Measurement of the Bs0 Production Cross Section with Bs0-->J/psivarphi Decays in pp Collisions at s=7TeV

EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH (CERN)

CERN-PH-EP/2011-0632011/06/22

CMS-BPH-10-013

Measurement of the B0s Production Cross Section with

B0s → J/ψ φ Decays in pp Collisions at

√s = 7 TeV

The CMS Collaboration∗

Abstract

The B0s differential production cross section is measured as functions of the trans-

verse momentum and rapidity in pp collisions at√

s = 7 TeV, using the B0s → J/ψ φ

decay, and compared with predictions based on perturbative QCD calculations atnext-to-leading order. The data sample, collected by the CMS experiment at the LHC,corresponds to an integrated luminosity of 40 pb−1. The B0

s is reconstructed from thedecays J/ψ→ µ+µ− and φ→ K+K−. The integrated B0

s cross section times B0s → J/ψ φ

branching fraction in the range 8 < pBT < 50 GeV/c and

∣∣yB∣∣ < 2.4 is measured to be

6.9± 0.6± 0.6 nb, where the first uncertainty is statistical and the second is systematic.

Submitted to Physical Review D (Rapid Communications)

∗See Appendix A for the list of collaboration members

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The measurements of differential cross sections for heavy-quark production in high-energyhadronic interactions are critical input for the underlying next-to-leading order (NLO) Quan-tum Chromodynamics (QCD) calculations [1]. While progress has been achieved in the under-standing of heavy-quark production at Tevatron energies [2–10], large theoretical uncertaintiesremain due to the dependence on the renormalization and factorization scales. Measurementsof b-hadron production at the higher energies provided by the LHC represent an importantnew test of theoretical approaches that aim to reduce the scale dependence of NLO QCD calcu-lations [11, 12]. The Compact Muon Solenoid (CMS) experiment, that covers a rapidity rangecomplementary to the specialised b-physics experiment LHCb [13], recently measured the crosssections for production of B+ [14] and B0 [15] in pp collisions at

√s = 7 TeV. This paper presents

the first measurement of the production of B0s , with B0

s decaying into J/ψ φ, and adds informa-tion to improve the understanding of b-quark production at this energy. Data and theoreticalpredictions are compared at the level of NLO heavy-quark production.

The decay channel B0s → J/ψ φ is of wide interest for the indirect search of physics beyond the

standard model at the LHC. This decay proceeds via the b→ ccs transition that probes the CP-violating phase related to B0

s -B0s mixing. The standard model predicts this phase to be close to

zero [16] while new phenomena may alter the observed phase [17]. The differential productioncross section analysis prototypes the signal extraction towards time-dependent measurementsin this final state.

A sample of exclusive B0s → J/ψ φ decays, with J/ψ → µ+µ− and φ → K+K−, is reconstructed

in the data collected in 2010 by the CMS experiment, corresponding to an integrated lumi-nosity of 39.6± 1.6 pb−1. The differential production cross sections, dσ/dpB

T and dσ/dyB, aredetermined as functions of the transverse momentum pB

T and rapidity∣∣yB∣∣ of the reconstructed

B0s candidate. Here, the rapidity yB is defined as 1

2 ln E+cpLE−cpL

, where E is the particle’s energyand pL is the particle’s momentum along the counterclockwise beam direction. The differentialcross sections are calculated from the measured signal yields (nsig), corrected for the overallefficiency (ε), bin size (∆x, with x = pB

T,∣∣yB∣∣), and integrated luminosity (L),

dσ(pp→ B0s → J/ψ φ)

dx=

nsig

2 · ε · B · L · ∆x, (1)

where B is the product of the branching fractions for the decays of the J/ψ and φ mesons. Ineach bin the signal yield is extracted with an unbinned maximum likelihood fit to the J/ψ φinvariant mass and proper decay length ct of the B0

s candidates. The factor of 2 in Eq. (1)accounts for the choice of quoting the cross section for B0

s production, while nsig includes both

B0s and B

0s states. The size of the bins is chosen such that the statistical uncertainty on nsig is

comparable in each of them.

A detailed description of the CMS detector can be found elsewhere [18]. The primary compo-nents used in this analysis are the silicon tracker and the muon systems. The tracker operates ina 3.8 T axial magnetic field generated by a superconducting solenoid having an internal diam-eter of 6 m. The tracker consists of three cylindrical layers of pixel detectors complemented bytwo disks in the forward and backward directions. The radial region between 20 and 116 cm isoccupied by several layers of silicon strip detectors in barrel and disk configurations, ensuringat least nine hits in the pseudorapidity range |η| < 2.4, where η = − ln [tan (θ/2)] and θ is thepolar angle of the track relative to the counterclockwise beam direction. An impact parameterresolution around 15 µm and a pT resolution around 1.5 % are achieved for charged particleswith transverse momenta up to 100 GeV/c. Muons are identified in the range |η| < 2.4, withdetection planes made of drift tubes, cathode strip chambers, and resistive plate chambers,

2

embedded in the steel return yoke.

The first level of the CMS trigger system uses information from the crystal electromagnetic cal-orimeter, the brass/scintillator hadron calorimeter, and the muon detectors to select the mostinteresting events in less than 1 µs. The high level trigger (HLT) employs software algorithmsand a farm of commercial processors to further decrease the event rate using information fromall detector subsystems. The events used in the measurement reported in this paper were col-lected with a trigger requiring the presence of two muons at the HLT, with no explicit momen-tum threshold.

Reconstruction of B0s → J/ψ φ candidates begins by identifying J/ψ→ µ+µ− decays. The muon

candidates must have one or more reconstructed segments in the muon system that matchthe extrapolated position of a track reconstructed in the tracker. Furthermore, the muons arerequired to lie within a kinematic acceptance region defined as: pµ

T > 3.3 GeV/c for |ηµ| < 1.3;total momentum pµ > 2.9 GeV/c for 1.3 < |ηµ| < 2.2; and pµ

T > 0.8 GeV/c for 2.2 < |ηµ| <2.4. Two oppositely charged muon candidates are paired and are required to originate froma common vertex using a Kalman vertex fit. The muon pair is required to have a transversemomentum pT > 0.5 GeV/c and an invariant mass within 150 MeV/c2 of the world average J/ψmass value [19], which corresponds to more than three times the measured dimuon invariantmass resolution [20].

Candidate φ mesons are reconstructed from pairs of oppositely charged tracks with pT >0.7 GeV/c that are selected from a sample with the muon candidate tracks removed. The tracksare required to have at least five hits in the silicon tracker detectors, and a track χ2 per degreeof freedom less than five. Each track is assumed to be a kaon and the invariant mass of a trackpair has to be within 10 MeV/c2 of the world average φ-meson mass [19].

The B0s candidates are formed by combining a J/ψ with a φ candidate. The two muons and

the two kaons are subjected to a combined vertex and kinematic fit [21], where in addition thedimuon invariant mass is constrained to the nominal J/ψ mass. The selected candidates musthave a resulting χ2 vertex probability greater than 2%, an invariant mass between 5.20 and5.65 GeV/c2, and be in the kinematic range 8 < pB

T < 50 GeV/c and∣∣yB∣∣ < 2.4. For events

with more than one candidate, the one with the highest vertex-fit probability is selected, whichresults in the correct choice 97% of the time, as determined from simulated signal events.

The proper decay length of each selected B0s candidate is calculated using the formula ct =

c(MB/pBT)Lxy, where the transverse decay length Lxy is the length of the vector~s pointing from

the primary vertex [22] to the secondary vertex projected onto the B0s transverse momentum:

Lxy = (~s · ~pBT)/pB

T, with MB being the reconstructed mass of the B0s candidate. Candidate B0

smesons are accepted within the range −0.05 < ct < 0.35 cm.

A total of 6200 events pass all the selection criteria. The efficiency of the B0s reconstruction is

computed with a combination of techniques using the data and large samples of simulatedsignal events generated using PYTHIA 6.422 [23]. The decays of unstable particles are describedby the EVTGEN [24] simulation. Long-lived particles are then propagated through a detaileddescription of the CMS detector based on the GEANT4 [25] package. The trigger and muon-reconstruction efficiencies are obtained from a large sample of inclusive J/ψ→ µ+µ− decays indata using a (tag-and-probe) technique similar to that described in Ref. [20], where one muon(the tag) is identified with stringent quality requirements, and the second muon (the probe)is identified using information either exclusively from the tracker (to measure the trigger andmuon-identification efficiencies), or from the muon system (to measure the silicon trackingefficiency). The dimuon efficiencies are calculated as the product of the single-muon efficiencies

3

obtained with this method. Corrections to account for correlations between the two muons (1–3%) are obtained from simulation studies. The correction factors are determined in bins ofsingle muon pµ

T and ηµ, and are applied independently to each muon from a B0s → J/ψ φ decay

in the simulation to determine the total corrected efficiency. The probabilities for the muons tolie within the kinematic acceptance region and for the φ and B0

s candidates to pass the selectionrequirements are determined from the simulated events. The efficiencies for hadronic trackreconstruction [26] and the vertex-quality requirement are found to be consistent between realdata and simulated events within their uncertainties (up to 5%). The total efficiency of thisselection, defined as the fraction of B0

s → J/ψ φ decays produced with 8 < pBT < 50 GeV/c and∣∣yB

∣∣ < 2.4 that pass all criteria, ranges from 1.3% for pBT ≈ 8 GeV/c to 19.6% for pB

T > 23 GeV/c.

Backgrounds are dominated by prompt and non-prompt J/ψ production. The latter back-ground is dominated by B+ and B0 mesons that decay to a J/ψ and a higher-mass K-meson state(such as the K+

1). Such events tend to contribute to the low-mass side of the MB mass distri-bution. Inspection of a large variety of potential background channels confirms that there is nosingle dominant component and that the channel B0 → J/ψ K∗(892) (with K∗(892)0 → K+π−),which a priori is kinematically similar to the signal decay and more abundantly produced, isstrongly suppressed by the restriction on the K+K− invariant mass. A study of the sidebands ofthe dimuon invariant mass distribution confirms that the contamination from events without aJ/ψ decay to two muons is negligible after all selection criteria have been applied.

The signal yields in each pBT and

∣∣yB∣∣ bin, given in Table 1, are obtained using an unbinned

extended maximum-likelihood fit to MB and ct. The likelihood for event j is obtained by sum-ming the product of the yield ni and the probability density functions (PDF) Pi and Qi foreach of the signal and background hypotheses i. Three individual components are considered:signal, non-prompt b→ J/ψ X, and prompt J/ψ. The extended likelihood function is then theproduct of likelihoods for each event j:

L = exp

(−

3

∑i=1

ni

)∏

j

[3

∑i=1

niPi(MB; ~αi)Qi(ct; ~βi)

]. (2)

The PDFs Pi and Qi are parameterized separately for each fit component with shape param-eters ~αi for MB and ~βi for ct. The yields ni are then determined by minimizing the quantity− lnL with respect to the signal yields and a subset of the PDF parameters [27]. Possible cor-relations between MB and ct are found to be less than 2%. Therefore, they are assumed to havea negligible impact on the fit, and potential biases arising from this assumption are accountedfor in the systematic uncertainty on the fitted signal yield as described below.

The PDFs are constructed from basic analytical functions that satisfactorily describe the vari-able distributions from simulated events. Shape parameters are obtained from data when pos-sible. The MB PDF is the sum of two Gaussian functions for the signal, a second-order polyno-mial for the non-prompt J/ψ that allows for possible curvature in the shape, and a first-orderpolynomial for prompt J/ψ. The resolution on MB is approximately 20 MeV/c2 near the B0

smass.

For the signal, the ct PDF is a single exponential parameterized in terms of a proper decaylength cτ. It is convolved with a resolution function that is a combination of two Gaussian func-tions to account for a dominant core and small outlier distribution; the core fraction is varied inthe fit and found to be consistently larger than 95%. The ct distribution for the non-prompt J/ψbackground is described by a sum of two exponentials, with effective lifetimes that are allowedto be different. The “long-lifetime exponential” corresponds to decays of b-hadrons to a J/ψplus some charged particles that survive the φ selection, while the “short-lifetime exponential”

4

Table 1: Signal yield nsig, efficiency ε (%), and measured differential cross sections dσ/dpBT and

dσ/dyB, compared to the MC@NLO and PYTHIA predictions, in different pBT and

∣∣yB∣∣ intervals.

The uncertainties on the measured cross sections are statistical and systematic, respectively,excluding the common luminosity of 4% and the 1.4% from the J/ψ and φ branching fractions.

pBT ( GeV/c) nsig ε (%) dσ/dpB

T (nb/ GeV/c)Data MC@NLO PYTHIA

8–12 138 ± 16 1.28 ± 0.05 1.172± 0.136± 0.113 0.719 1.51312–16 176 ± 17 5.26 ± 0.23 0.364± 0.035± 0.034 0.240 0.51516–23 162 ± 16 11.9 ± 0.6 0.085± 0.008± 0.008 0.074 0.14423–50 86 ± 11 19.6 ± 1.1 0.007± 0.001± 0.001 0.008 0.010∣∣yB

∣∣ nsig ε (%) dσ/dyB (nb)Data MC@NLO PYTHIA

0.00–0.80 151 ± 15 2.75 ± 0.09 1.484± 0.147± 0.148 1.040 2.2810.80–1.40 144 ± 15 4.65 ± 0.18 1.123± 0.117± 0.102 1.023 2.0511.40–1.70 129 ± 15 5.68 ± 0.31 1.634± 0.190± 0.160 0.929 1.8331.70–2.40 139 ± 17 3.26 ± 0.20 1.316± 0.161± 0.139 0.801 1.559

accounts for events where the muons from the J/ψ decay are wrongly combined with hadrontracks originating from the pp collision point. The exponential functions are convolved with aresolution function with the same parameters as the signal. For the prompt J/ψ component thepure resolution function is used. The core resolution in ct is measured in data to be 45 µm.

All background shapes are obtained directly from data, while the signal shape in MB is takenfrom a fit to reconstructed signal events from the simulation. The effective lifetime and resolu-tion function parameters for prompt and non-prompt backgrounds are extracted, using the fulldata sample irrespectively of pB

T and∣∣yB∣∣, from regions in MB that are separated by more than

four times the width of the observed B0s signal from the mean B0

s peak position (MB sidebands):5.20 < MB < 5.29 GeV/c2 and 5.45 < MB < 5.65 GeV/c2. A comparison of the PDF shapes forthe different sideband regions in simulated events confirms that their average over the signal-free regions is a good representation of the background in the signal region. With the lifetimesfor signal and non-prompt background fixed from this first step, the resolution function pa-rameters are then determined separately in each pB

T and∣∣yB∣∣ bin, from the MB sidebands. The

signal and background yields in each pBT and

∣∣yB∣∣ bin are determined in a final iteration, using

the full MB range, with all parameters floating except the background lifetimes and the lifetimeresolution functions, which are fixed to the results of the fit to the MB sidebands. It has beenverified that leaving all parameters floating changes the signal yield by an amount smaller thanthe systematic uncertainty assigned to the fit procedure.

Many detailed studies have been conducted to validate the accuracy and robustness of the fitprocedure. A large number of pseudo-experiments were performed, each corresponding to theyields observed in each pB

T and∣∣yB∣∣ bin for a data sample corresponding to an integrated lu-

minosity of 40 pb−1, where signal and background events were generated randomly from thePDFs in each bin. The fit yields were found to be unbiased and their uncertainties estimatedproperly. The effects of residual correlations between MB and ct were studied by mixing fullysimulated signal and background events to produce pseudo-experiments. The observed devi-ations between the fitted and generated yields (1–2%) are taken as the systematic uncertainty

5

due to potential biases in the fit method.

Figure 1 shows the fit projections for MB and ct from the inclusive sample with 8 < pBT <

50 GeV/c and∣∣yB∣∣ < 2.4. When plotting MB, the selection ct > 0.01 cm is applied for better

visibility of the individual contributions. The number of signal events in the entire data sampleis 549± 32, where the uncertainty is statistical only. The obtained proper decay length of thesignal, cτ = 478± 26 µm, is within 1.4 standard deviations of the world average value [19],even though this analysis was not optimized for lifetime measurements.

Table 1 summarizes the fitted signal yield in each bin of pBT and

∣∣yB∣∣. The differential cross

section is calculated according to Eq. (1), using the product of the branching fractions B(J/ψ→µ+µ−) = (5.93± 0.06)× 10−2 and B(φ → K+K−) = (48.9± 0.5)× 10−2 [19]. All efficienciesare calculated separately in each bin, and account for bin-to-bin migrations (less than 1%) dueto the finite resolution of the measured momentum and rapidity.

The cross section measurement is affected by several sources of systematic uncertainty arisingfrom uncertainties on the fit, efficiencies, branching fractions, and integrated luminosity. Inevery bin the total uncertainty is about 11%. Uncertainties on the muon efficiencies from thetrigger, identification, and tracking are determined directly from data (3–5%). The uncertaintyof the method employed to measure the efficiency in the data has been estimated from a largesample of full-detector simulated events (1–3%). The tracking efficiency for the charged kaonshas been shown to be consistent with simulation. A conservative uncertainty of at most 9%in each bin has been assigned for the hadronic track reconstruction (adding linearly the un-certainties on the two kaon tracks [26]), which includes the uncertainty due to misalignmentof the silicon detectors. The uncertainty on the fit procedure arising from potential biases andimperfect knowledge of the PDF parameters is estimated by varying the parameters by onestandard deviation (2–4%). The contribution related to the B0

s momentum spectrum (1–3%)is evaluated by reweighting the shape of the pB

T distribution generated with PYTHIA to matchthe spectrum predicted by MC@NLO [28]. An uncertainty of 1% is assigned to the variationof the selection criteria applied to the vertex fit probability, the transverse momentum of thekaons, the B0

s transverse momentum, and the K+K− invariant mass window. An uncertaintyis added to account for the limited number of simulated events (at most 3% in the highest pB

Tbin). The total uncorrelated systematic uncertainty on the cross-section measurement is com-puted in each bin as the sum in quadrature of the individual uncertainties, and is summarizedin Table 1. In addition, there are common uncertainties of 4% from the integrated luminositymeasurement [29] and 1.4% from the J/ψ and φ branching fractions. As the reported resultis a measurement of the B0

s cross section times the B0s → J/ψ φ branching fraction, the 30%

uncertainty on the B0s → J/ψ φ branching fraction [19] is not included in the result.

The differential cross sections times branching fraction as functions of pBT and

∣∣yB∣∣ are listed in

Table 1 and plotted in Fig. 2, together with predictions from MC@NLO and PYTHIA. The predic-

tions of MC@NLO use the renormalization and factorization scales µ =√

m2bc4 + p2

Tc2, where

pT is the transverse momentum of the b quark, a b-quark mass of mb = 4.75 GeV/c2, andthe CTEQ6M parton distribution functions [30]. The uncertainty on the MC@NLO cross sectionis obtained simultaneously varying the renormalization and factorization scales by factors oftwo, varying mb by±0.25 GeV/c2, and using the CTEQ6.6 parton distribution function set. Theprediction of PYTHIA uses the CTEQ6L1 parton distribution functions [30], a b-quark mass of4.8 GeV/c2, and the Z2 tune [31] to simulate the underlying event. The total integrated B0

s crosssection times B0

s → J/ψ φ branching fraction for the range 8 < pBT < 50 GeV/c and

∣∣yB∣∣ < 2.4

is measured to be 6.9± 0.6± 0.6 nb, where the first uncertainty is statistical and the second issystematic. The statistical and systematic uncertainties are derived from the bin-by-bin uncer-

6

)2 invariant mass (GeV/cφψJ/5.2 5.25 5.3 5.35 5.4 5.45 5.5 5.55 5.6 5.65

)2E

ven

ts /

(0.0

18 G

eV/c

0

20

40

60

80

100

120

140

160

180

200

220

)2 invariant mass (GeV/cφψJ/5.2 5.25 5.3 5.35 5.4 5.45 5.5 5.55 5.6 5.65

)2E

ven

ts /

(0.0

18 G

eV/c

0

20

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= 7 TeVsCMS -1L = 40 pb

(a)

ct > 0.01 cm

ct (cm)-0.05 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35

Eve

nts

/ (0

.01

cm)

-110

1

10

210

310

410

ct (cm)-0.05 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35

Eve

nts

/ (0

.01

cm)

-110

1

10

210

310

410

= 7 TeVsCMS -1L = 40 pb

(b)

Figure 1: Projections of the fit results in MB (a) and ct (b) for 8 < pBT < 50 GeV/c and

∣∣yB∣∣ < 2.4.

The curves in each plot are: the sum of all contributions (solid line); signal (dashed); prompt J/ψ(dotted); and non-prompt J/ψ (dot-dashed). For better visibility of the individual contributions,plot (a) includes the requirement ct > 0.01 cm.

7

)[GeV/c]s

(BT

p10 15 20 25 30 35 40 45 50

|<2.

4)[n

b/(

GeV

/c)]

B;

|yφ

ψ J

/→ s

B→

(pp

T/d

pσd -310

-210

-110

1 Data

PYTHIA (MSEL 1, CTEQ6L1, Z2 tuning)

)2= 4.75 GeV/cb

MC@NLO (CTEQ6M, m

MC@NLO total uncertainty

= 7 TeVsCMS -1L = 40 pb

(a)

BF (30%) and Lumi (4%) uncertainties not shown

)|s

|y(B0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4

<50

GeV

/c)[

nb

]B T

; 8<

pφ

ψ J

/→ s

B→

/dy(

pp

σd

0.5

1

1.5

2

2.5

3 Data

PYTHIA (MSEL 1, CTEQ6L1, Z2 tuning)

)2= 4.75 GeV/cb

MC@NLO (CTEQ6M, m

MC@NLO total uncertainty

= 7 TeVsCMS -1L = 40 pb

(b)

BF (30%) and Lumi (4%) uncertainties not shown

Figure 2: Measured differential cross sections dσ/dpBT (a) and dσ/dyB (b) compared with the-

oretical predictions. The (yellow) band represents the sum in quadrature of statistical andsystematic uncertainties. The dotted (red) line is the PYTHIA prediction; the solid and dashed(blue) lines are the MC@NLO prediction and its uncertainty, respectively. The common uncer-tainties of 4% on the data points, due to the integrated luminosity, and of 30% on the theorycurves, due to the B0

s → J/ψ φ branching fraction, are not shown.

8

tainties and propagated through the sum. The result lies between the theoretical predictionsof MC@NLO (4.6+1.9

−1.7 ± 1.4 nb) and PYTHIA (9.4 ± 2.8 nb), where the last uncertainty is fromthe B0

s → J/ψ φ branching fraction [19]. Also the previous CMS cross-section measurementsof B+ [14] and B0 [15] production in pp collisions at

√s = 7 TeV, gave values between the two

theory predictions, indicating internal consistency amongst the three different B-meson results.

In summary, the first measurements of the B0s differential cross sections dσ/dpB

T and dσ/dyB, inthe decay channel B0

s → J/ψ φ and in pp collisions at√

s = 7 TeV, have been presented. Theresults cover the kinematical window

∣∣yB∣∣ < 2.4 and 8 < pB

T < 50 GeV/c. They add com-plementary information to previous results in moving towards a comprehensive description ofb-hadron production at

√s = 7 TeV.

We wish to congratulate our colleagues in the CERN accelerator departments for the excellentperformance of the LHC machine. We thank the technical and administrative staff at CERN andother CMS institutes, and acknowledge support from: FMSR (Austria); FNRS and FWO (Bel-gium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, andNSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sci-ences 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 andMAE (Russia); MSTD (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzer-land); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF(USA).

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11

A The CMS CollaborationYerevan Physics Institute, Yerevan, ArmeniaS. Chatrchyan, V. Khachatryan, A.M. Sirunyan, A. Tumasyan

Institut fur Hochenergiephysik der OeAW, Wien, AustriaW. Adam, T. Bergauer, M. Dragicevic, J. Ero, C. Fabjan, M. Friedl, R. Fruhwirth, V.M. Ghete,J. Hammer1, S. Hansel, M. Hoch, N. Hormann, J. Hrubec, M. Jeitler, W. Kiesenhofer,M. Krammer, D. Liko, I. Mikulec, M. Pernicka, H. Rohringer, R. Schofbeck, J. Strauss, A. Taurok,F. Teischinger, P. Wagner, W. Waltenberger, G. Walzel, E. Widl, C.-E. Wulz

National Centre for Particle and High Energy Physics, Minsk, BelarusV. Mossolov, N. Shumeiko, J. Suarez Gonzalez

Universiteit Antwerpen, Antwerpen, BelgiumS. Bansal, L. Benucci, E.A. De Wolf, X. Janssen, J. Maes, T. Maes, L. Mucibello, S. Ochesanu,B. Roland, R. Rougny, M. Selvaggi, H. Van Haevermaet, P. Van Mechelen, N. Van Remortel

Vrije Universiteit Brussel, Brussel, BelgiumF. Blekman, S. Blyweert, J. D’Hondt, O. Devroede, R. Gonzalez Suarez, A. Kalogeropoulos,M. Maes, W. Van Doninck, P. Van Mulders, G.P. Van Onsem, I. Villella

Universite Libre de Bruxelles, Bruxelles, BelgiumO. Charaf, B. Clerbaux, G. De Lentdecker, V. Dero, A.P.R. Gay, G.H. Hammad, T. Hreus,P.E. Marage, L. Thomas, C. Vander Velde, P. Vanlaer

Ghent University, Ghent, BelgiumV. Adler, A. Cimmino, S. Costantini, M. Grunewald, B. Klein, J. Lellouch, A. Marinov,J. Mccartin, D. Ryckbosch, F. Thyssen, M. Tytgat, L. Vanelderen, P. Verwilligen, S. Walsh,N. Zaganidis

Universite Catholique de Louvain, Louvain-la-Neuve, BelgiumS. Basegmez, G. Bruno, J. Caudron, L. Ceard, E. Cortina Gil, J. De Favereau De Jeneret,C. Delaere1, D. Favart, A. Giammanco, G. Gregoire, J. Hollar, V. Lemaitre, J. Liao, O. Militaru,C. Nuttens, S. Ovyn, D. Pagano, A. Pin, K. Piotrzkowski, N. Schul

Universite de Mons, Mons, BelgiumN. Beliy, T. Caebergs, E. Daubie

Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, BrazilG.A. Alves, D. De Jesus Damiao, M.E. Pol, M.H.G. Souza

Universidade do Estado do Rio de Janeiro, Rio de Janeiro, BrazilW. Carvalho, E.M. Da Costa, C. De Oliveira Martins, S. Fonseca De Souza, L. Mundim,H. Nogima, V. Oguri, W.L. Prado Da Silva, A. Santoro, S.M. Silva Do Amaral, A. Sznajder

Instituto de Fisica Teorica, Universidade Estadual Paulista, Sao Paulo, BrazilC.A. Bernardes2, F.A. Dias, T.R. Fernandez Perez Tomei, E. M. Gregores2, C. Lagana,F. Marinho, P.G. Mercadante2, S.F. Novaes, Sandra S. Padula

Institute for Nuclear Research and Nuclear Energy, Sofia, BulgariaN. Darmenov1, V. Genchev1, P. Iaydjiev1, S. Piperov, M. Rodozov, S. Stoykova, G. Sultanov,V. Tcholakov, R. Trayanov

12 A The CMS Collaboration

University of Sofia, Sofia, BulgariaA. Dimitrov, R. Hadjiiska, A. Karadzhinova, V. Kozhuharov, L. Litov, M. Mateev, B. Pavlov,P. Petkov

Institute of High Energy Physics, Beijing, ChinaJ.G. Bian, G.M. Chen, H.S. Chen, C.H. Jiang, D. Liang, S. Liang, X. Meng, J. Tao, J. Wang,J. Wang, X. Wang, Z. Wang, H. Xiao, M. Xu, J. Zang, Z. Zhang

State Key Lab. of Nucl. Phys. and Tech., Peking University, Beijing, ChinaY. Ban, S. Guo, Y. Guo, W. Li, Y. Mao, S.J. Qian, H. Teng, B. Zhu, W. Zou

Universidad de Los Andes, Bogota, ColombiaA. Cabrera, B. Gomez Moreno, A.A. Ocampo Rios, A.F. Osorio Oliveros, J.C. Sanabria

Technical University of Split, Split, CroatiaN. Godinovic, D. Lelas, K. Lelas, R. Plestina3, D. Polic, I. Puljak

University of Split, Split, CroatiaZ. Antunovic, M. Dzelalija

Institute Rudjer Boskovic, Zagreb, CroatiaV. Brigljevic, S. Duric, K. Kadija, S. Morovic

University of Cyprus, Nicosia, CyprusA. Attikis, M. Galanti, J. Mousa, C. Nicolaou, F. Ptochos, P.A. Razis

Charles University, Prague, Czech RepublicM. Finger, M. Finger Jr.

Academy of Scientific Research and Technology of the Arab Republic of Egypt, EgyptianNetwork of High Energy Physics, Cairo, EgyptY. Assran4, S. Khalil5, M.A. Mahmoud6

National Institute of Chemical Physics and Biophysics, Tallinn, EstoniaA. Hektor, M. Kadastik, M. Muntel, M. Raidal, L. Rebane

Department of Physics, University of Helsinki, Helsinki, FinlandV. Azzolini, P. Eerola, G. Fedi

Helsinki Institute of Physics, Helsinki, FinlandS. Czellar, J. Harkonen, A. Heikkinen, V. Karimaki, R. Kinnunen, M.J. Kortelainen, T. Lampen,K. Lassila-Perini, S. Lehti, T. Linden, P. Luukka, T. Maenpaa, E. Tuominen, J. Tuominiemi,E. Tuovinen, D. Ungaro, L. Wendland

Lappeenranta University of Technology, Lappeenranta, FinlandK. Banzuzi, A. Karjalainen, A. Korpela, T. Tuuva

Laboratoire d’Annecy-le-Vieux de Physique des Particules, IN2P3-CNRS, Annecy-le-Vieux,FranceD. Sillou

DSM/IRFU, CEA/Saclay, Gif-sur-Yvette, FranceM. Besancon, S. Choudhury, M. Dejardin, D. Denegri, B. Fabbro, J.L. Faure, F. Ferri, S. Ganjour,F.X. Gentit, A. Givernaud, P. Gras, G. Hamel de Monchenault, P. Jarry, E. Locci, J. Malcles,M. Marionneau, L. Millischer, J. Rander, A. Rosowsky, I. Shreyber, M. Titov, P. Verrecchia

13

Laboratoire Leprince-Ringuet, Ecole Polytechnique, IN2P3-CNRS, Palaiseau, FranceS. Baffioni, F. Beaudette, L. Benhabib, L. Bianchini, M. Bluj7, C. Broutin, P. Busson, C. Charlot,T. Dahms, L. Dobrzynski, S. Elgammal, R. Granier de Cassagnac, M. Haguenauer, P. Mine,C. Mironov, C. Ochando, P. Paganini, D. Sabes, R. Salerno, Y. Sirois, C. Thiebaux, B. Wyslouch8,A. Zabi

Institut Pluridisciplinaire Hubert Curien, Universite de Strasbourg, Universite de HauteAlsace Mulhouse, CNRS/IN2P3, Strasbourg, FranceJ.-L. Agram9, J. Andrea, D. Bloch, D. Bodin, J.-M. Brom, M. Cardaci, E.C. Chabert, C. Collard,E. Conte9, F. Drouhin9, C. Ferro, J.-C. Fontaine9, D. Gele, U. Goerlach, S. Greder, P. Juillot,M. Karim9, A.-C. Le Bihan, Y. Mikami, P. Van Hove

Centre de Calcul de l’Institut National de Physique Nucleaire et de Physique desParticules (IN2P3), Villeurbanne, FranceF. Fassi, D. Mercier

Universite de Lyon, Universite Claude Bernard Lyon 1, CNRS-IN2P3, Institut de PhysiqueNucleaire de Lyon, Villeurbanne, FranceC. Baty, S. Beauceron, N. Beaupere, M. Bedjidian, O. Bondu, G. Boudoul, D. Boumediene,H. Brun, J. Chasserat, R. Chierici, D. Contardo, P. Depasse, H. El Mamouni, J. Fay, S. Gascon,B. Ille, T. Kurca, T. Le Grand, M. Lethuillier, L. Mirabito, S. Perries, V. Sordini, S. Tosi, Y. Tschudi,P. Verdier

Institute of High Energy Physics and Informatization, Tbilisi State University, Tbilisi,GeorgiaD. Lomidze

RWTH Aachen University, I. Physikalisches Institut, Aachen, GermanyG. Anagnostou, S. Beranek, M. Edelhoff, L. Feld, N. Heracleous, O. Hindrichs, R. Jussen,K. Klein, J. Merz, N. Mohr, A. Ostapchuk, A. Perieanu, F. Raupach, J. Sammet, S. Schael,D. Sprenger, H. Weber, M. Weber, B. Wittmer

RWTH Aachen University, III. Physikalisches Institut A, Aachen, GermanyM. Ata, E. Dietz-Laursonn, M. Erdmann, T. Hebbeker, A. Hinzmann, K. Hoepfner,T. Klimkovich, D. Klingebiel, P. Kreuzer, D. Lanske†, C. Magass, M. Merschmeyer, A. Meyer,P. Papacz, H. Pieta, H. Reithler, S.A. Schmitz, L. Sonnenschein, J. Steggemann, D. Teyssier

RWTH Aachen University, III. Physikalisches Institut B, Aachen, GermanyM. Bontenackels, M. Davids, M. Duda, G. Flugge, H. Geenen, M. Giffels, W. Haj Ahmad,D. Heydhausen, F. Hoehle, B. Kargoll, T. Kress, Y. Kuessel, A. Linn, A. Nowack, L. Perchalla,O. Pooth, J. Rennefeld, P. Sauerland, A. Stahl, M. Thomas, D. Tornier, M.H. Zoeller

Deutsches Elektronen-Synchrotron, Hamburg, GermanyM. Aldaya Martin, W. Behrenhoff, U. Behrens, M. Bergholz10, A. Bethani, K. Borras, A. Cakir,A. Campbell, E. Castro, D. Dammann, G. Eckerlin, D. Eckstein, A. Flossdorf, G. Flucke,A. Geiser, J. Hauk, H. Jung1, M. Kasemann, I. Katkov11, P. Katsas, C. Kleinwort, H. Kluge,A. Knutsson, M. Kramer, D. Krucker, E. Kuznetsova, W. Lange, W. Lohmann10, R. Mankel,M. Marienfeld, I.-A. Melzer-Pellmann, A.B. Meyer, J. Mnich, A. Mussgiller, J. Olzem,A. Petrukhin, D. Pitzl, A. Raspereza, A. Raval, M. Rosin, R. Schmidt10, T. Schoerner-Sadenius,N. Sen, A. Spiridonov, M. Stein, J. Tomaszewska, R. Walsh, C. Wissing

University of Hamburg, Hamburg, GermanyC. Autermann, V. Blobel, S. Bobrovskyi, J. Draeger, H. Enderle, U. Gebbert, M. Gorner,K. Kaschube, G. Kaussen, H. Kirschenmann, R. Klanner, J. Lange, B. Mura, S. Naumann-Emme,

14 A The CMS Collaboration

F. Nowak, N. Pietsch, C. Sander, H. Schettler, P. Schleper, E. Schlieckau, M. Schroder, T. Schum,J. Schwandt, H. Stadie, G. Steinbruck, J. Thomsen

Institut fur Experimentelle Kernphysik, Karlsruhe, GermanyC. Barth, J. Bauer, J. Berger, V. Buege, T. Chwalek, W. De Boer, A. Dierlamm, G. Dirkes,M. Feindt, J. Gruschke, C. Hackstein, F. Hartmann, M. Heinrich, H. Held, K.H. Hoffmann,S. Honc, J.R. Komaragiri, T. Kuhr, D. Martschei, S. Mueller, Th. Muller, M. Niegel, O. Oberst,A. Oehler, J. Ott, T. Peiffer, G. Quast, K. Rabbertz, F. Ratnikov, N. Ratnikova, M. Renz, C. Saout,A. Scheurer, P. Schieferdecker, F.-P. Schilling, G. Schott, H.J. Simonis, F.M. Stober, D. Troendle,J. Wagner-Kuhr, T. Weiler, M. Zeise, V. Zhukov11, E.B. Ziebarth

Institute of Nuclear Physics ”Demokritos”, Aghia Paraskevi, GreeceG. Daskalakis, T. Geralis, S. Kesisoglou, A. Kyriakis, D. Loukas, I. Manolakos, A. Markou,C. Markou, C. Mavrommatis, E. Ntomari, E. Petrakou

University of Athens, Athens, GreeceL. Gouskos, T.J. Mertzimekis, A. Panagiotou, E. Stiliaris

University of Ioannina, Ioannina, GreeceI. Evangelou, C. Foudas, P. Kokkas, N. Manthos, I. Papadopoulos, V. Patras, F.A. Triantis

KFKI Research Institute for Particle and Nuclear Physics, Budapest, HungaryA. Aranyi, G. Bencze, L. Boldizsar, C. Hajdu1, P. Hidas, D. Horvath12, A. Kapusi, K. Krajczar13,F. Sikler1, G.I. Veres13, G. Vesztergombi13

Institute of Nuclear Research ATOMKI, Debrecen, HungaryN. Beni, J. Molnar, J. Palinkas, Z. Szillasi, V. Veszpremi

University of Debrecen, Debrecen, HungaryP. Raics, Z.L. Trocsanyi, B. Ujvari

Panjab University, Chandigarh, IndiaS.B. Beri, V. Bhatnagar, N. Dhingra, R. Gupta, M. Jindal, M. Kaur, J.M. Kohli, M.Z. Mehta,N. Nishu, L.K. Saini, A. Sharma, A.P. Singh, J. Singh, S.P. Singh

University of Delhi, Delhi, IndiaS. Ahuja, B.C. Choudhary, B. Gomber, P. Gupta, S. Jain, S. Jain, R. Khurana, A. Kumar,M. Naimuddin, K. Ranjan, R.K. Shivpuri

Saha Institute of Nuclear Physics, Kolkata, IndiaS. Bhattacharya, S. Dutta, S. Sarkar

Bhabha Atomic Research Centre, Mumbai, IndiaR.K. Choudhury, D. Dutta, S. Kailas, V. Kumar, P. Mehta, A.K. Mohanty1, L.M. Pant, P. Shukla

Tata Institute of Fundamental Research - EHEP, Mumbai, IndiaT. Aziz, M. Guchait14, A. Gurtu, M. Maity15, D. Majumder, G. Majumder, K. Mazumdar,G.B. Mohanty, A. Saha, K. Sudhakar, N. Wickramage

Tata Institute of Fundamental Research - HECR, Mumbai, IndiaS. Banerjee, S. Dugad, N.K. Mondal

Institute for Research and Fundamental Sciences (IPM), Tehran, IranH. Arfaei, H. Bakhshiansohi16, S.M. Etesami, A. Fahim16, M. Hashemi, A. Jafari16, M. Khakzad,A. Mohammadi17, M. Mohammadi Najafabadi, S. Paktinat Mehdiabadi, B. Safarzadeh,M. Zeinali18

15

INFN Sezione di Bari a, Universita di Bari b, Politecnico di Bari c, Bari, ItalyM. Abbresciaa,b, L. Barbonea,b, C. Calabriaa ,b, A. Colaleoa, D. Creanzaa,c, N. De Filippisa,c,1,M. De Palmaa ,b, L. Fiorea, G. Iasellia,c, L. Lusitoa ,b, G. Maggia,c, M. Maggia, N. Mannaa ,b,B. Marangellia ,b, S. Mya ,c, S. Nuzzoa,b, N. Pacificoa,b, G.A. Pierroa, A. Pompilia ,b, G. Pugliesea,c,F. Romanoa ,c, G. Rosellia ,b, G. Selvaggia,b, L. Silvestrisa, R. Trentaduea, S. Tupputia ,b, G. Zitoa

INFN Sezione di Bologna a, Universita di Bologna b, Bologna, ItalyG. Abbiendia, A.C. Benvenutia, D. Bonacorsia, S. Braibant-Giacomellia,b, L. Brigliadoria,P. Capiluppia,b, A. Castroa,b, F.R. Cavalloa, M. Cuffiania ,b, G.M. Dallavallea, F. Fabbria,A. Fanfania ,b, D. Fasanellaa, P. Giacomellia, M. Giuntaa, C. Grandia, S. Marcellinia, G. Masettib,M. Meneghellia ,b, A. Montanaria, F.L. Navarriaa ,b, F. Odoricia, A. Perrottaa, F. Primaveraa,A.M. Rossia,b, T. Rovellia ,b, G. Sirolia,b, R. Travaglinia,b

INFN Sezione di Catania a, Universita di Catania b, Catania, ItalyS. Albergoa,b, G. Cappelloa ,b, M. Chiorbolia ,b ,1, S. Costaa,b, A. Tricomia,b, C. Tuvea ,b

INFN Sezione di Firenze a, Universita di Firenze b, Firenze, ItalyG. Barbaglia, V. Ciullia,b, C. Civininia, R. D’Alessandroa ,b, E. Focardia ,b, S. Frosalia ,b, E. Galloa,S. Gonzia,b, P. Lenzia,b, M. Meschinia, S. Paolettia, G. Sguazzonia, A. Tropianoa,1

INFN Laboratori Nazionali di Frascati, Frascati, ItalyL. Benussi, S. Bianco, S. Colafranceschi19, F. Fabbri, D. Piccolo

INFN Sezione di Genova, Genova, ItalyP. Fabbricatore, R. Musenich

INFN Sezione di Milano-Bicocca a, Universita di Milano-Bicocca b, Milano, ItalyA. Benagliaa,b, F. De Guioa ,b ,1, L. Di Matteoa,b, S. Gennai1, A. Ghezzia,b, S. Malvezzia,A. Martellia ,b, A. Massironia,b, D. Menascea, L. Moronia, M. Paganonia,b, D. Pedrinia,S. Ragazzia,b, N. Redaellia, S. Salaa, T. Tabarelli de Fatisa,b

INFN Sezione di Napoli a, Universita di Napoli ”Federico II” b, Napoli, ItalyS. Buontempoa, C.A. Carrillo Montoyaa,1, N. Cavalloa ,20, A. De Cosaa ,b, F. Fabozzia ,20,A.O.M. Iorioa ,1, L. Listaa, M. Merolaa ,b, P. Paoluccia

INFN Sezione di Padova a, Universita di Padova b, Universita di Trento (Trento) c, Padova,ItalyP. Azzia, N. Bacchettaa, P. Bellana ,b, D. Biselloa,b, A. Brancaa, R. Carlina,b, P. Checchiaa, M. DeMattiaa,b, T. Dorigoa, U. Dossellia, F. Fanzagoa, F. Gasparinia,b, U. Gasparinia,b, A. Gozzelino,S. Lacapraraa,21, I. Lazzizzeraa,c, M. Margonia,b, M. Mazzucatoa, A.T. Meneguzzoa ,b,M. Nespoloa,1, L. Perrozzia ,1, N. Pozzobona,b, P. Ronchesea ,b, F. Simonettoa,b, E. Torassaa,M. Tosia ,b, S. Vaninia ,b, P. Zottoa ,b, G. Zumerlea,b

INFN Sezione di Pavia a, Universita di Pavia b, Pavia, ItalyP. Baessoa,b, U. Berzanoa, S.P. Rattia,b, C. Riccardia,b, P. Torrea ,b, P. Vituloa,b, C. Viviania,b

INFN Sezione di Perugia a, Universita di Perugia b, Perugia, ItalyM. Biasinia ,b, G.M. Bileia, B. Caponeria,b, L. Fanoa,b, P. Laricciaa,b, A. Lucaronia ,b ,1,G. Mantovania ,b, M. Menichellia, A. Nappia,b, F. Romeoa ,b, A. Santocchiaa ,b, S. Taronia ,b ,1,M. Valdataa,b

INFN Sezione di Pisa a, Universita di Pisa b, Scuola Normale Superiore di Pisa c, Pisa, ItalyP. Azzurria,c, G. Bagliesia, J. Bernardinia,b, T. Boccalia ,1, G. Broccoloa ,c, R. Castaldia,R.T. D’Agnoloa ,c, R. Dell’Orsoa, F. Fioria ,b, L. Foaa,c, A. Giassia, A. Kraana, F. Ligabuea ,c,

16 A The CMS Collaboration

T. Lomtadzea, L. Martinia ,22, A. Messineoa,b, F. Pallaa, G. Segneria, A.T. Serbana, P. Spagnoloa,R. Tenchinia, G. Tonellia ,b ,1, A. Venturia ,1, P.G. Verdinia

INFN Sezione di Roma a, Universita di Roma ”La Sapienza” b, Roma, ItalyL. Baronea ,b, F. Cavallaria, D. Del Rea,b, E. Di Marcoa,b, M. Diemoza, D. Francia ,b, M. Grassia,1,E. Longoa,b, P. Meridiani, S. Nourbakhsha, G. Organtinia ,b, F. Pandolfia,b ,1, R. Paramattia,S. Rahatloua ,b, C. Rovelli1

INFN Sezione di Torino a, Universita di Torino b, Universita del Piemonte Orientale (No-vara) c, Torino, ItalyN. Amapanea,b, R. Arcidiaconoa ,c, S. Argiroa ,b, M. Arneodoa ,c, C. Biinoa, C. Bottaa ,b ,1,N. Cartigliaa, R. Castelloa ,b, M. Costaa ,b, N. Demariaa, A. Grazianoa ,b ,1, C. Mariottia,M. Maronea,b, S. Masellia, E. Migliorea,b, G. Milaa,b, V. Monacoa,b, M. Musicha ,b,M.M. Obertinoa,c, N. Pastronea, M. Pelliccionia,b, A. Potenzaa ,b, A. Romeroa,b, M. Ruspaa,c,R. Sacchia ,b, V. Solaa,b, A. Solanoa ,b, A. Staianoa, A. Vilela Pereiraa

INFN Sezione di Trieste a, Universita di Trieste b, Trieste, ItalyS. Belfortea, F. Cossuttia, G. Della Riccaa,b, B. Gobboa, D. Montaninoa,b, A. Penzoa

Kangwon National University, Chunchon, KoreaS.G. Heo, S.K. Nam

Kyungpook National University, Daegu, KoreaS. Chang, J. Chung, D.H. Kim, G.N. Kim, J.E. Kim, D.J. Kong, H. Park, S.R. Ro, D. Son, D.C. Son,T. Son

Chonnam National University, Institute for Universe and Elementary Particles, Kwangju,KoreaZero Kim, J.Y. Kim, S. Song

Korea University, Seoul, KoreaS. Choi, B. Hong, M. Jo, H. Kim, J.H. Kim, T.J. Kim, K.S. Lee, D.H. Moon, S.K. Park, K.S. Sim

University of Seoul, Seoul, KoreaM. Choi, S. Kang, H. Kim, C. Park, I.C. Park, S. Park, G. Ryu

Sungkyunkwan University, Suwon, KoreaY. Choi, Y.K. Choi, J. Goh, M.S. Kim, E. Kwon, J. Lee, S. Lee, H. Seo, I. Yu

Vilnius University, Vilnius, LithuaniaM.J. Bilinskas, I. Grigelionis, M. Janulis, D. Martisiute, P. Petrov, T. Sabonis

Centro de Investigacion y de Estudios Avanzados del IPN, Mexico City, MexicoH. Castilla-Valdez, E. De La Cruz-Burelo, I. Heredia-de La Cruz, R. Lopez-Fernandez,R. Magana Villalba, A. Sanchez-Hernandez, L.M. Villasenor-Cendejas

Universidad Iberoamericana, Mexico City, MexicoS. Carrillo Moreno, F. Vazquez Valencia

Benemerita Universidad Autonoma de Puebla, Puebla, MexicoH.A. Salazar Ibarguen

Universidad Autonoma de San Luis Potosı, San Luis Potosı, MexicoE. Casimiro Linares, A. Morelos Pineda, M.A. Reyes-Santos

University of Auckland, Auckland, New ZealandD. Krofcheck, J. Tam

17

University of Canterbury, Christchurch, New ZealandP.H. Butler, R. Doesburg, H. Silverwood

National Centre for Physics, Quaid-I-Azam University, Islamabad, PakistanM. Ahmad, I. Ahmed, M.I. Asghar, H.R. Hoorani, W.A. Khan, T. Khurshid, S. Qazi

Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, PolandG. Brona, M. Cwiok, W. Dominik, K. Doroba, A. Kalinowski, M. Konecki, J. Krolikowski

Soltan Institute for Nuclear Studies, Warsaw, PolandT. Frueboes, R. Gokieli, M. Gorski, M. Kazana, K. Nawrocki, K. Romanowska-Rybinska,M. Szleper, G. Wrochna, P. Zalewski

Laboratorio de Instrumentacao e Fısica Experimental de Partıculas, Lisboa, PortugalN. Almeida, P. Bargassa, A. David, P. Faccioli, P.G. Ferreira Parracho, M. Gallinaro, P. Musella,A. Nayak, J. Pela1, P.Q. Ribeiro, J. Seixas, J. Varela

Joint Institute for Nuclear Research, Dubna, RussiaS. Afanasiev, I. Belotelov, P. Bunin, I. Golutvin, A. Kamenev, V. Karjavin, G. Kozlov, A. Lanev,P. Moisenz, V. Palichik, V. Perelygin, S. Shmatov, V. Smirnov, A. Volodko, A. Zarubin

Petersburg Nuclear Physics Institute, Gatchina (St Petersburg), RussiaV. Golovtsov, Y. Ivanov, V. Kim, P. Levchenko, V. Murzin, V. Oreshkin, I. Smirnov, V. Sulimov,L. Uvarov, S. Vavilov, A. Vorobyev, An. Vorobyev

Institute for Nuclear Research, Moscow, RussiaYu. Andreev, A. Dermenev, S. Gninenko, N. Golubev, M. Kirsanov, N. Krasnikov, V. Matveev,A. Pashenkov, A. Toropin, S. Troitsky

Institute for Theoretical and Experimental Physics, Moscow, RussiaV. Epshteyn, V. Gavrilov, V. Kaftanov†, M. Kossov1, A. Krokhotin, N. Lychkovskaya, V. Popov,G. Safronov, S. Semenov, V. Stolin, E. Vlasov, A. Zhokin

Moscow State University, Moscow, RussiaE. Boos, M. Dubinin23, L. Dudko, A. Ershov, A. Gribushin, O. Kodolova, I. Lokhtin, A. Markina,S. Obraztsov, M. Perfilov, S. Petrushanko, L. Sarycheva, V. Savrin, A. Snigirev

P.N. Lebedev Physical Institute, Moscow, RussiaV. Andreev, M. Azarkin, I. Dremin, M. Kirakosyan, A. Leonidov, S.V. Rusakov, A. Vinogradov

State Research Center of Russian Federation, Institute for High Energy Physics, Protvino,RussiaI. Azhgirey, I. Bayshev, S. Bitioukov, V. Grishin1, V. Kachanov, D. Konstantinov, A. Korablev,V. Krychkine, V. Petrov, R. Ryutin, A. Sobol, L. Tourtchanovitch, S. Troshin, N. Tyurin,A. Uzunian, A. Volkov

University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences, Belgrade,SerbiaP. Adzic24, M. Djordjevic, D. Krpic24, J. Milosevic

Centro de Investigaciones Energeticas Medioambientales y Tecnologicas (CIEMAT),Madrid, SpainM. Aguilar-Benitez, J. Alcaraz Maestre, P. Arce, C. Battilana, E. Calvo, M. Cepeda, M. Cerrada,M. Chamizo Llatas, N. Colino, B. De La Cruz, A. Delgado Peris, C. Diez Pardos, D. DomınguezVazquez, C. Fernandez Bedoya, J.P. Fernandez Ramos, A. Ferrando, J. Flix, M.C. Fouz,

18 A The CMS Collaboration

P. Garcia-Abia, O. Gonzalez Lopez, S. Goy Lopez, J.M. Hernandez, M.I. Josa, G. Merino,J. Puerta Pelayo, I. Redondo, L. Romero, J. Santaolalla, M.S. Soares, C. Willmott

Universidad Autonoma de Madrid, Madrid, SpainC. Albajar, G. Codispoti, J.F. de Troconiz

Universidad de Oviedo, Oviedo, SpainJ. Cuevas, J. Fernandez Menendez, S. Folgueras, I. Gonzalez Caballero, L. Lloret Iglesias,J.M. Vizan Garcia

Instituto de Fısica de Cantabria (IFCA), CSIC-Universidad de Cantabria, Santander, SpainJ.A. Brochero Cifuentes, I.J. Cabrillo, A. Calderon, S.H. Chuang, J. Duarte Campderros,M. Felcini25, M. Fernandez, G. Gomez, J. Gonzalez Sanchez, C. Jorda, P. Lobelle Pardo, A. LopezVirto, J. Marco, R. Marco, C. Martinez Rivero, F. Matorras, F.J. Munoz Sanchez, J. PiedraGomez26, T. Rodrigo, A.Y. Rodrıguez-Marrero, A. Ruiz-Jimeno, L. Scodellaro, M. SobronSanudo, I. Vila, R. Vilar Cortabitarte

CERN, European Organization for Nuclear Research, Geneva, SwitzerlandD. Abbaneo, E. Auffray, G. Auzinger, P. Baillon, A.H. Ball, D. Barney, A.J. Bell27, D. Benedetti,C. Bernet3, W. Bialas, P. Bloch, A. Bocci, S. Bolognesi, M. Bona, H. Breuker, K. Bunkowski,T. Camporesi, G. Cerminara, T. Christiansen, J.A. Coarasa Perez, B. Cure, D. D’Enterria, A. DeRoeck, S. Di Guida, N. Dupont-Sagorin, A. Elliott-Peisert, B. Frisch, W. Funk, A. Gaddi,G. Georgiou, H. Gerwig, D. Gigi, K. Gill, D. Giordano, F. Glege, R. Gomez-Reino Garrido,M. Gouzevitch, P. Govoni, S. Gowdy, L. Guiducci, M. Hansen, C. Hartl, J. Harvey, J. Hegeman,B. Hegner, H.F. Hoffmann, A. Honma, V. Innocente, P. Janot, K. Kaadze, E. Karavakis, P. Lecoq,C. Lourenco, T. Maki, M. Malberti, L. Malgeri, M. Mannelli, L. Masetti, A. Maurisset, F. Meijers,S. Mersi, E. Meschi, R. Moser, M.U. Mozer, M. Mulders, E. Nesvold1, M. Nguyen, T. Orimoto,L. Orsini, E. Perez, A. Petrilli, A. Pfeiffer, M. Pierini, M. Pimia, D. Piparo, G. Polese, A. Racz,J. Rodrigues Antunes, G. Rolandi28, T. Rommerskirchen, M. Rovere, H. Sakulin, C. Schafer,C. Schwick, I. Segoni, A. Sharma, P. Siegrist, M. Simon, P. Sphicas29, M. Spiropulu23, M. Stoye,P. Tropea, A. Tsirou, P. Vichoudis, M. Voutilainen, W.D. Zeuner

Paul Scherrer Institut, Villigen, SwitzerlandW. Bertl, K. Deiters, W. Erdmann, K. Gabathuler, R. Horisberger, Q. Ingram, H.C. Kaestli,S. Konig, D. Kotlinski, U. Langenegger, F. Meier, D. Renker, T. Rohe, J. Sibille30,A. Starodumov31

Institute for Particle Physics, ETH Zurich, Zurich, SwitzerlandL. Bani, P. Bortignon, L. Caminada32, N. Chanon, Z. Chen, S. Cittolin, G. Dissertori, M. Dittmar,J. Eugster, K. Freudenreich, C. Grab, W. Hintz, P. Lecomte, W. Lustermann, C. Marchica32,P. Martinez Ruiz del Arbol, P. Milenovic33, F. Moortgat, C. Nageli32, P. Nef, F. Nessi-Tedaldi,L. Pape, F. Pauss, T. Punz, A. Rizzi, F.J. Ronga, M. Rossini, L. Sala, A.K. Sanchez, M.-C. Sawley,B. Stieger, L. Tauscher†, A. Thea, K. Theofilatos, D. Treille, C. Urscheler, R. Wallny, M. Weber,L. Wehrli, J. Weng

Universitat Zurich, Zurich, SwitzerlandE. Aguilo, C. Amsler, V. Chiochia, S. De Visscher, C. Favaro, M. Ivova Rikova, B. Millan Mejias,P. Otiougova, C. Regenfus, P. Robmann, A. Schmidt, H. Snoek

National Central University, Chung-Li, TaiwanY.H. Chang, K.H. Chen, C.M. Kuo, S.W. Li, W. Lin, Z.K. Liu, Y.J. Lu, D. Mekterovic, R. Volpe,J.H. Wu, S.S. Yu

19

National Taiwan University (NTU), Taipei, TaiwanP. Bartalini, P. Chang, Y.H. Chang, Y.W. Chang, Y. Chao, K.F. Chen, W.-S. Hou, Y. Hsiung,K.Y. Kao, Y.J. Lei, R.-S. Lu, J.G. Shiu, Y.M. Tzeng, M. Wang

Cukurova University, Adana, TurkeyA. Adiguzel, M.N. Bakirci34, S. Cerci35, C. Dozen, I. Dumanoglu, E. Eskut, S. Girgis,G. Gokbulut, I. Hos, E.E. Kangal, A. Kayis Topaksu, G. Onengut, K. Ozdemir, S. Ozturk36,A. Polatoz, K. Sogut37, D. Sunar Cerci35, B. Tali35, H. Topakli34, D. Uzun, L.N. Vergili, M. Vergili

Middle East Technical University, Physics Department, Ankara, TurkeyI.V. Akin, T. Aliev, B. Bilin, S. Bilmis, M. Deniz, H. Gamsizkan, A.M. Guler, K. Ocalan,A. Ozpineci, M. Serin, R. Sever, U.E. Surat, E. Yildirim, M. Zeyrek

Bogazici University, Istanbul, TurkeyM. Deliomeroglu, D. Demir38, E. Gulmez, B. Isildak, M. Kaya39, O. Kaya39, M. Ozbek,S. Ozkorucuklu40, N. Sonmez41

National Scientific Center, Kharkov Institute of Physics and Technology, Kharkov, UkraineL. Levchuk

University of Bristol, Bristol, United KingdomF. Bostock, J.J. Brooke, T.L. Cheng, E. Clement, D. Cussans, R. Frazier, J. Goldstein, M. Grimes,M. Hansen, D. Hartley, G.P. Heath, H.F. Heath, L. Kreczko, S. Metson, D.M. Newbold42,K. Nirunpong, A. Poll, S. Senkin, V.J. Smith, S. Ward

Rutherford Appleton Laboratory, Didcot, United KingdomL. Basso43, K.W. Bell, A. Belyaev43, C. Brew, R.M. Brown, B. Camanzi, D.J.A. Cockerill,J.A. Coughlan, K. Harder, S. Harper, J. Jackson, B.W. Kennedy, E. Olaiya, D. Petyt,B.C. Radburn-Smith, C.H. Shepherd-Themistocleous, I.R. Tomalin, W.J. Womersley, S.D. Worm

Imperial College, London, United KingdomR. Bainbridge, G. Ball, J. Ballin, R. Beuselinck, O. Buchmuller, D. Colling, N. Cripps, M. Cutajar,G. Davies, M. Della Negra, W. Ferguson, J. Fulcher, D. Futyan, A. Gilbert, A. Guneratne Bryer,G. Hall, Z. Hatherell, J. Hays, G. Iles, M. Jarvis, G. Karapostoli, L. Lyons, B.C. MacEvoy, A.-M. Magnan, J. Marrouche, B. Mathias, R. Nandi, J. Nash, A. Nikitenko31, A. Papageorgiou,M. Pesaresi, K. Petridis, M. Pioppi44, D.M. Raymond, S. Rogerson, N. Rompotis, A. Rose,M.J. Ryan, C. Seez, P. Sharp, A. Sparrow, A. Tapper, S. Tourneur, M. Vazquez Acosta, T. Virdee,S. Wakefield, N. Wardle, D. Wardrope, T. Whyntie

Brunel University, Uxbridge, United KingdomM. Barrett, M. Chadwick, J.E. Cole, P.R. Hobson, A. Khan, P. Kyberd, D. Leslie, W. Martin,I.D. Reid, L. Teodorescu

Baylor University, Waco, USAK. Hatakeyama, H. Liu

The University of Alabama, Tuscaloosa, USAC. Henderson

Boston University, Boston, USAT. Bose, E. Carrera Jarrin, C. Fantasia, A. Heister, J. St. John, P. Lawson, D. Lazic, J. Rohlf,D. Sperka, L. Sulak

Brown University, Providence, USAA. Avetisyan, S. Bhattacharya, J.P. Chou, D. Cutts, A. Ferapontov, U. Heintz, S. Jabeen,

20 A The CMS Collaboration

G. Kukartsev, G. Landsberg, M. Luk, M. Narain, D. Nguyen, M. Segala, T. Sinthuprasith,T. Speer, K.V. Tsang

University of California, Davis, Davis, USAR. Breedon, M. Calderon De La Barca Sanchez, S. Chauhan, M. Chertok, J. Conway, P.T. Cox,J. Dolen, R. Erbacher, E. Friis, W. Ko, A. Kopecky, R. Lander, H. Liu, S. Maruyama, T. Miceli,M. Nikolic, D. Pellett, J. Robles, S. Salur, T. Schwarz, M. Searle, J. Smith, M. Squires, M. Tripathi,R. Vasquez Sierra, C. Veelken

University of California, Los Angeles, Los Angeles, USAV. Andreev, K. Arisaka, D. Cline, R. Cousins, A. Deisher, J. Duris, S. Erhan, C. Farrell, J. Hauser,M. Ignatenko, C. Jarvis, C. Plager, G. Rakness, P. Schlein†, J. Tucker, V. Valuev

University of California, Riverside, Riverside, USAJ. Babb, A. Chandra, R. Clare, J. Ellison, J.W. Gary, F. Giordano, G. Hanson, G.Y. Jeng,S.C. Kao, F. Liu, H. Liu, O.R. Long, A. Luthra, H. Nguyen, B.C. Shen†, R. Stringer, J. Sturdy,S. Sumowidagdo, R. Wilken, S. Wimpenny

University of California, San Diego, La Jolla, USAW. Andrews, J.G. Branson, G.B. Cerati, D. Evans, F. Golf, A. Holzner, R. Kelley, M. Lebourgeois,J. Letts, B. Mangano, S. Padhi, C. Palmer, G. Petrucciani, H. Pi, M. Pieri, R. Ranieri, M. Sani,V. Sharma, S. Simon, E. Sudano, M. Tadel, Y. Tu, A. Vartak, S. Wasserbaech45, F. Wurthwein,A. Yagil, J. Yoo

University of California, Santa Barbara, Santa Barbara, USAD. Barge, R. Bellan, C. Campagnari, M. D’Alfonso, T. Danielson, K. Flowers, P. Geffert,J. Incandela, C. Justus, P. Kalavase, S.A. Koay, D. Kovalskyi, V. Krutelyov, S. Lowette, N. Mccoll,V. Pavlunin, F. Rebassoo, J. Ribnik, J. Richman, R. Rossin, D. Stuart, W. To, J.R. Vlimant

California Institute of Technology, Pasadena, USAA. Apresyan, A. Bornheim, J. Bunn, Y. Chen, M. Gataullin, Y. Ma, A. Mott, H.B. Newman,C. Rogan, K. Shin, V. Timciuc, P. Traczyk, J. Veverka, R. Wilkinson, Y. Yang, R.Y. Zhu

Carnegie Mellon University, Pittsburgh, USAB. Akgun, R. Carroll, T. Ferguson, Y. Iiyama, D.W. Jang, S.Y. Jun, Y.F. Liu, M. Paulini, J. Russ,H. Vogel, I. Vorobiev

University of Colorado at Boulder, Boulder, USAJ.P. Cumalat, M.E. Dinardo, B.R. Drell, C.J. Edelmaier, W.T. Ford, A. Gaz, B. Heyburn, E. LuiggiLopez, U. Nauenberg, J.G. Smith, K. Stenson, K.A. Ulmer, S.R. Wagner, S.L. Zang

Cornell University, Ithaca, USAL. Agostino, J. Alexander, D. Cassel, A. Chatterjee, S. Das, N. Eggert, L.K. Gibbons, B. Heltsley,W. Hopkins, A. Khukhunaishvili, B. Kreis, G. Nicolas Kaufman, J.R. Patterson, D. Puigh,A. Ryd, E. Salvati, X. Shi, W. Sun, W.D. Teo, J. Thom, J. Thompson, J. Vaughan, Y. Weng,L. Winstrom, P. Wittich

Fairfield University, Fairfield, USAA. Biselli, G. Cirino, D. Winn

Fermi National Accelerator Laboratory, Batavia, USAS. Abdullin, M. Albrow, J. Anderson, G. Apollinari, M. Atac, J.A. Bakken, S. Banerjee,L.A.T. Bauerdick, A. Beretvas, J. Berryhill, P.C. Bhat, I. Bloch, F. Borcherding, K. Burkett,J.N. Butler, V. Chetluru, H.W.K. Cheung, F. Chlebana, S. Cihangir, W. Cooper, D.P. Eartly,V.D. Elvira, S. Esen, I. Fisk, J. Freeman, Y. Gao, E. Gottschalk, D. Green, K. Gunthoti,

21

O. Gutsche, J. Hanlon, R.M. Harris, J. Hirschauer, B. Hooberman, H. Jensen, M. Johnson,U. Joshi, R. Khatiwada, B. Klima, K. Kousouris, S. Kunori, S. Kwan, C. Leonidopoulos,P. Limon, D. Lincoln, R. Lipton, J. Lykken, K. Maeshima, J.M. Marraffino, D. Mason, P. McBride,T. Miao, K. Mishra, S. Mrenna, Y. Musienko46, C. Newman-Holmes, V. O’Dell, R. Pordes,O. Prokofyev, N. Saoulidou, E. Sexton-Kennedy, S. Sharma, W.J. Spalding, L. Spiegel, P. Tan,L. Taylor, S. Tkaczyk, L. Uplegger, E.W. Vaandering, R. Vidal, J. Whitmore, W. Wu, F. Yang,F. Yumiceva, J.C. Yun

University of Florida, Gainesville, USAD. Acosta, P. Avery, D. Bourilkov, M. Chen, M. De Gruttola, G.P. Di Giovanni, D. Dobur,A. Drozdetskiy, R.D. Field, M. Fisher, Y. Fu, I.K. Furic, J. Gartner, B. Kim, J. Konigsberg,A. Korytov, A. Kropivnitskaya, T. Kypreos, K. Matchev, G. Mitselmakher, L. Muniz, C. Prescott,R. Remington, M. Schmitt, B. Scurlock, P. Sellers, N. Skhirtladze, M. Snowball, D. Wang,J. Yelton, M. Zakaria

Florida International University, Miami, USAC. Ceron, V. Gaultney, L. Kramer, L.M. Lebolo, S. Linn, P. Markowitz, G. Martinez, D. Mesa,J.L. Rodriguez

Florida State University, Tallahassee, USAT. Adams, A. Askew, J. Bochenek, J. Chen, B. Diamond, S.V. Gleyzer, J. Haas,S. Hagopian, V. Hagopian, M. Jenkins, K.F. Johnson, H. Prosper, L. Quertenmont, S. Sekmen,V. Veeraraghavan

Florida Institute of Technology, Melbourne, USAM.M. Baarmand, B. Dorney, S. Guragain, M. Hohlmann, H. Kalakhety, R. Ralich,I. Vodopiyanov

University of Illinois at Chicago (UIC), Chicago, USAM.R. Adams, I.M. Anghel, L. Apanasevich, Y. Bai, V.E. Bazterra, R.R. Betts, J. Callner,R. Cavanaugh, C. Dragoiu, L. Gauthier, C.E. Gerber, D.J. Hofman, S. Khalatyan, G.J. Kunde47,F. Lacroix, M. Malek, C. O’Brien, C. Silkworth, C. Silvestre, A. Smoron, D. Strom, N. Varelas

The University of Iowa, Iowa City, USAU. Akgun, E.A. Albayrak, B. Bilki, W. Clarida, F. Duru, C.K. Lae, E. McCliment, J.-P. Merlo,H. Mermerkaya48, A. Mestvirishvili, A. Moeller, J. Nachtman, C.R. Newsom, E. Norbeck,J. Olson, Y. Onel, F. Ozok, S. Sen, J. Wetzel, T. Yetkin, K. Yi

Johns Hopkins University, Baltimore, USAB.A. Barnett, B. Blumenfeld, A. Bonato, C. Eskew, D. Fehling, G. Giurgiu, A.V. Gritsan, Z.J. Guo,G. Hu, P. Maksimovic, S. Rappoccio, M. Swartz, N.V. Tran, A. Whitbeck

The University of Kansas, Lawrence, USAP. Baringer, A. Bean, G. Benelli, O. Grachov, R.P. Kenny Iii, M. Murray, D. Noonan, S. Sanders,J.S. Wood, V. Zhukova

Kansas State University, Manhattan, USAA.F. Barfuss, T. Bolton, I. Chakaberia, A. Ivanov, S. Khalil, M. Makouski, Y. Maravin, S. Shrestha,I. Svintradze, Z. Wan

Lawrence Livermore National Laboratory, Livermore, USAJ. Gronberg, D. Lange, D. Wright

University of Maryland, College Park, USAA. Baden, M. Boutemeur, S.C. Eno, D. Ferencek, J.A. Gomez, N.J. Hadley, R.G. Kellogg, M. Kirn,

22 A The CMS Collaboration

Y. Lu, A.C. Mignerey, K. Rossato, P. Rumerio, F. Santanastasio, A. Skuja, J. Temple, M.B. Tonjes,S.C. Tonwar, E. Twedt

Massachusetts Institute of Technology, Cambridge, USAB. Alver, G. Bauer, J. Bendavid, W. Busza, E. Butz, I.A. Cali, M. Chan, V. Dutta, P. Everaerts,G. Gomez Ceballos, M. Goncharov, K.A. Hahn, P. Harris, Y. Kim, M. Klute, Y.-J. Lee, W. Li,C. Loizides, P.D. Luckey, T. Ma, S. Nahn, C. Paus, D. Ralph, C. Roland, G. Roland, M. Rudolph,G.S.F. Stephans, F. Stockli, K. Sumorok, K. Sung, E.A. Wenger, R. Wolf, S. Xie, M. Yang,Y. Yilmaz, A.S. Yoon, M. Zanetti

University of Minnesota, Minneapolis, USAS.I. Cooper, P. Cushman, B. Dahmes, A. De Benedetti, P.R. Dudero, G. Franzoni, J. Haupt,K. Klapoetke, Y. Kubota, J. Mans, N. Pastika, V. Rekovic, R. Rusack, M. Sasseville, A. Singovsky,N. Tambe

University of Mississippi, University, USAL.M. Cremaldi, R. Godang, R. Kroeger, L. Perera, R. Rahmat, D.A. Sanders, D. Summers

University of Nebraska-Lincoln, Lincoln, USAK. Bloom, S. Bose, J. Butt, D.R. Claes, A. Dominguez, M. Eads, J. Keller, T. Kelly, I. Kravchenko,J. Lazo-Flores, H. Malbouisson, S. Malik, G.R. Snow

State University of New York at Buffalo, Buffalo, USAU. Baur, A. Godshalk, I. Iashvili, S. Jain, A. Kharchilava, A. Kumar, S.P. Shipkowski, K. Smith

Northeastern University, Boston, USAG. Alverson, E. Barberis, D. Baumgartel, O. Boeriu, M. Chasco, S. Reucroft, J. Swain, D. Trocino,D. Wood, J. Zhang

Northwestern University, Evanston, USAA. Anastassov, A. Kubik, N. Odell, R.A. Ofierzynski, B. Pollack, A. Pozdnyakov, M. Schmitt,S. Stoynev, M. Velasco, S. Won

University of Notre Dame, Notre Dame, USAL. Antonelli, D. Berry, A. Brinkerhoff, M. Hildreth, C. Jessop, D.J. Karmgard, J. Kolb, T. Kolberg,K. Lannon, W. Luo, S. Lynch, N. Marinelli, D.M. Morse, T. Pearson, R. Ruchti, J. Slaunwhite,N. Valls, M. Wayne, J. Ziegler

The Ohio State University, Columbus, USAB. Bylsma, L.S. Durkin, J. Gu, C. Hill, P. Killewald, K. Kotov, T.Y. Ling, M. Rodenburg,G. Williams

Princeton University, Princeton, USAN. Adam, E. Berry, P. Elmer, D. Gerbaudo, V. Halyo, P. Hebda, A. Hunt, J. Jones, E. Laird,D. Lopes Pegna, D. Marlow, T. Medvedeva, M. Mooney, J. Olsen, P. Piroue, X. Quan, H. Saka,D. Stickland, C. Tully, J.S. Werner, A. Zuranski

University of Puerto Rico, Mayaguez, USAJ.G. Acosta, X.T. Huang, A. Lopez, H. Mendez, S. Oliveros, J.E. Ramirez Vargas,A. Zatserklyaniy

Purdue University, West Lafayette, USAE. Alagoz, V.E. Barnes, G. Bolla, L. Borrello, D. Bortoletto, A. Everett, A.F. Garfinkel, L. Gutay,Z. Hu, M. Jones, O. Koybasi, M. Kress, A.T. Laasanen, N. Leonardo, C. Liu, V. Maroussov,

23

P. Merkel, D.H. Miller, N. Neumeister, I. Shipsey, D. Silvers, A. Svyatkovskiy, H.D. Yoo,J. Zablocki, Y. Zheng

Purdue University Calumet, Hammond, USAP. Jindal, N. Parashar

Rice University, Houston, USAC. Boulahouache, K.M. Ecklund, F.J.M. Geurts, B.P. Padley, R. Redjimi, J. Roberts, J. Zabel

University of Rochester, Rochester, USAB. Betchart, A. Bodek, Y.S. Chung, R. Covarelli, P. de Barbaro, R. Demina, Y. Eshaq, H. Flacher,A. Garcia-Bellido, P. Goldenzweig, Y. Gotra, J. Han, A. Harel, D.C. Miner, D. Orbaker,G. Petrillo, D. Vishnevskiy, M. Zielinski

The Rockefeller University, New York, USAA. Bhatti, R. Ciesielski, L. Demortier, K. Goulianos, G. Lungu, S. Malik, C. Mesropian, M. Yan

Rutgers, the State University of New Jersey, Piscataway, USAO. Atramentov, A. Barker, D. Duggan, Y. Gershtein, R. Gray, E. Halkiadakis, D. Hidas, D. Hits,A. Lath, S. Panwalkar, R. Patel, K. Rose, S. Schnetzer, S. Somalwar, R. Stone, S. Thomas

University of Tennessee, Knoxville, USAG. Cerizza, M. Hollingsworth, S. Spanier, Z.C. Yang, A. York

Texas A&M University, College Station, USAR. Eusebi, W. Flanagan, J. Gilmore, A. Gurrola, T. Kamon, V. Khotilovich, R. Montalvo,I. Osipenkov, Y. Pakhotin, J. Pivarski, A. Safonov, S. Sengupta, A. Tatarinov, D. Toback,M. Weinberger

Texas Tech University, Lubbock, USAN. Akchurin, C. Bardak, J. Damgov, C. Jeong, K. Kovitanggoon, S.W. Lee, T. Libeiro, P. Mane,Y. Roh, A. Sill, I. Volobouev, R. Wigmans, E. Yazgan

Vanderbilt University, Nashville, USAE. Appelt, E. Brownson, D. Engh, C. Florez, W. Gabella, M. Issah, W. Johns, P. Kurt, C. Maguire,A. Melo, P. Sheldon, B. Snook, S. Tuo, J. Velkovska

University of Virginia, Charlottesville, USAM.W. Arenton, M. Balazs, S. Boutle, B. Cox, B. Francis, R. Hirosky, A. Ledovskoy, C. Lin, C. Neu,R. Yohay

Wayne State University, Detroit, USAS. Gollapinni, R. Harr, P.E. Karchin, P. Lamichhane, M. Mattson, C. Milstene, A. Sakharov

University of Wisconsin, Madison, USAM. Anderson, M. Bachtis, J.N. Bellinger, D. Carlsmith, S. Dasu, J. Efron, K. Flood, L. Gray,K.S. Grogg, M. Grothe, R. Hall-Wilton, M. Herndon, A. Herve, P. Klabbers, J. Klukas, A. Lanaro,C. Lazaridis, J. Leonard, R. Loveless, A. Mohapatra, F. Palmonari, D. Reeder, I. Ross, A. Savin,W.H. Smith, J. Swanson, M. Weinberg

†: Deceased1: Also at CERN, European Organization for Nuclear Research, Geneva, Switzerland2: Also at Universidade Federal do ABC, Santo Andre, Brazil3: Also at Laboratoire Leprince-Ringuet, Ecole Polytechnique, IN2P3-CNRS, Palaiseau, France4: Also at Suez Canal University, Suez, Egypt5: Also at British University, Cairo, Egypt

24 A The CMS Collaboration

6: Also at Fayoum University, El-Fayoum, Egypt7: Also at Soltan Institute for Nuclear Studies, Warsaw, Poland8: Also at Massachusetts Institute of Technology, Cambridge, USA9: Also at Universite de Haute-Alsace, Mulhouse, France10: Also at Brandenburg University of Technology, Cottbus, Germany11: Also at Moscow State University, Moscow, Russia12: Also at Institute of Nuclear Research ATOMKI, Debrecen, Hungary13: Also at Eotvos Lorand University, Budapest, Hungary14: Also at Tata Institute of Fundamental Research - HECR, Mumbai, India15: Also at University of Visva-Bharati, Santiniketan, India16: Also at Sharif University of Technology, Tehran, Iran17: Also at Shiraz University, Shiraz, Iran18: Also at Isfahan University of Technology, Isfahan, Iran19: Also at Facolta Ingegneria Universita di Roma ”La Sapienza”, Roma, Italy20: Also at Universita della Basilicata, Potenza, Italy21: Also at Laboratori Nazionali di Legnaro dell’ INFN, Legnaro, Italy22: Also at Universita degli studi di Siena, Siena, Italy23: Also at California Institute of Technology, Pasadena, USA24: Also at Faculty of Physics of University of Belgrade, Belgrade, Serbia25: Also at University of California, Los Angeles, Los Angeles, USA26: Also at University of Florida, Gainesville, USA27: Also at Universite de Geneve, Geneva, Switzerland28: Also at Scuola Normale e Sezione dell’ INFN, Pisa, Italy29: Also at University of Athens, Athens, Greece30: Also at The University of Kansas, Lawrence, USA31: Also at Institute for Theoretical and Experimental Physics, Moscow, Russia32: Also at Paul Scherrer Institut, Villigen, Switzerland33: Also at University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences,Belgrade, Serbia34: Also at Gaziosmanpasa University, Tokat, Turkey35: Also at Adiyaman University, Adiyaman, Turkey36: Also at The University of Iowa, Iowa City, USA37: Also at Mersin University, Mersin, Turkey38: Also at Izmir Institute of Technology, Izmir, Turkey39: Also at Kafkas University, Kars, Turkey40: Also at Suleyman Demirel University, Isparta, Turkey41: Also at Ege University, Izmir, Turkey42: Also at Rutherford Appleton Laboratory, Didcot, United Kingdom43: Also at School of Physics and Astronomy, University of Southampton, Southampton,United Kingdom44: Also at INFN Sezione di Perugia; Universita di Perugia, Perugia, Italy45: Also at Utah Valley University, Orem, USA46: Also at Institute for Nuclear Research, Moscow, Russia47: Also at Los Alamos National Laboratory, Los Alamos, USA48: Also at Erzincan University, Erzincan, Turkey