Measurements of the Upsilon(1S), Upsilon(2S), and Upsilon(3S) differential cross sections in pp collisions at root s=7 TeV

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UNIVERSIDADE ESTADUAL DE CAMPINAS SISTEMA DE BIBLIOTECAS DA UNICAMP REPOSITÓRIO DA PRODUÇÃO CIENTIFICA E INTELECTUAL DA UNICAMP __________________________________________________________________________________

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https://www.sciencedirect.com/science/article/pii/S037026931500547X?via%3Dihub

DOI: 10.1016/j.physletb.2015.07.037

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2015 by Elsevier. All rights reserved.

DIRETORIA DE TRATAMENTO DA INFORMAÇÃO Cidade Universitária Zeferino Vaz Barão Geraldo

CEP 13083-970 – Campinas SP Fone: (19) 3521-6493 http://www.repositorio.unicamp.br

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Contents lists available atScienceDirect

Physics

Letters

B

www.elsevier.com/locate/physletb

Measurements

of

the

ϒ (

1S

)

,

ϒ (

2S

)

,

and

ϒ (

3S

)

differential

cross

sections

in

pp

collisions

at

√

s

=

7 TeV

.CMSCollaboration CERN,Switzerland

a r t i c l e i n f o a b s t ra c t

Articlehistory:

Received30January2015 Receivedinrevisedform1July2015 Accepted16July2015

Availableonline22July2015 Editor:M.Doser Keywords: CMS Upsilon B-Physics Crosssection

DifferentialcrosssectionsasafunctionoftransversemomentumpTarepresentedfortheproductionof

ϒ(nS)(n=1,2,3)statesdecayingintoapairofmuons.Datacorrespondingtoanintegratedluminosity of4.9 fb−1_in_pp_collisions_at√_s₌₇_{TeV were}_collected_with_the_CMS_detector_at_the_LHC._The_analysis

selects events withdimuon rapidity _|y_|<1.2 and dimuontransverse momentum inthe range 10< pT<100GeV.The measurements showatransition froman exponentialtoapower-law behaviorat

pT≈20GeV forthe threeϒ states.Abovethat transition,theϒ(3S) spectrumissigniﬁcantlyharder

thanthatoftheϒ(1S).Theratiosoftheϒ(3S)andϒ(2S)differentialcrosssectionstotheϒ(1S)cross sectionshowariseaspTincreasesatlowpT,thenbecomeﬂatterathigherpT.

1. Introduction

HadronicproductionofS-wavebb mesonshasbeenextensively studiedformanyyears.AttheCERNLHC,theCMS[1,2],ATLAS[3], andLHCb[4]Collaborationshavepublishedresultsonϒ(nS)(n= 1,2,3)productioncrosssectionstimesdimuonbranchingfractions inpp collisions at√s=7TeV as a functionof the ϒ transverse momentum pT,rapidity y,andpolarization[5].The CMSand

AT-LASpTand|y|distributionsinthecentralrapidityregion|y|<2.0

aresimilarinshapetothosefrompp productionat√s=1.96TeV, asmeasuredby theD0 [6]andCDF[7]experimentsatthe Teva-tron.NeithertheATLASnortheCMSresultsshow anystatistically signiﬁcantrapidity dependenceofthe crosssectioninthecentral region.TheCMSanalyses coverthe pT rangeupto50 GeV,while

theATLASresultsgoto70 GeV.

InthisLetterwepresentameasurementofthedifferential pro-ductioncrosssectionsofthethreelowest-massϒ(nS)statesinpp collisions at√s=7 TeV upto pT=100 GeV,reachinghigher pT

than previous measurements.We measure the pT dependence of

the ϒ(nS) differential cross section times the branching fraction to μ+μ−usingthe2011dataset,correspondingtoan integrated luminosityof4.9 fb−1_._The_measured_cross_sections_include

feed-downfromhigherbb excitations.

_E-mail_address:_{[email protected]}_.

Measurements of S-wave bb mesons provide an important probeofquantumchromodynamics(QCD).Thereareseveral mod-els that predict differential cross section shapes at high ϒ(nS)

pT in pp collisions. A commonfeature ofall the models is that

differentcontributingterms havedifferent pT variations,some of

whichare power-lawforms.The nonrelativisticQCD(NRQCD) ap-proach [8,9] uses an effective ﬁeld theory to factorize the per-turbative term and nonpertubative long-distance matrix element (LDME) terms. Agood description ofearly LHC resultsfor ϒ(1S)

productionforpT<30GeV wasachievedusingNRQCDwith

next-to-leading-order (NLO) corrections [10]. However, there are the-oretical corrections to perturbative NRQCD that have character-istic power-law behavior at high pT, andmeasurements at high pT can help to clarify the theoretical picture [11,12]. The NLO

NRQCD calculation has recently been extended to treat all three

ϒ(nS) states[13].The updated calculationincludesnot onlyNLO terms but also uses LDMEs computed using only high-pT data.

Color singletmodels (CSM) withhigher-order pT-dependent

cor-rections [14] and the kT-factorization model [15] are consistent

with data from the LHC for pT approaching 50 GeV. A recent

analysisofquarkoniumpolarizationandproductionmeasurements found that raising pT thresholds stabilizes the ﬁts in evaluating

the LDMEs[16].At higher pT differentcorrectionsbecome

domi-nant inthesemodels.New dataathigh pT willchallenge all the

currentapproaches. http://dx.doi.org/10.1016/j.physletb.2015.07.037

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2. CMSdetector

The central feature of the CMS apparatus is a superconduct-ingsolenoidof6 m internaldiameterhavinga3.8 T ﬁeld. Within thesuperconductingsolenoidvolumeare asiliconpixelandstrip tracker, a lead tungstate crystal electromagnetic calorimeter,and a brass and scintillator hadron calorimeter. Muons are measured ingas-ionizationdetectorsembeddedinthesteelﬂux-returnyoke outsidethesolenoid, withdetectionplanesare madeusingthree technologies: drift tubes, cathode strip chambers, and resistive-platechambers. Muonsare measuredinthepseudorapidityrange |η|<2.4.

Thesilicontrackermeasureschargedparticleswithinthe pseu-dorapidity range |η|<2.5. It consists of 1440 silicon pixel and 15 148siliconstripdetectormodulesandprovidesatypical trans-verseimpactparameterresolutionof25–90 μm.Matchingmuons to tracks measured in the silicon tracker results in a transverse momentumresolution between1% and2.8%, for pT valuesup to

100 GeV[17].

ThefirstleveloftheCMStriggersystem, composedofcustom hardware processors,uses informationfrom thecalorimeters and muon detectors to select the most interesting events in a fixed time interval of less than 4 μs. The high-level trigger processor farm further decreases the event rate from around 100 kHz to around 400 Hz, before data storage.A more detailed description oftheCMS detector,together witha definitionof thecoordinate systemusedandtherelevantkinematicvariables,canbefoundin Ref.[18].

3. Differentialcrosssectionmeasurementmethodology

Eventselection starts witha dimuontrigger involvingthe sil-icon trackerandmuon systems.The trigger, whichis exposed to the full integrated luminosity, requires at least two muons with dimuonrapidity |y|<1.25, dimuoninvariant mass 8.5<Mμμ<

11.5GeV, andadimuon vertexﬁtwitha χ2 _probability _>₀_._5%.

Thetriggerselectsonlypairsofmuonsthatbendawayfromeach other in the magnetic ﬁeld (“seagull selection”), i.e., events for which the difference in azimuthal angle between the positively chargedand negatively charged muonsis lessthan zero. Requir-ing that muon trajectories do not cross in the transverse plane improves the muon eﬃciency. Trigger pT thresholds varied from

5–9 GeV asthebeamconditionschanged.Oﬄineselectioncriteria requiredpT>10GeV,|y|<1.2,andadimuonvertexﬁt χ2

proba-bility>1%.StandardCMSqualityrequirementsareusedtoidentify muonsandmuonsarerestrictedto|η(μ)|<1.6.Themuontracks arerequiredtohaveatleasttenhitsinthesilicontracker,atleast onehitinthesiliconpixeldetector,andbe matchedwithatleast onesegmentofthemuonsystem.Themuontrackﬁtqualitymust havea χ2 _per_degree_of_freedom_of_less_than_1.8. _The_distance_of

thetrackfromtheclosestprimaryvertexmustbelessthan15 cm inthelongitudinaldirectionand3 cm inthetransversedirection. Thefollowingkinematicrequirementsarealsoimposed toensure accuratemuondetectioneﬃciencyevaluation:

pT(μ) >3 GeV for 1.4<|η(μ)| <1.6, pT(μ) >3.5 GeV for 1.2<|η(μ)| <1.4,

pT(μ) >4.5 GeV for|η(μ)| <1.2. (1)

The differential cross sections are measured for two rapidity ranges:|y|≤0.6 and0.6<|y|<1.2,aswellasfortheentirerange |y|<1.2.IneachrapidityrangethedataarebinnedinpT,withbin

edgesat2 GeV intervalsbetween10and40 GeV,thenwiderbins withedgesat43,46,50,55,60,70,and100 GeV.

The ϒ(nS) differential cross section times dimuon branching fraction,integratedovereitherofthetwo|y|rangesandinagiven pT binofwidthpT,is dσpp→ ϒ(nS) dpT |y|range Bϒ(nS)→μ+μ− = N ﬁt ϒ (nS)(pT) LpTμμ(pT)A(pT)sgvp , (2)

where Nﬁt_ϒ(_nS₎ is the ﬁtted number of ϒ(nS) events from the dimuoninvariantmassdistributioninapTbinfortheselected|y|

range, μμ isthedimuon eﬃciency, L isthe integrated luminos-ity,Aisthepolarization-correctedacceptance, sg istheeﬃciency

of the seagull selection, and vp is the eﬃciency ofthe dimuon

vertex χ2 _probability _requirement. _The _eﬃciency _and_acceptance

determinationsaredescribedbelow.

The totalyield N_ϒ(ﬁt_nS₎ forthe threeϒ(nS)statesin the rapid-ityrange|y|<1.2 are412900±600ϒ(1S)events,151700±400

ϒ(2S)events,and111100±300ϒ(3S)events,wherethe uncer-taintiesarestatisticalonly.TheﬁnegranularityoftheCMStracker kept the eﬃciency independent of changes in the LHC instanta-neousluminositythroughoutthe√s=7TeV operations.

3.1. Eﬃciencyfactors

Thedimuoneﬃciencyforagiveneventisparameterizedas:

μμ≡1[pT(μ1),η(μ1)]2[pT(μ2),η(μ2)]ρ, (3)

where i[pT(μi), η(μi)] is the overall single-muon quality and

trigger eﬃciency.The kinematic dependenceof the ρ factorwas determined in a study based on Monte Carlo (MC) simulation using evtgen [19] with a detector simulation performed with Geant4[20].Theparameter ρaccountsforthepossibilitythattwo genuine muonscanbe merged during thereconstruction or trig-gerselection, causing an ineﬃciency.It was found to dependon the quadrature sum of the differences pT/(637 GeV), η, and

1.2φbetweenthetwomuons.TheMCsimulationresultwas val-idatedbymeasuringthe ρ factorwithϒ(nS)eventsreconstructed usingadatasetthatrequiredonlyasingle-muontrigger.Inevents suchasthosewithpT<50GeV,wherethemuonsarewell

sepa-rated, ρ=1.Forhigh-pT eventsofpT>80GeV,wherethemuons

areclosertogether, ρ dropstoapproximately0.7.

The single-muonefficiencies are measured usingthe tag-and-probeapproachbasedoncontrolsamplesindata,asdescribed in Ref. [21], times the tracking efficiency(0.99±0.01), determined fromMCsimulation.Weassumethatthedimuonefficiencywithin each ϒ(nS) mass region is the same for signal and background. Thedimuonefficiency μμ foragiven(pT,|y|) isobtainedby

av-eragingthe calculatedeventdimuoneﬃciency μμ foreach data event in the bin.This is done separately for the three ϒ states, using a massrange of±200MeV for the ϒ(1S) and±100MeV forthehigher-massstates.Thenarrowerrangefortheϒ(2S)and

ϒ(3S) statesischosen becauseofthe closenessinmass ofthese two states.The averageeﬃciency, μμ,istypically 0.75–0.80.For all(pT,y)binsthesystematicdifferencebetweenaveragingin μμ or1/μμ canbeneglectedincomparisontothequotedsystematic uncertaintydueto thesinglemuoneﬃciencies. Todetermine sg,

we note that there isa 50% probability that an ϒ(nS) state will decay inthe seagullconfiguration. It was verified in MC simula-tionthat sg=0.5.Theefficiency vp forthedimuonvertexfit χ2

probability requirementisdeterminedtobe 0.99±0.01 fromMC simulation,wheretheuncertaintyisstatistical.Thiseﬃciencywas

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validatedindatausingeventsfromatrigger thatdidnot require vertexselection. We also computedthe total acceptanceand ef-ﬁciencyproduct in theMC simulationand comparedit withthe resultbased on the factorized approach. The results agreed over theentirepTrangeofthemeasurement.

3.2. Acceptance

For each ϒ(nS) state the acceptance A is computed in each (pT,|y|)binanddeﬁnedasthefractionofitsdimuondecaysthat

satisfythesingle-muonkinematicselectionsgivenby Eq.(1).The acceptances are computed using generator-level muons, then re-peatedusingreconstructedmuonsinthefullsimulationstudy.The results agree to better than 2% at all pT values. Differences are

containedwithinthesystematicuncertaintyband(Section4.3) as-signed for the muon reconstruction. To account for the effectof theϒ(nS)polarizationonthemuonangulardistribution,eachMC simulationeventisweightedbyanangularfactorw:

w= 3 4π 1 3+ λθ

×1+ λθcos2θ+ λφsin2θcos 2φ+ λθ φsin 2θcosφ

, (4)

where λθ, λφ, λθ φ are the measured polarization parameters [5],

θ isthe polarangle,andφ the azimuthal angleof thepositively chargedmuon inthe ϒ(nS)helicity frame(HX).The polarization was measured in the range 10<pT<50 GeV in the same two

rapidity binsasthisanalysis. The measured polarization parame-tersdonotshow astatisticallysigniﬁcant dependenceon pT.We

linearlyinterpolateeachofthe measuredpolarization parameters in pT. Linear interpolation is also used forthe 68.3% conﬁdence

level(CL)uncertaintiesinthepolarizationmeasurementsto deter-mine the uncertainty in the three parameters from the analysis. Thepolarization parameters for pT>50GeV are takento bethe

averageofthemeasured valuesfor10<pT<50GeV.The largest

measuredabsoluteuncertaintyforeach parameterisusedforthe extrapolated uncertainties because the spread in nominal values issmall.Theacceptanceis computedinitiallyusinga ﬂat pT

dis-tributionwithinabin,thenreweighted afterﬁttingthemeasured pT distribution to a functional form (see Section 5). The

accep-tancesineach pT binforthethreerapidity intervalsare givenin

the supplemental material(Tables 7–15) for the measured polar-izationcentralvalueandthe68.3%CLuncertaintiesonthe param-eters[5].Inaddition,we reportthe acceptancecomputedforthe hypothesesofzero,100% transverse,and100%longitudinal polar-izationthatcorrespondtotheparametervaluesλφ= λθ φ=0 and

λθ =0,+1,and−1 respectively.Becauseoftheagreementinthe acceptancewhencomputedwithgenerator-levelandreconstructed muons,thecrosssectionresultsreportedherecanbescaledto ac-commodate anyother polarization by usinga generator-level MC simulationwithagivenpolarization.

4. Yielddeterminationprocedure

4.1. Lineshapedetermination

The ϒ(nS)lineshapeis determined usingthemeasured muon momentaandtheiruncertainties,alongwithagenerator-level sim-ulatedinvariantmass(SIM)distributionincludingﬁnal-state radi-ation(FSR)effects.Foreventsinagiven(pT,|y|)bin,the

distribu-tionofthedimuoninvariantmassuncertaintyζ iscomputedfrom themuontrackerrormatrices.

In order to describe the ϒ(nS) SIM distribution without de-tector resolution effects, we simulate dimuon events fora given

ϒ(nS)state using evtgen andcompute theFSRusing photos[22, 23]. Thestandard photos minimumphoton energyfortheϒ(nS)

statesis≈50MeV,whichisofthesameorderasourdimuon in-variant mass uncertainty. To improve the description, we extend thephotonenergyspectrumdownto2 MeV usingaﬁtoftheSIM distribution to the QED inner-bremsstrahlung formula [23]. The systematicuncertaintiesofthesoftphotonapproximationin pho-toscomparedtoexactQEDcalculationsarediscussedinRef.[23]. For the range of photon energies expected in ϒ(nS) decays the systematicuncertaintyisnegligible.

Ineach rapidityrange,the ϒ(nS) lineshapeforagiven pT bin

isexpressedbya probabilitydensityfunction(PDF)forthesignal dimuonmass Mμμ.ThisfunctionF(Mμμ;cw,δm)istheaverage

ofN valuesofthedimuonmassmi smearedwitharesolutionζi: F(Mμμ;cw, δm)= 1 N N i=1 1 √ 2πcwζi e−(Mμμ−mi−δm)2/2c2wζi2_. ₍₅₎

Eachϒ(nS)stateishandledinthesamefashion.Valuesofmiand ζi are selectedby randomlysamplingtheradiativemass function

and the ζ distribution for that (pT, |y|) bin. Twocorrection

fac-torsarecommontoallthreeϒ(nS)peaksinagiven(pT,|y|)bin:

a widthscale factor cw,to correctfor anyζ scale difference

be-tweendataandtheMCsimulation,andamass-shiftδm,tocorrect foranydifferenceinpTscalebetweendataandtheMCsimulation.

We sample N=25000 (mi,ζi) pointsper pT bin,storedina

his-togramwith0.25 MeV bins tosmooththeﬂuctuationsandretain shape features. This histogram gives the normalized, resolution-smearedmassPDFforagivenϒ(nS)stateinaparticular(pT,|y|)

bin.The procedurewas validatedinMCsimulationby generating the lineshapeusinga subsetofgenerated ϒ(1S) events,then ﬁt-tingtherestoftheeventswiththat lineshape.Theﬁttednumber ofeventswasconsistentwiththegeneratednumber.

4.2. Fittingforyields

Todeterminethe yieldsofthethreestatesineach pT and|y|

rangerequiresaﬁttothedimuonmassdistributioninevery(pT, |y|) bin. The total PDF for Mμμ describes the signal and back-ground contributions to the dimuon invariant mass distribution using a signal PDF as deﬁned in Eq. (5) for each of the ϒ(nS)

states,plusabackgroundfunction.Fourbackgroundfunctionsare studied:anexponentialandaChebyshevserieswithmaximum or-derof0,1,or2.

We measure the yield by performing an extended maximum-likelihood fit using RooFit [24] to determinethe number of sig-nal events associated with each normalized signal PDF. To allow cancellation of some common uncertainties in the muon accep-tance andefficiency calculationinthe measurementofthe ratios ofϒ(2S)andϒ(3S)differentialcrosssectionstothatoftheϒ(1S), we perform an additional fit normalized to the ϒ(1S) yield. For each pT bin the optimal background function is determined

us-ingtheAkaikeInformationCriterion(AIC)[25],takingthefunction withthelargestrelativeprobability,asdiscussedinRef.[26].This methodissimilartoamaximum-likelihoodevaluation,butitadds a termequal to twice the number offree parameters in the ﬁt, thus penalizing addition of free parameters. The parameters cw

andδm are determined fromtheﬁt foreach pT bin.Typical

val-uesandcorrespondinguncertaintiesforcw andδm are1.04±0.01

and3±1MeV, respectively.Theﬁtcorrelationmatrixshowsthat their inﬂuence on the yields is a small fractionof the statistical uncertaintyineachyield.

The plots inFig. 1 show two examples of ﬁtting the dimuon invariantmassdistributionusingthelineshapemethod.Thelower plotsshowthepull,(Ndata−Nﬁt)/σdata,ineachdimuonmassbin,

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Fig. 1. Results oftheﬁtstothedimuoninvariantmassdistributionforeventsintwo bins:(a):|y|<0.6,10<pT<12GeV and(b):0.6<|y|<1.2,50<pT<55GeV.

Thesolidlineistheresultofthefullfit.Thedash-dottedlineistheϒ(1S)signalfit, thelong-dashedlineistheϒ(2S)signalfit,andthedottedlineistheϒ(3S)signal fit.Theshort-dashedlineisthebackgroundcontribution.Thelowerplotsshowthe pullforeachmassbin.

where Ndata is the observednumber ofeventsin the bin,Nﬁt is

the integral of the ﬁtted signal and backgroundfunction in that bin,andtheuncertainty σdataisthePoissonstatisticaluncertainty.

Ascanbe seeninFig. 1, thelineshapedescriptionrepresentsthe datawell,evenathighpTandlargerapidity.

4.3.Systematicuncertainties

The overall systematic uncertainty in the cross section for a given(pT,|y|) binincludesuncertainties fromthebackgroundﬁt

method, the lineshape determination, the dimuon eﬃciency, the acceptancevariations dueto varying thepolarization parameters within their 68.3% CL ranges, and the integratedluminosity. The systematicuncertaintyfromthebackgroundfunctionisestimated usingthemaximumdifferenceinyields amongbackground func-tionswithanAICprobabilityabove5%[25,26]relativetothebest background choice. An upper limit of 1% on the systematic un-certainty fromthe lineshape function determinationfor all three

ϒ(nS) states and all (pT, |y|) bins is estimated by varying the

width of the mass region in which the mass resolution param-eter ζ is determined. The eﬃciency systematic is evaluated by

modifying μμ event by event, using the ±1 standard deviation values from the tag-and-probe measurements [5]. There is a 1% systematicuncertaintytoaccountforsmallvariations in μμ asa functionofMμμ observedinthedata.Themeasured ρfactor val-uesfromtheexperimentaldeterminationandfromMCsimulation agree over thefull pT range. We assigna systematic uncertainty

for ρ of0.5–5%,whichequals thefulldifferencebetweentheMC simulation and the experimental measurement. We compute the acceptancesystematicuncertaintybyraisingandloweringallthree polarizationparametersbytheirinterpolated68.3%CLvaluesfrom Ref.[5].Theresulting5–8%changeintheacceptanceisusedasthe systematicuncertaintyintheacceptanceastabulated inthe sup-plementalmaterial(Tables7–15).Thetotalsystematicuncertainty is found from the quadrature sum of the individual systematic uncertainties.Itiscomparabletoorsmallerthanthestatistical un-certainty for pT>40GeV. There isa 2.2% uncertainty [27] from

theintegratedluminositydeterminationthatappliestoallpT bins.

Thisuncertainty isnot included inthe uncertainties displayed in theﬁguresorgiveninthetables.

5. Results

The measured ϒ(nS) differential cross sectionsversus pT are

showninFig. 2overthefull rapidityrange|y|<1.2.The vertical barsonthepointsinFig. 2showthestatisticalandsystematic un-certaintiesaddedinquadrature.EarlierCMSmeasurements[2]are shownforcomparison,scaledby0.5toaccountforthesmaller|y| rangeinthe latestmeasurement,wherethe scalingassumesthat the rapidity distribution is ﬂat. The ϒ(nS) differential cross sec-tions peak near pT=4 GeV, as seen in Fig. 2. Their shape can

be described by an exponential function for 10pT20 GeV,

while for pT20 GeV the data lie above the exponential and

theslopechanges.Therefore,weﬁtthehigh-pTmeasurementsfor

eachϒ(nS)stateusingapower-lawparametrization:

dσpp→ ϒ(nS) dpT |y|range Bϒ(nS)→μ+μ− = A C+ pT p0 α, (6)

where A is a normalization with units of pb/GeV. The value of p0 is ﬁxed to 20 GeV and has no inﬂuence on the exponent α,

which describes the curvature of the function. The differential cross section ﬁts are evaluated using the integral value of the function overthe pT rangeofeach bin,andtheresultsare given

in Table 1. The bin centers are determined by the functional-weight method described in [28], using the exponential ﬁt for pT<20GeV and thepower-lawforminEq.(6)for pT>20GeV.

Shiftsfromthe pT-weighted meanvaluesarenegligibleinall

ex-ceptthehighest-pTbin,whereusingthefunctionalweightmoves

thebincenterfrom79to82 GeV.Tables 1–3inthesupplemental material give themeasured valuesshowninFig. 2 aswell asfor thetworapidityranges|y|<0.6 and0.6<|y|<1.2.

Toillustratethequality ofthisfunctionaldescription,Fig. 2(b) showstheﬁtresultsforthe ϒ(1S)statewith|y|<1.2.Thesolid lineis thepower-lawﬁtfor pT>20 GeV.Thedashed lineis the

exponential ﬁt for 10<pT<20 GeV. The lower plot shows, for

eachpTbin,thepulldeterminedfromthedifferentialcrosssection

valueina(pT,|y|)binanditstotaluncertainty.

Next,weconsiderthepTdependenceoftheratiosoftheϒ(nS)

productioncrosssectionstimestheir dimuonbranching fractions. The yieldﬁts areredonetocompute explicitlythe yieldratior21

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Fig. 2. (a) Theϒ(nS)differentialpT crosssectionstimesdimuonbranching

frac-tionsfor|y|<1.2.Theϒ(2S)andϒ(3S)measurementsarescaledby0.1and0.01, respectively,fordisplaypurposes.Theverticalbarsshowthetotaluncertainty, ex-cludingthesystematicuncertaintyintheintegratedluminosity.Thehorizontalbars showthebinwidths.PreviousCMSmeasurementsfor|y|<2.4 areshownas cross-hatchedareas[2].Theseresultshavebeenscaledby0.5toaccountforthesmaller

|y|rangeinthelatestmeasurement,wherethescalingassumesthattherapidity distributionisﬂat.ThesolidlinesaretheNLOcalculationsfromRef.[13]extended bytheauthorstocovertherangepT<100GeV.(b)Detailsoftheparametrized

crosssectionﬁtdescribedinthetextforϒ(1S)with|y|<1.2.Inthisplotthesolid lineistheresultofthepower-lawﬁt(seeEq.(6))forpT>20GeV.Thedashedline

showsanexponentialﬁttothedatafor10<pT<20GeV.Thelowerplotshows

thepullsoftheﬁtasdeﬁnedinthetext.

Table 1

ThevaluesoftheparametersinEq.(6)fromthepower-lawﬁttoϒ(1S)eventswith pT>20GeV and|y|<1.2,alongwiththeχ2valueandthenumberofdegreesof

freedomnd. ϒ(1S) ϒ(2S) ϒ(3S) A 14.00±0.75 6.88±0.48 4.01±0.30 α 5.75±0.07 5.62±0.10 5.26±0.10 C 0.45±0.13 0.62±0.18 0.26±0.15 χ2 ₈_.₇ ₁₁ ₁₅ nd 14 14 14

forϒ(2S)toϒ(1S)andr31forϒ(3S)toϒ(1S).Theeﬃciency

ra-tiois computedfor each (pT, |y|) bin.The polarization-weighted

acceptance and its uncertainty is computed for each state sep-arately, and the uncertainties are added in quadrature to deter-mine the uncertainty in the ratio. The corrected yield ratios are Rn1(pT, |y|)=rn1(pT, |y|) (A11)/(Ann),where n = 2, 3.The

Fig. 3. Measured differentialcrosssectionratiosasafunctionofpT.Correctedyield

ratios:(a)R21;(b)R31.Thedashedlineistheratiooftheexponentialﬁtstothe

individualdifferentialcrosssectionsfor10<pT<20GeV.Thesolidlineistheratio

ofthecorrespondingpower-lawﬁtsforpT>20GeV.

measured corrected ratios are shown in Fig. 3 and given in the supplemental material(Tables 4–6). The rapidrise of both ratios forpT<20GeV slowssigniﬁcantlyforpT20GeV.Thecurveson

theratioplotsaretheratiosofthecorresponding ﬁttedfunctions fromtheindividualϒ(nS) differentialcrosssectionﬁts (exponen-tial for pT<20 GeV, power-law for pT>20 GeV). The curves

conﬁrm thatthe changeinratiosoccursinthesame pT rangein

whichdσ/dpT alsochangesbehavior.

The measurements forthe ratio R31 inFig. 3(b),found inthe

supplementary material, can be ﬁt to a linear function and to a constant in order toquantify the visual evidence that the ϒ(3S)

productionisharderthanthatoftheϒ(1S).Thelinearﬁtto mea-surements with pT>20 GeV has χ2 probability 0.22, while the

ﬁttoaconstanthas χ2 _probability₂_.₆_×₁₀−5_._Thus,_with_relative

probability 85 000:1, we can saythat ϒ(3S) productionisharder thanthat oftheϒ(1S).Theϒ(2S)/ϒ (1S)productionratioversus pThasasimilartrend,butthestatisticaluncertaintiesaretoolarge

tomakeadeﬁnitestatement.

6. Discussion

Theoretical predictionsfortheϒ(nS)differentialcrosssections have been previously compared to the ﬁrst LHC cross section measurements [10,14,15]. A more recent CMS measurement [2] included the currently available predictions from the CSM [14],

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valid for pT <35 GeV, and an unpublished NRQCD prediction

that covers the range pT<30 GeV.The NRQCD+ NLO analysis

from Ref. [13] describes ϒ(nS) production at Tevatron and LHC energies for pT<50 GeV. An extension of these predictions to pT=100GeV iscomparedtotheCMSmeasurements inFig. 2(a).

Thecalculationsdescribethetrendsofthedataforallthreeϒ(nS)

states.

Thecolorevaporationmodel(CEM),avariantoftheCSM, pre-dictsthatabove aminimum pT≈Mϒ(1S),allbottomoniumstates shouldhavethesamepT dependence[29].Themeasuredratiosof

thedifferential cross sections asa function of pT inFig. 3 show

thatthisisnotthecaseforpT lessthanabout40 GeV.

Changingthe ϒ(nS)pT thresholdforthedataused in

calculat-ing the NRQCDpredictions results indifferent LDMEs [10,30,31]. Recent theoretical work [12,16] has demonstrated the impact of varying the pT thresholds in NRQCD analyses to study different

productionamplitudebehavior.ThesenewCMSdataprovidea sig-niﬁcantextension ofthe pT range thatcan beused inevaluating

matrixelementsandstudyingpT-dependentcorrectionsinNRQCD

andothermodels.Thenewresultsonϒ(3S)productionare suﬃ-ciently accurate to allow one to focus model building of the pT

behavior on that state, for which feeddown contributions come onlyfromthe χb(3P).

7.Summary

Measurementsofthedifferentialproductioncrosssectionsasa functionofpT fortheϒ(1S),ϒ(2S),andϒ(3S)statesinpp

colli-sionsat√s=7TeV havebeenpresented,basedonadatasample correspondingtoanintegratedluminosityof4.9 fb−1 _collected_by

theCMSexperimentattheLHC.Notonlydothesemeasurements signiﬁcantlyimprovetheprecisionoftheresultsinpreviously an-alyzed pT ranges [1–3], theyalso extendthemaximum pT range

from70to100 GeV.Evidencehasbeenpresentedfortheﬁrsttime ofthepower-lawnatureofthepTdistributionsforallthreeϒ(nS)

statesathigh pT.Combined withtheCMSϒ(nS) polarization

re-sults [5], the new bottomonium measurements are a formidable challenge to our theoretical understanding of the production of heavy-quarkboundstates.

Acknowledgements

WecongratulateourcolleaguesintheCERNaccelerator depart-ments for the excellent performance of the LHC and thank the technicalandadministrativestaffs atCERN andatother CMS in-stitutes for their contributions to the success of the CMS effort. Inaddition,wegratefullyacknowledgethecomputingcentersand personneloftheWorldwideLHCComputingGridfordeliveringso effectivelythecomputinginfrastructure essential toour analyses. Finally, we acknowledge the enduring support for the construc-tionandoperationofthe LHCandtheCMSdetectorprovided by thefollowingfundingagencies:BMWFWandFWF(Austria);FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES(Bulgaria);CERN;CAS,MOST,andNSFC(China);COLCIENCIAS (Colombia);MSESandCSF(Croatia);RPF(Cyprus);MoER,ERCIUT andERDF(Estonia); AcademyofFinland,MEC, andHIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NIH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); MSIP and NRF (Republic ofKorea); LAS (Lithuania);MOE andUM (Malaysia); CINVESTAV, CONACYT,SEP,andUASLP-FAI(Mexico);MBIE(NewZealand);PAEC (Pakistan);MSHEandNSC(Poland);FCT(Portugal);JINR(Dubna); MON,RosAtom,RASandRFBR(Russia);MESTD(Serbia);SEIDIand CPAN(Spain);SwissFundingAgencies(Switzerland);MST(Taipei); ThEPCenter,IPST,STARandNSTDA(Thailand);TUBITAKandTAEK

(Turkey);NASUandSFFR(Ukraine); STFC(United Kingdom);DOE andNSF(USA).

Individuals have received support from the Marie-Curie pro-gram andtheEuropeanResearchCouncil andEPLANET(European Union); the Leventis Foundation; the A.P. Sloan Foundation; the Alexandervon HumboldtFoundation;the BelgianFederalScience Policy Office; the Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); theMinistry ofEducation,Youth andSports(MEYS) oftheCzech Republic; the Council of Science and Industrial Research, India; the HOMING PLUSprogram ofFoundation for Polish Science, co-financed fromEuropean Union, Regional Development Fund;the CompagniadiSanPaolo(Torino); theConsorzioperlaFisica (Tri-este); MIUR project 20108T4XTM (Italy); the Thalis and Aristeia programs cofinanced by EU-ESF and the Greek NSRF; and the National Priorities Research Program by Qatar National Research Fund.

Appendix A. Supplementarymaterial

Supplementarymaterialrelatedtothisarticlecanbefound on-lineathttp://dx.doi.org/10.1016/j.physletb.2015.07.037.

References

[1] CMSCollaboration,Measurementoftheinclusiveϒproductioncrosssectionin ppcollisionsat√s=7TeV,Phys.Rev.D83(2011)112004,http://dx.doi.org/ 10.1103/PhysRevD.83.112004,arXiv:1012.5545.

[2] CMSCollaboration,Measurementoftheϒ(1S),ϒ(2S),andϒ(3S)cross sec-tions inpp collisionsat √s=7TeV, Phys. Lett. B727(2013) 101,http:// dx.doi.org/10.1016/j.physletb.2013.10.033,arXiv:1303.5900.

[3] ATLASCollaboration, Measurement ofupsilonproduction in7TeV pp col-lisions at ATLAS,Phys. Rev. D87 (2013) 052004, http://dx.doi.org/10.1103/ PhysRevD.87.052004,arXiv:1211.7255.

[4] LHCbCollaboration,Measurementofϒproduction inpp collisionsat√s=

7TeV,Eur.Phys.J. C72(2012)2025, http://dx.doi.org/10.1140/epjc/s10052-012-2025-y,arXiv:1202.6579.

[5] CMSCollaboration, Measurementofthe ϒ(1S), ϒ(2S)and ϒ(3S) polariza-tions in pp collisions at √s=7TeV, Phys. Rev.Lett. 110(2013) 081802,

http://dx.doi.org/10.1103/PhysRevLett.110.081802,arXiv:1209.2922.

[6] V.M.Abazov,et al., D0 Collaboration,Measurement ofinclusivedifferential crosssectionsforϒ(1S)productioninpp collisions¯ at√s=1.96TeV,Phys. Rev.Lett.94(2005) 232001,http://dx.doi.org/10.1103/PhysRevLett.94.232001, arXiv:hep-ex/0502030;

V.M. Abazov, et al., D0 Collaboration, Phys. Rev. Lett. 100(2008) 049902,

http://dx.doi.org/10.1103/PhysRevLett.100.049902(Erratum).

[7] D.Acosta,etal.,CDFCollaboration,ϒproductionandpolarizationinpp col-¯ lisionsat √s=1.8TeV,Phys.Rev.Lett.88(2002)161802,http://dx.doi.org/ 10.1103/PhysRevLett.88.161802.

[8] P.L.Cho, A.K. Leibovich,Color octet quarkoniaproduction, Phys. Rev.D 53 (1996)150,http://dx.doi.org/10.1103/PhysRevD.53.150,arXiv:hep-ph/9505329. [9] P.L. Cho, A.K. Leibovich, Color octet quarkonia production. II, Phys. Rev.

D53(1996)6203, http://dx.doi.org/10.1103/PhysRevD.53.6203,arXiv:hep-ph/ 9511315.

[10] K.Wang,Y.-Q.Ma,K.-T.Chao,ϒ(1S)promptproductionattheTevatronand LHCinnonrelativisticQCD,Phys.Rev.D85(2012)114003,http://dx.doi.org/ 10.1103/PhysRevD.85.114003,arXiv:1202.6012.

[11]G.T.Bodwin,E.Braaten,E.Eichten,S.L.Olsen,T.K.Pedlar,J.Russ,Quarkoniumat thefrontiersofhighenergyphysics:aSnowmasswhitepaper,arXiv:1307.7425, 2013.

[12] G.T.Bodwin,H.S.Chung,U.-R.Kim,J.Lee,FragmentationcontributionstoJ/ψ

productionat theTevatronandtheLHC,Phys.Rev.Lett.113(2014)022001,

[13] B. Gong, L.-P. Wan, J.-X. Wang, H.-F. Zhang, Complete next-to-leading-order study on the yield and polarization of ϒ(1S,2S,3S) at the Teva-tronand LHC,Phys.Rev.Lett.112(2014)032001, http://dx.doi.org/10.1103/ PhysRevLett.112.032001,arXiv:1305.0748.

[14] P.Artoisenet,J.M.Campbell,J.P.Lansberg,F.Maltoni,F.Tramontano,ϒ produc-tionatFermilabTevatronandLHCenergies,Phys.Rev.Lett.101(2008)152001,

[15] S.P. Baranov, Prompt ϒ(nS) production at the LHC in view of the kt-factorization approach, Phys. Rev.D86 (2012) 054015, http://dx.doi.org/

(8)

[16] P.Faccioli,V.Knünz,C.Lourenco,J.Seixas,H.K.Wöhri,Quarkonium produc-tion inthe LHCera: a polarized perspective,Phys. Lett. B736 (2014)98,

http://dx.doi.org/10.1016/j.physletb.2014.07.006,arXiv:1403.3970.

[17] CMSCollaboration,PerformanceofCMSmuonreconstructioninppcollision eventsat√s=7TeV,J.Instrum.7(2012)P10002,http://dx.doi.org/10.1088/ 1748-0221/7/10/P10002,arXiv:1206.4071.

[18] CMSCollaboration,TheCMSexperimentattheCERNLHC,J.Instrum.3(2008) S08004,http://dx.doi.org/10.1088/1748-0221/3/08/S08004.

[19] D.J.Lange,TheEvtGenparticledecaysimulationpackage,Nucl.Instrum. Meth-odsA462(2001)152,http://dx.doi.org/10.1016/S0168-9002(01)00089-4. [20] S. Agostinelli, et al., GEANT4 Collaboration, GEANT4—a simulation toolkit,

Nucl. Instrum. Methods A 506(2003) 250, http://dx.doi.org/10.1016/S0168-9002(03)01368-8.

[21] CMSCollaboration,MeasurementsofinclusiveW andZ crosssectionsinpp collisionsat√s=7TeV,J.HighEnergyPhys.01(2011)080,http://dx.doi.org/ 10.1007/JHEP01(2011)080,arXiv:1012.2466.

[22] E.Barberio,B.vanEijk, Z.W ˛as, PHOTOS:auniversal MonteCarlofor QED radiative corrections in decays, Comput. Phys. Commun. 66 (1991) 115,

http://dx.doi.org/10.1016/0010-4655(91)90012-A.

[23] E.Barberio,Z.W ˛as,PHOTOS:auniversalMonteCarloforQEDradiative cor-rections:version2.0,Comput.Phys.Commun.79(1994)291,http://dx.doi.org/ 10.1016/0010-4655(94)90074-4.

[24]W.Verkerke,D.P.Kirkby,TheRooFittoolkit fordatamodeling,in:2003

Com-putinginHighEnergyandNuclearPhysics,CHEP03,eConfC0303241,2003, MOLT007,2003,p. 186,arXiv:physics/0306116.

[25] H.Akaike,Anewlookatthestatisticalmodelidentiﬁcation,IEEETrans.Autom. Control19(1974)716,http://dx.doi.org/10.1109/TAC.1974.1100705.

[26] K.Burnham,D.Anderson,Multimodelinference:understandingAICandBICin modelselection,Sociol.MethodsRes.33(2004)261,http://dx.doi.org/10.1177/ 0049124104268644.

[27] CMS Collaboration, Absolute calibration of the luminosity measurement at CMS: winter 2012 update, CMS Physics Analysis Summary CMS-PAS-SMP-12-008,http://cds.cern.ch/record/1434360,2012.

[28] G.D. Lafferty,T.R.Wyatt,Wheretostickyourdatapoints:the treatmentof measurementswithinwidebins,Nucl.Instrum. MethodsA355(1995)541,

http://dx.doi.org/10.1016/0168-9002(94)01112-5.

[29] J.F. Amundson,O.J.P.Eboli,E.M.Gregores, F.Halzen,Colorlessstatesin per-turbativeQCD:charmoniumandrapiditygaps,Phys.Lett.B372(1996)127,

http://dx.doi.org/10.1016/0370-2693(96)00035-4,arXiv:hep-ph/9512248. [30] M. Butenschoen, B.A. Kniehl, World data of J/ψ production

consoli-date NRQCD factorizationat NLO, Phys. Rev.D 84 (2011) 051501, http:// dx.doi.org/10.1103/PhysRevD.84.051501,arXiv:1105.0820.

[31] M.Butenschoen,B.A.Kniehl,ReconcilingJ/ψproductionatHERA,RHIC, teva-tron,and LHCwith NRQCDfactorizationat next-to-leadingorder,Phys. Rev. Lett. 106 (2011) 022003, http://dx.doi.org/10.1103/PhysRevLett.106.022003, arXiv:1009.5662.

CMSCollaboration

V. Khachatryan,A.M. Sirunyan, A. Tumasyan

YerevanPhysicsInstitute,Yerevan,Armenia

W. Adam, T. Bergauer, M. Dragicevic,J. Erö, M. Friedl,R. Frühwirth1,V.M. Ghete, C. Hartl, N. Hörmann,

J. Hrubec, M. Jeitler1, W. Kiesenhofer,V. Knünz, M. Krammer1, I. Krätschmer,D. Liko, I. Mikulec,

D. Rabady2,B. Rahbaran, H. Rohringer, R. Schöfbeck, J. Strauss, W. Treberer-Treberspurg,

W. Waltenberger, C.-E. Wulz1

InstitutfürHochenergiephysikderOeAW,Wien,Austria

V. Mossolov,N. Shumeiko, J. Suarez Gonzalez

NationalCentreforParticleandHighEnergyPhysics,Minsk,Belarus

S. Alderweireldt, S. Bansal,T. Cornelis, E.A. De Wolf,X. Janssen, A. Knutsson,J. Lauwers, S. Luyckx,

S. Ochesanu,R. Rougny, M. Van De Klundert, H. Van Haevermaet,P. Van Mechelen, N. Van Remortel,

A. Van Spilbeeck

UniversiteitAntwerpen,Antwerpen,Belgium

F. Blekman,S. Blyweert, J. D’Hondt,N. Daci, N. Heracleous, J. Keaveney,S. Lowette, M. Maes, A. Olbrechts,

Q. Python, D. Strom, S. Tavernier,W. Van Doninck, P. Van Mulders, G.P. Van Onsem, I. Villella

VrijeUniversiteitBrussel,Brussel,Belgium

C. Caillol, B. Clerbaux, G. De Lentdecker, D. Dobur, L. Favart, A.P.R. Gay, A. Grebenyuk,A. Léonard,

A. Mohammadi, L. Perniè2, A. Randle-conde,T. Reis,T. Seva, L. Thomas, C. Vander Velde, P. Vanlaer,

J. Wang, F. Zenoni

UniversitéLibredeBruxelles,Bruxelles,Belgium

V. Adler,K. Beernaert, L. Benucci, A. Cimmino,S. Costantini, S. Crucy, S. Dildick,A. Fagot, G. Garcia,

J. Mccartin, A.A. Ocampo Rios,D. Poyraz, D. Ryckbosch, S. Salva Diblen, M. Sigamani,N. Strobbe,

F. Thyssen,M. Tytgat, E. Yazgan, N. Zaganidis

GhentUniversity,Ghent,Belgium

S. Basegmez, C. Beluﬃ3,G. Bruno,R. Castello, A. Caudron, L. Ceard, G.G. Da Silveira, C. Delaere,

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C. Nuttens, L. Perrini, A. Pin, K. Piotrzkowski,A. Popov5, L. Quertenmont,M. Selvaggi, M. Vidal Marono, J.M. Vizan Garcia

UniversitéCatholiquedeLouvain,Louvain-la-Neuve,Belgium

N. Beliy,T. Caebergs, E. Daubie, G.H. Hammad

UniversitédeMons,Mons,Belgium

W.L. Aldá Júnior, G.A. Alves,L. Brito,M. Correa Martins Junior, T. Dos Reis Martins, J. Molina,

C. Mora Herrera,M.E. Pol, P. Rebello Teles

CentroBrasileirodePesquisasFisicas,RiodeJaneiro,Brazil

W. Carvalho,J. Chinellato6, A. Custódio, E.M. Da Costa, D. De Jesus Damiao,C. De Oliveira Martins,

S. Fonseca De Souza, H. Malbouisson,D. Matos Figueiredo, L. Mundim, H. Nogima,W.L. Prado Da Silva,

J. Santaolalla,A. Santoro, A. Sznajder,E.J. Tonelli Manganote6, A. Vilela Pereira

UniversidadedoEstadodoRiodeJaneiro,RiodeJaneiro,Brazil

C.A. Bernardesb, S. Dograa,T.R. Fernandez Perez Tomeia, E.M. Gregoresb, P.G. Mercadanteb,

S.F. Novaesa, Sandra S. Padulaa

a_Universidade_Estadual_Paulista,_São_Paulo,_Brazil b_Universidade_Federal_do_ABC,_São_Paulo,_Brazil

A. Aleksandrov, V. Genchev2, R. Hadjiiska,P. Iaydjiev, A. Marinov, S. Piperov,M. Rodozov, S. Stoykova,

G. Sultanov,M. Vutova

InstituteforNuclearResearchandNuclearEnergy,Soﬁa,Bulgaria

A. Dimitrov,I. Glushkov, L. Litov, B. Pavlov,P. Petkov

UniversityofSoﬁa,Soﬁa,Bulgaria

J.G. Bian,G.M. Chen, H.S. Chen, M. Chen, T. Cheng,R. Du, C.H. Jiang, R. Plestina7, F. Romeo,J. Tao,

Z. Wang

InstituteofHighEnergyPhysics,Beijing,China

C. Asawatangtrakuldee, Y. Ban,S. Liu, Y. Mao,S.J. Qian, D. Wang, Z. Xu,L. Zhang, W. Zou

StateKeyLaboratoryofNuclearPhysicsandTechnology,PekingUniversity,Beijing,China

C. Avila,A. Cabrera, L.F. Chaparro Sierra, C. Florez,J.P. Gomez, B. Gomez Moreno, J.C. Sanabria

UniversidaddeLosAndes,Bogota,Colombia

N. Godinovic, D. Lelas,D. Polic, I. Puljak

UniversityofSplit,FacultyofElectricalEngineering,MechanicalEngineeringandNavalArchitecture,Split,Croatia

Z. Antunovic,M. Kovac

UniversityofSplit,FacultyofScience,Split,Croatia

V. Brigljevic,K. Kadija, J. Luetic,D. Mekterovic, L. Sudic

InstituteRudjerBoskovic,Zagreb,Croatia

A. Attikis, G. Mavromanolakis,J. Mousa, C. Nicolaou, F. Ptochos,P.A. Razis, H. Rykaczewski

UniversityofCyprus,Nicosia,Cyprus

M. Bodlak,M. Finger,M. Finger Jr.8

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Y. Assran9, A. Ellithi Kamel10,M.A. Mahmoud11, A. Radi12,13

AcademyofScientiﬁcResearchandTechnologyoftheArabRepublicofEgypt,EgyptianNetworkofHighEnergyPhysics,Cairo,Egypt

M. Kadastik, M. Murumaa, M. Raidal, A. Tiko

NationalInstituteofChemicalPhysicsandBiophysics,Tallinn,Estonia

P. Eerola, M. Voutilainen

DepartmentofPhysics,UniversityofHelsinki,Helsinki,Finland

J. Härkönen,V. Karimäki, R. Kinnunen, M.J. Kortelainen, T. Lampén, K. Lassila-Perini,S. Lehti, T. Lindén,

P. Luukka, T. Mäenpää,T. Peltola, E. Tuominen, J. Tuominiemi,E. Tuovinen, L. Wendland

HelsinkiInstituteofPhysics,Helsinki,Finland

J. Talvitie, T. Tuuva

LappeenrantaUniversityofTechnology,Lappeenranta,Finland

M. Besancon, F. Couderc,M. Dejardin, D. Denegri, B. Fabbro,J.L. Faure, C. Favaro,F. Ferri, S. Ganjour,

A. Givernaud, P. Gras, G. Hamel de Monchenault, P. Jarry,E. Locci, J. Malcles,J. Rander, A. Rosowsky,

M. Titov

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

S. Baﬃoni,F. Beaudette, P. Busson, E. Chapon, C. Charlot,T. Dahms, M. Dalchenko, L. Dobrzynski,

N. Filipovic, A. Florent,R. Granier de Cassagnac, L. Mastrolorenzo, P. Miné, I.N. Naranjo, M. Nguyen,

C. Ochando, G. Ortona,P. Paganini, S. Regnard, R. Salerno, J.B. Sauvan, Y. Sirois, C. Veelken,Y. Yilmaz,

A. Zabi

LaboratoireLeprince-Ringuet,EcolePolytechnique,IN2P3-CNRS,Palaiseau,France

J.-L. Agram14, J. Andrea, A. Aubin, D. Bloch,J.-M. Brom, E.C. Chabert,C. Collard, E. Conte14,

J.-C. Fontaine14,D. Gelé, U. Goerlach, C. Goetzmann,A.-C. Le Bihan, K. Skovpen, P. Van Hove

InstitutPluridisciplinaireHubertCurien,UniversitédeStrasbourg,UniversitédeHauteAlsaceMulhouse,CNRS/IN2P3,Strasbourg,France S. Gadrat

CentredeCalculdel’InstitutNationaldePhysiqueNucleaireetdePhysiquedesParticules,CNRS/IN2P3,Villeurbanne,France

S. Beauceron,N. Beaupere, C. Bernet7,G. Boudoul2, E. Bouvier, S. Brochet, C.A. Carrillo Montoya,

J. Chasserat, R. Chierici,D. Contardo2,B. Courbon, P. Depasse, H. El Mamouni, J. Fan, J. Fay, S. Gascon,

M. Gouzevitch, B. Ille, T. Kurca, M. Lethuillier, L. Mirabito,A.L. Pequegnot, S. Perries, J.D. Ruiz Alvarez,

D. Sabes,L. Sgandurra, V. Sordini,M. Vander Donckt, P. Verdier,S. Viret, H. Xiao

UniversitédeLyon,UniversitéClaudeBernardLyon1,CNRS-IN2P3,InstitutdePhysiqueNucléairedeLyon,Villeurbanne,France

I. Bagaturia15

InstituteofHighEnergyPhysicsandInformatization,TbilisiStateUniversity,Tbilisi,Georgia

C. Autermann, S. Beranek,M. Bontenackels, M. Edelhoff,L. Feld, A. Heister, K. Klein,M. Lipinski,

A. Ostapchuk, M. Preuten,F. Raupach, J. Sammet, S. Schael, J.F. Schulte, H. Weber, B. Wittmer,

V. Zhukov5

RWTHAachenUniversity,I.PhysikalischesInstitut,Aachen,Germany

M. Ata, M. Brodski,E. Dietz-Laursonn, D. Duchardt, M. Erdmann, R. Fischer,A. Güth, T. Hebbeker,

(11)

M. Olschewski, K. Padeken,P. Papacz, H. Reithler,S.A. Schmitz,L. Sonnenschein, D. Teyssier,S. Thüer, M. Weber

RWTHAachenUniversity,III.PhysikalischesInstitutA,Aachen,Germany

V. Cherepanov, Y. Erdogan,G. Flügge, H. Geenen, M. Geisler, W. Haj Ahmad, F. Hoehle,B. Kargoll,

T. Kress,Y. Kuessel, A. Künsken, J. Lingemann2,A. Nowack, I.M. Nugent,O. Pooth,A. Stahl

RWTHAachenUniversity,III.PhysikalischesInstitutB,Aachen,Germany

M. Aldaya Martin,I. Asin, N. Bartosik, J. Behr, U. Behrens,A.J. Bell, A. Bethani,K. Borras, A. Burgmeier,

A. Cakir,L. Calligaris, A. Campbell,S. Choudhury, F. Costanza, C. Diez Pardos,G. Dolinska,S. Dooling,

T. Dorland,G. Eckerlin, D. Eckstein, T. Eichhorn, G. Flucke, J. Garay Garcia, A. Geiser, A. Gizhko,

P. Gunnellini, J. Hauk, M. Hempel16,H. Jung, A. Kalogeropoulos, O. Karacheban16, M. Kasemann,

P. Katsas, J. Kieseler, C. Kleinwort,I. Korol, D. Krücker,W. Lange, J. Leonard, K. Lipka,A. Lobanov,

W. Lohmann16,B. Lutz, R. Mankel, I. Marﬁn16,I.-A. Melzer-Pellmann, A.B. Meyer, G. Mittag, J. Mnich,

A. Mussgiller,S. Naumann-Emme, A. Nayak,E. Ntomari, H. Perrey,D. Pitzl, R. Placakyte, A. Raspereza,

P.M. Ribeiro Cipriano,B. Roland, E. Ron, M.Ö. Sahin,J. Salfeld-Nebgen, P. Saxena,T. Schoerner-Sadenius,

M. Schröder,C. Seitz, S. Spannagel, A.D.R. Vargas Trevino, R. Walsh, C. Wissing

DeutschesElektronen-Synchrotron,Hamburg,Germany

V. Blobel, M. Centis Vignali, A.R. Draeger,J. Erﬂe, E. Garutti,K. Goebel, M. Görner, J. Haller,

M. Hoffmann,R.S. Höing,A. Junkes, H. Kirschenmann, R. Klanner, R. Kogler,T. Lapsien, T. Lenz,

I. Marchesini,D. Marconi, J. Ott, T. Peiffer, A. Perieanu, N. Pietsch,J. Poehlsen,T. Poehlsen, D. Rathjens,

C. Sander,H. Schettler, P. Schleper, E. Schlieckau, A. Schmidt, M. Seidel, V. Sola,H. Stadie, G. Steinbrück,

D. Troendle,E. Usai, L. Vanelderen, A. Vanhoefer

UniversityofHamburg,Hamburg,Germany

C. Barth,C. Baus, J. Berger,C. Böser, E. Butz, T. Chwalek, W. De Boer,A. Descroix, A. Dierlamm,

M. Feindt,F. Frensch, M. Giffels, A. Gilbert,F. Hartmann2,T. Hauth, U. Husemann, I. Katkov5,

A. Kornmayer2, P. Lobelle Pardo, M.U. Mozer,T. Müller, Th. Müller, A. Nürnberg, G. Quast, K. Rabbertz,

S. Röcker,H.J. Simonis, F.M. Stober,R. Ulrich, J. Wagner-Kuhr, S. Wayand, T. Weiler, R. Wolf

InstitutfürExperimentelleKernphysik,Karlsruhe,Germany

G. Anagnostou,G. Daskalakis, T. Geralis,V.A. Giakoumopoulou, A. Kyriakis, D. Loukas,A. Markou,

C. Markou, A. Psallidas,I. Topsis-Giotis

InstituteofNuclearandParticlePhysics(INPP),NCSRDemokritos,AghiaParaskevi,Greece

A. Agapitos,S. Kesisoglou, A. Panagiotou,N. Saoulidou, E. Stiliaris

UniversityofAthens,Athens,Greece

X. Aslanoglou,I. Evangelou, G. Flouris,C. Foudas, P. Kokkas, N. Manthos, I. Papadopoulos,E. Paradas,

J. Strologas

UniversityofIoánnina,Ioánnina,Greece

G. Bencze,C. Hajdu, P. Hidas,D. Horvath17, F. Sikler,V. Veszpremi, G. Vesztergombi18, A.J. Zsigmond

WignerResearchCentreforPhysics,Budapest,Hungary

N. Beni,S. Czellar, J. Karancsi19,J. Molnar, J. Palinkas, Z. Szillasi

InstituteofNuclearResearchATOMKI,Debrecen,Hungary

A. Makovec,P. Raics, Z.L. Trocsanyi, B. Ujvari

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S.K. Swain

NationalInstituteofScienceEducationandResearch,Bhubaneswar,India

S.B. Beri, V. Bhatnagar,R. Gupta, U. Bhawandeep, A.K. Kalsi, M. Kaur, R. Kumar,M. Mittal, N. Nishu,

J.B. Singh

PanjabUniversity,Chandigarh,India

Ashok Kumar, Arun Kumar,S. Ahuja, A. Bhardwaj, B.C. Choudhary,A. Kumar, S. Malhotra,M. Naimuddin,

K. Ranjan,V. Sharma

UniversityofDelhi,Delhi,India

S. Banerjee, S. Bhattacharya, K. Chatterjee,S. Dutta, B. Gomber, Sa. Jain, Sh. Jain,R. Khurana, A. Modak,

S. Mukherjee,D. Roy, S. Sarkar, M. Sharan

SahaInstituteofNuclearPhysics,Kolkata,India

A. Abdulsalam, D. Dutta, V. Kumar, A.K. Mohanty2,L.M. Pant, P. Shukla, A. Topkar

BhabhaAtomicResearchCentre,Mumbai,India

T. Aziz, S. Banerjee, S. Bhowmik20,R.M. Chatterjee, R.K. Dewanjee, S. Dugad, S. Ganguly,S. Ghosh,

M. Guchait,A. Gurtu21,G. Kole, S. Kumar, M. Maity20, G. Majumder, K. Mazumdar,G.B. Mohanty,

B. Parida,K. Sudhakar, N. Wickramage22

TataInstituteofFundamentalResearch,Mumbai,India S. Sharma

IndianInstituteofScienceEducationandResearch(IISER),Pune,India

H. Bakhshiansohi,H. Behnamian, S.M. Etesami23, A. Fahim24, R. Goldouzian, M. Khakzad,

M. Mohammadi Najafabadi, M. Naseri, S. Paktinat Mehdiabadi, F. Rezaei Hosseinabadi, B. Safarzadeh25,

M. Zeinali

InstituteforResearchinFundamentalSciences(IPM),Tehran,Iran

M. Felcini,M. Grunewald

UniversityCollegeDublin,Dublin,Ireland

M. Abbresciaa,b, C. Calabriaa,b,S.S. Chhibraa,b, A. Colaleoa, D. Creanzaa,c,L. Cristellaa,b,

N. De Filippisa,c, M. De Palmaa,b,L. Fiorea,G. Iasellia,c,G. Maggia,c,M. Maggia, S. Mya,c, S. Nuzzoa,b, A. Pompilia,b,G. Pugliesea,c,R. Radognaa,b,2, G. Selvaggia,b, A. Sharmaa, L. Silvestrisa,2, R. Vendittia,b,

P. Verwilligena

a_INFN_Sezione_di_Bari,_Bari,_Italy b_Università_di_Bari,_Bari,_Italy c_Politecnico_di_Bari,_Bari,_Italy

G. Abbiendia,A.C. Benvenutia,D. Bonacorsia,b, S. Braibant-Giacomellia,b, L. Brigliadoria,b, R. Campaninia,b, P. Capiluppia,b,A. Castroa,b,F.R. Cavalloa, G. Codispotia,b, M. Cuﬃania,b,

G.M. Dallavallea,F. Fabbria, A. Fanfania,b, D. Fasanellaa,b,P. Giacomellia,C. Grandia,L. Guiduccia,b, S. Marcellinia, G. Masettia, A. Montanaria, F.L. Navarriaa,b,A. Perrottaa, A.M. Rossia,b,T. Rovellia,b, G.P. Sirolia,b,N. Tosia,b, R. Travaglinia,b

a_INFN_Sezione_di_Bologna,_Bologna,_Italy b_Università_di_Bologna,_Bologna,_Italy

S. Albergoa,b,G. Cappelloa, M. Chiorbolia,b, S. Costaa,b, F. Giordanoa,2,R. Potenzaa,b, A. Tricomia,b, C. Tuvea,b

a_INFN_Sezione_di_Catania,_Catania,_Italy b_Università_di_Catania,_Catania,_Italy c_CSFNSM,_Catania,_Italy

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G. Barbaglia,V. Ciullia,b,C. Civininia, R. D’Alessandroa,b, E. Focardia,b,E. Galloa, S. Gonzia,b, V. Goria,b, P. Lenzia,b, M. Meschinia, S. Paolettia,G. Sguazzonia,A. Tropianoa,b

a_INFN_Sezione_di_Firenze,_Firenze,_Italy b_Università_di_Firenze,_Firenze,_Italy

L. Benussi,S. Bianco, F. Fabbri, D. Piccolo

INFNLaboratoriNazionalidiFrascati,Frascati,Italy

R. Ferrettia,b,F. Ferroa,M. Lo Veterea,b,E. Robuttia, S. Tosia,b

a_INFN_Sezione_di_Genova,_Genova,_Italy b_Università_di_Genova,_Genova,_Italy

M.E. Dinardoa,b, S. Fiorendia,b, S. Gennaia,2, R. Gerosaa,b,2,A. Ghezzia,b, P. Govonia,b,M.T. Lucchinia,b,2, S. Malvezzia, R.A. Manzonia,b, A. Martellia,b, B. Marzocchia,b,2, D. Menascea,L. Moronia,

M. Paganonia,b,D. Pedrinia, S. Ragazzia,b, N. Redaellia,T. Tabarelli de Fatisa,b

a_INFN_Sezione_di_{Milano-Bicocca,}_Milano,_Italy b_Università_di_{Milano-Bicocca,}_Milano,_Italy

S. Buontempoa, N. Cavalloa,c,S. Di Guidaa,d,2, F. Fabozzia,c,A.O.M. Iorioa,b, L. Listaa,S. Meolaa,d,2,

M. Merolaa, P. Paoluccia,2

a_INFN_Sezione_di_Napoli,_Napoli,_Italy b_Università_di_Napoli_‘Federico_II’,_Napoli,_Italy c_Università_della_Basilicata_(Potenza),_Napoli,_Italy d_Università_G._Marconi_(Roma),_Napoli,_Italy

P. Azzia, N. Bacchettaa, D. Biselloa,b, A. Brancaa,b,R. Carlina,b,P. Checchiaa, M. Dall’Ossoa,b, T. Dorigoa, U. Dossellia,F. Gasparinia,b,U. Gasparinia,b, A. Gozzelinoa, K. Kanishcheva,c,S. Lacapraraa,

M. Margonia,b, A.T. Meneguzzoa,b,J. Pazzinia,b,N. Pozzobona,b, P. Ronchesea,b,F. Simonettoa,b, E. Torassaa,M. Tosia,b, P. Zottoa,b, A. Zucchettaa,b, G. Zumerlea,b

a_INFN_Sezione_di_Padova,_Padova,_Italy b_Università_di_Padova,_Padova,_Italy c_Università_di_Trento_(Trento),_Padova,_Italy

M. Gabusia,b,S.P. Rattia,b, V. Rea,C. Riccardia,b,P. Salvinia,P. Vituloa,b

a_INFN_Sezione_di_Pavia,_Pavia,_Italy b_Università_di_Pavia,_Pavia,_Italy

M. Biasinia,b,G.M. Bileia,D. Ciangottinia,b,2,L. Fanòa,b, P. Laricciaa,b, G. Mantovania,b, M. Menichellia, A. Sahaa, A. Santocchiaa,b,A. Spieziaa,b,2

a_INFN_Sezione_di_Perugia,_Perugia,_Italy b_Università_di_Perugia,_Perugia,_Italy

K. Androsova,26,P. Azzurria,G. Bagliesia,J. Bernardinia,T. Boccalia,G. Broccoloa,c,R. Castaldia, M.A. Cioccia,26,R. Dell’Orsoa, S. Donatoa,c,2,G. Fedi, F. Fioria,c,L. Foàa,c,A. Giassia, M.T. Grippoa,26, F. Ligabuea,c,T. Lomtadzea,L. Martinia,b, A. Messineoa,b, C.S. Moona,27, F. Pallaa,2, A. Rizzia,b, A. Savoy-Navarroa,28,A.T. Serbana, P. Spagnoloa, P. Squillaciotia,26,R. Tenchinia,G. Tonellia,b, A. Venturia,P.G. Verdinia,C. Vernieria,c

a_INFN_Sezione_di_Pisa,_Pisa,_Italy b_Università_di_Pisa,_Pisa,_Italy

c_Scuola_Normale_Superiore_di_Pisa,_Pisa,_Italy

L. Baronea,b, F. Cavallaria,G. D’imperioa,b,D. Del Rea,b, M. Diemoza,C. Jordaa, E. Longoa,b,

F. Margarolia,b, P. Meridiania,F. Michelia,b,2,G. Organtinia,b, R. Paramattia,S. Rahatloua,b, C. Rovellia, F. Santanastasioa,b, L. Soﬃa,b,P. Traczyka,b,2

a_INFN_Sezione_di_Roma,_Roma,_Italy b_Università_di_Roma,_Roma,_Italy

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N. Amapanea,b, R. Arcidiaconoa,c,S. Argiroa,b,M. Arneodoa,c,R. Bellana,b, C. Biinoa, N. Cartigliaa, S. Casassoa,b,2, M. Costaa,b, R. Covarelli,A. Deganoa,b, N. Demariaa,L. Fincoa,b,2, C. Mariottia, S. Masellia, E. Migliorea,b,V. Monacoa,b,M. Musicha, M.M. Obertinoa,c,L. Pachera,b,N. Pastronea, M. Pelliccionia,G.L. Pinna Angionia,b, A. Potenzaa,b,A. Romeroa,b, M. Ruspaa,c,R. Sacchia,b,

A. Solanoa,b, A. Staianoa, U. Tamponia

a_INFN_Sezione_di_Torino,_Torino,_Italy b_Università_di_Torino,_Torino,_Italy

c_Università_del_Piemonte_Orientale_(Novara),_Torino,_Italy

S. Belfortea,V. Candelisea,b,2, M. Casarsaa,F. Cossuttia, G. Della Riccaa,b,B. Gobboa,C. La Licataa,b, M. Maronea,b_,_{A. Schizzi}a,b_, _{T. Umer}a,b_,_{A. Zanetti}a

a_INFN_Sezione_di_Trieste,_Trieste,_Italy b_Università_di_Trieste,_Trieste,_Italy

S. Chang, A. Kropivnitskaya,S.K. Nam

KangwonNationalUniversity,Chunchon,RepublicofKorea

D.H. Kim,G.N. Kim, M.S. Kim,D.J. Kong, S. Lee, Y.D. Oh,H. Park, A. Sakharov, D.C. Son

KyungpookNationalUniversity,Daegu,RepublicofKorea

T.J. Kim, M.S. Ryu

ChonbukNationalUniversity,Jeonju,RepublicofKorea

J.Y. Kim, D.H. Moon,S. Song

ChonnamNationalUniversity,InstituteforUniverseandElementaryParticles,Kwangju,RepublicofKorea

S. Choi, D. Gyun,B. Hong, M. Jo,H. Kim, Y. Kim,B. Lee, K.S. Lee, S.K. Park,Y. Roh

KoreaUniversity,Seoul,RepublicofKorea H.D. Yoo

SeoulNationalUniversity,Seoul,RepublicofKorea

M. Choi,J.H. Kim, I.C. Park, G. Ryu

UniversityofSeoul,Seoul,RepublicofKorea

Y. Choi,Y.K. Choi, J. Goh,D. Kim, E. Kwon, J. Lee, I. Yu

SungkyunkwanUniversity,Suwon,RepublicofKorea A. Juodagalvis

VilniusUniversity,Vilnius,Lithuania

J.R. Komaragiri, M.A.B. Md Ali

NationalCentreforParticlePhysics,UniversitiMalaya,KualaLumpur,Malaysia

E. Casimiro Linares, H. Castilla-Valdez, E. De La Cruz-Burelo,I. Heredia-de La Cruz,

A. Hernandez-Almada,R. Lopez-Fernandez, A. Sanchez-Hernandez

CentrodeInvestigacionydeEstudiosAvanzadosdelIPN,MexicoCity,Mexico

S. Carrillo Moreno, F. Vazquez Valencia

UniversidadIberoamericana,MexicoCity,Mexico

I. Pedraza, H.A. Salazar Ibarguen

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A. Morelos Pineda

UniversidadAutónomadeSanLuisPotosí,SanLuisPotosí,Mexico D. Krofcheck

UniversityofAuckland,Auckland,NewZealand

P.H. Butler,S. Reucroft

UniversityofCanterbury,Christchurch,NewZealand

A. Ahmad, M. Ahmad, Q. Hassan,H.R. Hoorani, W.A. Khan,T. Khurshid, M. Shoaib

NationalCentreforPhysics,Quaid-I-AzamUniversity,Islamabad,Pakistan

H. Bialkowska,M. Bluj, B. Boimska,T. Frueboes, M. Górski, M. Kazana, K. Nawrocki,

K. Romanowska-Rybinska,M. Szleper, P. Zalewski

NationalCentreforNuclearResearch,Swierk,Poland

G. Brona,K. Bunkowski, M. Cwiok,W. Dominik,K. Doroba, A. Kalinowski,M. Konecki, J. Krolikowski,

M. Misiura, M. Olszewski

InstituteofExperimentalPhysics,FacultyofPhysics,UniversityofWarsaw,Warsaw,Poland

P. Bargassa,C. Beirão Da Cruz E Silva, P. Faccioli, P.G. Ferreira Parracho,M. Gallinaro, L. Lloret Iglesias,

F. Nguyen, J. Rodrigues Antunes,J. Seixas, J. Varela, P. Vischia

LaboratóriodeInstrumentaçãoeFísicaExperimentaldePartículas,Lisboa,Portugal

S. Afanasiev,P. Bunin,M. Gavrilenko,I. Golutvin, I. Gorbunov, A. Kamenev,V. Karjavin, V. Konoplyanikov,

A. Lanev,A. Malakhov,V. Matveev29, P. Moisenz, V. Palichik,V. Perelygin, S. Shmatov, N. Skatchkov,

V. Smirnov,A. Zarubin

JointInstituteforNuclearResearch,Dubna,Russia

V. Golovtsov,Y. Ivanov, V. Kim30,E. Kuznetsova, P. Levchenko, V. Murzin, V. Oreshkin, I. Smirnov,

V. Sulimov,L. Uvarov, S. Vavilov, A. Vorobyev,An. Vorobyev

PetersburgNuclearPhysicsInstitute,Gatchina(St.Petersburg),Russia

Yu. Andreev,A. Dermenev,S. Gninenko, N. Golubev, M. Kirsanov, N. Krasnikov, A. Pashenkov, D. Tlisov,

A. Toropin

InstituteforNuclearResearch,Moscow,Russia

V. Epshteyn,V. Gavrilov, N. Lychkovskaya,V. Popov, I. Pozdnyakov,G. Safronov, S. Semenov,

A. Spiridonov,V. Stolin, E. Vlasov,A. Zhokin

InstituteforTheoreticalandExperimentalPhysics,Moscow,Russia

V. Andreev,M. Azarkin31,I. Dremin31, M. Kirakosyan, A. Leonidov31,G. Mesyats, S.V. Rusakov,

A. Vinogradov

P.N.LebedevPhysicalInstitute,Moscow,Russia

A. Belyaev,E. Boos,M. Dubinin32, L. Dudko,A. Ershov, A. Gribushin,V. Klyukhin, O. Kodolova,I. Lokhtin,

S. Obraztsov,S. Petrushanko,V. Savrin, A. Snigirev

SkobeltsynInstituteofNuclearPhysics,LomonosovMoscowStateUniversity,Moscow,Russia

I. Azhgirey,I. Bayshev,S. Bitioukov, V. Kachanov, A. Kalinin, D. Konstantinov,V. Krychkine, V. Petrov,

R. Ryutin, A. Sobol,L. Tourtchanovitch, S. Troshin, N. Tyurin, A. Uzunian,A. Volkov

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P. Adzic33, M. Ekmedzic,J. Milosevic,V. Rekovic UniversityofBelgrade,FacultyofPhysicsandVincaInstituteofNuclearSciences,Belgrade,Serbia

J. Alcaraz Maestre, C. Battilana,E. Calvo, M. Cerrada,M. Chamizo Llatas, N. Colino, B. De La Cruz,

A. Delgado Peris,D. Domínguez Vázquez, A. Escalante Del Valle, C. Fernandez Bedoya,

J.P. Fernández Ramos,J. Flix, M.C. Fouz,P. Garcia-Abia,O. Gonzalez Lopez, S. Goy Lopez, J.M. Hernandez,

M.I. Josa,E. Navarro De Martino, A. Pérez-Calero Yzquierdo, J. Puerta Pelayo, A. Quintario Olmeda,

I. Redondo,L. Romero, M.S. Soares

CentrodeInvestigacionesEnergéticasMedioambientalesyTecnológicas(CIEMAT),Madrid,Spain

C. Albajar, J.F. de Trocóniz, M. Missiroli, D. Moran

UniversidadAutónomadeMadrid,Madrid,Spain

H. Brun, J. Cuevas,J. Fernandez Menendez, S. Folgueras, I. Gonzalez Caballero

UniversidaddeOviedo,Oviedo,Spain

J.A. Brochero Cifuentes, I.J. Cabrillo, A. Calderon, J. Duarte Campderros,M. Fernandez, G. Gomez,

A. Graziano, A. Lopez Virto,J. Marco, R. Marco,C. Martinez Rivero, F. Matorras, F.J. Munoz Sanchez,

J. Piedra Gomez, T. Rodrigo,A.Y. Rodríguez-Marrero,A. Ruiz-Jimeno, L. Scodellaro,I. Vila,

R. Vilar Cortabitarte

InstitutodeFísicadeCantabria(IFCA),CSIC-UniversidaddeCantabria,Santander,Spain

D. Abbaneo, E. Auffray, G. Auzinger, M. Bachtis,P. Baillon, A.H. Ball, D. Barney, A. Benaglia, J. Bendavid,

L. Benhabib,J.F. Benitez, P. Bloch, A. Bocci, A. Bonato, O. Bondu,C. Botta, H. Breuker, T. Camporesi,

G. Cerminara, S. Colafranceschi34,M. D’Alfonso, D. d’Enterria, A. Dabrowski, A. David,F. De Guio,

A. De Roeck, S. De Visscher, E. Di Marco,M. Dobson, M. Dordevic, B. Dorney, N. Dupont-Sagorin,

A. Elliott-Peisert, G. Franzoni, W. Funk, D. Gigi,K. Gill, D. Giordano, M. Girone,F. Glege, R. Guida,

S. Gundacker, M. Guthoff,J. Hammer, M. Hansen,P. Harris,J. Hegeman, V. Innocente, P. Janot,

K. Kousouris,K. Krajczar, P. Lecoq,C. Lourenço, N. Magini, L. Malgeri,M. Mannelli, J. Marrouche,

L. Masetti, F. Meijers, S. Mersi,E. Meschi, F. Moortgat, S. Morovic, M. Mulders, L. Orsini, L. Pape,E. Perez,

A. Petrilli, G. Petrucciani,A. Pfeiffer, M. Pimiä, D. Piparo, M. Plagge, A. Racz,G. Rolandi35, M. Rovere,

H. Sakulin, C. Schäfer, C. Schwick,A. Sharma,P. Siegrist, P. Silva,M. Simon, P. Sphicas36,D. Spiga,

J. Steggemann,B. Stieger, M. Stoye,Y. Takahashi, D. Treille, A. Tsirou, G.I. Veres18,N. Wardle, H.K. Wöhri,

H. Wollny, W.D. Zeuner

CERN,EuropeanOrganizationforNuclearResearch,Geneva,Switzerland

W. Bertl,K. Deiters, W. Erdmann, R. Horisberger, Q. Ingram, H.C. Kaestli, D. Kotlinski,U. Langenegger,

D. Renker, T. Rohe

PaulScherrerInstitut,Villigen,Switzerland

F. Bachmair, L. Bäni, L. Bianchini, M.A. Buchmann,B. Casal, N. Chanon, G. Dissertori, M. Dittmar,

M. Donegà, M. Dünser,P. Eller, C. Grab,D. Hits, J. Hoss,W. Lustermann, B. Mangano,A.C. Marini,

M. Marionneau, P. Martinez Ruiz del Arbol, M. Masciovecchio, D. Meister,N. Mohr, P. Musella,

C. Nägeli37,F. Nessi-Tedaldi, F. Pandolﬁ, F. Pauss,L. Perrozzi, M. Peruzzi,M. Quittnat, L. Rebane,

M. Rossini,A. Starodumov38, M. Takahashi, K. Theoﬁlatos,R. Wallny, H.A. Weber

InstituteforParticlePhysics,ETHZurich,Zurich,Switzerland

C. Amsler39, M.F. Canelli,V. Chiochia,A. De Cosa, A. Hinzmann, T. Hreus, B. Kilminster, C. Lange,

J. Ngadiuba,D. Pinna, P. Robmann, F.J. Ronga,S. Taroni, M. Verzetti, Y. Yang

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M. Cardaci,K.H. Chen, C. Ferro, C.M. Kuo, W. Lin, Y.J. Lu,R. Volpe, S.S. Yu NationalCentralUniversity,Chung-Li,Taiwan

P. Chang, Y.H. Chang,Y. Chao, K.F. Chen, P.H. Chen, C. Dietz, U. Grundler,W.-S. Hou,Y.F. Liu, R.-S. Lu,

M. Miñano Moya,E. Petrakou, Y.M. Tzeng,R. Wilken

NationalTaiwanUniversity(NTU),Taipei,Taiwan

B. Asavapibhop,G. Singh, N. Srimanobhas, N. Suwonjandee

ChulalongkornUniversity,FacultyofScience,DepartmentofPhysics,Bangkok,Thailand

A. Adiguzel, M.N. Bakirci40,S. Cerci41, C. Dozen,I. Dumanoglu, E. Eskut, S. Girgis, G. Gokbulut, Y. Guler,

E. Gurpinar,I. Hos, E.E. Kangal42,A. Kayis Topaksu, G. Onengut43,K. Ozdemir44,S. Ozturk40, A. Polatoz,

D. Sunar Cerci41, B. Tali41, H. Topakli40, M. Vergili, C. Zorbilmez

CukurovaUniversity,Adana,Turkey

I.V. Akin,B. Bilin, S. Bilmis, H. Gamsizkan45, B. Isildak46, G. Karapinar47,K. Ocalan48,S. Sekmen,

U.E. Surat,M. Yalvac, M. Zeyrek

MiddleEastTechnicalUniversity,PhysicsDepartment,Ankara,Turkey

E.A. Albayrak49, E. Gülmez,M. Kaya50,O. Kaya51, T. Yetkin52

BogaziciUniversity,Istanbul,Turkey

K. Cankocak,F.I. Vardarlı

IstanbulTechnicalUniversity,Istanbul,Turkey

L. Levchuk,P. Sorokin

NationalScientiﬁcCenter,KharkovInstituteofPhysicsandTechnology,Kharkov,Ukraine

J.J. Brooke,E. Clement, D. Cussans, H. Flacher, J. Goldstein,M. Grimes, G.P. Heath, H.F. Heath,J. Jacob,

L. Kreczko,C. Lucas, Z. Meng, D.M. Newbold53,S. Paramesvaran, A. Poll, T. Sakuma,S. Seif El Nasr-storey,

S. Senkin,V.J. Smith

UniversityofBristol,Bristol,UnitedKingdom

K.W. Bell,A. Belyaev54,C. Brew, R.M. Brown, D.J.A. Cockerill, J.A. Coughlan, K. Harder,S. Harper,

E. Olaiya,D. Petyt, C.H. Shepherd-Themistocleous, A. Thea,I.R. Tomalin, T. Williams, W.J. Womersley,

S.D. Worm

RutherfordAppletonLaboratory,Didcot,UnitedKingdom

M. Baber,R. Bainbridge, O. Buchmuller, D. Burton,D. Colling, N. Cripps,P. Dauncey, G. Davies,

M. Della Negra,P. Dunne, A. Elwood, W. Ferguson, J. Fulcher, D. Futyan,G. Hall, G. Iles, M. Jarvis,

G. Karapostoli,M. Kenzie, R. Lane,R. Lucas53, L. Lyons,A.-M. Magnan, S. Malik,B. Mathias, J. Nash,

A. Nikitenko38,J. Pela, M. Pesaresi, K. Petridis,D.M. Raymond, S. Rogerson, A. Rose,C. Seez, P. Sharp†,

A. Tapper,M. Vazquez Acosta, T. Virdee,S.C. Zenz

ImperialCollege,London,UnitedKingdom

J.E. Cole, P.R. Hobson,A. Khan, P. Kyberd,D. Leggat, D. Leslie,I.D. Reid, P. Symonds, L. Teodorescu,

M. Turner

BrunelUniversity,Uxbridge,UnitedKingdom

J. Dittmann, K. Hatakeyama,A. Kasmi, H. Liu, N. Pastika, T. Scarborough,Z. Wu