Measurement of the production cross section ratio σ(χb2(1P))/σ(χb1(1P)) in pp collisions at s=8TeV

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Physics

Letters

B

www.elsevier.com/locate/physletb

Measurement

of

the

production

cross

section

ratio

σ

(

χ

(

1P

))/

σ

(

χ

(

1P

))

in

pp

collisions

at

√

s

=

8 TeV

Receivedinrevisedform12February2015 Accepted19February2015

Availableonline24February2015 Editor:M.Doser Keywords: CMS Quarkoniumproduction P-wavestates Bottomonium

Ameasurementoftheproductioncrosssectionratioσ(χb2(1P))/σ(χb1(1P))ispresented.Theχb1(1P)

and χb2(1P) bottomonium states,promptly producedin ppcollisions at√s₌8 TeV,are detected by the CMS experiment at the CERN LHC through their radiative decays χb1,2(1P)→ ϒ(1S)+γ. The emitted photons are measured throughtheir conversion to e+_e− _{pairs, whose reconstruction allows} the two states to be resolved. The ϒ (1S) is measured through its decay to two muons. An event samplecorresponding toan integrated luminosity of20.7 fb−1 is used tomeasure thecross section

ratio in a phase-space region defined by the photon pseudorapidity, |ηγ_{|<1.0; the ϒ (1S) rapidity,} |yϒ_{|<1.5; and the ϒ (1S) transverse momentum, 7<p}ϒ

T <40 GeV. The cross sectionratio shows

no significant dependence on the ϒ (1S) transverse momentum, with a measured average value of

0.85±0.07(stat+syst)±0.08(BF),wherethefirstuncertaintyisthecombinationoftheexperimental statistical and systematicuncertainties and thesecondis fromthe uncertainty intheratio ofthe χb

branchingfractions.

©2015CERNforthebenefitoftheCMSCollaboration.PublishedbyElsevierB.V.Thisisanopenaccess articleundertheCCBYlicense(http://creativecommons.org/licenses/by/4.0/).FundedbySCOAP3_.

1. Introduction

Despiteconsiderableeffortsover thelast decades,hadron for-mation, which is part of the nonperturbative sector of quantum chromodynamics (QCD), remains poorly understood within the standardmodelofparticlephysics.Heavy-quarkoniumproduction isanexcellentprobeofhadronformation.Inthepastyears, signif-icantprogress hasbeenmade inthetheory sector [1],especially inthe frameworkofnonrelativisticQCD(NRQCD) [2].This frame-workfactorizesintodistinct processestheshort-distance creation ofaheavyquark–antiquarkpair,ineitheracolor-singletora color-octetconfiguration,andthelong-distanceformationofthe quarko-niumbound-state.Thefirstprocessispresentlycalculatedto next-to-leadingorder inperturbative QCD [3]. Thebound-state forma-tion is described by transition probabilities, called long-distance matrixelements (LDMEs),which areassumedto beconstant (in-dependentofquarkoniumtransversemomentumandrapidity)and universal(independentofthecollisionsystemandenergy).Inthe Fock-stateexpansion oftheheavy-quarkonium state,only asmall number of color-singlet and color-octet terms contribute in the limitofsmallrelativequark velocityv. Thecolor-octetLDMEsare

⋆ _{E-mailaddress:cms-publication-committee-chair@cern.ch.}

noteasilycalculableandthedominantonesare,therefore,treated as free parameters andadjusted to agree with the experimental data[4–6].

The ratio of P-wave quarkonia production cross sections is a reliabletestofpredictionsbecausemanytheoretical,aswellas ex-perimental, uncertainties cancelout.Prompt χc measurements in hadroncollisionswerenotpossibleuntiltheadventofprecise ver-texdetectorsthatallowedtheseparationofpromptlyproduced χc fromthosecomingfromthedecayofBmesons[7].Thisabilityis important,asNRQCDpredictionsarevalidonlyforpromptly pro-duced χc. In the case of bottomonium, measurements are more difficult owing to the reduced productioncross sections and the smallseparationinmass(19.4 MeV)betweenthe χb1(1P)andthe

χb2(1P)(forreadabilitythe1P isdroppedhereafter).The produc-tionratioof χc2 and χc1 isdiscussedinrecenttheoretical papers [3,8],butthedebateontheimportanceofcolor-octetcontributions remainsopen.Inthebottomoniumsector,theNRQCDvelocity ex-pansionis more rigorouslyvalidgiven thesmaller relative quark velocity.Therefore,themeasurementofthe χb2to χb1production crosssectionratioshouldgivefurtherinsightintothemechanism thatgovernsquarkonium production[8].AttheLHC,the charmo-nium χc2/χc1productioncrosssectionratiowas measuredbythe LHCb [9], CMS[10], andATLAS [11] experiments,usingdata col-lected in pp collisions at √s=7 TeV. More recently, the LHCb

http://dx.doi.org/10.1016/j.physletb.2015.02.048

0370-2693/©2015CERNforthebenefitoftheCMSCollaboration.PublishedbyElsevierB.V.ThisisanopenaccessarticleundertheCCBYlicense (http://creativecommons.org/licenses/by/4.0/).FundedbySCOAP3_.

experimentalsoreportedameasurementofthe χb1 and χb2 pro-duction cross section ratio using combined √s=7 and 8 TeV data[12].

ThisLetterpresentsameasurementofthe χb2/χb1 production cross section ratio. The χb1 and χb2 states are reconstructed by detecting their radiative decays χb1,2→ ϒ(1S)+γ,which isthe dominantdecaymode,withthe ϒ (1S)decayinginto twomuons. An accurate measurement of thephoton energy(typically inthe range0.5–2 GeV)is obtainedfromthereconstruction ofthe mo-mentumoftheelectron–positronpairoriginatingfromthephoton conversioninthebeampipeorintheinnerlayersoftheCMS sil-icon tracker. The resulting mass resolution of the χb candidates, around5 MeV, issufficient toresolvethe two χb1,2 peaksatthe expenseofalimitedyield,giventhesmallreconstructionefficiency forsuchlow-energyphotons.Thecrosssectionratioisobtainedas R≡σ(pp→χb2+X) σ(pp→χb1+X) =Nχb2 Nχb1 ·εχb1 εχb2 ·B(χb1→ ϒ(1S)+γ) B(χb2→ ϒ(1S)+γ), (1)

where Nχb1,2 are theyields of χb1,2 signalcandidates, simultane-ously obtained froman unbinned maximum likelihood fit ofthe

µµγ invariant-mass spectrum, εχb1/εχb2 is the ratio of the

ac-ceptanceandefficiencycorrectionsforthetwoprocessesobtained fromafulldetectorsimulation,andB(χb1,2→ ϒ(1S)+γ)arethe branchingfractionsofthecorrespondingradiativedecays[13].The resultsarepresentedinfourbinsofϒ (1S)transversemomentum,

pϒ

T, in the range 7–40 GeV. This choice was driven by the trig-gerrequirements atlow pT,and theamount ofavailable data at high pT.

2. CMSdetectorandeventsamples

The central feature of the CMS apparatus is a superconduct-ing solenoidof6 m internaldiameter, providinga magneticfield of 3.8 T. Withinthe superconducting solenoid volume are a sili-conpixelandstriptracker,aleadtungstatecrystalelectromagnetic calorimeter,andabrass/scintillatorhadroncalorimeter.Muonsare measuredinthepseudorapidityrange|ηµ|<2.4 ingas-ionization detectors embedded in the steel flux-return yoke outside the solenoid. The first level ofthe CMS trigger system, composed of customhardware processors,usesinformationfromthe calorime-tersandmuondetectorstoselectthemostinterestingevents.The high-level triggerprocessorfarm furtherdecreases theeventrate beforedatastorage.AmoredetaileddescriptionoftheCMS detec-tor,together witha definitionofthecoordinatesystemused and therelevantkinematicvariables,canbefoundinRef.[14].

The analysisisbased on the√s₌8 TeV pp datasample col-lected by CMS in 2012 at the CERN LHC, corresponding to an integratedluminosity of20.7 fb−1.Theeventshavebeenselected at the triggerlevel by requiring opposite-sign muon pairs of in-variant mass in the range 8.5–11.5 GeV, dimuon pT larger than 6.9 GeV,adistanceofclosestapproachofeachmuontracktothe beamaxisoflessthan5 mm,anda χ2 _{probabilityfromthe} kine-maticfitofthemuonstoacommonvertexlargerthan0.5%.

Toparameterizethereconstructed χb1,2 massdistributionsand evaluatethereconstructionefficiency,adetailedMonteCarlo(MC) simulationbasedon Geant4[15]wasperformed.About40 million eventsforeach χb statewerepropagatedthroughanaccurate de-scriptionoftheCMSdetector,includingrealistictriggeremulations andreconstruction algorithms identical to those used to process thecollecteddata.Since thephotonconversionprobability multi-pliedby the reconstructionefficiency islessthan 1% forphotons ofenergybelow1 GeV,alargenumberofeventsisneeded.To re-duceCPUusage,the χb mesonsweregeneratedalone,withoutany

“underlyingevent”.Thissimplificationshouldhavenoinfluenceon theresultsoftheanalysisbecauseanypossibleeffectof accompa-nyingparticleson thetrackreconstruction efficienciesisidentical forthetwo χb states,canceling intheratio.Both χb sampleswere produced using the pythia event generator [16], withthe χb pT distributionsparameterizedonthebasisoftheϒ (2S)pT spectrum measured byCMS[17].The χb mesonsweregeneratedinthe ra-pidityrange|y|<2.0 andforcedtodecayintoϒ (1S)+γ,withthe ϒ (1S)mesonsdecayingtodimuons.Onlysimulatedeventswhere a photon conversion occurredwere further processedand recon-structed.

3. Eventreconstructionandselection

TheCMSmuonreconstructionprocedure[18]identifiesmuons by requiring that tracks reconstructed in the silicon tracker be matched withat leastone muon segmentin anymuon detector. Toensure an accurate pT measurement andto suppressthe con-tributionfromdecays-in-flightofpionsandkaons,thenumberof silicontrackerlayerswithatleastonehitmustbelargerthanfive, withtwo ofthem inthesiliconpixel layers,andthe track-fit χ2 per degreeoffreedom mustbe smallerthan 1.8.Looseselections are applied to the transverse and longitudinal muon impact pa-rameters,dxy<3 cm and|dz|<30 cm,respectively,tofurther sup-pressdecaysinflight andcosmic raymuons. Theselectedmuons musthavea transversemomentum pµ_T andpseudorapidity ηµ in the fiducial kinematicregion pµ_T >3.5 GeV and |ηµ|<1.9.Each eventcontainingapairofopposite-signmuonsiskeptinthe anal-ysissampleifthedimuoninvariantmassmµµ isbetween8.5and 11 GeV, its absolute rapidity is lessthan 1.5, andthe χ2 prob-ability of the dimuon kinematic fit (with the two muon tracks constrainedtoacommonvertex)islargerthan1%.Toselectϒ (1S) candidates, mµµ isrequiredto be within 3σ of theϒ (1S)mass, wherethedimuonmassresolution σ isparameterizedasa func-tion ofthe ϒ (1S)rapidity,andis obtainedbyfittingthe dimuon mass distribution in narrow dimuon rapidity bins. This parame-terization accountsfor thesignificant rapidity dependenceof the dimuonmassresolution,fromaround65 MeV at y₌0 toaround 120 MeVat|y_|=1.5.

The low-energy photons produced in the χb radiative decays thatconvertintoelectronsandpositronsoftenproducetracksthat areratherasymmetric,withoneofthetwotrackscarryingasmall fractionofthephoton’senergy.Giventhatthesetracksrarelyreach the calorimeter,they are reconstructedexclusivelyusing informa-tion from the silicontracker. An algorithm optimized forthe re-construction oflow-pT displacedtrackshasbeenused,relying on aniterativetrackingprocedure[19].

The trackpairs usedto reconstructtheconvertedphotons are required to fulfill the following selection criteria: the two tracks mustbeofoppositecharge;onemusthaveatleastfourhitsinthe silicon trackerlayersandthe other atleastthree hits;the inner-most hitsof thetwo tracks must be lessthan 5 cm apart along thebeamdirection;bothtracks musthaveareducedtrack-fit χ2 smallerthan10;thetwotracksshould bealmostparalleltoeach other,havingangularseparations((cotθ )<0.1 and(φ <0.2 rad, where θ and φ are the polarand azimuthal angles, respectively, defined atthecommon vertex;theprimary pp vertexassociated with the photon conversion is required to lie outside both track helices; defining dm asthe distance between the centers of the

twocirclesformedbythetracksinthetransverseplaneminusthe sumoftheir radii,thecondition −0.25<dm<1 cm mustbe

sat-isfied;finally,theconversionvertexmustbe atleast1.5 cmaway fromthe beamaxisinthe transverseplane, inorder tosuppress thebackgroundfrom π0 _{Dalitzdecays.}

Table 1

Parametersextractedfromthefitstothemeasuredµµγ invariantmass distribu-tions,inthefourϒ (1S)pTbinsconsidered.Thequoteduncertaintiesarestatistical

only.Theparametersaredefinedinthetext.

pϒ T [GeV] 7–11 11–16 16–20 20–40 Nχb2/Nχb1 0.65±0.12 0.51±0.06 0.49±0.08 0.54±0.07 Nχb1 392±37 655±39 343±27 474±31 Nbkg 5772±86 3909±72 1401±43 1431±44 λ 3.50±0.23 2.08±0.45 0.78±0.72 0.79±0.71 ν[GeV−1_{] 6.01±0.66 4.09±1.17 1.59±1.80 3.19±1.85}

Theanalysisisperformedoneventshavingaphotonwith pseu-dorapidity|ηγ|<1.0,wherethephoton energyismeasured with thebestresolution,animportantfactorforacleanseparation be-tween the two χb peaks. When the ϒ (1S), loosely selected as describedinabove, andconvertedphotonsare pairedtoform χb candidates,thedistancealongthebeamaxisbetweenthedimuon vertex and the extrapolated photon trajectory is required to be lessthan 1 mm. The invariant mass ofthe χb candidate,mµµγ , iscalculatedthroughakinematicfit,whichconstrainsthedimuon invariant mass to the ϒ (1S) mass and the electron–positron in-variant mass to zero. In addition, the electron and positron are constrainedto a common vertex, asare the two muons andthe photon.The χbcandidatesareretainedifthe χ2 probabilityofthe kinematicfitislargerthan2%.Thisapproachsignificantlyreduces theeffectofthemuonmomentumresolutiononthe χbmass res-olution.

4. Analysisprocedure

Theshape ofthereconstructed invariant-massdistributions of the χb candidatesisevaluatedthrough MCsimulation,performed under the assumption that the intrinsic width of the χb states, predictedtobesmallerthan1 MeV[20],isnegligiblecomparedto themassresolution,whichisoftheorderof5 MeV.Sincethe low-masstailofthe χb2shapefallsunderthe χb1peak,itisimportant touseareliableparameterizationoftheresolutionfunctionwhen evaluatingtheratioofthe χb2and χb1yields, Nχb2/Nχb1.The χb

massresolutionisdominatedbytheenergyresolutionofthe con-vertedphoton andhas aclearlow-mass tail,typical ofprocesses involvingradiativelosses(the electronsandpositronsloseenergy whentraversingthetrackermaterial).The simulatedsignal shape alsorevealsthepresenceofasmallhigh-masstailduetomultiple scattering;thesignalresponseisparameterizedbyadouble-sided CrystalBall(CB) function [21] consistingofa Gaussiancore with two power-law tails, with independent exponents andtransition points.

Theratio Nχb2/Nχb1 ismeasuredwithan unbinnedmaximum

likelihoodfittothe µµγ invariant-massdistribution,infourbins of ϒ (1S)pT. The χb1 and χb2 probability density functions are modeled bydouble-sidedCB functionswithshapeparameters fit-ted to the simulated distributions in each pT bin of the ϒ (1S). The total χb1 yield, the Nχb2/Nχb1 ratio, and the total number

of background events Nbkg are free parameters when fitting the data.The underlying continuum background,composed predom-inantly of events where the ϒ (1S) and photon are unrelated, ismodeled by a probability distribution function proportional to (m−m0)λ·exp(−ν(m−m0)),wheremisthe µµγ invariantmass obtainedfrom the four-track kinematic fit, m0=9.5 GeV,and λ and ν arefreeparameters.Thefitisperformedinthe µµγ mass region9.7–10.1 GeV.Fig. 1showsthefittedinvariant-mass distri-butions fromdata foreach of the fourϒ (1S)pT bins considered, whileTable 1givesthecorrespondingfitresults.

The measurement of the cross section ratio _R, defined in Eq. (1), depends on the ratio of the χb1 and χb2 measurement

Table 2

Acceptanceandefficiencyratios,εχb1/εχb2,computedfromMCsimulation.

Uncer-taintiesarestatisticalonly.

pϒ

T [GeV] 7–11 11–16 16–20 20–40

εχb1/εχb2 0.85±0.05 0.91±0.05 0.91±0.07 0.92±0.04

acceptanceandefficiencies, εχb1/εχb2= (Nrecχb1/N

gen χb1)

!

(N_χrec_b2/Nχgenb2),

where, foreach pϒ

T bin, Nrec is the numberof simulated candi-dates thatare reconstructedandpasstheeventselectioncriteria, while Ngen _{isthecorresponding numberofgeneratedcandidates,} in the kinematic window |yϒ_{|<1.5, p}µ

T >3.5 GeV, |ηµ|<1.9, and |ηγ_{|<1.0. The reconstructed kinematic distributions of the} simulateddecayproducts are found tobe inagreement withthe measuredones.Thevaluesoftheacceptanceandefficiencyratios,

εχb1/εχb2,areshowninTable 2.Theratiooftheacceptancestimes

efficienciesdiffersfromunityowingtotheincreaseddetection ef-ficiencyofthehigher-energyphotonfromthe χb2decay.

5. Systematicuncertainties

The χb1and χb2signalshapesarederivedfromMCsimulation. Toevaluatetheuncertaintyinthe Nχb2/Nχb1 ratiostemmingfrom

theimperfectparameterizationoftheMCsignalshape,causedby thefinitenumberofsimulatedevents,alargenumberof pseudo-experiments are generated, randomly drawing sets of shape pa-rametersusingthecovariancematricesofthefitstothesimulated distributions.Theyarethen usedtofitthemeasured mass distri-butions, andthe resulting Nχb2/Nχb1 distribution is fittedwitha

Gaussianfunction,thestandarddeviationofwhichistakenasthe systematicuncertaintycorrespondingtothe“signalparameters”.

To account for possible discrepancies between the simulated andmeasuredeventsregarding,inparticular,theenergyscale cal-ibration and the measurement resolution, alternative data-fitting schemes are used, leaving some of the signal shape parameters free in the fit to the measured mass distributions. A Chebyshev polynomial function is also used asan alternative model forthe shape ofthemass distributionof thebackground.The maximum variationinthe Nχb2/Nχb1 ratiowiththesedifferentfitting

strate-gies is taken as the “signal and background modeling” system-aticuncertainty.Thefittingprocedureisfound tobeunbiased,as judgedusingpseudo-experimentswhereacertain Nχb2/Nχb1 value

isinjected;thefittedresultsdeviateonaveragefromtheinput val-uesbylessthan10%ofthestatisticaluncertainty.Ithasalsobeen verified that the Nχb2/Nχb1 ratio isinsensitive to theaddition of

a signal termdescribing the χb0 state. The possible influence of multipleprimaryverticesintheevent(“pileup”)ontheNχb2/Nχb1

measurement was investigated by repeating the analysis in sub-samplesofeventswithdifferentnumbersofreconstructedprimary vertices.Nostatisticallysignificanteffectisobserved.

AnothersourceofsystematicuncertaintyintheevaluationofR isthestatisticaluncertaintyin εχb1/εχb2,reflectingthefinitesize

ofthesimulatedeventsamplesusedtoevaluatethemeasurement acceptances andefficiencies. The influence of the generated χb1 and χb2 pT spectraon εχb1/εχb2 isevaluatedby usingalternative

functionsinsteadoftheϒ (2S)spectrum.Areweightingprocedure isusedtoobtainthevaluesof εχb1/εχb2correspondingtoscenarios

wherethe χb1and χb2arebothproducedaccordingtotheϒ (1S) orϒ (3S) pTspectra,aswellastomixedscenarioswherethetwo stateshavedifferentspectra:ϒ (1S)forthe χb1andϒ (2S)forthe

χb2,or ϒ (2S)forthe χb1andϒ (3S)forthe χb2.The maximum variation in the εχb1/εχb2 values obtainedwithall hypotheses is

takenasthe χb pT spectra uncertainty.Possible dependenciesof the εχb1/εχb2 determinationonthedescriptionofthetracking

de-Fig. 1. Invariant-massdistributionsoftheµµγ candidatesforeachofthefourϒ (1S)pTbinsconsideredintheanalysis.Thefittedχb1andχb2signalsareparameterized

withdouble-sidedCBfunctionsdeterminedusingsimulatedevents.Thecombinatorialbackgroundisdescribedbytheproductofanexponentialandapower-lawfunction. Thesolidlinegivestheresultoftheoverallfit,withthedashedanddashed–dottedlinesshowingtheχb1andχb2contributions,respectively.Thedottedlinerepresentsthe

backgroundcontribution.

tectormaterialintheMCsimulationhavebeenfoundtobe negli-gible.

The acceptances and efficiencies are evaluated under the as-sumption that the χb1 and χb2 are both produced unpolarized. PolarizationaffectstheangularandpTdistributionsoftheradiated photon;sincethephotonreconstructionefficiencysignificantly de-pendsonthe photon pT,especially atlow pT,the ratioof accep-tances and efficiencies depends on the polarization scenario. In order to investigate this effect,the unpolarized MC distributions are reweighted to reproduce the theoretical angulardistributions of χb decayproducts expectedfordifferent χb polarizations[22]. The acceptanceand efficiencyratiois recalculated assuming that the χb1isproduced unpolarizedorwithhelicitymχb1=0,±1,in

combinationwiththeassumptionthatthe χb2isproduced unpo-larizedorwithhelicitymχb2=0,±1,±2,bothinthehelicityand

Collins–Soper[23]frames. Themaximalvariations of εχb1/εχb2 in

these4×6 scenarioswithrespecttothe“both unpolarized”case haveanegligibleinfluence(atthepercentlevel)onthecross sec-tionratio,wellbelowtheotheruncertainties.Table 3summarizes thesystematicuncertaintiesconsideredintheanalysis.

Table 3

Relativesystematicuncertaintiesin Nχ_b2 Nχb1 ·

εχ_b1

εχb2, inpercent,forthefour p ϒ T bins considered. pϒ T [GeV] 7–11 11–16 16–20 20–40 Signal parameters 3.2 3.5 3.3 3.5

Signal and background modeling 6.8 5.3 5.2 6.1

εχb1/εχb2statistical uncertainty 6.4 5.8 7.2 4.4

Choice ofχb pTspectra 3.0 3.0 2.8 4.8

Total 10.3 9.1 9.9 9.6

6. Resultsanddiscussion

The ratio _R ofthe χb2 and χb1 production cross sections in theϒ (1S)+γ decaychannelforeach pϒ

T binisobtainedby cor-rectingthe Nχb2/Nχb1 yieldratio(Table 1)withthecorresponding

acceptanceandefficiencyratio εχb1/εχb2 (Table 2).

Fig. 2 showsthe measured σ(χb2)/σ(χb1) crosssection ratio, asa function of pϒ

T, before(left) andafter(right)multiplying by the decay branching fractions, taken from Ref. [13]. The relative uncertainty intheratio ofthebranching fractions is9%. The nu-mericalvaluesaregiveninTable 4.

Table 4

Thecrosssectionratioσ(χb2)/σ(χb1)measuredinfourpϒ

T binsbeforeandaftermultiplyingbytheχb→ ϒ(1S)₊γ branching fractions[13].ThesecondcolumngivestheaveragepTvalueforeachbin.Thefirstuncertaintyisstatistical,thesecondissystematic,

andthethirdreflectstheuncertaintyinthebranchingfraction.

pϒ T [GeV] ⟨pϒT⟩[GeV] σ(χb2) /σ(χb1)_{× B(}χb2) /B(χb1) σ(χb2) /σ(χb1) 7–11 8.7 0.56±0.10±0.06 0.99±0.18±0.10±0.09 11–16 12.9 0.47±0.06±0.04 0.83±0.10±0.08±0.07 16–20 17.5 0.45±0.07±0.04 0.80±0.13±0.08±0.07 20–40 26.2 0.50±0.06±0.05 0.89±0.11±0.09±0.08

Fig. 2. Theratiooftheχb2 andχb1 productioncrosssections,asafunctionofpTϒ,before(left)andafter(right)multiplyingbytheratioofthe ϒ(1S)+γ branching

fractions,asmeasuredbyCMSandLHCb[12](rightonly).Theverticalbarsrepresentthestatistical(innerbars)andtotal(outerbars)experimentaluncertainty,respectively. Thehorizontalbarsshowthewidthofeachbin.ThedashedlineintherightplotisafitofaconstanttotheCMSmeasurements,andthehorizontalbandisthetotal uncertaintyinthefitresult.The9%uncertaintyintheratioofbranchingfractions,whichappliestoallbinsofpϒ

T,isnotincluded.Thecurvedbandrepresentstheresultof

atheoreticalcalculation[24].

The open circles in Fig. 2, right panel, show the LHCb mea-surement[12],whichcanbecomparedtotheCMSresultsinceno significantdependenceoftheratioontherapidityisexpected.The shadedareaintherightpanelofFig. 2showsatheoretical calcula-tion[24]performedintheframeworkofNRQCD.Sincedataon χb productionwerenotavailableuntilrecently,inthiscalculationthe LDMEsareextractedfromexperimentaldataonthe σ(χc2)/σ(χc1) cross section ratio [7,9,10] and extrapolated, using NRQCD scal-ingrules,tothecaseofP-wavebottomonium.Thedashedlinein Fig. 2 (right)gives the resultof a fit of the CMS measurements toaconstant,correspondingto0.85±0.07,wheretheuncertainty includesboth statisticalandsystematicuncertainties,butnot the uncertaintyintheratioofthe χb branchingfractions. Aconstant behavior is expected in the case of color-octet dominance. The measurements do not indicate the large increase in the ratio at low pϒ

T anddifferbymorethantwostandarddeviationsfromthe asymptotic value at high pT predicted by the theory. More pre-cisemeasurementsmaybeneededinordertothoroughlytestthe validityofNRQCDintheP-wavebottomoniumsector.

7.Summary

Theproduction crosssection ratio σ(χb2(1P))/σ(χb1(1P))has beenmeasured in pp collisionsby detecting theradiative decays toaϒ (1S)andaphoton,withtheϒ (1S)decayingtotwomuons. Events are selected where the ϒ (1S) and photon are emitted in the phase-spaceregion defined by |yϒ_{|<1.5 and |η}γ_|<1.0,in four bins of ϒ (1S) pT, spanning the range 7–40 GeV. The mea-surement has been performed using a data sample collected by

theCMSexperimentin2012,at√s=8 TeV, correspondingtoan integrated luminosity of 20.7 fb−1. The cross section ratio aver-agedovertheϒ (1S) pTrangeismeasuredtobe0.85±0.07(stat+ syst)±0.08(BF),wherethefirstuncertaintyisthecombinationof the experimental statisticaland systematicuncertainties andthe second is fromthe uncertainty in the ratio of the χb branching fractions.Theratiodoesnotshowasignificantdependenceonthe ϒ (1S) pT. This is the most precise measurement to date of the

χb2and χb1relativeproductioncrosssectionsinhadroncollisions, whichcomplementsandextendsthe resultsofRef.[12] obtained inthekinematicregion2.0<y(χb)<4.5,5.0<pT(ϒ )<25 GeV.

Acknowledgements

WecongratulateourcolleaguesintheCERNaccelerator depart-ments for the excellent performance of the LHC and thank the technicalandadministrative staffsatCERN andatother CMS in-stitutes for their contributions to the success of the CMS effort. Inaddition,wegratefullyacknowledgethecomputingcentresand personneloftheWorldwideLHCComputingGridfordeliveringso effectivelythe computinginfrastructureessential to ouranalyses. Finally, we acknowledge the enduring support for the construc-tionandoperation oftheLHC andtheCMSdetectorprovidedby 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);Academy ofFinland,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); NRF and WCU (Republic of Korea); LAS (Lithuania); MOE and UM(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-gramme and the European Research Council and EPLANET (Eu-ropean Union); the Leventis Foundation; the A.P. Sloan Founda-tion; the Alexander von Humboldt Foundation; the Belgian Fed-eral Science Policy Office; the Fonds pour la Formation à la Recherchedansl’Industrieetdansl’Agriculture(FRIA-Belgium);the AgentschapvoorInnovatiedoorWetenschapenTechnologie (IWT-Belgium);the Ministry ofEducation,Youth andSports (MEYS) of theCzechRepublic;theCouncilofScienceandIndustrialResearch, India; the HOMING PLUS programme of Foundation For Polish Science, cofinanced from European Union, Regional Development Fund;the CompagniadiSan Paolo(Torino); theConsorzio per la Fisica (Trieste);MIUR project20108T4XTM(Italy); the Thalisand Aristeia programmes cofinanced by EU-ESF andthe Greek NSRF; andtheNationalPrioritiesResearchProgrambyQatarNational Re-searchFund.

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CMSCollaboration

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

YerevanPhysicsInstitute,Yerevan,Armenia

W. Adam, T. Bergauer, M. Dragicevic,J. Erö, C. Fabjan1_{,M. Friedl, R. Frühwirth}1_{,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,A. Taurok,}

W. Treberer-Treberspurg,W. Waltenberger, C.-E. Wulz1

InstitutfürHochenergiephysikderOeAW,Wien,Austria

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

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

S. Ochesanu,B. Roland, 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_{,T. Reis, T. Seva, L. Thomas, C. Vander Velde, P. Vanlaer,J. Wang}

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. 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,}

T. du Pree,D. Favart,L. Forthomme, A. Giammanco4,J. Hollar, P. Jez, M. Komm,V. Lemaitre, C. Nuttens, D. Pagano,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, C. Mora Herrera, M.E. Pol

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. Dogra}a_{,T.R. Fernandez Perez Tomei}a_{, E.M. Gregores}b_{, P.G. Mercadante}b_,

S.F. Novaesa, Sandra S. Padulaa

a_{UniversidadeEstadualPaulista,SãoPaulo,Brazil} b_{UniversidadeFederaldoABC,SãoPaulo,Brazil}

A. Aleksandrov, V. Genchev2, P. Iaydjiev, A. Marinov,S. Piperov, M. Rodozov,S. Stoykova, G. Sultanov,

V. Tcholakov, M. Vutova

InstituteforNuclearResearchandNuclearEnergy,Sofia,Bulgaria

A. Dimitrov,I. Glushkov, R. Hadjiiska, V. Kozhuharov,L. Litov, B. Pavlov,P. Petkov

UniversityofSofia,Sofia,Bulgaria

J.G. Bian,G.M. Chen, H.S. Chen, M. Chen,R. Du, C.H. Jiang, S. Liang,R. Plestina7, J. Tao, X. Wang,Z. Wang

InstituteofHighEnergyPhysics,Beijing,China

StateKeyLaboratoryofNuclearPhysicsandTechnology,PekingUniversity,Beijing,China

C. Avila,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

UniversityofCyprus,Nicosia,Cyprus

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

CharlesUniversity,Prague,CzechRepublic

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, G. Fedi,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

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, C. Charlot, T. Dahms, M. Dalchenko,L. Dobrzynski, N. Filipovic, A. Florent,R. Granier de Cassagnac, L. Mastrolorenzo, P. Miné, C. Mironov, I.N. Naranjo, M. Nguyen, C. Ochando, 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, P. Van Hove

InstitutPluridisciplinaireHubertCurien,UniversitédeStrasbourg,UniversitédeHauteAlsaceMulhouse,CNRS/IN2P3,Strasbourg,France

CentredeCalculdel’InstitutNationaldePhysiqueNucleaireetdePhysiquedesParticules,CNRS/IN2P3,Villeurbanne,France

S. Beauceron,N. Beaupere, G. Boudoul2,E. Bouvier, S. Brochet,C.A. Carrillo Montoya, J. Chasserat, R. Chierici,D. Contardo2, P. Depasse,H. El Mamouni, J. Fan, J. Fay, S. Gascon, M. Gouzevitch, B. Ille, T. Kurca, M. Lethuillier,L. Mirabito, S. Perries,J.D. Ruiz Alvarez, D. Sabes,L. Sgandurra, V. Sordini, M. Vander Donckt, P. Verdier,S. Viret, H. Xiao

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

Z. Tsamalaidze8

InstituteofHighEnergyPhysicsandInformatization,TbilisiStateUniversity,Tbilisi,Georgia

C. Autermann,S. Beranek, M. Bontenackels, M. Edelhoff,L. Feld, O. Hindrichs, K. Klein, A. Ostapchuk, A. Perieanu,F. Raupach, J. Sammet,S. Schael, H. Weber, B. Wittmer, V. Zhukov5

RWTHAachenUniversity,I.PhysikalischesInstitut,Aachen,Germany

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

K. Hoepfner,D. Klingebiel,S. Knutzen, P. Kreuzer,M. Merschmeyer, A. Meyer, P. Millet,M. Olschewski, K. Padeken,P. Papacz, H. Reithler,S.A. Schmitz,L. Sonnenschein, D. Teyssier,S. Thüer, M. Weber

RWTHAachenUniversity,III.PhysikalischesInstitutA,Aachen,Germany

V. Cherepanov, Y. Erdogan,G. Flügge, H. Geenen, M. Geisler, W. Haj Ahmad, A. Heister, F. Hoehle, B. Kargoll, T. Kress, Y. Kuessel,J. Lingemann2_{, A. Nowack,I.M. Nugent,L. Perchalla, O. Pooth,A. Stahl} RWTHAachenUniversity,III.PhysikalischesInstitutB,Aachen,Germany

I. Asin,N. Bartosik, J. Behr,W. Behrenhoff, U. Behrens,A.J. Bell, M. Bergholz15_{,A. Bethani, K. Borras,}

A. Burgmeier,A. Cakir,L. Calligaris, A. Campbell, S. Choudhury, F. Costanza, C. Diez Pardos,S. Dooling, T. Dorland,G. Eckerlin, D. Eckstein, T. Eichhorn, G. Flucke, J. Garay Garcia, A. Geiser, P. Gunnellini, J. Hauk, M. Hempel, D. Horton, H. Jung,A. Kalogeropoulos, M. Kasemann,P. Katsas, J. Kieseler,

C. Kleinwort,D. Krücker, W. Lange,J. Leonard, K. Lipka,A. Lobanov, W. Lohmann15, B. Lutz, R. Mankel, I. Marfin,I.-A. Melzer-Pellmann, A.B. Meyer, G. Mittag, J. Mnich, A. Mussgiller, S. Naumann-Emme, A. Nayak,O. Novgorodova, F. Nowak,E. Ntomari, H. Perrey,D. Pitzl, R. Placakyte, A. Raspereza, P.M. Ribeiro Cipriano,E. Ron, M.Ö. Sahin,J. Salfeld-Nebgen, P. Saxena, R. Schmidt15,

T. Schoerner-Sadenius,M. Schröder, C. Seitz,S. Spannagel, A.D.R. Vargas Trevino, R. Walsh, C. Wissing

DeutschesElektronen-Synchrotron,Hamburg,Germany

M. Aldaya Martin,V. Blobel, M. Centis Vignali, A.R. Draeger, J. Erfle,E. Garutti, K. Goebel, M. Görner, J. Haller, M. Hoffmann,R.S. Höing, H. Kirschenmann,R. Klanner, R. Kogler, J. Lange,T. Lapsien, T. Lenz, I. Marchesini,J. Ott, T. Peiffer, 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

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, F. Hartmann2, T. Hauth2,U. Husemann, I. Katkov5,A. Kornmayer2, E. Kuznetsova, P. Lobelle Pardo, M.U. Mozer,Th. Müller, A. Nürnberg, G. Quast, K. Rabbertz, F. Ratnikov, 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

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

UniversityofIoánnina,Ioánnina,Greece

G. Bencze,C. Hajdu, P. Hidas, D. Horvath16, F. Sikler,V. Veszpremi, G. Vesztergombi17,A.J. Zsigmond

WignerResearchCentreforPhysics,Budapest,Hungary

N. Beni, S. Czellar, J. Karancsi18,J. Molnar, J. Palinkas, Z. Szillasi

InstituteofNuclearResearchATOMKI,Debrecen,Hungary

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

UniversityofDebrecen,Debrecen,Hungary

S.K. Swain

NationalInstituteofScienceEducationandResearch,Bhubaneswar,India

S.B. Beri, V. Bhatnagar,N. Dhingra, R. Gupta, U. Bhawandeep, A.K. Kalsi, M. Kaur, 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, S. Kailas,V. Kumar, A.K. Mohanty2, L.M. Pant, P. Shukla,A. Topkar

BhabhaAtomicResearchCentre,Mumbai,India

T. Aziz, S. Banerjee, S. Bhowmik19,R.M. Chatterjee, R.K. Dewanjee, S. Dugad, S. Ganguly,S. Ghosh, M. Guchait,A. Gurtu20,G. Kole, S. Kumar, M. Maity19, G. Majumder, K. Mazumdar,G.B. Mohanty,

B. Parida,K. Sudhakar, N. Wickramage21

TataInstituteofFundamentalResearch,Mumbai,India

H. Bakhshiansohi,H. Behnamian, S.M. Etesami22_{, A. Fahim}23_{, R. Goldouzian, A. Jafari,M. Khakzad,}

M. Mohammadi Najafabadi, M. Naseri, S. Paktinat Mehdiabadi, F. Rezaei Hosseinabadi, B. Safarzadeh24,

M. Zeinali

InstituteforResearchinFundamentalSciences(IPM),Tehran,Iran

M. Felcini,M. Grunewald

UniversityCollegeDublin,Dublin,Ireland

M. Abbresciaa,b_{, L. Barbone}a,b_{,C. Calabria}a,b_{,S.S. Chhibra}a,b_{,A. Colaleo}a_{,D. Creanza}a,c_,

N. De Filippisa,c_{, M. De Palma}a,b_{,L. Fiore}a_{,G. Iaselli}a,c_{,G. Maggi}a,c_{,M. Maggi}a_{, S. My}a,c_{, S. Nuzzo}a,b_,

A. Pompilia,b_{,G. Pugliese}a,c_{,R. Radogna}a,b,2_{, G. Selvaggi}a,b_{, L. Silvestris}a,2_{,G. Singh}a,b_{, R. Venditti}a,b_,

P. Verwilligena_{, G. Zito}a

b_{UniversitàdiBari,Bari,Italy} c_{PolitecnicodiBari,Bari,Italy}

G. Abbiendia_{,A.C. Benvenuti}a_{, D. Bonacorsi}a,b_{, S. Braibant-Giacomelli}a,b_{,L. Brigliadori}a,b_,

R. Campaninia,b_{,P. Capiluppi}a,b_{,A. Castro}a,b_{, F.R. Cavallo}a_{,G. Codispoti}a,b_{, M. Cuffiani}a,b_,

G.M. Dallavallea_{,F. Fabbri}a_{,A. Fanfani}a,b_{,D. Fasanella}a,b_{, P. Giacomelli}a_{, C. Grandi}a_{, L. Guiducci}a,b_,

S. Marcellinia, G. Masettia,2_{, A. Montanari}a_{, F.L. Navarria}a,b_{,A. Perrotta}a_{, F. Primavera}a,b_{, A.M. Rossi}a,b_,

T. Rovellia,b_{, G.P. Siroli}a,b_{,N. Tosi}a,b_{, R. Travaglini}a,b

a_{INFNSezionediBologna,Bologna,Italy} b_{UniversitàdiBologna,Bologna,Italy}

S. Albergoa,b_{, G. Cappello}a_{,M. Chiorboli}a,b_{,S. Costa}a,b_{,F. Giordano}a,2_{,R. Potenza}a,b_{,A. Tricomi}a,b_,

C. Tuvea,b

a_{INFNSezionediCatania,Catania,Italy} b_{UniversitàdiCatania,Catania,Italy} c_{CSFNSM,Catania,Italy}

G. Barbaglia,V. Ciullia,b_{,C. Civinini}a_{, R. D’Alessandro}a,b_{, E. Focardi}a,b_{,E. Gallo}a_{, S. Gonzi}a,b_,

V. Goria,b,2_{,P. Lenzi}a,b_{,M. Meschini}a_{,S. Paoletti}a_{, G. Sguazzoni}a_{, A. Tropiano}a,b

a_{INFNSezionediFirenze,Firenze,Italy} b_{UniversitàdiFirenze,Firenze,Italy}

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

INFNLaboratoriNazionalidiFrascati,Frascati,Italy

F. Ferroa, M. Lo Veterea,b_{, E. Robutti}a_{,S. Tosi}a,b

a_{INFNSezionediGenova,Genova,Italy} b_{UniversitàdiGenova,Genova,Italy}

M.E. Dinardoa,b_{, S. Fiorendi}a,b,2_{, S. Gennai}a,2_{,R. Gerosa}2_{, A. Ghezzi}a,b_{,P. Govoni}a,b_{,M.T. Lucchini}a,b,2_,

S. Malvezzia_{, R.A. Manzoni}a,b_{, A. Martelli}a,b_{, B. Marzocchi,D. Menasce}a_{,L. Moroni}a_{,M. Paganoni}a,b_,

D. Pedrinia,S. Ragazzia,b_{,N. Redaelli}a_{, T. Tabarelli de Fatis}a,b

a_{INFNSezionediMilano-Bicocca,Milano,Italy} b_{UniversitàdiMilano-Bicocca,Milano,Italy}

S. Buontempoa_{, N. Cavallo}a,c_{,S. Di Guida}a,d,2_{, F. Fabozzi}a,c_{,A.O.M. Iorio}a,b_{, L. Lista}a_{,S. Meola}a,d,2_,

M. Merolaa, P. Paoluccia,2

a_{INFNSezionediNapoli,Napoli,Italy} b_{UniversitàdiNapoli‘FedericoII’,Napoli,Italy} c_{UniversitàdellaBasilicata(Potenza),Napoli,Italy} d_{UniversitàG.Marconi(Roma),Napoli,Italy}

P. Azzia_{, N. Bacchetta}a_{, D. Bisello}a,b_{, A. Branca}a,b_{,R. Carlin}a,b_{,P. Checchia}a_{, M. Dall’Osso}a,b_{, T. Dorigo}a_,

U. Dossellia,M. Galantia,b_{, F. Gasparini}a,b_{, U. Gasparini}a,b_{,P. Giubilato}a,b_{,F. Gonella}a_{, A. Gozzelino}a_,

K. Kanishcheva,c_{,S. Lacaprara}a_{, M. Margoni}a,b_{, F. Montecassiano}a_{, J. Pazzini}a,b_{, N. Pozzobon}a,b_,

P. Ronchesea,b_{,F. Simonetto}a,b_{, M. Tosi}a,b_{,P. Zotto}a,b_{,A. Zucchetta}a,b_{,G. Zumerle}a,b

a_{INFNSezionediPadova,Padova,Italy} b_{UniversitàdiPadova,Padova,Italy} c_{UniversitàdiTrento(Trento),Padova,Italy}

M. Gabusia,b_{,S.P. Ratti}a,b_{, C. Riccardi}a,b_{,P. Salvini}a_{,P. Vitulo}a,b

a_{INFNSezionediPavia,Pavia,Italy} b_{UniversitàdiPavia,Pavia,Italy}

M. Biasinia,b_{,G.M. Bilei}a_{,D. Ciangottini}a,b_{, L. Fanò}a,b_{,P. Lariccia}a,b_{,G. Mantovani}a,b_{, M. Menichelli}a_,

a_{INFNSezionediPerugia,Perugia,Italy} b_{UniversitàdiPerugia,Perugia,Italy}

K. Androsova,25_{,P. Azzurri}a_{,G. Bagliesi}a_{,J. Bernardini}a_{,T. Boccali}a_{,G. Broccolo}a,c_{,R. Castaldi}a_,

M.A. Cioccia,25_{, R. Dell’Orso}a_{,S. Donato}a,c_{,F. Fiori}a,c_{,L. Foà}a,c_{,A. Giassi}a_{, M.T. Grippo}a,25_{, F. Ligabue}a,c_,

T. Lomtadzea_{, L. Martini}a,b_{, A. Messineo}a,b_{,C.S. Moon}a,26_{, F. Palla}a,2_{, A. Rizzi}a,b_{, A. Savoy-Navarro}a,27_,

A.T. Serbana,P. Spagnoloa,P. Squillaciotia,25_{,R. Tenchini}a_{, G. Tonelli}a,b_{,A. Venturi}a_{, P.G. Verdini}a_,

C. Vernieria,c,2

a_{INFNSezionediPisa,Pisa,Italy} b_{UniversitàdiPisa,Pisa,Italy}

c_{ScuolaNormaleSuperiorediPisa,Pisa,Italy}

L. Baronea,b_{,F. Cavallari}a_{, G. D’imperio}a,b_{,D. Del Re}a,b_{,M. Diemoz}a_{, M. Grassi}a,b_{,C. Jorda}a_,

E. Longoa,b_{, F. Margaroli}a,b_{,P. Meridiani}a_{,F. Micheli}a,b,2_{, S. Nourbakhsh}a,b_{,G. Organtini}a,b_,

R. Paramattia,S. Rahatloua,b_{,C. Rovelli}a_{, F. Santanastasio}a,b_{, L. Soffi}a,b,2_{,P. Traczyk}a,b

a_{INFNSezionediRoma,Roma,Italy} b_{UniversitàdiRoma,Roma,Italy}

N. Amapanea,b_{, R. Arcidiacono}a,c_{,S. Argiro}a,b,2_{, M. Arneodo}a,c_{, R. Bellan}a,b_{, C. Biino}a_{,N. Cartiglia}a_,

S. Casassoa,b,2_{, M. Costa}a,b_{, A. Degano}a,b_{,N. Demaria}a_{,G. Dujany}a,b_{,L. Finco}a,b_{,C. Mariotti}a_,

S. Masellia_{, E. Migliore}a,b_{,V. Monaco}a,b_{,M. Musich}a_{, M.M. Obertino}a,c,2_{,G. Ortona}a,b_{,L. Pacher}a,b_,

N. Pastronea,M. Pelliccionia, G.L. Pinna Angionia,b_{,A. Potenza}a,b_{, A. Romero}a,b_{,M. Ruspa}a,c_,

R. Sacchia,b_{, A. Solano}a,b_{, A. Staiano}a_{, U. Tamponi}a

a_{INFNSezionediTorino,Torino,Italy} b_{UniversitàdiTorino,Torino,Italy}

c_{UniversitàdelPiemonteOrientale(Novara),Torino,Italy}

S. Belfortea,V. Candelisea,b_{,M. Casarsa}a_{, F. Cossutti}a_{,G. Della Ricca}a,b_{, B. Gobbo}a_{, C. La Licata}a,b_,

M. Maronea,b_{,D. Montanino}a,b_{,A. Schizzi}a,b,2_{,T. Umer}a,b_{, A. Zanetti}a

a_{INFNSezionediTrieste,Trieste,Italy} b_{UniversitàdiTrieste,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

ChonbukNationalUniversity,Jeonju,RepublicofKorea

J.Y. Kim, 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

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

UniversityofSeoul,Seoul,RepublicofKorea

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

SungkyunkwanUniversity,Suwon,RepublicofKorea

VilniusUniversity,Vilnius,Lithuania

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

NationalCentreforParticlePhysics,UniversitiMalaya,KualaLumpur,Malaysia

H. Castilla-Valdez,E. De La Cruz-Burelo, I. Heredia-de La Cruz28_{,R. Lopez-Fernandez,}

A. Sanchez-Hernandez

CentrodeInvestigacionydeEstudiosAvanzadosdelIPN,MexicoCity,Mexico

S. Carrillo Moreno, F. Vazquez Valencia

UniversidadIberoamericana,MexicoCity,Mexico

I. Pedraza, H.A. Salazar Ibarguen

BenemeritaUniversidadAutonomadePuebla,Puebla,Mexico

E. Casimiro Linares, 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, S. Khalid, W.A. Khan, T. Khurshid,M.A. Shah, 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, W. Wolszczak

InstituteofExperimentalPhysics,FacultyofPhysics,UniversityofWarsaw,Warsaw,Poland

P. Bargassa,C. Beirão Da Cruz E Silva, P. Faccioli, P.G. Ferreira Parracho,M. Gallinaro, F. Nguyen, J. Rodrigues Antunes,J. Seixas, J. Varela, P. Vischia

LaboratóriodeInstrumentaçãoeFísicaExperimentaldePartículas,Lisboa,Portugal

I. Golutvin, I. Gorbunov, V. Karjavin, V. Konoplyanikov,V. Korenkov, A. Lanev, A. Malakhov,

V. Matveev29,V.V. Mitsyn, P. Moisenz,V. Palichik, V. Perelygin, S. Shmatov, N. Skatchkov, V. Smirnov, E. Tikhonenko, B.S. Yuldashev30_{,A. Zarubin}

JointInstituteforNuclearResearch,Dubna,Russia

V. Golovtsov,Y. Ivanov, V. Kim31_{,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

V. Epshteyn, V. Gavrilov, N. Lychkovskaya,V. Popov, G. Safronov, S. Semenov, A. Spiridonov, V. Stolin, E. Vlasov, A. Zhokin

InstituteforTheoreticalandExperimentalPhysics,Moscow,Russia

V. Andreev,M. Azarkin, I. Dremin, M. Kirakosyan, A. Leonidov, 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

StateResearchCenterofRussianFederation,InstituteforHighEnergyPhysics,Protvino,Russia

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,G. Merino, 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, L. Lloret Iglesias

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, C. Bernet7,G. Bianchi, 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, M. Dobson, M. Dordevic, N. Dupont-Sagorin, A. Elliott-Peisert, J. Eugster,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, P. Musella, L. Orsini, L. Pape,E. Perez, L. Perrozzi,A. Petrilli, G. Petrucciani, A. Pfeiffer,M. Pierini, 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, D. Treille, A. Tsirou, G.I. Veres17_{, J.R. Vlimant, N. Wardle, H.K. Wöhri, H. Wollny, W.D. Zeuner}

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, P. Bortignon, M.A. Buchmann,B. Casal, N. Chanon, A. Deisher,

G. Dissertori, M. Dittmar, M. Donegà, M. Dünser, P. Eller, C. Grab,D. Hits, W. Lustermann,B. Mangano, A.C. Marini,P. Martinez Ruiz del Arbol, D. Meister, N. Mohr,C. Nägeli37_{,F. Nessi-Tedaldi, F. Pandolfi,}

F. Pauss,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, B. Millan Mejias, J. Ngadiuba,P. Robmann, F.J. Ronga,S. Taroni, M. Verzetti, Y. Yang

UniversitätZürich,Zurich,Switzerland

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.W. Chang,Y. Chao, K.F. Chen, P.H. Chen, C. Dietz,U. Grundler,W.-S. Hou,K.Y. Kao, Y.J. Lei, Y.F. Liu,R.-S. Lu, D. Majumder, E. Petrakou, Y.M. Tzeng,R. Wilken

NationalTaiwanUniversity(NTU),Taipei,Taiwan

B. Asavapibhop,N. Srimanobhas, N. Suwonjandee

ChulalongkornUniversity,FacultyofScience,DepartmentofPhysics,Bangkok,Thailand

A. Adiguzel, M.N. Bakirci40_{,S. Cerci}41_{, C. Dozen,I. Dumanoglu, E. Eskut, S. Girgis, G. Gokbulut,}

E. Gurpinar,I. Hos, E.E. Kangal, A. Kayis Topaksu,G. Onengut42, K. Ozdemir, S. Ozturk40, A. Polatoz, K. Sogut43_{, D. Sunar Cerci}41_{,B. Tali}41_{, H. Topakli}40_{,M. Vergili}

CukurovaUniversity,Adana,Turkey

I.V. Akin,B. Bilin, S. Bilmis, H. Gamsizkan, G. Karapinar44_{,K. Ocalan, S. Sekmen, U.E. Surat,M. Yalvac,}

M. Zeyrek

MiddleEastTechnicalUniversity,PhysicsDepartment,Ankara,Turkey

E. Gülmez,B. Isildak45,M. Kaya46,O. Kaya47

BogaziciUniversity,Istanbul,Turkey

H. Bahtiyar48,E. Barlas, K. Cankocak, F.I. Vardarlı, M. Yücel

IstanbulTechnicalUniversity,Istanbul,Turkey

L. Levchuk,P. Sorokin

NationalScientificCenter,KharkovInstituteofPhysicsandTechnology,Kharkov,Ukraine

J.J. Brooke,E. Clement, D. Cussans,H. Flacher, R. Frazier,J. Goldstein, M. Grimes, G.P. Heath, H.F. Heath, J. Jacob,L. Kreczko, C. Lucas, Z. Meng, D.M. Newbold49,S. Paramesvaran,A. Poll, S. Senkin, V.J. Smith, T. Williams

UniversityofBristol,Bristol,UnitedKingdom

K.W. Bell,A. Belyaev50_{,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, W.J. Womersley, S.D. Worm

M. Baber, R. Bainbridge,O. Buchmuller, D. Burton,D. Colling, N. Cripps, M. Cutajar,P. Dauncey, G. Davies, M. Della Negra, P. Dunne,W. Ferguson, J. Fulcher, D. Futyan, A. Gilbert,G. Hall, G. Iles, M. Jarvis, G. Karapostoli,M. Kenzie, R. Lane,R. Lucas49,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

ImperialCollege,London,UnitedKingdom

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

L. Teodorescu,M. Turner

BrunelUniversity,Uxbridge,UnitedKingdom

J. Dittmann, K. Hatakeyama,A. Kasmi, H. Liu, T. Scarborough

BaylorUniversity,Waco,USA

O. Charaf,S.I. Cooper, C. Henderson, P. Rumerio

TheUniversityofAlabama,Tuscaloosa,USA

A. Avetisyan, T. Bose,C. Fantasia, P. Lawson, C. Richardson, J. Rohlf, D. Sperka, J. St. John,L. Sulak

BostonUniversity,Boston,USA

J. Alimena,E. Berry, S. Bhattacharya, G. Christopher, D. Cutts, Z. Demiragli, A. Ferapontov,A. Garabedian, U. Heintz, G. Kukartsev,E. Laird, G. Landsberg, M. Luk, M. Narain, M. Segala, T. Sinthuprasith, T. Speer, J. Swanson

BrownUniversity,Providence,USA

R. Breedon,G. Breto, M. Calderon De La Barca Sanchez, S. Chauhan,M. Chertok, J. Conway,R. Conway,

P.T. Cox, R. Erbacher,M. Gardner, W. Ko, R. Lander,T. Miceli, M. Mulhearn, D. Pellett, J. Pilot, F. Ricci-Tam, M. Searle, S. Shalhout, J. Smith, M. Squires, D. Stolp, M. Tripathi, S. Wilbur,R. Yohay

UniversityofCalifornia,Davis,Davis,USA

R. Cousins,P. Everaerts,C. Farrell, J. Hauser, M. Ignatenko, G. Rakness, E. Takasugi, V. Valuev,M. Weber

UniversityofCalifornia,LosAngeles,USA

J. Babb, K. Burt, R. Clare,J. Ellison, J.W. Gary, G. Hanson,J. Heilman, M. Ivova Rikova, P. Jandir, E. Kennedy, F. Lacroix,H. Liu, O.R. Long, A. Luthra, M. Malberti,H. Nguyen, M. Olmedo Negrete,

A. Shrinivas,S. Sumowidagdo, S. Wimpenny

UniversityofCalifornia,Riverside,Riverside,USA

W. Andrews, J.G. Branson, G.B. Cerati,S. Cittolin, R.T. D’Agnolo, D. Evans,A. Holzner, R. Kelley, D. Klein, M. Lebourgeois,J. Letts, I. Macneill, D. Olivito, S. Padhi, C. Palmer,M. Pieri, M. Sani, V. Sharma, S. Simon, E. Sudano, M. Tadel,Y. Tu, A. Vartak, C. Welke,F. Würthwein,A. Yagil, J. Yoo

UniversityofCalifornia,SanDiego,LaJolla,USA

D. Barge, J. Bradmiller-Feld, C. Campagnari, T. Danielson, A. Dishaw,K. Flowers, M. Franco Sevilla, P. Geffert,C. George, F. Golf, L. Gouskos, J. Incandela,C. Justus,N. Mccoll, J. Richman, D. Stuart, W. To, C. West

UniversityofCalifornia,SantaBarbara,SantaBarbara,USA

A. Apresyan,A. Bornheim, J. Bunn, Y. Chen, E. Di Marco,J. Duarte, A. Mott, H.B. Newman, C. Pena, C. Rogan, M. Spiropulu, V. Timciuc, R. Wilkinson,S. Xie, R.Y. Zhu

V. Azzolini,A. Calamba, B. Carlson, T. Ferguson, Y. Iiyama,M. Paulini, J. Russ, H. Vogel, I. Vorobiev

CarnegieMellonUniversity,Pittsburgh,USA

J.P. Cumalat,W.T. Ford, A. Gaz, E. Luiggi Lopez,U. Nauenberg, J.G. Smith, K. Stenson,K.A. Ulmer, S.R. Wagner

UniversityofColoradoatBoulder,Boulder,USA

J. Alexander, A. Chatterjee, J. Chu,S. Dittmer, N. Eggert, N. Mirman, G. Nicolas Kaufman, J.R. Patterson, A. Ryd,E. Salvati, L. Skinnari, W. Sun, W.D. Teo,J. Thom, J. Thompson, J. Tucker, Y. Weng, L. Winstrom, P. Wittich

CornellUniversity,Ithaca,USA

D. Winn

FairfieldUniversity,Fairfield,USA

S. Abdullin,M. Albrow, J. Anderson, G. Apollinari, L.A.T. Bauerdick, A. Beretvas, J. Berryhill,P.C. Bhat, K. Burkett, J.N. Butler, H.W.K. Cheung, F. Chlebana,S. Cihangir, V.D. Elvira, I. Fisk,J. Freeman, Y. Gao, E. Gottschalk,L. Gray, D. Green, S. Grünendahl, O. Gutsche, J. Hanlon, D. Hare, R.M. Harris, J. Hirschauer, B. Hooberman, S. Jindariani, M. Johnson,U. Joshi, K. Kaadze, B. Klima, B. Kreis, S. Kwan,J. Linacre, D. Lincoln,R. Lipton, T. Liu, J. Lykken,K. Maeshima, J.M. Marraffino, V.I. Martinez Outschoorn,

S. Maruyama,D. Mason, P. McBride, K. Mishra,S. Mrenna, Y. Musienko29,S. Nahn, C. Newman-Holmes,

V. O’Dell,O. Prokofyev, E. Sexton-Kennedy, S. Sharma,A. Soha, W.J. Spalding, L. Spiegel, L. Taylor, S. Tkaczyk, N.V. Tran,L. Uplegger, E.W. Vaandering, R. Vidal,A. Whitbeck, J. Whitmore, F. Yang

FermiNationalAcceleratorLaboratory,Batavia,USA

D. Acosta, P. Avery, D. Bourilkov,M. Carver, T. Cheng, D. Curry,S. Das, M. De Gruttola, G.P. Di Giovanni, R.D. Field, M. Fisher, I.K. Furic,J. Hugon, J. Konigsberg,A. Korytov, T. Kypreos, J.F. Low,K. Matchev, P. Milenovic51,G. Mitselmakher,L. Muniz, A. Rinkevicius, L. Shchutska,M. Snowball, J. Yelton,M. Zakaria

UniversityofFlorida,Gainesville,USA

S. Hewamanage, S. Linn, P. Markowitz, G. Martinez, J.L. Rodriguez

FloridaInternationalUniversity,Miami,USA

T. Adams,A. Askew, J. Bochenek,B. Diamond, J. Haas, S. Hagopian,V. Hagopian, K.F. Johnson, H. Prosper,

V. Veeraraghavan,M. Weinberg

FloridaStateUniversity,Tallahassee,USA

M.M. Baarmand,M. Hohlmann, H. Kalakhety, F. Yumiceva

FloridaInstituteofTechnology,Melbourne,USA

M.R. Adams,L. Apanasevich, V.E. Bazterra, D. Berry, R.R. Betts, I. Bucinskaite,R. Cavanaugh, O. Evdokimov,L. Gauthier, C.E. Gerber,D.J. Hofman, S. Khalatyan,P. Kurt, D.H. Moon, C. O’Brien, C. Silkworth,P. Turner,N. Varelas

UniversityofIllinoisatChicago(UIC),Chicago,USA

E.A. Albayrak48, B. Bilki52, W. Clarida,K. Dilsiz, F. Duru, M. Haytmyradov, J.-P. Merlo, H. Mermerkaya53, A. Mestvirishvili,A. Moeller, J. Nachtman, H. Ogul, Y. Onel, F. Ozok48,A. Penzo, R. Rahmat, S. Sen,P. Tan, E. Tiras,J. Wetzel, T. Yetkin54,K. Yi

TheUniversityofIowa,IowaCity,USA