Dijet Azimuthal Decorrelations in pp
Collisions at √s=7� [square root of s=7]�TeV
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Khachatryan, V. et al. (CMS Collaboration) "Dijet Azimuthal
Decorrelations in pp Collisions at √s=7��TeV" Phys. Rev. Lett. 106,
122003 (2011) © 2011 CERN, for the CMS Collaboration
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http://dx.doi.org/10.1103/PhysRevLett.106.122003
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American Physical Society
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Final published version
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Dijet Azimuthal Decorrelations in pp Collisions at
p
ffiffiffi
s
¼ 7 TeV
V. Khachatryan et al.* (CMS Collaboration)
(Received 26 January 2011; published 22 March 2011)
Measurements of dijet azimuthal decorrelations in pp collisions at pffiffiffis¼ 7 TeV using the CMS detector at the CERN LHC are presented. The analysis is based on an inclusive dijet event sample corresponding to an integrated luminosity of 2:9 pb1. The results are compared to predictions from perturbative QCD calculations and various Monte Carlo event generators. The dijet azimuthal distribu-tions are found to be sensitive to initial-state gluon radiation.
DOI:10.1103/PhysRevLett.106.122003 PACS numbers: 13.85.Ni, 12.38.Bx, 12.38.Qk, 13.87.Ce
High-energy proton-proton collisions with high momen-tum transfer are described within the framework of quanmomen-tum chromodynamics (QCD) as pointlike scatterings between the proton constituents, collectively referred to as partons. The outgoing partons manifest themselves, through quark and gluon soft radiation and hadronization processes, as localized streams of particles, identified as jets. At Born level, dijets are produced with equal transverse momenta pT
with respect to the beam axis and back to back in the azimuthal angle (’dijet¼ j’jet1’jet2j ¼ ). Soft-gluon
emission will decorrelate the two highest pT (leading) jets
and cause small deviations from . Larger decorrelations from occur in the case of hard multijet production. Three-jet topologies dominate the region of 2=3 < ’dijet< ,
whereas angles smaller than 2=3 are populated by four-jet events.
Dijet azimuthal decorrelations, i.e., the deviation of
’dijetfrom for the two leading jets in hard-scattering
events, can be used to study QCD radiation effects over a wide range of jet multiplicities without the need to measure all the additional jets. Such studies are important because an accurate description of multiple-parton radiation is still lacking in perturbative QCD (pQCD). Experiments there-fore rely on Monte Carlo (MC) event generators to take these higher-order processes into account in searches for new physics and for a wide variety of precision measure-ments. The observable chosen to study the radiation effects is the differential dijet cross section in ’dijet, normalized
by the dijet cross section integrated over the entire ’dijet
phase space: ð1=dijetÞðddijet=d’dijetÞ. By normalizing
the ’dijetdistributions in this manner, many experimental
and theoretical uncertainties are significantly reduced. Measurements of dijet azimuthal decorrelations at the Tevatron have previously been reported by the D0
Collaboration [1]. In this Letter, we present the first measurements of dijet azimuthal decorrelations in pp collisions at pffiffiffis¼ 7 TeV at the CERN Large Hadron Collider (LHC).
The central feature of the Compact Muon Solenoid (CMS) apparatus is a superconducting solenoid, of 6 m internal diameter, providing an axial field of 3.8 T. Charged particle trajectories are measured by the silicon pixel and strip tracker, covering 0 < ’ < 2 in azimuth and jj < 2:5, where pseudorapidity ¼ ln½tanð=2Þ and is the polar angle relative to the counterclockwise proton beam direction with respect to the center of the detector. A lead-tungstate crystal electromagnetic calorimeter and a brass-scintillator hadronic calorimeter surround the track-ing volume. The calorimeter cells are grouped in projective towers of granularity ’ ¼ 0:087 0:087 at central pseudorapidities. The granularity becomes coarser at for-ward pseudorapidities. A preshower detector made of silicon sensor planes and lead absorbers is installed in front of the electromagnetic calorimeter at 1:653 < jj < 2:6. Muons are measured in gas-ionization detectors embedded in the steel magnetic field return yoke. A detailed descrip-tion of the CMS detector can be found elsewhere [2].
CMS uses a two-tiered trigger system to select events on-line: level 1 and the high level trigger. In this analysis, events were selected by using two inclusive single-jet triggers that required a level-1 jet with pT> 20
(30) GeV and a high level trigger jet with pT> 30
(50) GeV. The jets at level 1 and the high level trigger are reconstructed by using energies measured by the elec-tromagnetic and hadronic calorimeters and are not cor-rected for the jet energy response of the calorimeters. The trigger efficiency for a given corrected pT threshold
of the leading jet (pTmax) was measured by using events
selected by a lower-threshold trigger. For the event selec-tion, pTmaxthresholds were chosen so that this efficiency
exceeded 99%. The corresponding off-line corrected pTmax
values are 80 (110) GeV for the low (high) threshold jet trigger.
Jets were reconstructed off-line by using the anti-kT
clustering algorithm with a distance parameter R ¼ 0:5 [3].
*Full author list given at the end of the article.
Published by 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.
The four-vectors of particles reconstructed by the CMS particle-flow algorithm were used as input to the jet-clustering algorithm. The particle-flow algorithm combines information from all CMS subdetectors to provide a com-plete list of long-lived particles in the event. Muons, elec-trons, photons, and charged and neutral hadrons are reconstructed individually. As a result, the residual correc-tions to the jet four-vectors, arising from the detector response, are relatively small (at the level of 5%–10% in the central region) [4]. A detailed description of the particle-flow algorithm can be found elsewhere [5,6].
Spurious jets from noise and noncollision backgrounds were eliminated by applying loose quality cuts on the jet properties [7]. Events were required to have a primary vertex reconstructed along the beam axis and within 24 cm of the detector center [8]. Further cuts were applied to reject inter-actions from the beam halo. Events were selected having two leading jets each with pT> 30 GeV and rapidity jyj < 1:1,
where y ¼12ln½ðE þ pzÞ=ðEpzÞ, with E being the total jet
energy and pzthe projection of the jet momentum along the
beam axis. Each event is put into one of five mutually exclusive regions, which are based on the pTmax in the
event. The five regions are 80 < pTmax< 110 GeV, 110 <
pTmax< 140 GeV, 140 < pTmax< 200 GeV, 200 <
pTmax< 300 GeV, and 300 GeV < p
Tmax. The data
corre-spond to an integrated luminosity of 0:3 pb1for the lowest pTmax region and 2:9 pb1 for the other pTmax regions.
The uncertainty on the integrated luminosity is estimated to be 11% [9]. After the application of all selection criteria, the numbers of events remaining in each of the five pTmax
regions, starting from the lowest, are 60 837, 160 388, 69 009, 14 383, and 2284.
The ’dijetdistributions are corrected for event
migra-tion effects due to the finite jet pTand position resolutions
of the detector. The distributions are sensitive to the jet pT
resolution because fluctuations in the jet response can cause low-energy jets to be misidentified as leading jets, and events can migrate between different pTmax regions.
The finite resolution in azimuthal angle causes event migration between ’dijet bins, while the resolution in
rapidity can move jets in and out of the central rapidity region (jyj < 1:1). The correction factors were determined by using two independent MC samples: PYTHIA 6.422 (PYTHIA6) [10] tune D6T [11], andHERWIGþþ 2.4.2 [12].
The pT, rapidity, and azimuthal angle of each generated jet
were smeared according to the measured resolutions [13]. The ratio of the two dijet azimuthal distributions (the generated distribution and the smeared one) deter-mined the unfolding correction factors for each pTmax
region, for a given MC sample. The average of the correc-tion factors for each pTmax region from the two MC
samples was used as the final unfolding correction applied to the data. The unfolding correction factors modify the measured ’dijetdistributions by less than 2% for 5=6 <
’dijet< . For ’dijet =2, the changes range from
11%, for the highest pTmax region, to 19%, for the
lowest.
The main sources of systematic uncertainty arise from uncertainties in the jet energy calibration, the jet pT
reso-lution, and the unfolding correction. The jet energy cali-bration uncertainties have been tabulated for the considered phase space in the variables of jet pT and
[4]. Typical values are between 2.5% and 3.5%. The result-ing uncertainties on the normalized ’dijet distributions
range from 5% at ’dijet =2 to 1% at ’dijet . The
effect of the jet pT resolution uncertainty on the ’dijet
distributions was estimated by varying the jet pT
resolu-tions by 10% [13] and comparing the ’dijetunfolding
correction before and after the change. This yields a varia-tion on the normalized ’dijetdistributions ranging from
5% at ’dijet =2 to 1% at ’dijet . The
uncertain-ties on the unfolding correction factors were estimated by comparing the corrections from different event generators andPYTHIA6tunes that vary significantly in their modeling of the jet kinematic distributions and ’dijetdistributions.
The resulting uncertainty varies from 8% at ’dijet =2
to 1.5% at ’dijet . The systematic uncertainty from
using a parametrized model to simulate the finite jet pTand
position resolutions of the detector to determine the unfolding correction factors was estimated to be about 2.5% in all pTmax regions. The combined systematic
un-certainty, calculated as the quadratic sum of all systematic uncertainties, varies from 11% at ’dijet =2 to 3% at
’dijet .
The corrected differential ’dijetdistributions,
normal-ized to the integrated dijet cross section, are shown in Fig. 1 for the five pTmax regions. The distributions are
scaled by multiplicative factors for presentation purposes. Each data point is plotted at the abscissa value for which the predicted differential ’dijetdistribution has the same
value as the bin average obtained by using PYTHIA6 tune D6T, which provides a good description of the data [14].
The ’dijet distributions are strongly peaked at and
become steeper with increasing pTmax. The simulated
’dijet distributions from the PYTHIA6 (D6T and Z2 [15]
tunes), PYTHIA 8.135 (PYTHIA8) [16], HERWIGþþ, and MADGRAPH 4.4.32 [17] event generators are presented for comparison. TheMADGRAPHgenerator is based on leading-order matrix element multiparton final-state predictions, usingPYTHIA6for parton showering and hadronization, and
the Mangano method [18] to map the parton-level event into a parton shower history. The MADGRAPH predictions included tree-level processes of up to four partons. For
PYTHIA6, PYTHIA8, and MADGRAPH event generators the CTEQ6L [19] parton distribution functions (PDFs) were used; forHERWIGþþ, the MRST2001 PDFs [20].
Figure 2 shows the ratios of the measured ’dijet
distributions to the predictions of PYTHIA6, PYTHIA8,
HERWIGþþ, and MADGRAPH in the five pTmax regions. PRL106, 122003 (2011) P H Y S I C A L R E V I E W L E T T E R S 25 MARCH 2011
The combined systematic uncertainty on the experimental measurements is shown by the shaded band. The predic-tions fromPYTHIA6andHERWIGþþ describe the shape of
the data distributions well, while MADGRAPH (PYTHIA8) predicts less (more) azimuthal decorrelation than is observed in the data.
Figure 3 displays the ratios of the measured ’dijet
distributions to the next-to-leading-order (NLO) predic-tions of pQCD calculapredic-tions from the parton-level generator
NLOJETþþ [21] within the FASTNLOframework [22]. The
predictions include 2 ! 3 processes at NLO, normalized to dijetat NLO: 1 dijet
NLOd’ddijetdijet
NLO:
The predictions near ’dijet¼ have been excluded
be-cause of their sensitivity to higher-order corrections not included in the present calculations.
Uncertainties due to the renormalization (r) and
factorization (f) scales are evaluated by varying the
default choice of r¼ f¼ pTmax between pTmax=2
and 2pTmaxin the following six combinations:ð
r; fÞ ¼
ðpTmax=2; pTmax=2Þ, ð2pTmax; 2pTmaxÞ, ðpTmax; pTmax=2Þ,
ðpTmax; 2pTmaxÞ, ðpTmax=2; pTmaxÞ, and ð2pTmax; pTmaxÞ.
These scale variations modify the predictions of the nor-malized ’dijetdistributions by less than 50%. The PDFs
and the associated uncertainties were obtained from CTEQ6.6 [19]. The PDF uncertainties were derived by using the 22 CTEQ6.6 uncertainty eigenvectors and found to be 9% at ’dijet =2 and 2% at ’dijet< .
Following the proposal of the PDF4LHC working group [23], the impact of other global PDF fits [24–26] was investigated and found to be negligible in the context of this analysis.
Nonperturbative corrections due to hadronization and multiple-parton interactions were applied to the pQCD pre-dictions. The correction factors were determined from the
PYTHIA6andHERWIGþþ simulations and modify the
predic-tions from þ4% (’dijet ) to 13% (’dijet =2). The uncertainty due to the nonperturbative corrections is estimated to be 6% at ’dijet =2 and 2% at
’dijet . The effects due to the scale variations, as well
as the uncertainties due to PDFs and nonperturbative corrections, are also shown in Fig.3. The NLO predictions provide a good description of the shape of the data
0.5 1 1.5 2 0.5 1 1.5 2 CMSCMSCMSCMSCMS T > 300 GeV max p 0.5 1 1.5 2 0.5 1 1.5 2 200 < pTmax < 300 GeV 0.5 1 1.5 2 0.5 1 1.5 2 140 < pTmax < 200 GeV 0.5 1 1.5 2 0.5 1 1.5 2 < 140 GeV T max 110 < p 0.5 1 1.5 2 0.5 1 1.5 2 80 < pTmax < 110 GeV PYTHIA6 D6T PYTHIA6 Z2 PYTHIA8 HERWIG++ MADGRAPH Systematic Uncert. = 7 TeV |y| < 1.1 s -1 L = 2.9 pb /2 π 2π/3 5π/6 π [ rad ] dijet ϕ ∆ dijet ϕ∆ d dijet σ d dijet σ 1 MC DATA
FIG. 2 (color online). Ratios of measured normalized ’dijet distributions to PYTHIA6,PYTHIA8,HERWIGþþ, andMADGRAPH predictions in several pTmaxregions. The shaded bands indicate the total systematic uncertainty.
[ rad ] dijet ϕ ∆ ] -1 [ rad dijet ϕ∆ d dijet σ d dijet σ 1 -2 10 -1 10 1 10 2 10 3 10 4 10 5 10 > 300 GeV (×104) T max p ) 3 10 × < 300 GeV ( T max 200 < p ) 2 10 × < 200 GeV ( T max 140 < p 10) × < 140 GeV ( T max 110 < p < 110 GeV T max 80 < p PYTHIA6 D6T PYTHIA6 Z2 PYTHIA8 HERWIG++ MADGRAPH -1 L = 2.9 pb = 7 TeV s |y| < 1.1 CMS /2 π 2π/3 5π/6 π
FIG. 1 (color online). Normalized ’dijetdistributions in sev-eral pTmaxregions, scaled by the multiplicative factors given in the figure for easier presentation. The curves represent predic-tions fromPYTHIA6,PYTHIA8,HERWIGþþ, andMADGRAPH. The error bars on the data points include statistical and systematic uncertainties.
distributions over much of the ’dijet range. Compared to
the data, the reduced decorrelation in the theoretical predic-tion and the increased sensitivity to the r and f scale
variations for ’dijet< 2=3 shown in Fig.3are attributed
to the fact that the pQCD prediction in this region is effec-tively available only at leading order, since the contribution from tree-level four-parton final states dominates.
The sensitivity of the ’dijetdistributions to initial-state
parton shower radiation (ISR) is investigated by varying the input parameter kISR [PARP(67)] inPYTHIA6 tune D6T.
The product of kISR and the square of the hard-scattering
scale gives the maximum allowed parton virtuality (i.e., the maximum allowed pT) in the initial-state shower. Previous
studies have shown that kISR is the only parameter in
PYTHIA6that has significant impact on the ’dijet distribu-tions [27]. The default value of kISRinPYTHIA6tune D6T is
2.5, determined from the D0 dijet azimuthal decorrelation results [1]. Figure4shows comparisons of the measured ’dijetdistributions toPYTHIA6 distributions with various
kISR values. The effects are more pronounced for smaller
’dijet angles, where multigluon radiation dominates.
Varying kISR by 0:5 about its default value yields a
change of about 30% on the PYTHIA6 prediction for
’dijet =2, suggesting that our results could be used
to tune parameters in the MC event generators that control radiative effects in the initial state. In PYTHIA6tune D6T, the maximum pTallowed in the final-state radiation parton
shower is controlled through the parameter PARP(71). We varied the value of this parameter from 2.5 to 8 (the default value is 4.0) and observed less than10% changes in the ’dijetdistributions in all pT regions.
In summary, we have measured dijet azimuthal decorre-lations in different leading-jet pT regions from pp
colli-sions atpffiffiffis¼ 7 TeV. ThePYTHIA6andHERWIGþþ event
generators are found to best describe the shape of the measured distributions over the entire range of ’dijet.
The predictions from NLO pQCD are in reasonable agree-ment with the measured distributions, except at small
’dijetwhere multiparton radiation effects dominate. The
’dijetdistributions are found to be sensitive to initial-state
gluon radiation.
We congratulate our colleagues in the CERN accelerator departments for the excellent performance of the LHC
1 2 3 1 2 3 CMS NLO QCD Predictions CTEQ 6.6
max T = p f µ = r µ > 300 GeV T max p 1 2 3 1 2 3 T < 300 GeV max 200 < p 1 2 3 1 2 3 T < 200 GeV max 140 < p 1 2 3 1 2 3 T < 140 GeV max 110 < p 1 2 3 1 2 3 T < 110 GeV max 80 < p Scale Dependence f µ , r µ PDF Uncertainty Non-Pert. Uncertainty = 7 TeV |y| < 1.1 s -1 L = 2.9 pb /2 π 2π/3 5π/6 π [ rad ] dijet ϕ ∆ dijet ϕ∆ d dijet σ d dijet σ 1 THEORY DATA
FIG. 3 (color online). Ratios of measured normalized ’dijet distributions to NLO pQCD predictions with nonperturbative corrections in several pTmaxregions. The error bars on the data points include statistical and systematic uncertainties. The ef-fects on the NLO pQCD predictions due to r and f scale variations and PDF uncertainties, as well as the uncertainties from the nonperturbative corrections, are shown.
1 2 3 1 2 3 CMS T > 300 GeV max p 1 2 3 1 2 3 T < 300 GeV max 200 < p 1 2 3 1 2 3 T < 200 GeV max 140 < p 1 2 3 1 2 3 T < 140 GeV max 110 < p 1 2 3 1 2 3 T < 110 GeV max 80 < p =1.0 ISR k =2.0 ISR k =2.5 ISR k =3.0 ISR k =4.0 ISR k Systematic Uncert. = 7 TeV |y| < 1.1 s -1 L = 2.9 pb /2 π 2π/3 5π/6 π [ rad ] dijet ϕ ∆ dijet ϕ∆ d dijet σ d dijet σ 1 PYTHIA6 DATA
FIG. 4 (color online). Ratios of measured normalized ’dijet distributions toPYTHIA6tune D6T with various values of kISRin several pTmax regions. The shaded bands indicate the total systematic uncertainty.
machine. We thank the technical and administrative staff at CERN and other CMS institutes and acknowledge support 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, ME, 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); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (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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V. Khachatryan,1A. M. Sirunyan,1A. Tumasyan,1W. Adam,2T. Bergauer,2M. Dragicevic,2J. Ero¨,2C. Fabjan,2 M. Friedl,2R. Fru¨hwirth,2V. M. Ghete,2J. Hammer,2,bS. Ha¨nsel,2C. Hartl,2M. Hoch,2N. Ho¨rmann,2J. Hrubec,2
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T. Hreus,6P. E. Marage,6L. Thomas,6C. Vander Velde,6P. Vanlaer,6J. Wickens,6V. Adler,7S. Costantini,7 M. Grunewald,7B. Klein,7A. Marinov,7J. Mccartin,7D. Ryckbosch,7F. Thyssen,7M. Tytgat,7L. Vanelderen,7
P. Verwilligen,7S. Walsh,7N. Zaganidis,7S. Basegmez,8G. Bruno,8J. Caudron,8L. Ceard,8 J. De Favereau De Jeneret,8C. Delaere,8P. Demin,8D. Favart,8A. Giammanco,8G. Gre´goire,8J. Hollar,8 V. Lemaitre,8J. Liao,8O. Militaru,8S. Ovyn,8D. Pagano,8A. Pin,8K. Piotrzkowski,8N. Schul,8N. Beliy,9 T. Caebergs,9E. Daubie,9G. A. Alves,10D. De Jesus Damiao,10M. E. Pol,10M. H. G. Souza,10W. Carvalho,11
E. M. Da Costa,11C. De Oliveira Martins,11S. Fonseca De Souza,11L. Mundim,11H. Nogima,11V. Oguri,11 W. L. Prado Da Silva,11A. Santoro,11S. M. Silva Do Amaral,11A. Sznajder,11F. A. Dias,12M. A. F. Dias,12
T. R. Fernandez Perez Tomei,12E. M. Gregores,12,cF. Marinho,12S. F. Novaes,12Sandra S. Padula,12 N. Darmenov,13,bL. Dimitrov,13V. Genchev,13,bP. Iaydjiev,13,bS. Piperov,13M. Rodozov,13S. Stoykova,13 PRL106, 122003 (2011) P H Y S I C A L R E V I E W L E T T E R S 25 MARCH 2011
G. Sultanov,13V. Tcholakov,13R. Trayanov,13I. Vankov,13M. Dyulendarova,14R. Hadjiiska,14V. Kozhuharov,14 L. Litov,14E. Marinova,14M. Mateev,14B. Pavlov,14P. Petkov,14J. G. Bian,15G. M. Chen,15H. S. Chen,15 C. H. Jiang,15D. Liang,15S. Liang,15J. Wang,15J. Wang,15X. Wang,15Z. Wang,15M. Xu,15M. Yang,15J. Zang,15 Z. Zhang,15Y. Ban,16S. Guo,16Y. Guo,16W. Li,16Y. Mao,16S. J. Qian,16H. Teng,16L. Zhang,16B. Zhu,16W. Zou,16 A. Cabrera,17B. Gomez Moreno,17A. A. Ocampo Rios,17A. F. Osorio Oliveros,17J. C. Sanabria,17N. Godinovic,18
D. Lelas,18K. Lelas,18R. Plestina,18,dD. Polic,18I. Puljak,18Z. Antunovic,19M. Dzelalija,19V. Brigljevic,20 S. Duric,20K. Kadija,20S. Morovic,20A. Attikis,21M. Galanti,21J. Mousa,21C. Nicolaou,21F. Ptochos,21 P. A. Razis,21H. Rykaczewski,21Y. Assran,22,eM. A. Mahmoud,22,fA. Hektor,23M. Kadastik,23K. Kannike,23 M. Mu¨ntel,23M. Raidal,23L. Rebane,23V. Azzolini,24P. Eerola,24S. Czellar,25J. Ha¨rko¨nen,25A. Heikkinen,25 V. Karima¨ki,25R. Kinnunen,25J. Klem,25M. J. Kortelainen,25T. Lampe´n,25K. Lassila-Perini,25S. Lehti,25
T. Linde´n,25P. Luukka,25T. Ma¨enpa¨a¨,25E. Tuominen,25J. Tuominiemi,25E. Tuovinen,25D. Ungaro,25 L. Wendland,25K. Banzuzi,26A. Korpela,26T. Tuuva,26D. Sillou,27M. Besancon,28S. Choudhury,28M. Dejardin,28
D. Denegri,28B. Fabbro,28J. L. Faure,28F. Ferri,28S. Ganjour,28F. X. Gentit,28A. Givernaud,28P. Gras,28 G. Hamel de Monchenault,28P. Jarry,28E. Locci,28J. Malcles,28M. Marionneau,28L. Millischer,28J. Rander,28 A. Rosowsky,28I. Shreyber,28M. Titov,28P. Verrecchia,28S. Baffioni,29F. Beaudette,29L. Bianchini,29M. Bluj,29,g C. Broutin,29P. Busson,29C. Charlot,29T. Dahms,29L. Dobrzynski,29R. Granier de Cassagnac,29M. Haguenauer,29
P. Mine´,29C. Mironov,29C. Ochando,29P. Paganini,29D. Sabes,29R. Salerno,29Y. Sirois,29C. Thiebaux,29 B. Wyslouch,29,hA. Zabi,29J.-L. Agram,30,iJ. Andrea,30A. Besson,30D. Bloch,30D. Bodin,30J.-M. Brom,30 M. Cardaci,30E. C. Chabert,30C. Collard,30E. Conte,30,iF. Drouhin,30,iC. Ferro,30J.-C. Fontaine,30,iD. Gele´,30
U. Goerlach,30S. Greder,30P. Juillot,30M. Karim,30,iA.-C. Le Bihan,30Y. Mikami,30P. Van Hove,30F. Fassi,31 D. Mercier,31C. Baty,32N. Beaupere,32M. Bedjidian,32O. Bondu,32G. Boudoul,32D. Boumediene,32H. Brun,32 N. Chanon,32R. Chierici,32D. Contardo,32P. Depasse,32H. El Mamouni,32A. Falkiewicz,32J. Fay,32S. Gascon,32 B. Ille,32T. Kurca,32T. Le Grand,32M. Lethuillier,32L. Mirabito,32S. Perries,32V. Sordini,32S. Tosi,32Y. Tschudi,32 P. Verdier,32H. Xiao,32L. Megrelidze,33V. Roinishvili,33D. Lomidze,34G. Anagnostou,35M. Edelhoff,35L. Feld,35 N. Heracleous,35O. Hindrichs,35R. Jussen,35K. Klein,35J. Merz,35N. Mohr,35A. Ostapchuk,35A. Perieanu,35
F. Raupach,35J. Sammet,35S. Schael,35D. Sprenger,35H. Weber,35M. Weber,35B. Wittmer,35M. Ata,36 W. Bender,36M. Erdmann,36J. Frangenheim,36T. Hebbeker,36A. Hinzmann,36K. Hoepfner,36C. Hof,36 T. Klimkovich,36D. Klingebiel,36P. Kreuzer,36D. Lanske,36,aC. Magass,36G. Masetti,36M. Merschmeyer,36
A. Meyer,36P. Papacz,36H. Pieta,36H. Reithler,36S. A. Schmitz,36L. Sonnenschein,36J. Steggemann,36 D. Teyssier,36M. Bontenackels,37M. Davids,37M. Duda,37G. Flu¨gge,37H. Geenen,37M. Giffels,37 W. Haj Ahmad,37D. Heydhausen,37T. Kress,37Y. Kuessel,37A. Linn,37A. Nowack,37L. Perchalla,37O. Pooth,37
J. Rennefeld,37P. Sauerland,37A. Stahl,37M. Thomas,37D. Tornier,37M. H. Zoeller,37M. Aldaya Martin,38 W. Behrenhoff,38U. Behrens,38M. Bergholz,38,jK. Borras,38A. Cakir,38A. Campbell,38E. Castro,38 D. Dammann,38G. Eckerlin,38D. Eckstein,38A. Flossdorf,38G. Flucke,38A. Geiser,38I. Glushkov,38J. Hauk,38
H. Jung,38M. Kasemann,38I. Katkov,38P. Katsas,38C. Kleinwort,38H. Kluge,38A. Knutsson,38D. Kru¨cker,38 E. Kuznetsova,38W. Lange,38W. Lohmann,38,jR. Mankel,38M. Marienfeld,38I.-A. Melzer-Pellmann,38 A. B. Meyer,38J. Mnich,38A. Mussgiller,38J. Olzem,38A. Parenti,38A. Raspereza,38A. Raval,38R. Schmidt,38,j
T. Schoerner-Sadenius,38N. Sen,38M. Stein,38J. Tomaszewska,38D. Volyanskyy,38R. Walsh,38C. Wissing,38 C. Autermann,39S. Bobrovskyi,39J. Draeger,39H. Enderle,39U. Gebbert,39K. Kaschube,39G. Kaussen,39 R. Klanner,39J. Lange,39B. Mura,39S. Naumann-Emme,39F. Nowak,39N. Pietsch,39C. Sander,39H. Schettler,39
P. Schleper,39M. Schro¨der,39T. Schum,39J. Schwandt,39A. K. Srivastava,39H. Stadie,39G. Steinbru¨ck,39 J. Thomsen,39R. Wolf,39C. Barth,40J. Bauer,40V. Buege,40T. Chwalek,40W. De Boer,40A. Dierlamm,40 G. Dirkes,40M. Feindt,40J. Gruschke,40C. Hackstein,40F. Hartmann,40S. M. Heindl,40M. Heinrich,40H. Held,40
K. H. Hoffmann,40S. Honc,40T. Kuhr,40D. Martschei,40S. Mueller,40Th. Mu¨ller,40M. Niegel,40O. Oberst,40 A. Oehler,40J. Ott,40T. Peiffer,40D. Piparo,40G. Quast,40K. Rabbertz,40F. Ratnikov,40M. Renz,40C. Saout,40 A. Scheurer,40P. Schieferdecker,40F.-P. Schilling,40G. Schott,40H. J. Simonis,40F. M. Stober,40D. Troendle,40 J. Wagner-Kuhr,40M. Zeise,40V. Zhukov,40,kE. B. Ziebarth,40G. Daskalakis,41T. Geralis,41S. Kesisoglou,41
A. Kyriakis,41D. Loukas,41I. Manolakos,41A. Markou,41C. Markou,41C. Mavrommatis,41E. Ntomari,41 E. Petrakou,41L. Gouskos,42T. J. Mertzimekis,42A. Panagiotou,42I. Evangelou,43C. Foudas,43P. Kokkas,43
N. Manthos,43I. Papadopoulos,43V. Patras,43F. A. Triantis,43A. Aranyi,44G. Bencze,44L. Boldizsar,44 G. Debreczeni,44C. Hajdu,44,bD. Horvath,44,lA. Kapusi,44K. Krajczar,44,mA. Laszlo,44F. Sikler,44 PRL106, 122003 (2011) P H Y S I C A L R E V I E W L E T T E R S 25 MARCH 2011
G. Vesztergombi,44,mN. Beni,45J. Molnar,45J. Palinkas,45Z. Szillasi,45V. Veszpremi,45P. Raics,46Z. L. Trocsanyi,46 B. Ujvari,46S. Bansal,47S. B. Beri,47V. Bhatnagar,47N. Dhingra,47R. Gupta,47M. Jindal,47M. Kaur,47J. M. Kohli,47
M. Z. Mehta,47N. Nishu,47L. K. Saini,47A. Sharma,47A. P. Singh,47J. B. Singh,47S. P. Singh,47S. Ahuja,48 S. Bhattacharya,48B. C. Choudhary,48P. Gupta,48S. Jain,48S. Jain,48A. Kumar,48R. K. Shivpuri,48 R. K. Choudhury,49D. Dutta,49S. Kailas,49S. K. Kataria,49A. K. Mohanty,49,bL. M. Pant,49P. Shukla,49T. Aziz,50
M. Guchait,50,nA. Gurtu,50M. Maity,50,oD. Majumder,50G. Majumder,50K. Mazumdar,50G. B. Mohanty,50 A. Saha,50K. Sudhakar,50N. Wickramage,50S. Banerjee,51S. Dugad,51N. K. Mondal,51H. Arfaei,52 H. Bakhshiansohi,52S. M. Etesami,52A. Fahim,52M. Hashemi,52A. Jafari,52M. Khakzad,52A. Mohammadi,52
M. Mohammadi Najafabadi,52S. Paktinat Mehdiabadi,52B. Safarzadeh,52M. Zeinali,52M. Abbrescia,53a,53b L. Barbone,53a,53bC. Calabria,53a,53bA. Colaleo,53aD. Creanza,53a,53cN. De Filippis,53a,53cM. De Palma,53a,53b
A. Dimitrov,53aL. Fiore,53aG. Iaselli,53a,53cL. Lusito,53a,53b,bG. Maggi,53a,53cM. Maggi,53aN. Manna,53a,53b B. Marangelli,53a,53bS. My,53a,53cS. Nuzzo,53a,53bN. Pacifico,53a,53bG. A. Pierro,53aA. Pompili,53a,53b G. Pugliese,53a,53cF. Romano,53a,53cG. Roselli,53a,53bG. Selvaggi,53a,53bL. Silvestris,53aR. Trentadue,53a S. Tupputi,53a,53bG. Zito,53aG. Abbiendi,54aA. C. Benvenuti,54aD. Bonacorsi,54aS. Braibant-Giacomelli,54a,54b
L. Brigliadori,54aP. Capiluppi,54a,54bA. Castro,54a,54bF. R. Cavallo,54aM. Cuffiani,54a,54bG. M. Dallavalle,54a F. Fabbri,54aA. Fanfani,54a,54bD. Fasanella,54aP. Giacomelli,54aM. Giunta,54aS. Marcellini,54a M. Meneghelli,54a,54bA. Montanari,54aF. L. Navarria,54a,54bF. Odorici,54aA. Perrotta,54aF. Primavera,54a A. M. Rossi,54a,54bT. Rovelli,54a,54bG. Siroli,54a,54bR. Travaglini,54a,54bS. Albergo,55a,55bG. Cappello,55a,55b M. Chiorboli,55a,55b,bS. Costa,55a,55bA. Tricomi,55a,55bC. Tuve,55aG. Barbagli,56aV. Ciulli,56a,56bC. Civinini,56a R. D’Alessandro,56a,56bE. Focardi,56a,56bS. Frosali,56a,56bE. Gallo,56aC. Genta,56aS. Gonzi,56a,56bP. Lenzi,56a,56b M. Meschini,56aS. Paoletti,56aG. Sguazzoni,56aA. Tropiano,56a,bL. Benussi,57S. Bianco,57S. Colafranceschi,57,p
F. Fabbri,57D. Piccolo,57P. Fabbricatore,58R. Musenich,58A. Benaglia,59a,59bF. De Guio,59a,59b,b L. Di Matteo,59a,59bA. Ghezzi,59a,59b,bM. Malberti,59a,59bS. Malvezzi,59aA. Martelli,59a,59bA. Massironi,59a,59b
D. Menasce,59aL. Moroni,59aM. Paganoni,59a,59bD. Pedrini,59aS. Ragazzi,59a,59bN. Redaelli,59aS. Sala,59a T. Tabarelli de Fatis,59a,59bV. Tancini,59a,59bS. Buontempo,60aC. A. Carrillo Montoya,60aA. Cimmino,60a,60b
A. De Cosa,60a,60bM. De Gruttola,60a,60bF. Fabozzi,60a,qA. O. M. Iorio,60aL. Lista,60aM. Merola,60a,60b P. Noli,60a,60bP. Paolucci,60aP. Azzi,61aN. Bacchetta,61aP. Bellan,61a,61bD. Bisello,61a,61bA. Branca,61a R. Carlin,61a,61bP. Checchia,61aM. De Mattia,61a,61bT. Dorigo,61aF. Gasparini,61a,61bU. Gasparini,61a,61b P. Giubilato,61a,61bF. Gonella,61aA. Gresele,61a,61cS. Lacaprara,61a,rrI. Lazzizzera,61a,61cM. Margoni,61a,61b M. Mazzucato,61aA. T. Meneguzzo,61a,61bM. Nespolo,61a,bL. Perrozzi,61a,bN. Pozzobon,61a,61bP. Ronchese,61a,61b
F. Simonetto,61a,61bE. Torassa,61aM. Tosi,61a,61bA. Triossi,61aS. Vanini,61a,61bP. Zotto,61a,61bG. Zumerle,61a,61b P. Baesso,62a,62bU. Berzano,62aC. Riccardi,62a,62bP. Torre,62a,62bP. Vitulo,62a,62bC. Viviani,62a,62bM. Biasini,63a,63b
G. M. Bilei,63aB. Caponeri,63a,63bL. Fano`,63a,63bP. Lariccia,63a,63bA. Lucaroni,63a,63b,bG. Mantovani,63a,63b M. Menichelli,63aA. Nappi,63a,63bA. Santocchia,63a,63bL. Servoli,63aS. Taroni,63a,63bM. Valdata,63a,63b R. Volpe,63a,63b,bP. Azzurri,64a,64cG. Bagliesi,64aJ. Bernardini,64a,64bT. Boccali,64a,bG. Broccolo,64a,64c R. Castaldi,64aR. T. D’Agnolo,64a,64cR. Dell’Orso,64aF. Fiori,64a,64bL. Foa`,64a,64cA. Giassi,64aA. Kraan,64a F. Ligabue,64a,64cT. Lomtadze,64aL. Martini,64a,rA. Messineo,64a,64bF. Palla,64aF. Palmonari,64aS. Sarkar,64a,64c
G. Segneri,64aA. T. Serban,64aP. Spagnolo,64aR. Tenchini,64aG. Tonelli,64a,64b,bA. Venturi,64a,bP. G. Verdini,64a L. Barone,65a,65bF. Cavallari,65aD. Del Re,65a,65bE. Di Marco,65a,65bM. Diemoz,65aD. Franci,65a,65bM. Grassi,65a
E. Longo,65a,65bG. Organtini,65a,65bA. Palma,65a,65bF. Pandolfi,65a,65b,bR. Paramatti,65aS. Rahatlou,65a,65b N. Amapane,66a,66bR. Arcidiacono,66a,66cS. Argiro,66a,66bM. Arneodo,66a,66cC. Biino,66aC. Botta,66a,66b,b
N. Cartiglia,66aR. Castello,66a,66bM. Costa,66a,66bN. Demaria,66aA. Graziano,66a,66b,bC. Mariotti,66a M. Marone,66a,66bS. Maselli,66aE. Migliore,66a,66bG. Mila,66a,66bV. Monaco,66a,66bM. Musich,66a,66b M. M. Obertino,66a,66cN. Pastrone,66aM. Pelliccioni,66a,66b,bA. Romero,66a,66bM. Ruspa,66a,66cR. Sacchi,66a,66b
V. Sola,66a,66bA. Solano,66a,66bA. Staiano,66aD. Trocino,66a,66bA. Vilela Pereira,66a,66b,bS. Belforte,67a F. Cossutti,67aG. Della Ricca,67a,67bB. Gobbo,67aD. Montanino,67a,67bA. Penzo,67aS. G. Heo,68S. Chang,69 J. Chung,69D. H. Kim,69G. N. Kim,69J. E. Kim,69D. J. Kong,69H. Park,69D. Son,69D. C. Son,69Zero Kim,70 J. Y. Kim,70S. Song,70S. Choi,71B. Hong,71M. Jo,71H. Kim,71J. H. Kim,71T. J. Kim,71K. S. Lee,71D. H. Moon,71 S. K. Park,71H. B. Rhee,71E. Seo,71S. Shin,71K. S. Sim,71M. Choi,72S. Kang,72H. Kim,72C. Park,72I. C. Park,72
S. Park,72G. Ryu,72Y. Choi,73Y. K. Choi,73J. Goh,73J. Lee,73S. Lee,73H. Seo,73I. Yu,73M. J. Bilinskas,74 I. Grigelionis,74M. Janulis,74D. Martisiute,74P. Petrov,74T. Sabonis,74H. Castilla Valdez,75E. De La Cruz Burelo,75 PRL106, 122003 (2011) P H Y S I C A L R E V I E W L E T T E R S 25 MARCH 2011
R. Lopez-Fernandez,75A. Sa´nchez Herna´ndez,75L. M. Villasenor-Cendejas,75S. Carrillo Moreno,76 F. Vazquez Valencia,76H. A. Salazar Ibarguen,77E. Casimiro Linares,78A. Morelos Pineda,78M. A. Reyes-Santos,78
P. Allfrey,79D. Krofcheck,79P. H. Butler,80R. Doesburg,80H. Silverwood,80M. Ahmad,81I. Ahmed,81 M. I. Asghar,81H. R. Hoorani,81W. A. Khan,81T. Khurshid,81S. Qazi,81M. Cwiok,82W. Dominik,82K. Doroba,82
A. Kalinowski,82M. Konecki,82J. Krolikowski,82T. Frueboes,83R. Gokieli,83M. Go´rski,83M. Kazana,83 K. Nawrocki,83K. Romanowska-Rybinska,83M. Szleper,83G. Wrochna,83P. Zalewski,83N. Almeida,84A. David,84
P. Faccioli,84P. G. Ferreira Parracho,84M. Gallinaro,84P. Martins,84P. Musella,84A. Nayak,84P. Q. Ribeiro,84 J. Seixas,84P. Silva,84J. Varela,84H. K. Wo¨hri,84I. Belotelov,85P. Bunin,85M. Finger,85M. Finger, Jr.,85 I. Golutvin,85A. Kamenev,85V. Karjavin,85G. Kozlov,85A. Lanev,85P. Moisenz,85V. Palichik,85V. Perelygin,85
S. Shmatov,85V. Smirnov,85A. Volodko,85A. Zarubin,85N. Bondar,86V. Golovtsov,86Y. Ivanov,86V. Kim,86 P. Levchenko,86V. Murzin,86V. Oreshkin,86I. Smirnov,86V. Sulimov,86L. Uvarov,86S. Vavilov,86A. Vorobyev,86
Yu. Andreev,87S. Gninenko,87N. Golubev,87M. Kirsanov,87N. Krasnikov,87V. Matveev,87A. Pashenkov,87 A. Toropin,87S. Troitsky,87V. Epshteyn,88V. Gavrilov,88V. Kaftanov,88,aM. Kossov,88,bA. Krokhotin,88 N. Lychkovskaya,88G. Safronov,88S. Semenov,88V. Stolin,88E. Vlasov,88A. Zhokin,88E. Boos,89M. Dubinin,89,s
L. Dudko,89A. Ershov,89A. Gribushin,89O. Kodolova,89I. Lokhtin,89S. Obraztsov,89S. Petrushanko,89 L. Sarycheva,89V. Savrin,89A. Snigirev,89V. Andreev,90M. Azarkin,90I. Dremin,90M. Kirakosyan,90 S. V. Rusakov,90A. Vinogradov,90I. Azhgirey,91S. Bitioukov,91V. Grishin,91,bV. Kachanov,91D. Konstantinov,91
A. Korablev,91V. Krychkine,91V. Petrov,91R. Ryutin,91S. Slabospitsky,91A. Sobol,91L. Tourtchanovitch,91 S. Troshin,91N. Tyurin,91A. Uzunian,91A. Volkov,91P. Adzic,92,tM. Djordjevic,92D. Krpic,92,tJ. Milosevic,92
M. Aguilar-Benitez,93J. Alcaraz Maestre,93P. Arce,93C. Battilana,93E. Calvo,93M. Cepeda,93M. Cerrada,93 N. Colino,93B. De La Cruz,93C. Diez Pardos,93D. Domı´nguez Va´zquez,93C. Fernandez Bedoya,93 J. P. Ferna´ndez Ramos,93A. Ferrando,93J. Flix,93M. C. Fouz,93P. Garcia-Abia,93O. Gonzalez Lopez,93 S. Goy Lopez,93J. M. Hernandez,93M. I. Josa,93G. Merino,93J. Puerta Pelayo,93I. Redondo,93L. Romero,93
J. Santaolalla,93C. Willmott,93C. Albajar,94G. Codispoti,94J. F. de Troco´niz,94J. Cuevas,95
J. Fernandez Menendez,95S. Folgueras,95I. Gonzalez Caballero,95L. Lloret Iglesias,95J. M. Vizan Garcia,95 J. A. Brochero Cifuentes,96I. J. Cabrillo,96A. Calderon,96M. Chamizo Llatas,96S. H. Chuang,96 J. Duarte Campderros,96M. Felcini,96,uM. Fernandez,96G. Gomez,96J. Gonzalez Sanchez,96C. Jorda,96
P. Lobelle Pardo,96A. Lopez Virto,96J. Marco,96R. Marco,96C. Martinez Rivero,96F. Matorras,96 F. J. Munoz Sanchez,96J. Piedra Gomez,96,vT. Rodrigo,96A. Ruiz Jimeno,96L. Scodellaro,96M. Sobron Sanudo,96 I. Vila,96R. Vilar Cortabitarte,96D. Abbaneo,97E. Auffray,97G. Auzinger,97P. Baillon,97A. H. Ball,97D. Barney,97
A. J. Bell,97,wD. Benedetti,97C. Bernet,97,dW. Bialas,97P. Bloch,97A. Bocci,97S. Bolognesi,97H. Breuker,97 G. Brona,97K. Bunkowski,97T. Camporesi,97E. Cano,97G. Cerminara,97T. Christiansen,97J. A. Coarasa Perez,97
B. Cure´,97D. D’Enterria,97A. De Roeck,97S. Di Guida,97F. Duarte Ramos,97A. Elliott-Peisert,97B. Frisch,97 W. Funk,97A. Gaddi,97S. Gennai,97G. Georgiou,97H. Gerwig,97D. Gigi,97K. Gill,97D. Giordano,97F. Glege,97 R. Gomez-Reino Garrido,97M. Gouzevitch,97P. Govoni,97S. Gowdy,97L. Guiducci,97M. Hansen,97J. Harvey,97 J. Hegeman,97B. Hegner,97C. Henderson,97G. Hesketh,97H. F. Hoffmann,97A. Honma,97V. Innocente,97P. Janot,97 K. Kaadze,97E. Karavakis,97P. Lecoq,97C. Lourenc¸o,97A. Macpherson,97T. Ma¨ki,97L. Malgeri,97M. Mannelli,97
L. Masetti,97F. Meijers,97S. Mersi,97E. Meschi,97R. Moser,97M. U. Mozer,97M. Mulders,97E. Nesvold,97,b M. Nguyen,97T. Orimoto,97L. Orsini,97E. Perez,97A. Petrilli,97A. Pfeiffer,97M. Pierini,97M. Pimia¨,97G. Polese,97 A. Racz,97J. Rodrigues Antunes,97G. Rolandi,97,xT. Rommerskirchen,97C. Rovelli,97,yM. Rovere,97H. Sakulin,97
C. Scha¨fer,97C. Schwick,97I. Segoni,97A. Sharma,97P. Siegrist,97M. Simon,97P. Sphicas,97,zD. Spiga,97 M. Spiropulu,97,sF. Sto¨ckli,97M. Stoye,97P. Tropea,97A. Tsirou,97A. Tsyganov,97G. I. Veres,97,mP. Vichoudis,97
M. Voutilainen,97W. D. Zeuner,97W. Bertl,98K. Deiters,98W. Erdmann,98K. Gabathuler,98R. Horisberger,98 Q. Ingram,98H. C. Kaestli,98S. Ko¨nig,98D. Kotlinski,98U. Langenegger,98F. Meier,98D. Renker,98T. Rohe,98
J. Sibille,98,aaA. Starodumov,98,bbP. Bortignon,99L. Caminada,99,ccZ. Chen,99S. Cittolin,99G. Dissertori,99 M. Dittmar,99J. Eugster,99K. Freudenreich,99C. Grab,99A. Herve´,99W. Hintz,99P. Lecomte,99W. Lustermann,99
C. Marchica,99,ccP. Martinez Ruiz del Arbol,99P. Meridiani,99P. Milenovic,99,ddF. Moortgat,99P. Nef,99 F. Nessi-Tedaldi,99L. Pape,99F. Pauss,99T. Punz,99A. Rizzi,99F. J. Ronga,99M. Rossini,99L. Sala,99 A. K. Sanchez,99M.-C. Sawley,99B. Stieger,99L. Tauscher,99,aA. Thea,99K. Theofilatos,99D. Treille,99 C. Urscheler,99R. Wallny,99M. Weber,99L. Wehrli,99J. Weng,99E. Aguilo´,100C. Amsler,100V. Chiochia,100
S. De Visscher,100C. Favaro,100M. Ivova Rikova,100B. Millan Mejias,100C. Regenfus,100P. Robmann,100 PRL106, 122003 (2011) P H Y S I C A L R E V I E W L E T T E R S 25 MARCH 2011
A. Schmidt,100H. Snoek,100Y. H. Chang,101K. H. Chen,101W. T. Chen,101S. Dutta,101A. Go,101C. M. Kuo,101 S. W. Li,101W. Lin,101M. H. Liu,101Z. K. Liu,101Y. J. Lu,101D. Mekterovic,101J. H. Wu,101S. S. Yu,101 P. Bartalini,102P. Chang,102Y. H. Chang,102Y. W. Chang,102Y. Chao,102K. F. Chen,102W.-S. Hou,102Y. Hsiung,102 K. Y. Kao,102Y. J. Lei,102R.-S. Lu,102J. G. Shiu,102Y. M. Tzeng,102M. Wang,102A. Adiguzel,103M. N. Bakirci,103,ee S. Cerci,103,ffC. Dozen,103I. Dumanoglu,103E. Eskut,103S. Girgis,103G. Gokbulut,103Y. Guler,103E. Gurpinar,103
I. Hos,103E. E. Kangal,103T. Karaman,103A. Kayis Topaksu,103A. Nart,103G. Onengut,103K. Ozdemir,103 S. Ozturk,103A. Polatoz,103K. Sogut,103,ggB. Tali,103H. Topakli,103,eeD. Uzun,103L. N. Vergili,103M. Vergili,103
C. Zorbilmez,103I. V. Akin,104T. Aliev,104S. Bilmis,104M. Deniz,104H. Gamsizkan,104A. M. Guler,104 K. Ocalan,104A. Ozpineci,104M. Serin,104R. Sever,104U. E. Surat,104E. Yildirim,104M. Zeyrek,104 M. Deliomeroglu,105D. Demir,105,hhE. Gu¨lmez,105A. Halu,105B. Isildak,105M. Kaya,105,iiO. Kaya,105,ii S. Ozkorucuklu,105,jjN. Sonmez,105,kkL. Levchuk,106P. Bell,107F. Bostock,107J. J. Brooke,107T. L. Cheng,107
E. Clement,107D. Cussans,107R. Frazier,107J. Goldstein,107M. Grimes,107M. Hansen,107D. Hartley,107 G. P. Heath,107H. F. Heath,107B. Huckvale,107J. Jackson,107L. Kreczko,107S. Metson,107D. M. Newbold,107,ll K. Nirunpong,107A. Poll,107S. Senkin,107V. J. Smith,107S. Ward,107L. Basso,108K. W. Bell,108A. Belyaev,108 C. Brew,108R. M. Brown,108B. Camanzi,108D. J. A. Cockerill,108J. A. Coughlan,108K. Harder,108S. Harper,108
B. W. Kennedy,108E. Olaiya,108D. Petyt,108B. C. Radburn-Smith,108C. H. Shepherd-Themistocleous,108 I. R. Tomalin,108W. J. Womersley,108S. D. Worm,108R. Bainbridge,109G. Ball,109J. Ballin,109R. Beuselinck,109
O. Buchmuller,109D. Colling,109N. Cripps,109M. Cutajar,109G. Davies,109M. Della Negra,109J. Fulcher,109 D. Futyan,109A. Guneratne Bryer,109G. Hall,109Z. Hatherell,109J. Hays,109G. Iles,109G. Karapostoli,109 L. Lyons,109A.-M. Magnan,109J. Marrouche,109R. Nandi,109J. Nash,109A. Nikitenko,109,bbA. Papageorgiou,109
M. Pesaresi,109K. Petridis,109M. Pioppi,109,mmD. M. Raymond,109N. Rompotis,109A. Rose,109M. J. Ryan,109 C. Seez,109P. Sharp,109A. Sparrow,109A. Tapper,109S. Tourneur,109M. Vazquez Acosta,109T. Virdee,109 S. Wakefield,109D. Wardrope,109T. Whyntie,109M. Barrett,110M. Chadwick,110J. E. Cole,110P. R. Hobson,110 A. Khan,110P. Kyberd,110D. Leslie,110W. Martin,110I. D. Reid,110L. Teodorescu,110K. Hatakeyama,111T. Bose,112 E. Carrera Jarrin,112A. Clough,112C. Fantasia,112A. Heister,112J. St. John,112P. Lawson,112D. Lazic,112J. Rohlf,112
D. Sperka,112L. Sulak,112A. Avetisyan,113S. Bhattacharya,113J. P. Chou,113D. Cutts,113A. Ferapontov,113 U. Heintz,113S. Jabeen,113G. Kukartsev,113G. Landsberg,113M. Narain,113D. Nguyen,113M. Segala,113T. Speer,113 K. V. Tsang,113M. A. Borgia,114R. Breedon,114M. Calderon De La Barca Sanchez,114D. Cebra,114S. Chauhan,114
M. Chertok,114J. Conway,114P. T. Cox,114J. Dolen,114R. Erbacher,114E. Friis,114W. Ko,114A. Kopecky,114 R. Lander,114H. Liu,114S. Maruyama,114T. Miceli,114M. Nikolic,114D. Pellett,114J. Robles,114S. Salur,114 T. Schwarz,114M. Searle,114J. Smith,114M. Squires,114M. Tripathi,114R. Vasquez Sierra,114C. Veelken,114 V. Andreev,115K. Arisaka,115D. Cline,115R. Cousins,115A. Deisher,115J. Duris,115S. Erhan,115C. Farrell,115 J. Hauser,115M. Ignatenko,115C. Jarvis,115C. Plager,115G. Rakness,115P. Schlein,115,aJ. Tucker,115V. Valuev,115
J. Babb,116R. Clare,116J. Ellison,116J. W. Gary,116F. Giordano,116G. Hanson,116G. Y. Jeng,116S. C. Kao,116 F. Liu,116H. Liu,116A. Luthra,116H. Nguyen,116G. Pasztor,116,nnA. Satpathy,116B. C. Shen,116,aR. Stringer,116 J. Sturdy,116S. Sumowidagdo,116R. Wilken,116S. Wimpenny,116W. Andrews,117J. G. Branson,117G. B. Cerati,117
E. Dusinberre,117D. Evans,117F. Golf,117A. Holzner,117R. Kelley,117M. Lebourgeois,117J. Letts,117 B. Mangano,117J. Muelmenstaedt,117S. Padhi,117C. Palmer,117G. Petrucciani,117H. Pi,117M. Pieri,117 R. Ranieri,117M. Sani,117V. Sharma,117,bS. Simon,117Y. Tu,117A. Vartak,117F. Wu¨rthwein,117A. Yagil,117 D. Barge,118R. Bellan,118C. Campagnari,118M. D’Alfonso,118T. Danielson,118K. Flowers,118P. Geffert,118 J. Incandela,118C. Justus,118P. Kalavase,118S. A. Koay,118D. Kovalskyi,118V. Krutelyov,118S. Lowette,118 N. Mccoll,118V. Pavlunin,118F. Rebassoo,118J. Ribnik,118J. Richman,118R. Rossin,118D. Stuart,118W. To,118 J. R. Vlimant,118A. Bornheim,119J. Bunn,119Y. Chen,119M. Gataullin,119D. Kcira,119V. Litvine,119Y. Ma,119 A. Mott,119H. B. Newman,119C. Rogan,119V. Timciuc,119P. Traczyk,119J. Veverka,119R. Wilkinson,119Y. Yang,119
R. Y. Zhu,119B. Akgun,120R. Carroll,120T. Ferguson,120Y. Iiyama,120D. W. Jang,120S. Y. Jun,120Y. F. Liu,120 M. Paulini,120J. Russ,120N. Terentyev,120H. Vogel,120I. Vorobiev,120J. P. Cumalat,121M. E. Dinardo,121 B. R. Drell,121C. J. Edelmaier,121W. T. Ford,121A. Gaz,121B. Heyburn,121E. Luiggi Lopez,121U. Nauenberg,121
J. G. Smith,121K. Stenson,121K. A. Ulmer,121S. R. Wagner,121S. L. Zang,121L. Agostino,122J. Alexander,122 A. Chatterjee,122S. Das,122N. Eggert,122L. J. Fields,122L. K. Gibbons,122B. Heltsley,122W. Hopkins,122 A. Khukhunaishvili,122B. Kreis,122V. Kuznetsov,122G. Nicolas Kaufman,122J. R. Patterson,122D. Puigh,122 D. Riley,122A. Ryd,122X. Shi,122W. Sun,122W. D. Teo,122J. Thom,122J. Thompson,122J. Vaughan,122Y. Weng,122 PRL106, 122003 (2011) P H Y S I C A L R E V I E W L E T T E R S 25 MARCH 2011
L. Winstrom,122P. Wittich,122A. Biselli,123G. Cirino,123D. Winn,123S. Abdullin,124M. Albrow,124J. Anderson,124 G. Apollinari,124M. Atac,124J. A. Bakken,124S. Banerjee,124L. A. T. Bauerdick,124A. Beretvas,124J. Berryhill,124 P. C. Bhat,124I. Bloch,124F. Borcherding,124K. Burkett,124J. N. Butler,124V. Chetluru,124H. W. K. Cheung,124 F. Chlebana,124S. Cihangir,124M. Demarteau,124D. P. Eartly,124V. D. Elvira,124S. Esen,124I. Fisk,124J. Freeman,124 Y. Gao,124E. Gottschalk,124D. Green,124K. Gunthoti,124O. Gutsche,124A. Hahn,124J. Hanlon,124R. M. Harris,124
J. Hirschauer,124B. Hooberman,124E. James,124H. Jensen,124M. Johnson,124U. Joshi,124R. Khatiwada,124 B. Kilminster,124B. Klima,124K. Kousouris,124S. Kunori,124S. Kwan,124C. Leonidopoulos,124P. Limon,124 R. Lipton,124J. Lykken,124K. Maeshima,124J. M. Marraffino,124D. Mason,124P. McBride,124T. McCauley,124 T. Miao,124K. Mishra,124S. Mrenna,124Y. Musienko,124,ooC. Newman-Holmes,124V. O’Dell,124S. Popescu,124,pp R. Pordes,124O. Prokofyev,124N. Saoulidou,124E. Sexton-Kennedy,124S. Sharma,124A. Soha,124W. J. Spalding,124
L. Spiegel,124P. Tan,124L. Taylor,124S. Tkaczyk,124L. Uplegger,124E. W. Vaandering,124R. Vidal,124 J. Whitmore,124W. Wu,124F. Yang,124F. Yumiceva,124J. C. Yun,124D. Acosta,125P. Avery,125D. Bourilkov,125
M. Chen,125G. P. Di Giovanni,125D. Dobur,125A. Drozdetskiy,125R. D. Field,125M. Fisher,125Y. Fu,125 I. K. Furic,125J. Gartner,125S. Goldberg,125B. Kim,125S. Klimenko,125J. Konigsberg,125A. Korytov,125 A. Kropivnitskaya,125T. Kypreos,125K. Matchev,125G. Mitselmakher,125L. Muniz,125Y. Pakhotin,125 C. Prescott,125R. Remington,125M. Schmitt,125B. Scurlock,125P. Sellers,125N. Skhirtladze,125D. Wang,125 J. Yelton,125M. Zakaria,125C. Ceron,126V. Gaultney,126L. Kramer,126L. M. Lebolo,126S. Linn,126P. Markowitz,126
G. Martinez,126J. L. Rodriguez,126T. Adams,127A. Askew,127D. Bandurin,127J. Bochenek,127J. Chen,127 B. Diamond,127S. V. Gleyzer,127J. Haas,127S. Hagopian,127V. Hagopian,127M. Jenkins,127K. F. Johnson,127
H. Prosper,127L. Quertenmont,127S. Sekmen,127V. Veeraraghavan,127M. M. Baarmand,128B. Dorney,128 S. Guragain,128M. Hohlmann,128H. Kalakhety,128R. Ralich,128I. Vodopiyanov,128M. R. Adams,129 I. M. Anghel,129L. Apanasevich,129Y. Bai,129V. E. Bazterra,129R. R. Betts,129J. Callner,129R. Cavanaugh,129 C. Dragoiu,129E. J. Garcia-Solis,129L. Gauthier,129C. E. Gerber,129D. J. Hofman,129S. Khalatyan,129F. Lacroix,129
M. Malek,129C. O’Brien,129C. Silvestre,129A. Smoron,129D. Strom,129N. Varelas,129U. Akgun,130 E. A. Albayrak,130B. Bilki,130K. Cankocak,130,qqW. Clarida,130F. Duru,130C. K. Lae,130E. McCliment,130
J.-P. Merlo,130H. Mermerkaya,130A. Mestvirishvili,130A. Moeller,130J. Nachtman,130C. R. Newsom,130 E. Norbeck,130J. Olson,130Y. Onel,130F. Ozok,130S. Sen,130J. Wetzel,130T. Yetkin,130K. Yi,130B. A. Barnett,131 B. Blumenfeld,131A. Bonato,131C. Eskew,131D. Fehling,131G. Giurgiu,131A. V. Gritsan,131Z. J. Guo,131G. Hu,131
P. Maksimovic,131S. Rappoccio,131M. Swartz,131N. V. Tran,131A. Whitbeck,131P. Baringer,132A. Bean,132 G. Benelli,132O. Grachov,132M. Murray,132D. Noonan,132V. Radicci,132S. Sanders,132J. S. Wood,132 V. Zhukova,132T. Bolton,133I. Chakaberia,133A. Ivanov,133M. Makouski,133Y. Maravin,133S. Shrestha,133 I. Svintradze,133Z. Wan,133J. Gronberg,134D. Lange,134D. Wright,134A. Baden,135M. Boutemeur,135S. C. Eno,135
D. Ferencek,135J. A. Gomez,135N. J. Hadley,135R. G. Kellogg,135M. Kirn,135Y. Lu,135A. C. Mignerey,135 K. Rossato,135P. Rumerio,135F. Santanastasio,135A. Skuja,135J. Temple,135M. B. Tonjes,135S. C. Tonwar,135 E. Twedt,135B. Alver,136G. Bauer,136J. Bendavid,136W. Busza,136E. Butz,136I. A. Cali,136M. Chan,136V. Dutta,136
P. Everaerts,136G. Gomez Ceballos,136M. Goncharov,136K. A. Hahn,136P. Harris,136Y. Kim,136M. Klute,136 Y.-J. Lee,136W. Li,136C. Loizides,136P. D. Luckey,136T. Ma,136S. Nahn,136C. Paus,136D. Ralph,136C. Roland,136
G. Roland,136M. Rudolph,136G. S. F. Stephans,136K. Sumorok,136K. Sung,136E. A. Wenger,136S. Xie,136 M. Yang,136Y. Yilmaz,136A. S. Yoon,136M. Zanetti,136P. Cole,137S. I. Cooper,137P. Cushman,137B. Dahmes,137
A. De Benedetti,137P. R. Dudero,137G. Franzoni,137J. Haupt,137K. Klapoetke,137Y. Kubota,137J. Mans,137 V. Rekovic,137R. Rusack,137M. Sasseville,137A. Singovsky,137L. M. Cremaldi,138R. Godang,138R. Kroeger,138 L. Perera,138R. Rahmat,138D. A. Sanders,138D. Summers,138K. Bloom,139S. Bose,139J. Butt,139D. R. Claes,139
A. Dominguez,139M. Eads,139J. Keller,139T. Kelly,139I. Kravchenko,139J. Lazo-Flores,139C. Lundstedt,139 H. Malbouisson,139S. Malik,139G. R. Snow,139U. Baur,140A. Godshalk,140I. Iashvili,140S. Jain,140 A. Kharchilava,140A. Kumar,140S. P. Shipkowski,140K. Smith,140G. Alverson,141E. Barberis,141D. Baumgartel,141
O. Boeriu,141M. Chasco,141S. Reucroft,141J. Swain,141D. Wood,141J. Zhang,141A. Anastassov,142A. Kubik,142 N. Odell,142R. A. Ofierzynski,142B. Pollack,142A. Pozdnyakov,142M. Schmitt,142S. Stoynev,142M. Velasco,142 S. Won,142L. Antonelli,143D. Berry,143M. Hildreth,143C. Jessop,143D. J. Karmgard,143J. Kolb,143T. Kolberg,143 K. Lannon,143W. Luo,143S. Lynch,143N. Marinelli,143D. M. Morse,143T. Pearson,143R. Ruchti,143J. Slaunwhite,143
N. Valls,143J. Warchol,143M. Wayne,143J. Ziegler,143B. Bylsma,144L. S. Durkin,144J. Gu,144C. Hill,144 P. Killewald,144K. Kotov,144T. Y. Ling,144M. Rodenburg,144G. Williams,144N. Adam,145E. Berry,145P. Elmer,145 PRL106, 122003 (2011) P H Y S I C A L R E V I E W L E T T E R S 25 MARCH 2011
D. Gerbaudo,145V. Halyo,145P. Hebda,145A. Hunt,145J. Jones,145E. Laird,145D. Lopes Pegna,145D. Marlow,145 T. Medvedeva,145M. Mooney,145J. Olsen,145P. Piroue´,145X. Quan,145H. Saka,145D. Stickland,145C. Tully,145
J. S. Werner,145A. Zuranski,145J. G. Acosta,146X. T. Huang,146A. Lopez,146H. Mendez,146S. Oliveros,146 J. E. Ramirez Vargas,146A. Zatserklyaniy,146E. Alagoz,147V. E. Barnes,147G. Bolla,147L. Borrello,147 D. Bortoletto,147A. Everett,147A. F. Garfinkel,147Z. Gecse,147L. Gutay,147Z. Hu,147M. Jones,147O. Koybasi,147
A. T. Laasanen,147N. Leonardo,147C. Liu,147V. Maroussov,147P. Merkel,147D. H. Miller,147N. Neumeister,147 I. Shipsey,147D. Silvers,147A. Svyatkovskiy,147H. D. Yoo,147J. Zablocki,147Y. Zheng,147P. Jindal,148 N. Parashar,148C. Boulahouache,149V. Cuplov,149K. M. Ecklund,149F. J. M. Geurts,149J. H. Liu,149B. P. Padley,149
R. Redjimi,149J. Roberts,149J. Zabel,149B. Betchart,150A. Bodek,150Y. S. Chung,150R. Covarelli,150 P. de Barbaro,150R. Demina,150Y. Eshaq,150H. Flacher,150A. Garcia-Bellido,150P. Goldenzweig,150Y. Gotra,150 J. Han,150A. Harel,150D. C. Miner,150D. Orbaker,150G. Petrillo,150D. Vishnevskiy,150M. Zielinski,150A. Bhatti,151 R. Ciesielski,151L. Demortier,151K. Goulianos,151G. Lungu,151C. Mesropian,151M. Yan,151O. Atramentov,152
A. Barker,152D. Duggan,152Y. Gershtein,152R. Gray,152E. Halkiadakis,152D. Hidas,152D. Hits,152A. Lath,152 S. Panwalkar,152R. Patel,152A. Richards,152K. Rose,152S. Schnetzer,152S. Somalwar,152R. Stone,152S. Thomas,152
G. Cerizza,153M. Hollingsworth,153S. Spanier,153Z. C. Yang,153A. York,153J. Asaadi,154R. Eusebi,154 J. Gilmore,154A. Gurrola,154T. Kamon,154V. Khotilovich,154R. Montalvo,154C. N. Nguyen,154I. Osipenkov,154
J. Pivarski,154A. Safonov,154S. Sengupta,154A. Tatarinov,154D. Toback,154M. Weinberger,154N. Akchurin,155 C. Bardak,155J. Damgov,155C. Jeong,155K. Kovitanggoon,155S. W. Lee,155P. Mane,155Y. Roh,155A. Sill,155
I. Volobouev,155R. Wigmans,155E. Yazgan,155E. Appelt,156E. Brownson,156D. Engh,156C. Florez,156 W. Gabella,156W. Johns,156P. Kurt,156C. Maguire,156A. Melo,156P. Sheldon,156J. Velkovska,156M. W. Arenton,157 M. Balazs,157S. Boutle,157M. Buehler,157S. Conetti,157B. Cox,157B. Francis,157R. Hirosky,157A. Ledovskoy,157 C. Lin,157C. Neu,157R. Yohay,157S. Gollapinni,158R. Harr,158P. E. Karchin,158P. Lamichhane,158M. Mattson,158 C. Milste`ne,158A. Sakharov,158M. Anderson,159M. Bachtis,159J. N. Bellinger,159D. Carlsmith,159S. Dasu,159
J. Efron,159L. Gray,159K. S. Grogg,159M. Grothe,159R. Hall-Wilton,159,bM. Herndon,159P. Klabbers,159 J. Klukas,159A. Lanaro,159C. Lazaridis,159J. Leonard,159R. Loveless,159A. Mohapatra,159D. Reeder,159I. Ross,159
A. Savin,159W. H. Smith,159J. Swanson,159and M. Weinberg159 (CMS Collaboration)
1Yerevan Physics Institute, Yerevan, Armenia 2Institut fu¨r Hochenergiephysik der OeAW, Wien, Austria
3National Centre for Particle and High Energy Physics, Minsk, Republic of 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
14University of Sofia, Sofia, Bulgaria 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 19
University of Split, Split, Croatia 20Institute Rudjer Boskovic, Zagreb, Croatia
21University of Cyprus, Nicosia, Cyprus
22Academy of Scientific Research and Technology of the Arab Republic of Egypt, Egyptian Network of High Energy Physics, Cairo, Egypt
23National Institute of Chemical Physics and Biophysics, Tallinn, Estonia 24Department of Physics, University of Helsinki, Helsinki, Finland
25Helsinki Institute of Physics, Helsinki, Finland
26Lappeenranta University of Technology, Lappeenranta, Finland
27Laboratoire d’Annecy-le-Vieux de Physique des Particules, IN2P3-CNRS, Annecy-le-Vieux, France 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
33
E. Andronikashvili Institute of Physics, Academy of Science, Tbilisi, Georgia 34Institute of High Energy Physics and Informatization, Tbilisi State University, Tbilisi, Georgia
35RWTH Aachen University, I. Physikalisches Institut, Aachen, Germany 36RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany 37RWTH Aachen University, III. Physikalisches Institut B, Aachen, Germany
38Deutsches Elektronen-Synchrotron, Hamburg, Germany 39University of Hamburg, Hamburg, Germany 40Institut fu¨r Experimentelle Kernphysik, Karlsruhe, Germany 41Institute of Nuclear Physics ‘‘Demokritos,’’ Aghia Paraskevi, Greece
42University of Athens, Athens, Greece 43University of Ioa´nnina, Ioa´nnina, Greece
44KFKI Research Institute for Particle and Nuclear Physics, Budapest, Hungary 45Institute of Nuclear Research ATOMKI, Debrecen, Hungary
46University of Debrecen, Debrecen, Hungary 47Panjab University, Chandigarh, India
48University of Delhi, Delhi, India 49
Bhabha Atomic Research Centre, Mumbai, India 50Tata Institute of Fundamental Research - EHEP, Mumbai, India 51Tata Institute of Fundamental Research - HECR, Mumbai, India 52Institute for Research and 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 56aINFN 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-Biccoca, 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 61bUniversita` di Trento (Trento), Padova, Italy 61cUniversita` di Trento (Trento), Padova, Italy
62aINFN Sezione di Pavia, Pavia, Italy 62b
Universita` di Pavia, Pavia, Italy 63aINFN Sezione di Perugia, Perugia, Italy
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 66b
Universita` di Torino, Torino, Italy
66cUniversita` 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 71Korea University, Seoul, Korea
72University of Seoul, Seoul, Korea 73Sungkyunkwan University, Suwon, Korea
74Vilnius University, Vilnius, Lithuania
75Centro de Investigacion y de Estudios Avanzados del IPN, Mexico City, Mexico 76Universidad Iberoamericana, Mexico City, Mexico
77
Benemerita Universidad Autonoma de Puebla, Puebla, Mexico 78Universidad Auto´noma de San Luis Potosı´, San Luis Potosı´, Mexico
79University of Auckland, Auckland, New Zealand 80University of Canterbury, Christchurch, New Zealand
81National Centre for Physics, Quaid-I-Azam University, Islamabad, Pakistan 82Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland
83Soltan Institute for Nuclear Studies, Warsaw, Poland
84Laborato´rio de Instrumentac¸a˜o e Fı´sica Experimental de Partı´culas, Lisboa, Portugal 85Joint Institute for Nuclear Research, Dubna, Russia
86Petersburg Nuclear Physics Institute, Gatchina (St. Petersburg), Russia 87Institute for Nuclear Research, Moscow, Russia
88Institute for Theoretical and Experimental Physics, Moscow, Russia 89Moscow State University, Moscow, Russia
90P. N. Lebedev Physical Institute, Moscow, Russia
91State Research Center of Russian Federation, Institute for High Energy Physics, Protvino, Russia 92University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences, Belgrade, Serbia
93
Centro de Investigaciones Energe´ticas Medioambientales y Tecnolo´gicas (CIEMAT), Madrid, Spain 94Universidad Auto´noma de Madrid, Madrid, Spain
95Universidad de Oviedo, Oviedo, Spain
96Instituto de Fı´sica de Cantabria (IFCA), CSIC-Universidad de Cantabria, Santander, Spain 97CERN, European Organization for Nuclear Research, Geneva, Switzerland
98Paul Scherrer Institut, Villigen, Switzerland
99Institute for Particle Physics, ETH Zurich, Zurich, Switzerland 100Universita¨t Zu¨rich, Zurich, Switzerland
101National Central University, Chung-Li, Taiwan 102National Taiwan University (NTU), Taipei, Taiwan
103Cukurova University, Adana, Turkey
104Middle East Technical University, Physics Department, Ankara, Turkey 105Bogazici University, Istanbul, Turkey
106National Scientific Center, Kharkov Institute of Physics and Technology, Kharkov, Ukraine 107University of Bristol, Bristol, United Kingdom
108Rutherford Appleton Laboratory, Didcot, United Kingdom 109Imperial College, London, United Kingdom 110Brunel University, Uxbridge, United Kingdom
111Baylor University, Waco, Texas, USA 112Boston University, Boston, Massachusetts, USA 113Brown University, Providence, Rhode Island, USA 114University of California, Davis, Davis, California, USA 115University of California, Los Angeles, Los Angeles, California, USA
116
University of California, Riverside, Riverside, California, USA 117University of California, San Diego, La Jolla, California, USA 118University of California, Santa Barbara, Santa Barbara, California, USA
119California Institute of Technology, Pasadena, California, USA 120Carnegie Mellon University, Pittsburgh, Pennsylvania, USA 121University of Colorado at Boulder, Boulder, Colorado, USA
122Cornell University, Ithaca, New York, USA 123Fairfield University, Fairfield, Connecticut, USA 124Fermi National Accelerator Laboratory, Batavia, Illinois, USA
125
University of Florida, Gainesville, Florida, USA 126Florida International University, Miami, Florida, USA
127Florida State University, Tallahassee, Florida, USA 128Florida Institute of Technology, Melbourne, Florida, USA 129University of Illinois at Chicago (UIC), Chicago, Illinois, USA
130The University of Iowa, Iowa City, Iowa, USA 131Johns Hopkins University, Baltimore, Maryland, USA
132The University of Kansas, Lawrence, Kansas, USA 133Kansas State University, Manhattan, Kansas, USA
134Lawrence Livermore National Laboratory, Livermore, California, USA 135University of Maryland, College Park, Maryland, USA 136Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
137University of Minnesota, Minneapolis, Minnesota, USA 138
University of Mississippi, University, Mississippi, USA 139University of Nebraska-Lincoln, Lincoln, Nebraska, USA 140State University of New York at Buffalo, Buffalo, New York, USA
141Northeastern University, Boston, Massachusetts, USA 142Northwestern University, Evanston, Illinois, USA 143University of Notre Dame, Notre Dame, Indiana, USA
144The Ohio State University, Columbus, Ohio, USA 145Princeton University, Princeton, New Jersey, USA 146University of Puerto Rico, Mayaguez, Puerto Rico, USA
147Purdue University, West Lafayette, Indiana, USA 148Purdue University Calumet, Hammond, Indiana, USA
149Rice University, Houston, Texas, USA 150University of Rochester, Rochester, New York, USA 151The Rockefeller University, New York, New York, USA
152Rutgers, the State University of New Jersey, Piscataway, New York, USA 153University of Tennessee, Knoxville, Tennessee, USA
154
Texas A&M University, College Station, Texas, USA 155Texas Tech University, Lubbock, Texas, USA 156Vanderbilt University, Nashville, Tennessee, USA 157University of Virginia, Charlottesville, Virginia, USA
158Wayne State University, Detroit, Michigan, USA 159University of Wisconsin, Madison, Wisconsin, USA
aDeceased. b
Also at CERN, European Organization for Nuclear Research, Geneva, Switzerland.
cAlso at Universidade Federal do ABC, Santo Andre, Brazil.
dAlso at Laboratoire Leprince-Ringuet, Ecole Polytechnique, IN2P3-CNRS, Palaiseau, France. eAlso at Suez Canal University, Suez, Egypt.
fAlso at Fayoum University, El-Fayoum, Egypt.
gAlso at Soltan Institute for Nuclear Studies, Warsaw, Poland.
hAlso at Massachusetts Institute of Technology, Cambridge, MA, USA. iAlso at Universite´ de Haute-Alsace, Mulhouse, France.
jAlso at Brandenburg University of Technology, Cottbus, Germany. kAlso at Moscow State University, Moscow, Russia.
lAlso at Institute of Nuclear Research ATOMKI, Debrecen, Hungary. mAlso at Eo¨tvo¨s Lora´nd University, Budapest, Hungary.
nAlso at Tata Institute of Fundamental Research - HECR, Mumbai, India. oAlso at University of Visva-Bharati, Santiniketan, India.
p
Also at Facolta` Ingegneria Universita` di Roma ‘‘La Sapienza,’’ Roma, Italy.
qAlso at Universita` della Basilicata, Potenza, Italy. rAlso at Universita` degli studi di Siena, Siena, Italy.
sAlso at California Institute of Technology, Pasadena, CA, USA. tAlso at Faculty of Physics of University of Belgrade, Belgrade, Serbia. uAlso at University of California, Los Angeles, Los Angeles, CA, USA. vAlso at University of Florida, Gainesville, FL, USA.
wAlso at Universite´ de Gene`ve, Geneva, Switzerland. xAlso at Scuola Normale e Sezione dell’ INFN, Pisa, Italy.
yAlso at INFN Sezione di Roma, Universita` di Roma ‘‘La Sapienza,’’ Roma, Italy. zAlso at University of Athens, Athens, Greece.
aaAlso at The University of Kansas, Lawrence, KS, USA.
bbAlso at Institute for Theoretical and Experimental Physics, Moscow, Russia. ccAlso at Paul Scherrer Institut, Villigen, Switzerland.
ddAlso at University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences, Belgrade, Serbia. eeAlso at Gaziosmanpasa University, Tokat, Turkey.
ffAlso at Adiyaman University, Adiyaman, Turkey. ggAlso at Mersin University, Mersin, Turkey.
hhAlso at Izmir Institute of Technology, Izmir, Turkey. iiAlso at Kafkas University, Kars, Turkey.
jjAlso at Suleyman Demirel University, Isparta, Turkey. kkAlso at Ege University, Izmir, Turkey.
llAlso at Rutherford Appleton Laboratory, Didcot, United Kingdom. mmAlso at INFN Sezione di Perugia, Universita` di Perugia, Perugia, Italy.
nnAlso at KFKI Research Institute for Particle and Nuclear Physics, Budapest, Hungary. ooAlso at Institute for Nuclear Research, Moscow, Russia.
pp
Also at Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH), Bucharest, Romania.
qqAlso at Istanbul Technical University, Istanbul, Turkey.
rrAlso at Laboratori Nazionale di Legnaro dell’INFN, Legnaro, Italy.
