,29Y. Sirois,29C. Veelken,29A. Zabi,29J.-L. Agram,30,lJ. Andrea,30D. Bloch,30

D. Bodin,30J.-M. Brom,30M. Cardaci,30E. C. Chabert,30C. Collard,30E. Conte,30,lF. Drouhin,30,lC. Ferro,30 J.-C. Fontaine,30,lD. Gele´,30U. Goerlach,30P. Juillot,30M. Karim,30,lA.-C. Le Bihan,30P. Van Hove,30F. Fassi,31 D. Mercier,31S. Beauceron,32N. Beaupere,32O. Bondu,32G. Boudoul,32H. Brun,32J. Chasserat,32R. Chierici,32,b

D. Contardo,32P. Depasse,32H. El Mamouni,32J. Fay,32S. Gascon,32M. Gouzevitch,32B. Ille,32T. Kurca,32 M. Lethuillier,32L. Mirabito,32S. Perries,32V. Sordini,32S. Tosi,32Y. Tschudi,32P. Verdier,32S. Viret,32 Z. Tsamalaidze,33G. Anagnostou,34S. Beranek,34M. Edelhoff,34L. Feld,34N. Heracleous,34O. Hindrichs,34

R. Jussen,34K. Klein,34J. Merz,34A. Ostapchuk,34A. Perieanu,34F. Raupach,34J. Sammet,34S. Schael,34 D. Sprenger,34H. Weber,34B. Wittmer,34V. Zhukov,34,mM. Ata,35J. Caudron,35E. Dietz-Laursonn,35 D. Duchardt,35M. Erdmann,35A. Gu¨th,35T. Hebbeker,35C. Heidemann,35K. Hoepfner,35T. Klimkovich,35 D. Klingebiel,35P. Kreuzer,35D. Lanske,35,aJ. Lingemann,35C. Magass,35M. Merschmeyer,35A. Meyer,35 M. Olschewski,35P. Papacz,35H. Pieta,35H. Reithler,35S. A. Schmitz,35L. Sonnenschein,35J. Steggemann,35

D. Teyssier,35M. Weber,35M. Bontenackels,36V. Cherepanov,36M. Davids,36G. Flu¨gge,36H. Geenen,36 M. Geisler,36W. Haj Ahmad,36F. Hoehle,36B. Kargoll,36T. Kress,36Y. Kuessel,36A. Linn,36A. Nowack,36

L. Perchalla,36O. Pooth,36J. Rennefeld,36P. Sauerland,36A. Stahl,36M. Aldaya Martin,37J. Behr,37 W. Behrenhoff,37U. Behrens,37M. Bergholz,37,nA. Bethani,37K. Borras,37A. Burgmeier,37A. Cakir,37 L. Calligaris,37A. Campbell,37E. Castro,37F. Costanza,37D. Dammann,37G. Eckerlin,37D. Eckstein,37D. Fischer,37

G. Flucke,37A. Geiser,37I. Glushkov,37S. Habib,37J. Hauk,37H. Jung,37,bM. Kasemann,37P. Katsas,37 C. Kleinwort,37H. Kluge,37A. Knutsson,37M. Kra¨mer,37D. Kru¨cker,37E. Kuznetsova,37W. Lange,37 W. Lohmann,37,nB. Lutz,37R. Mankel,37I. Marfin,37M. Marienfeld,37I.-A. Melzer-Pellmann,37A. B. Meyer,37

J. Mnich,37A. Mussgiller,37S. Naumann-Emme,37J. Olzem,37H. Perrey,37A. Petrukhin,37D. Pitzl,37 A. Raspereza,37P. M. Ribeiro Cipriano,37C. Riedl,37M. Rosin,37J. Salfeld-Nebgen,37R. Schmidt,37,n T. Schoerner-Sadenius,37N. Sen,37A. Spiridonov,37M. Stein,37R. Walsh,37C. Wissing,37C. Autermann,38 V. Blobel,38S. Bobrovskyi,38J. Draeger,38H. Enderle,38J. Erfle,38U. Gebbert,38M. Go¨rner,38T. Hermanns,38 R. S. Ho¨ing,38K. Kaschube,38G. Kaussen,38H. Kirschenmann,38R. Klanner,38J. Lange,38B. Mura,38F. Nowak,38 N. Pietsch,38D. Rathjens,38C. Sander,38H. Schettler,38P. Schleper,38E. Schlieckau,38A. Schmidt,38M. Schro¨der,38

T. Schum,38M. Seidel,38H. Stadie,38G. Steinbru¨ck,38J. Thomsen,38C. Barth,39J. Berger,39T. Chwalek,39 W. De Boer,39A. Dierlamm,39M. Feindt,39M. Guthoff,39,bC. Hackstein,39F. Hartmann,39M. Heinrich,39H. Held,39

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Th. Mu¨ller,39M. Niegel,39A. Nu¨rnberg,39O. Oberst,39A. Oehler,39J. Ott,39T. Peiffer,39G. Quast,39K. Rabbertz,39 F. Ratnikov,39N. Ratnikova,39S. Ro¨cker,39C. Saout,39A. Scheurer,39F.-P. Schilling,39M. Schmanau,39G. Schott,39

H. J. Simonis,39F. M. Stober,39D. Troendle,39R. Ulrich,39J. Wagner-Kuhr,39T. Weiler,39M. Zeise,39 E. B. Ziebarth,39G. Daskalakis,40T. Geralis,40S. Kesisoglou,40A. Kyriakis,40D. Loukas,40I. Manolakos,40 A. Markou,40C. Markou,40C. Mavrommatis,40E. Ntomari,40L. Gouskos,41T. J. Mertzimekis,41A. Panagiotou,41

N. Saoulidou,41I. Evangelou,42C. Foudas,42,bP. Kokkas,42N. Manthos,42I. Papadopoulos,42V. Patras,42 G. Bencze,43C. Hajdu,43,bP. Hidas,43D. Horvath,43,oK. Krajczar,43,pB. Radics,43F. Sikler,43,bV. Veszpremi,43

G. Vesztergombi,43,pN. Beni,44S. Czellar,44J. Molnar,44J. Palinkas,44Z. Szillasi,44J. Karancsi,45P. Raics,45 Z. L. Trocsanyi,45B. Ujvari,45S. B. Beri,46V. Bhatnagar,46N. Dhingra,46R. Gupta,46M. Jindal,46M. Kaur,46 J. M. Kohli,46M. Z. Mehta,46N. Nishu,46L. K. Saini,46A. Sharma,46J. Singh,46S. P. Singh,46S. Ahuja,47

B. C. Choudhary,47A. Kumar,47A. Kumar,47S. Malhotra,47M. Naimuddin,47K. Ranjan,47V. Sharma,47 R. K. Shivpuri,47S. Banerjee,48S. Bhattacharya,48S. Dutta,48B. Gomber,48Sa. Jain,48Sh. Jain,48R. Khurana,48

S. Sarkar,48A. Abdulsalam,49R. K. Choudhury,49D. Dutta,49S. Kailas,49V. Kumar,49A. K. Mohanty,49,b L. M. Pant,49P. Shukla,49T. Aziz,50S. Ganguly,50M. Guchait,50,qA. Gurtu,50M. Maity,50,rG. Majumder,50 K. Mazumdar,50G. B. Mohanty,50B. Parida,50K. Sudhakar,50N. Wickramage,50S. Banerjee,51S. Dugad,51 H. Arfaei,52H. Bakhshiansohi,52,sS. M. Etesami,52,tA. Fahim,52,sM. Hashemi,52H. Hesari,52A. Jafari,52,s M. Khakzad,52A. Mohammadi,52,uM. Mohammadi Najafabadi,52S. Paktinat Mehdiabadi,52B. Safarzadeh,52,v

M. Zeinali,52,tM. Abbrescia,53a,53bL. Barbone,53a,53bC. Calabria,53a,53b,bS. S. Chhibra,53a,53bA. Colaleo,53a D. Creanza,53a,53cN. De Filippis,53a,53c,bM. De Palma,53a,53bL. Fiore,53aG. Iaselli,53a,53cL. Lusito,53a,53b G. Maggi,53a,53cM. Maggi,53aB. Marangelli,53a,53bS. My,53a,53cS. Nuzzo,53a,53bN. Pacifico,53a,53bA. Pompili,53a,53b G. Pugliese,53a,53cG. Selvaggi,53a,53bL. Silvestris,53aG. Singh,53a,53bG. Zito,53aG. Abbiendi,54aA. C. Benvenuti,54a

D. Bonacorsi,54a,54bS. Braibant-Giacomelli,54a,54bL. Brigliadori,54a,54bP. Capiluppi,54a,54bA. Castro,54a,54b F. R. Cavallo,54aM. Cuffiani,54a,54bG. M. Dallavalle,54aF. Fabbri,54aA. Fanfani,54a,54bD. Fasanella,54a,54b,b

P. Giacomelli,54aC. Grandi,54aL. Guiducci,54aS. Marcellini,54aG. Masetti,54aM. Meneghelli,54a,54b,b A. Montanari,54aF. L. Navarria,54a,54bF. Odorici,54aA. Perrotta,54aF. Primavera,54a,54bA. M. Rossi,54a,54b T. Rovelli,54a,54bG. Siroli,54a,54bR. Travaglini,54a,54bS. Albergo,55a,55bG. Cappello,55a,55bM. Chiorboli,55a,55b S. Costa,55a,55bR. Potenza,55a,55bA. Tricomi,55a,55bC. Tuve,55a,55bG. Barbagli,56aV. Ciulli,56a,56bC. Civinini,56a R. D’Alessandro,56a,56bE. Focardi,56a,56bS. Frosali,56a,56bE. Gallo,56aS. Gonzi,56a,56bM. Meschini,56aS. Paoletti,56a

G. Sguazzoni,56aA. Tropiano,56a,bL. Benussi,57S. Bianco,57S. Colafranceschi,57,wF. Fabbri,57D. Piccolo,57 P. Fabbricatore,58R. Musenich,58A. Benaglia,59a,59b,bF. De Guio,59a,59bL. Di Matteo,59a,59b,bS. Fiorendi,59a,59b

S. Gennai,59a,bA. Ghezzi,59a,59bS. Malvezzi,59aR. A. Manzoni,59a,59bA. Martelli,59a,59bA. Massironi,59a,59b,b D. Menasce,59aL. Moroni,59aM. Paganoni,59a,59bD. Pedrini,59aS. Ragazzi,59a,59bN. Redaelli,59aS. Sala,59a T. Tabarelli de Fatis,59a,59bS. Buontempo,60aC. A. Carrillo Montoya,60a,bN. Cavallo,60a,xA. De Cosa,60a,60b O. Dogangun,60a,60bF. Fabozzi,60a,xA. O. M. Iorio,60a,bL. Lista,60aS. Meola,60a,yM. Merola,60a,60bP. Paolucci,60a

P. Azzi,61aN. Bacchetta,61a,bD. Bisello,61a,61bA. Branca,61a,bR. Carlin,61a,61bP. Checchia,61aT. Dorigo,61a U. Dosselli,61aF. Gasparini,61a,61bA. Gozzelino,61aK. Kanishchev,61a,61cS. Lacaprara,61aI. Lazzizzera,61a,61c M. Margoni,61a,61bA. T. Meneguzzo,61a,61bM. Nespolo,61a,bL. Perrozzi,61aN. Pozzobon,61a,61bP. Ronchese,61a,61b

F. Simonetto,61a,61bE. Torassa,61aM. Tosi,61a,61b,bS. Vanini,61a,61bP. Zotto,61a,61bG. Zumerle,61a,61b M. Gabusi,62a,62bS. P. Ratti,62a,62bC. Riccardi,62a,62bP. Torre,62a,62bP. Vitulo,62a,62bG. M. Bilei,63aL. Fano`,63a,63b

P. Lariccia,63a,63bA. Lucaroni,63a,63b,bG. Mantovani,63a,63bM. Menichelli,63aA. Nappi,63a,63bF. Romeo,63a,63b A. Saha,63aA. Santocchia,63a,63bS. Taroni,63a,63b,bP. Azzurri,64a,64cG. Bagliesi,64aT. Boccali,64aG. Broccolo,64a,64c

R. Castaldi,64aR. T. D’Agnolo,64a,64cR. Dell’Orso,64aF. Fiori,64a,64b,bL. Foa`,64a,64cA. Giassi,64aA. Kraan,64a F. Ligabue,64a,64cT. Lomtadze,64aL. Martini,64a,zA. Messineo,64a,64bF. Palla,64aF. Palmonari,64aA. Rizzi,64a,64b

A. T. Serban,64a,aaP. Spagnolo,64aP. Squillacioti,64a,bR. Tenchini,64aG. Tonelli,64a,64b,bA. Venturi,64a,b P. G. Verdini,64aL. Barone,65a,65bF. Cavallari,65aD. Del Re,65a,65b,bM. Diemoz,65aC. Fanelli,65a,65bM. Grassi,65a,b

E. Longo,65a,65bP. Meridiani,65a,bF. Micheli,65a,65bS. Nourbakhsh,65aG. Organtini,65a,65bF. Pandolfi,65a,65b R. Paramatti,65aS. Rahatlou,65a,65bM. Sigamani,65aL. Soffi,65a,65bN. Amapane,66a,66bR. Arcidiacono,66a,66c S. Argiro,66a,66bM. Arneodo,66a,66cC. Biino,66aC. Botta,66a,66bN. Cartiglia,66aR. Castello,66a,66bM. Costa,66a,66b

N. Demaria,66aA. Graziano,66a,66bC. Mariotti,66a,bS. Maselli,66aE. Migliore,66a,66bV. Monaco,66a,66b M. Musich,66a,bM. M. Obertino,66a,66cN. Pastrone,66aM. Pelliccioni,66aA. Potenza,66a,66bA. Romero,66a,66b M. Ruspa,66a,66cR. Sacchi,66a,66bV. Sola,66a,66bA. Solano,66a,66bA. Staiano,66aA. Vilela Pereira,66aS. Belforte,67a

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F. Cossutti,67aG. Della Ricca,67a,67bB. Gobbo,67aM. Marone,67a,67b,bD. Montanino,67a,67b,bA. Penzo,67a A. Schizzi,67a,67bS. G. Heo,68T. Y. Kim,68S. K. Nam,68S. Chang,69J. Chung,69D. H. Kim,69G. N. Kim,69 D. J. Kong,69H. Park,69S. R. Ro,69D. C. Son,69T. Son,69J. Y. Kim,70Zero J. Kim,70S. Song,70H. Y. Jo,71S. Choi,72 D. Gyun,72B. Hong,72M. Jo,72H. Kim,72T. J. Kim,72K. S. Lee,72D. H. Moon,72S. K. Park,72E. Seo,72M. Choi,73 S. Kang,73H. Kim,73J. H. Kim,73C. Park,73I. C. Park,73S. Park,73G. Ryu,73Y. Cho,74Y. Choi,74Y. K. Choi,74 J. Goh,74M. S. Kim,74E. Kwon,74B. Lee,74J. Lee,74S. Lee,74H. Seo,74I. Yu,74M. J. Bilinskas,75I. Grigelionis,75

M. Janulis,75A. Juodagalvis,75H. Castilla-Valdez,76E. De La Cruz-Burelo,76I. Heredia-de La Cruz,76 R. Lopez-Fernandez,76R. Magan˜a Villalba,76J. Martı´nez-Ortega,76A. Sa´nchez-Herna´ndez,76 L. M. Villasenor-Cendejas,76S. Carrillo Moreno,77F. Vazquez Valencia,77H. A. Salazar Ibarguen,78 E. Casimiro Linares,79A. Morelos Pineda,79M. A. Reyes-Santos,79D. Krofcheck,80A. J. Bell,81P. H. Butler,81

R. Doesburg,81S. Reucroft,81H. Silverwood,81M. Ahmad,82M. I. Asghar,82H. R. Hoorani,82S. Khalid,82 W. A. Khan,82T. Khurshid,82S. Qazi,82M. A. Shah,82M. Shoaib,82G. Brona,83K. Bunkowski,83M. Cwiok,83 W. Dominik,83K. Doroba,83A. Kalinowski,83M. Konecki,83J. Krolikowski,83H. Bialkowska,84B. Boimska,84 T. Frueboes,84R. Gokieli,84M. Go´rski,84M. Kazana,84K. Nawrocki,84K. Romanowska-Rybinska,84M. Szleper,84

G. Wrochna,84P. Zalewski,84N. Almeida,85P. Bargassa,85A. David,85P. Faccioli,85P. G. Ferreira Parracho,85 M. Gallinaro,85P. Musella,85J. Seixas,85J. Varela,85P. Vischia,85S. Afanasiev,86I. Belotelov,86P. Bunin,86 M. Gavrilenko,86I. Golutvin,86A. Kamenev,86V. Karjavin,86G. Kozlov,86A. Lanev,86A. Malakhov,86P. Moisenz,86

V. Palichik,86V. Perelygin,86S. Shmatov,86V. Smirnov,86A. Volodko,86A. Zarubin,86S. Evstyukhin,87 V. Golovtsov,87Y. Ivanov,87V. Kim,87P. Levchenko,87V. Murzin,87V. Oreshkin,87I. Smirnov,87V. Sulimov,87

L. Uvarov,87S. Vavilov,87A. Vorobyev,87An. Vorobyev,87Yu. Andreev,88A. Dermenev,88S. Gninenko,88 N. Golubev,88M. Kirsanov,88N. Krasnikov,88V. Matveev,88A. Pashenkov,88D. Tlisov,88A. Toropin,88 V. Epshteyn,89M. Erofeeva,89V. Gavrilov,89M. Kossov,89,bN. Lychkovskaya,89V. Popov,89G. Safronov,89

S. Semenov,89V. Stolin,89E. Vlasov,89A. Zhokin,89A. Belyaev,90E. Boos,90A. Ershov,90A. Gribushin,90 V. Klyukhin,90O. Kodolova,90V. Korotkikh,90I. Lokhtin,90A. Markina,90S. Obraztsov,90M. Perfilov,90 S. Petrushanko,90L. Sarycheva,90,aV. Savrin,90A. Snigirev,90I. Vardanyan,90V. Andreev,91M. Azarkin,91 I. Dremin,91M. Kirakosyan,91A. Leonidov,91G. Mesyats,91S. V. Rusakov,91A. Vinogradov,91I. Azhgirey,92 I. Bayshev,92S. Bitioukov,92V. Grishin,92,bV. Kachanov,92D. Konstantinov,92A. Korablev,92V. Krychkine,92 V. Petrov,92R. Ryutin,92A. Sobol,92L. Tourtchanovitch,92S. Troshin,92N. Tyurin,92A. Uzunian,92A. Volkov,92

P. Adzic,93,bbM. Djordjevic,93M. Ekmedzic,93D. Krpic,93,bbJ. Milosevic,93M. Aguilar-Benitez,94 J. Alcaraz Maestre,94P. Arce,94C. Battilana,94E. Calvo,94M. Cerrada,94M. Chamizo Llatas,94N. Colino,94

B. De La Cruz,94A. Delgado Peris,94C. Diez Pardos,94D. Domı´nguez Va´zquez,94C. Fernandez Bedoya,94 J. P. Ferna´ndez Ramos,94A. Ferrando,94J. Flix,94M. C. Fouz,94P. Garcia-Abia,94O. Gonzalez Lopez,94 S. Goy Lopez,94J. M. Hernandez,94M. I. Josa,94G. Merino,94J. Puerta Pelayo,94I. Redondo,94L. Romero,94

J. Santaolalla,94M. S. Soares,94C. Willmott,94C. Albajar,95G. Codispoti,95J. F. de Troco´niz,95J. Cuevas,96 J. Fernandez Menendez,96S. Folgueras,96I. Gonzalez Caballero,96L. Lloret Iglesias,96J. Piedra Gomez,96,cc

J. M. Vizan Garcia,96J. A. Brochero Cifuentes,97I. J. Cabrillo,97A. Calderon,97S. H. Chuang,97 J. Duarte Campderros,97M. Felcini,97,ddM. Fernandez,97G. Gomez,97J. Gonzalez Sanchez,97C. Jorda,97

P. Lobelle Pardo,97A. Lopez Virto,97J. Marco,97R. Marco,97C. Martinez Rivero,97F. Matorras,97 F. J. Munoz Sanchez,97T. Rodrigo,97A. Y. Rodrı´guez-Marrero,97A. Ruiz-Jimeno,97L. Scodellaro,97 M. Sobron Sanudo,97I. Vila,97R. Vilar Cortabitarte,97D. Abbaneo,98E. Auffray,98G. Auzinger,98P. Baillon,98

A. H. Ball,98D. Barney,98C. Bernet,98,fG. Bianchi,98P. Bloch,98A. Bocci,98A. Bonato,98H. Breuker,98 T. Camporesi,98G. Cerminara,98T. Christiansen,98J. A. Coarasa Perez,98D. D’Enterria,98A. De Roeck,98 S. Di Guida,98M. Dobson,98N. Dupont-Sagorin,98A. Elliott-Peisert,98B. Frisch,98W. Funk,98G. Georgiou,98 M. Giffels,98D. Gigi,98K. Gill,98D. Giordano,98M. Giunta,98F. Glege,98R. Gomez-Reino Garrido,98P. Govoni,98

S. Gowdy,98R. Guida,98M. Hansen,98P. Harris,98C. Hartl,98J. Harvey,98B. Hegner,98A. Hinzmann,98 V. Innocente,98P. Janot,98K. Kaadze,98E. Karavakis,98K. Kousouris,98P. Lecoq,98P. Lenzi,98C. Lourenc¸o,98

T. Ma¨ki,98M. Malberti,98L. Malgeri,98M. Mannelli,98L. Masetti,98F. Meijers,98S. Mersi,98E. Meschi,98 R. Moser,98M. U. Mozer,98M. Mulders,98E. Nesvold,98M. Nguyen,98T. Orimoto,98L. Orsini,98 E. Palencia Cortezon,98E. Perez,98A. Petrilli,98A. Pfeiffer,98M. Pierini,98M. Pimia¨,98D. Piparo,98G. Polese,98

L. Quertenmont,98A. Racz,98W. Reece,98J. Rodrigues Antunes,98G. Rolandi,98,eeT. Rommerskirchen,98 C. Rovelli,98,ffM. Rovere,98H. Sakulin,98F. Santanastasio,98C. Scha¨fer,98C. Schwick,98I. Segoni,98S. Sekmen,98

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A. Sharma,98P. Siegrist,98P. Silva,98M. Simon,98P. Sphicas,98,ggD. Spiga,98M. Spiropulu,98,eM. Stoye,98 A. Tsirou,98G. I. Veres,98,pJ. R. Vlimant,98H. K. Wo¨hri,98S. D. Worm,98,hhW. D. Zeuner,98W. Bertl,99K. Deiters,99

W. Erdmann,99K. Gabathuler,99R. Horisberger,99Q. Ingram,99H. C. Kaestli,99S. Ko¨nig,99D. Kotlinski,99 U. Langenegger,99F. Meier,99D. Renker,99T. Rohe,99J. Sibille,99,iiL. Ba¨ni,100P. Bortignon,100M. A. Buchmann,100 B. Casal,100N. Chanon,100Z. Chen,100A. Deisher,100G. Dissertori,100M. Dittmar,100M. Du¨nser,100J. Eugster,100 K. Freudenreich,100C. Grab,100P. Lecomte,100W. Lustermann,100A. C. Marini,100P. Martinez Ruiz del Arbol,100 N. Mohr,100F. Moortgat,100C. Na¨geli,100,jjP. Nef,100F. Nessi-Tedaldi,100L. Pape,100F. Pauss,100M. Peruzzi,100

F. J. Ronga,100M. Rossini,100L. Sala,100A. K. Sanchez,100A. Starodumov,100,kkB. Stieger,100M. Takahashi,100 L. Tauscher,100,aA. Thea,100K. Theofilatos,100D. Treille,100C. Urscheler,100R. Wallny,100H. A. Weber,100 L. Wehrli,100E. Aguilo,101C. Amsler,101V. Chiochia,101S. De Visscher,101C. Favaro,101M. Ivova Rikova,101 B. Millan Mejias,101P. Otiougova,101P. Robmann,101H. Snoek,101S. Tupputi,101M. Verzetti,101Y. H. Chang,102

K. H. Chen,102A. Go,102C. M. Kuo,102S. W. Li,102W. Lin,102Z. K. Liu,102Y. J. Lu,102D. Mekterovic,102 A. P. Singh,102R. Volpe,102S. S. Yu,102P. Bartalini,103P. Chang,103Y. H. Chang,103Y. W. Chang,103Y. Chao,103

K. F. Chen,103C. Dietz,103U. Grundler,103W.-S. Hou,103Y. Hsiung,103K. Y. Kao,103Y. J. Lei,103R.-S. Lu,103 D. Majumder,103E. Petrakou,103X. Shi,103J. G. Shiu,103Y. M. Tzeng,103M. Wang,103A. Adiguzel,104 M. N. Bakirci,104,llS. Cerci,104,mmC. Dozen,104I. Dumanoglu,104E. Eskut,104S. Girgis,104G. Gokbulut,104I. Hos,104 E. E. Kangal,104G. Karapinar,104A. Kayis Topaksu,104G. Onengut,104K. Ozdemir,104S. Ozturk,104,nnA. Polatoz,104 K. Sogut,104,ooD. Sunar Cerci,104,mmB. Tali,104,mmH. Topakli,104,llL. N. Vergili,104M. Vergili,104I. V. Akin,105 T. Aliev,105B. Bilin,105S. Bilmis,105M. Deniz,105H. Gamsizkan,105A. M. Guler,105K. Ocalan,105A. Ozpineci,105

M. Serin,105R. Sever,105U. E. Surat,105M. Yalvac,105E. Yildirim,105M. Zeyrek,105M. Deliomeroglu,106 E. Gu¨lmez,106B. Isildak,106M. Kaya,106,ppO. Kaya,106,ppS. Ozkorucuklu,106,qqN. Sonmez,106,rrK. Cankocak,107

L. Levchuk,108F. Bostock,109J. J. Brooke,109E. Clement,109D. Cussans,109H. Flacher,109R. Frazier,109 J. Goldstein,109M. Grimes,109G. P. Heath,109H. F. Heath,109L. Kreczko,109S. Metson,109D. M. Newbold,109,hh K. Nirunpong,109A. Poll,109S. Senkin,109V. J. Smith,109T. Williams,109L. Basso,110,ssA. Belyaev,110,ssC. Brew,110 R. M. Brown,110D. J. A. Cockerill,110J. A. Coughlan,110K. Harder,110S. Harper,110J. Jackson,110B. W. Kennedy,110

E. Olaiya,110D. Petyt,110B. C. Radburn-Smith,110C. H. Shepherd-Themistocleous,110I. R. Tomalin,110 W. J. Womersley,110R. Bainbridge,111G. Ball,111R. Beuselinck,111O. Buchmuller,111D. Colling,111N. Cripps,111

M. Cutajar,111P. Dauncey,111G. Davies,111M. Della Negra,111W. Ferguson,111J. Fulcher,111D. Futyan,111 A. Gilbert,111A. Guneratne Bryer,111G. Hall,111Z. Hatherell,111J. Hays,111G. Iles,111M. Jarvis,111 G. Karapostoli,111L. Lyons,111A.-M. Magnan,111J. Marrouche,111B. Mathias,111R. Nandi,111J. Nash,111

A. Nikitenko,111,kkA. Papageorgiou,111J. Pela,111,bM. Pesaresi,111K. Petridis,111M. Pioppi,111,tt D. M. Raymond,111S. Rogerson,111N. Rompotis,111A. Rose,111M. J. Ryan,111C. Seez,111P. Sharp,111,a A. Sparrow,111A. Tapper,111M. Vazquez Acosta,111T. Virdee,111S. Wakefield,111N. Wardle,111T. Whyntie,111 M. Barrett,112M. Chadwick,112J. E. Cole,112P. R. Hobson,112A. Khan,112P. Kyberd,112D. Leggat,112D. Leslie,112

W. Martin,112I. D. Reid,112P. Symonds,112L. Teodorescu,112M. Turner,112K. Hatakeyama,113H. Liu,113 T. Scarborough,113C. Henderson,114P. Rumerio,114A. Avetisyan,115T. Bose,115C. Fantasia,115A. Heister,115 J. St. John,115P. Lawson,115D. Lazic,115J. Rohlf,115D. Sperka,115L. Sulak,115J. Alimena,116S. Bhattacharya,116

D. Cutts,116A. Ferapontov,116U. Heintz,116S. Jabeen,116G. Kukartsev,116G. Landsberg,116M. Luk,116 M. Narain,116D. Nguyen,116M. Segala,116T. Sinthuprasith,116T. Speer,116K. V. Tsang,116R. Breedon,117 G. Breto,117M. Calderon De La Barca Sanchez,117S. Chauhan,117M. Chertok,117J. Conway,117R. Conway,117

P. T. Cox,117J. Dolen,117R. Erbacher,117M. Gardner,117R. Houtz,117W. Ko,117A. Kopecky,117R. Lander,117 O. Mall,117T. Miceli,117R. Nelson,117D. Pellett,117B. Rutherford,117M. Searle,117J. Smith,117M. Squires,117

M. Tripathi,117R. Vasquez Sierra,117V. Andreev,118D. Cline,118R. Cousins,118J. Duris,118S. Erhan,118 P. Everaerts,118C. Farrell,118J. Hauser,118M. Ignatenko,118C. Plager,118G. Rakness,118P. Schlein,118,aJ. Tucker,118

V. Valuev,118M. Weber,118J. Babb,119R. Clare,119M. E. Dinardo,119J. Ellison,119J. W. Gary,119F. Giordano,119 G. Hanson,119G. Y. Jeng,119,uuH. Liu,119O. R. Long,119A. Luthra,119H. Nguyen,119S. Paramesvaran,119 J. Sturdy,119S. Sumowidagdo,119R. Wilken,119S. Wimpenny,119W. Andrews,120J. G. Branson,120G. B. Cerati,120

S. Cittolin,120D. Evans,120F. Golf,120A. Holzner,120R. Kelley,120M. Lebourgeois,120J. Letts,120I. Macneill,120 B. Mangano,120J. Muelmenstaedt,120S. Padhi,120C. Palmer,120G. Petrucciani,120M. Pieri,120R. Ranieri,120 M. Sani,120V. Sharma,120S. Simon,120E. Sudano,120M. Tadel,120Y. Tu,120A. Vartak,120S. Wasserbaech,120,vv

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T. Danielson,121K. Flowers,121P. Geffert,121J. Incandela,121C. Justus,121P. Kalavase,121S. A. Koay,121 D. Kovalskyi,121,bV. Krutelyov,121S. Lowette,121N. Mccoll,121V. Pavlunin,121F. Rebassoo,121J. Ribnik,121 J. Richman,121R. Rossin,121D. Stuart,121W. To,121C. West,121A. Apresyan,122A. Bornheim,122Y. Chen,122 E. Di Marco,122J. Duarte,122M. Gataullin,122Y. Ma,122A. Mott,122H. B. Newman,122C. Rogan,122V. Timciuc,122 P. Traczyk,122J. Veverka,122R. Wilkinson,122Y. Yang,122R. Y. Zhu,122B. Akgun,123R. Carroll,123T. Ferguson,123 Y. Iiyama,123D. W. Jang,123Y. F. Liu,123M. Paulini,123H. Vogel,123I. Vorobiev,123J. P. Cumalat,124B. R. Drell,124 C. J. Edelmaier,124W. T. Ford,124A. Gaz,124B. Heyburn,124E. Luiggi Lopez,124J. G. Smith,124K. Stenson,124 K. A. Ulmer,124S. R. Wagner,124L. Agostino,125J. Alexander,125A. Chatterjee,125N. Eggert,125L. K. Gibbons,125

B. Heltsley,125W. Hopkins,125A. Khukhunaishvili,125B. Kreis,125N. Mirman,125G. Nicolas Kaufman,125 J. R. Patterson,125A. Ryd,125E. Salvati,125W. Sun,125W. D. Teo,125J. Thom,125J. Thompson,125J. Vaughan,125

Y. Weng,125L. Winstrom,125P. Wittich,125D. Winn,126S. Abdullin,127M. Albrow,127J. Anderson,127 L. A. T. Bauerdick,127A. Beretvas,127J. Berryhill,127P. C. Bhat,127I. Bloch,127K. Burkett,127J. N. Butler,127 V. Chetluru,127H. W. K. Cheung,127F. Chlebana,127V. D. Elvira,127I. Fisk,127J. Freeman,127Y. Gao,127D. Green,127

O. Gutsche,127A. Hahn,127J. Hanlon,127R. M. Harris,127J. Hirschauer,127B. Hooberman,127S. Jindariani,127 M. Johnson,127U. Joshi,127B. Kilminster,127B. Klima,127S. Kunori,127S. Kwan,127D. Lincoln,127R. Lipton,127 L. Lueking,127J. Lykken,127K. Maeshima,127J. M. Marraffino,127S. Maruyama,127D. Mason,127P. McBride,127

K. Mishra,127S. Mrenna,127Y. Musienko,127,wwC. Newman-Holmes,127V. O’Dell,127O. Prokofyev,127 E. Sexton-Kennedy,127S. Sharma,127W. J. Spalding,127L. Spiegel,127P. Tan,127L. Taylor,127S. Tkaczyk,127

N. V. Tran,127L. Uplegger,127E. W. Vaandering,127R. Vidal,127J. Whitmore,127W. Wu,127F. Yang,127 F. Yumiceva,127J. C. Yun,127D. Acosta,128P. Avery,128D. Bourilkov,128M. Chen,128S. Das,128M. De Gruttola,128

G. P. Di Giovanni,128D. Dobur,128A. Drozdetskiy,128R. D. Field,128M. Fisher,128Y. Fu,128I. K. Furic,128 J. Gartner,128J. Hugon,128B. Kim,128J. Konigsberg,128A. Korytov,128A. Kropivnitskaya,128T. Kypreos,128

J. F. Low,128K. Matchev,128P. Milenovic,128,xxG. Mitselmakher,128L. Muniz,128R. Remington,128 A. Rinkevicius,128P. Sellers,128N. Skhirtladze,128M. Snowball,128J. Yelton,128M. Zakaria,128V. Gaultney,129

L. M. Lebolo,129S. Linn,129P. Markowitz,129G. Martinez,129J. L. Rodriguez,129T. Adams,130A. Askew,130 J. Bochenek,130J. Chen,130B. Diamond,130S. V. Gleyzer,130J. Haas,130S. Hagopian,130V. Hagopian,130 M. Jenkins,130K. F. Johnson,130H. Prosper,130V. Veeraraghavan,130M. Weinberg,130M. M. Baarmand,131

B. Dorney,131M. Hohlmann,131H. Kalakhety,131I. Vodopiyanov,131M. R. Adams,132I. M. Anghel,132 L. Apanasevich,132Y. Bai,132V. E. Bazterra,132R. R. Betts,132J. Callner,132R. Cavanaugh,132C. Dragoiu,132

O. Evdokimov,132E. J. Garcia-Solis,132L. Gauthier,132C. E. Gerber,132D. J. Hofman,132S. Khalatyan,132 F. Lacroix,132M. Malek,132C. O’Brien,132C. Silkworth,132D. Strom,132N. Varelas,132U. Akgun,133 E. A. Albayrak,133B. Bilki,133,yyK. Chung,133W. Clarida,133F. Duru,133S. Griffiths,133C. K. Lae,133J.-P. Merlo,133

H. Mermerkaya,133,zzA. Mestvirishvili,133A. Moeller,133J. Nachtman,133C. R. Newsom,133E. Norbeck,133 J. Olson,133Y. Onel,133F. Ozok,133S. Sen,133E. Tiras,133J. Wetzel,133T. Yetkin,133K. Yi,133B. A. Barnett,134

B. Blumenfeld,134S. Bolognesi,134D. Fehling,134G. Giurgiu,134A. V. Gritsan,134Z. J. Guo,134G. Hu,134 P. Maksimovic,134S. Rappoccio,134M. Swartz,134A. Whitbeck,134P. Baringer,135A. Bean,135G. Benelli,135

O. Grachov,135R. P. Kenny Iii,135M. Murray,135D. Noonan,135V. Radicci,135S. Sanders,135R. Stringer,135 G. Tinti,135J. S. Wood,135V. Zhukova,135A. F. Barfuss,136T. Bolton,136I. Chakaberia,136A. Ivanov,136S. Khalil,136

M. Makouski,136Y. Maravin,136S. Shrestha,136I. Svintradze,136J. Gronberg,137D. Lange,137D. Wright,137 A. Baden,138M. Boutemeur,138B. Calvert,138S. C. Eno,138J. A. Gomez,138N. J. Hadley,138R. G. Kellogg,138

M. Kirn,138T. Kolberg,138Y. Lu,138M. Marionneau,138A. C. Mignerey,138A. Peterman,138K. Rossato,138 A. Skuja,138J. Temple,138M. B. Tonjes,138S. C. Tonwar,138E. Twedt,138G. Bauer,139J. Bendavid,139W. Busza,139

E. Butz,139I. A. Cali,139M. Chan,139V. Dutta,139G. Gomez Ceballos,139M. Goncharov,139K. A. Hahn,139 Y. Kim,139M. Klute,139Y.-J. Lee,139W. Li,139P. D. Luckey,139T. Ma,139S. Nahn,139C. Paus,139D. Ralph,139

C. Roland,139G. Roland,139M. Rudolph,139G. S. F. Stephans,139F. Sto¨ckli,139K. Sumorok,139K. Sung,139 D. Velicanu,139E. A. Wenger,139R. Wolf,139B. Wyslouch,139S. Xie,139M. Yang,139Y. Yilmaz,139A. S. Yoon,139

M. Zanetti,139S. I. Cooper,140P. Cushman,140B. Dahmes,140A. De Benedetti,140G. Franzoni,140A. Gude,140 J. Haupt,140S. C. Kao,140K. Klapoetke,140Y. Kubota,140J. Mans,140N. Pastika,140R. Rusack,140M. Sasseville,140

A. Singovsky,140N. Tambe,140J. Turkewitz,140L. M. Cremaldi,141R. Kroeger,141L. Perera,141R. Rahmat,141 D. A. Sanders,141E. Avdeeva,142K. Bloom,142S. Bose,142J. Butt,142D. R. Claes,142A. Dominguez,142M. Eads,142

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U. Baur,143A. Godshalk,143I. Iashvili,143S. Jain,143A. Kharchilava,143A. Kumar,143S. P. Shipkowski,143 K. Smith,143G. Alverson,144E. Barberis,144D. Baumgartel,144M. Chasco,144J. Haley,144D. Trocino,144 D. Wood,144J. Zhang,144A. Anastassov,145A. Kubik,145N. Mucia,145N. Odell,145R. A. Ofierzynski,145 B. Pollack,145A. Pozdnyakov,145M. Schmitt,145S. Stoynev,145M. Velasco,145S. Won,145L. Antonelli,146 D. Berry,146A. Brinkerhoff,146M. Hildreth,146C. Jessop,146D. J. Karmgard,146J. Kolb,146K. Lannon,146W. Luo,146

S. Lynch,146N. Marinelli,146D. M. Morse,146T. Pearson,146R. Ruchti,146J. Slaunwhite,146N. Valls,146 J. Warchol,146M. Wayne,146M. Wolf,146J. Ziegler,146B. Bylsma,147L. S. Durkin,147C. Hill,147R. Hughes,147

P. Killewald,147K. Kotov,147T. Y. Ling,147D. Puigh,147M. Rodenburg,147C. Vuosalo,147G. Williams,147 B. L. Winer,147N. Adam,148E. Berry,148P. Elmer,148D. Gerbaudo,148V. Halyo,148P. Hebda,148J. Hegeman,148 A. Hunt,148E. Laird,148D. Lopes Pegna,148P. Lujan,148D. Marlow,148T. Medvedeva,148M. Mooney,148J. Olsen,148

P. Piroue´,148X. Quan,148A. Raval,148H. Saka,148D. Stickland,148C. Tully,148J. S. Werner,148A. Zuranski,148 J. G. Acosta,149X. T. Huang,149A. Lopez,149H. Mendez,149S. Oliveros,149J. E. Ramirez Vargas,149 A. Zatserklyaniy,149E. Alagoz,150V. E. Barnes,150D. Benedetti,150G. Bolla,150D. Bortoletto,150M. De Mattia,150

A. Everett,150Z. Hu,150M. Jones,150O. Koybasi,150M. Kress,150A. T. Laasanen,150N. Leonardo,150 V. Maroussov,150P. Merkel,150D. H. Miller,150N. Neumeister,150I. Shipsey,150D. Silvers,150A. Svyatkovskiy,150

M. Vidal Marono,150H. D. Yoo,150J. Zablocki,150Y. Zheng,150S. Guragain,151N. Parashar,151A. Adair,152 C. Boulahouache,152V. Cuplov,152K. M. Ecklund,152F. J. M. Geurts,152B. P. Padley,152R. Redjimi,152J. Roberts,152 J. Zabel,152B. Betchart,153A. Bodek,153Y. S. Chung,153R. Covarelli,153P. de Barbaro,153R. Demina,153Y. Eshaq,153 A. Garcia-Bellido,153P. Goldenzweig,153Y. Gotra,153J. Han,153A. Harel,153S. Korjenevski,153D. C. Miner,153 D. Vishnevskiy,153M. Zielinski,153A. Bhatti,154R. Ciesielski,154L. Demortier,154K. Goulianos,154G. Lungu,154

S. Malik,154C. Mesropian,154S. Arora,155A. Barker,155J. P. Chou,155C. Contreras-Campana,155 E. Contreras-Campana,155D. Duggan,155D. Ferencek,155Y. Gershtein,155R. Gray,155E. Halkiadakis,155 D. Hidas,155D. Hits,155A. Lath,155S. Panwalkar,155M. Park,155R. Patel,155V. Rekovic,155A. Richards,155 J. Robles,155K. Rose,155S. Salur,155S. Schnetzer,155C. Seitz,155S. Somalwar,155R. Stone,155S. Thomas,155

G. Cerizza,156M. Hollingsworth,156S. Spanier,156Z. C. Yang,156A. York,156R. Eusebi,157W. Flanagan,157 J. Gilmore,157T. Kamon,157,aaaV. Khotilovich,157R. Montalvo,157I. Osipenkov,157Y. Pakhotin,157A. Perloff,157 J. Roe,157A. Safonov,157T. Sakuma,157S. Sengupta,157I. Suarez,157A. Tatarinov,157D. Toback,157N. Akchurin,158

J. Damgov,158P. R. Dudero,158C. Jeong,158K. Kovitanggoon,158S. W. Lee,158T. Libeiro,158Y. Roh,158 I. Volobouev,158E. Appelt,159D. Engh,159C. Florez,159S. Greene,159A. Gurrola,159W. Johns,159P. Kurt,159 C. Maguire,159A. Melo,159P. Sheldon,159B. Snook,159S. Tuo,159J. Velkovska,159M. W. Arenton,160M. Balazs,160

S. Boutle,160B. Cox,160B. Francis,160J. Goodell,160R. Hirosky,160A. Ledovskoy,160C. Lin,160C. Neu,160 J. Wood,160R. Yohay,160S. Gollapinni,161R. Harr,161P. E. Karchin,161C. Kottachchi Kankanamge Don,161 P. Lamichhane,161A. Sakharov,161M. Anderson,162M. Bachtis,162D. Belknap,162L. Borrello,162D. Carlsmith,162 M. Cepeda,162S. Dasu,162L. Gray,162K. S. Grogg,162M. Grothe,162R. Hall-Wilton,162M. Herndon,162A. Herve´,162

P. Klabbers,162J. Klukas,162A. Lanaro,162C. Lazaridis,162J. Leonard,162R. Loveless,162A. Mohapatra,162 I. Ojalvo,162G. A. Pierro,162I. Ross,162A. Savin,162W. H. Smith,162and J. Swanson162

(CMS Collaboration)

1Yerevan Physics Institute, Yerevan, Armenia 2Institut fu¨r Hochenergiephysik der OeAW, Wien, Austria

3National Centre for Particle and High Energy Physics, Minsk, Belarus

4Universiteit Antwerpen, Antwerpen, Belgium

5Vrije Universiteit Brussel, Brussel, Belgium 6Universite´ Libre de Bruxelles, Bruxelles, Belgium

7Ghent University, Ghent, Belgium

8Universite´ Catholique de Louvain, Louvain-la-Neuve, Belgium

9Universite´ de Mons, Mons, Belgium

10Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil

11Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil

12

Instituto de Fisica Teorica, Universidade Estadual Paulista, Sao Paulo, Brazil 13Institute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria

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15Institute of High Energy Physics, Beijing, China

16State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, China

17Universidad de Los Andes, Bogota, Colombia

18Technical University of Split, Split, Croatia 19University of Split, Split, Croatia 20Institute Rudjer Boskovic, Zagreb, Croatia

21University of Cyprus, Nicosia, Cyprus

22Charles University, Prague, Czech Republic

23

Academy of Scientific Research and Technology of the Arab Republic of Egypt, Egyptian Network of High Energy Physics, Cairo, Egypt

24National Institute of Chemical Physics and Biophysics, Tallinn, Estonia 25Department of Physics, University of Helsinki, Helsinki, Finland

26Helsinki Institute of Physics, Helsinki, Finland

27Lappeenranta University of Technology, Lappeenranta, Finland

28DSM/IRFU, CEA/Saclay, Gif-sur-Yvette, France

29Laboratoire Leprince-Ringuet, Ecole Polytechnique, IN2P3-CNRS, Palaiseau, France

30Institut Pluridisciplinaire Hubert Curien, Universite´ de Strasbourg, Universite´ de Haute-Alsace Mulhouse, CNRS/IN2P3, Strasbourg, France

31Centre de Calcul de l’Institut National de Physique Nucleaire et de Physique des Particules (IN2P3), Villeurbanne, France

32Universite´ de Lyon, Universite´ Claude Bernard Lyon 1, CNRS-IN2P3, Institut de Physique Nucle´aire de Lyon, Villeurbanne, France 33Institute of High Energy Physics and Informatization, Tbilisi State University, Tbilisi, Georgia

34RWTH Aachen University, I. Physikalisches Institut, Aachen, Germany

35RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany

36RWTH Aachen University, III. Physikalisches Institut B, Aachen, Germany

37

Deutsches Elektronen-Synchrotron, Hamburg, Germany

38University of Hamburg, Hamburg, Germany

39Institut fu¨r Experimentelle Kernphysik, Karlsruhe, Germany 40Institute of Nuclear Physics ‘‘Demokritos,’’ Aghia Paraskevi, Greece

41University of Athens, Athens, Greece 42University of Ioa´nnina, Ioa´nnina, Greece

43KFKI Research Institute for Particle and Nuclear Physics, Budapest, Hungary

44Institute of Nuclear Research ATOMKI, Debrecen, Hungary

45University of Debrecen, Debrecen, Hungary

46Panjab University, Chandigarh, India 47University of Delhi, Delhi, India 48Saha Institute of Nuclear Physics, Kolkata, India

49Bhabha Atomic Research Centre, Mumbai, India

50Tata Institute of Fundamental Research—EHEP, Mumbai, India

51Tata Institute of Fundamental Research—HECR, Mumbai, India

52Institute for Research in Fundamental Sciences (IPM), Tehran, Iran

53aINFN Sezione di Bari, Bari, Italy 53bUniversita` di Bari, Bari, Italy 53cPolitecnico di Bari, Bari, Italy

54aINFN Sezione di Bologna, Bologna, Italy

54bUniversita` di Bologna, Bologna, Italy 55aINFN Sezione di Catania, Catania, Italy

55bUniversita` di Catania, Catania, Italy 56a

INFN Sezione di Firenze, Firenze, Italy 56bUniversita` di Firenze, Firenze, Italy

57INFN Laboratori Nazionali di Frascati, Frascati, Italy

58INFN Sezione di Genova, Genova, Italy

59aINFN Sezione di Milano-Bicocca, Milano, Italy

59bUniversita` di Milano-Bicocca, Milano, Italy 60aINFN Sezione di Napoli, Napoli, Italy 60bUniversita` di Napoli ‘‘Federico II,’’ Napoli, Italy

61aINFN Sezione di Padova, Padova, Italy

61b

Universita` di Padova, Padova, Italy 61cUniversita` di Trento (Trento), Padova, Italy

62aINFN Sezione di Pavia, Pavia, Italy 62bUniversita` di Pavia, Pavia, Italy 63aINFN Sezione di Perugia, Perugia, Italy

(14)

63bUniversita` di Perugia, Perugia, Italy 64aINFN Sezione di Pisa, Pisa, Italy

64bUniversita` di Pisa, Pisa, Italy 64cScuola Normale Superiore di Pisa, Pisa, Italy

65aINFN Sezione di Roma, Roma, Italy

65bUniversita` di Roma ‘‘La Sapienza,’’ Roma, Italy 66aINFN Sezione di Torino, Torino, Italy

66bUniversita` di Torino, Torino, Italy 66c

Universita` del Piemonte Orientale (Novara), Torino, Italy 67aINFN Sezione di Trieste, Trieste, Italy

67bUniversita` di Trieste, Trieste, Italy

68Kangwon National University, Chunchon, Korea

69Kyungpook National University, Daegu, Korea

70Chonnam National University, Institute for Universe and Elementary Particles, Kwangju, Korea

71Konkuk University, Seoul, Korea 72Korea University, Seoul, Korea 73University of Seoul, Seoul, Korea

74Sungkyunkwan University, Suwon, Korea

75Vilnius University, Vilnius, Lithuania

76Centro de Investigacion y de Estudios Avanzados del IPN, Mexico City, Mexico

77Universidad Iberoamericana, Mexico City, Mexico

78Benemerita Universidad Autonoma de Puebla, Puebla, Mexico

79Universidad Auto´noma de San Luis Potosı´, San Luis Potosı´, Mexico

80University of Auckland, Auckland, New Zealand

81

University of Canterbury, Christchurch, New Zealand

82National Centre for Physics, Quaid-I-Azam University, Islamabad, Pakistan

83Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland

84Soltan Institute for Nuclear Studies, Warsaw, Poland

85Laborato´rio de Instrumentac¸a˜o e Fı´sica Experimental de Partı´culas, Lisboa, Portugal 86Joint Institute for Nuclear Research, Dubna, Russia

87Petersburg Nuclear Physics Institute, Gatchina (St Petersburg), Russia 88Institute for Nuclear Research, Moscow, Russia

89Institute for Theoretical and Experimental Physics, Moscow, Russia

90Moscow State University, Moscow, Russia

91P. N. Lebedev Physical Institute, Moscow, Russia

92State Research Center of Russian Federation, Institute for High Energy Physics, Protvino, Russia 93University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences, Belgrade, Serbia

94Centro de Investigaciones Energe´ticas Medioambientales y Tecnolo´gicas (CIEMAT), Madrid, Spain

95Universidad Auto´noma de Madrid, Madrid, Spain

96Universidad de Oviedo, Oviedo, Spain

97Instituto de Fı´sica de Cantabria (IFCA), CSIC-Universidad de Cantabria, Santander, Spain

98CERN, European Organization for Nuclear Research, Geneva, Switzerland

99Paul Scherrer Institut, Villigen, Switzerland

100Institute for Particle Physics, ETH Zurich, Zurich, Switzerland 101Universita¨t Zu¨rich, Zurich, Switzerland

102National Central University, Chung-Li, Taiwan

103National Taiwan University (NTU), Taipei, Taiwan

104

Cukurova University, Adana, Turkey

105Middle East Technical University, Physics Department, Ankara, Turkey

106Bogazici University, Istanbul, Turkey 107Istanbul Technical University, Istanbul, Turkey

108National Scientific Center, Kharkov Institute of Physics and Technology, Kharkov, Ukraine 109University of Bristol, Bristol, United Kingdom

110Rutherford Appleton Laboratory, Didcot, United Kingdom

111Imperial College, London, United Kingdom

112Brunel University, Uxbridge, United Kingdom

113

Baylor University, Waco, Texas, USA

114The University of Alabama, Tuscaloosa, Alabama, USA

115Boston University, Boston, Massachusetts, USA

116Brown University, Providence, Rhode Island, USA

(15)

118University of California, Los Angeles, Los Angeles, California, USA 119University of California, Riverside, Riverside, California, USA 120University of California, San Diego, La Jolla, California, USA

121University of California, Santa Barbara, Santa Barbara, California, USA

122California Institute of Technology, Pasadena, California, USA

123Carnegie Mellon University, Pittsburgh, Pennsylvania, USA

124University of Colorado at Boulder, Boulder, Colorado, USA

125Cornell University, Ithaca, New York, USA

126

Fairfield University, Fairfield, Connecticut, USA 127Fermi National Accelerator Laboratory, Batavia, Illinois, USA

128University of Florida, Gainesville, Florida, USA

129Florida International University, Miami, Florida, USA

130Florida State University, Tallahassee, Florida, USA

131Florida Institute of Technology, Melbourne, Florida, USA

132University of Illinois at Chicago (UIC), Chicago, Illinois, USA

133The University of Iowa, Iowa City, Iowa, USA

134Johns Hopkins University, Baltimore, Maryland, USA

135The University of Kansas, Lawrence, Kansas, USA

136Kansas State University, Manhattan, Kansas, USA

137Lawrence Livermore National Laboratory, Livermore, California, USA

138University of Maryland, College Park, Maryland, USA

139Massachusetts Institute of Technology, Cambridge, Massachusetts, USA

140University of Minnesota, Minneapolis, Minnesota, USA

141University of Mississippi, University, Mississippi, USA 142

University of Nebraska–Lincoln, Lincoln, Nebraska, USA

143State University of New York at Buffalo, Buffalo, New York, USA

144Northeastern University, Boston, Massachusetts, USA

145Northwestern University, Evanston, Illinois, USA

146University of Notre Dame, Notre Dame, Indiana, USA

147The Ohio State University, Columbus, Ohio, USA

148Princeton University, Princeton, New Jersey, USA

149University of Puerto Rico, Mayaguez, Puerto Rico, USA

150Purdue University, West Lafayette, Indiana, USA

151Purdue University Calumet, Hammond, Indiana, USA

152Rice University, Houston, Texas, USA

153University of Rochester, Rochester, New York, USA

154The Rockefeller University, New York, New York, USA

155Rutgers, the State University of New Jersey, Piscataway, New Jersey, USA

156University of Tennessee, Knoxville, Tennessee, USA 157Texas A&M University, College Station, Texas, USA

158Texas Tech University, Lubbock, Texas, USA

159Vanderbilt University, Nashville, Tennessee, USA 160University of Virginia, Charlottesville, Virginia, USA

161Wayne State University, Detroit, Michigan, USA

162University of Wisconsin, Madison, Wisconsin, USA

aDeceased.

bAlso at CERN, European Organization for Nuclear Research, Geneva, Switzerland.

cAlso at National Institute of Chemical Physics and Biophysics, Tallinn, Estonia.

dAlso at Universidade Federal do ABC, Santo Andre, Brazil.

eAlso at California Institute of Technology, Pasadena, CA, USA.

fAlso at Laboratoire Leprince-Ringuet, Ecole Polytechnique, IN2P3-CNRS, Palaiseau, France.

gAlso at Suez Canal University, Suez, Egypt. hAlso at Cairo University, Cairo, Egypt.

iAlso at British University, Cairo, Egypt. j

Also at Fayoum University, El-Fayoum, Egypt.

kAlso at Soltan Institute for Nuclear Studies, Warsaw, Poland. lAlso at Universite´ de Haute-Alsace, Mulhouse, France.

(16)

nAlso at Brandenburg University of Technology, Cottbus, Germany.

oAlso at Institute of Nuclear Research ATOMKI, Debrecen, Hungary.

pAlso at Eo¨tvo¨s Lora´nd University, Budapest, Hungary.

qAlso at Tata Institute of Fundamental Research - HECR, Mumbai, India.

rAlso at University of Visva-Bharati, Santiniketan, India. sAlso at Sharif University of Technology, Tehran, Iran. tAlso at Isfahan University of Technology, Isfahan, Iran. uAlso at Shiraz University, Shiraz, Iran.

vAlso at Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Teheran, Iran.

wAlso at Facolta` Ingegneria Universita` di Roma, Roma, Italy. xAlso at Universita` della Basilicata, Potenza, Italy.

yAlso at Universita` degli Studi Guglielmo Marconi, Roma, Italy. zAlso at Universita` degli studi di Siena, Siena, Italy.

aaAlso at University of Bucharest, Bucuresti-Magurele, Romania.

bb

Also at Faculty of Physics of University of Belgrade, Belgrade, Serbia.

ccAlso at University of Florida, Gainesville, FL, USA.

ddAlso at University of California, Los Angeles, Los Angeles, CA, USA.

eeAlso at Scuola Normale e Sezione dell’ INFN, Pisa, Italy.

ffAlso at INFN Sezione di Roma, Universita` di Roma ‘‘La Sapienza,’’ Roma, Italy.

ggAlso at University of Athens, Athens, Greece.

hhAlso at Rutherford Appleton Laboratory, Didcot, United Kingdom.

iiAlso at The University of Kansas, Lawrence, KS, USA.

jjAlso at Paul Scherrer Institut, Villigen, Switzerland.

kkAlso at Institute for Theoretical and Experimental Physics, Moscow, Russia. llAlso at Gaziosmanpasa University, Tokat, Turkey.

mmAlso at Adiyaman University, Adiyaman, Turkey.

nnAlso at The University of Iowa, Iowa City, IA, USA.

ooAlso at Mersin University, Mersin, Turkey. ppAlso at Kafkas University, Kars, Turkey. qq

Also at Suleyman Demirel University, Isparta, Turkey.

rrAlso at Ege University, Izmir, Turkey.

ssAlso at School of Physics and Astronomy, University of Southampton, Southampton, United Kingdom.

ttAlso at INFN Sezione di Perugia, Universita` di Perugia, Perugia, Italy. uuAlso at University of Sydney, Sydney, Australia.

vvAlso at Utah Valley University, Orem, UT, USA.

wwAlso at Institute for Nuclear Research, Moscow, Russia.

xxAlso at University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences, Belgrade, Serbia.

yyAlso at Argonne National Laboratory, Argonne, IL, USA.

zzAlso at Erzincan University, Erzincan, Turkey.

Figure

FIG. 2 (color online). The single-particle azimuthal anisotropy v 2 as a function of the number of participating nucleons with jj &lt; 1 (solid circles) and 1 &lt; jj &lt; 2 (open squares) for six selected p T ranges in Pb-Pb collisions at ffiffiffiffiffiffiffiffi

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