Contents lists available atScienceDirect
Physics
Letters
B
www.elsevier.com/locate/physletb
Search
for
a
Higgs
boson
decaying
into
γ
∗
γ
→
γ
with
low
dilepton
mass
in
pp
collisions
at
√
s
=
8 TeV
.CMSCollaboration
CERN, Switzerland
a r t i c l e i n f o a b s t ra c t
Article history:
Received10July2015
Receivedinrevisedform12October2015 Accepted14December2015
Availableonline17December2015 Editor:M.Doser Keywords: CMS Physics Higgsboson Dalitzdecay
A search is described for a Higgs boson decaying into two photons, one of which has an internal conversiontoamuonoranelectronpair(γ).Theanalysisisperformedusingproton–protoncollision datarecordedwiththeCMSdetectorattheLHCatacentre-of-massenergyof8 TeV,correspondingto anintegratedluminosityof19.7 fb−1.Theeventsselectedhaveanopposite-signmuonorelectronpair and ahightransverse momentumphoton.No excessabove backgroundhas beenfound inthe three-bodyinvariant mass range120<mγ <150 GeV,and limits have been derivedfor the Higgsboson
productioncrosssectiontimesbranchingfraction forthedecayH→γ∗γ→ γ,where thedilepton invariantmassislessthan20 GeV.ForaHiggsbosonwithmH=125 GeV,a95%confidencelevel(CL)
exclusionobserved(expected)limitis6.7(5.9+2.8
−1.8)timesthestandardmodelprediction.Additionally,an
upperlimitat95%CLonthebranchingfractionofH→ (J/ψ)γ forthe125 GeVHiggsbosonissetat 1.5×10−3.
©2015CERNforthebenefitoftheCMSCollaboration.PublishedbyElsevierB.V.Thisisanopenaccess articleundertheCCBYlicense(http://creativecommons.org/licenses/by/4.0/).FundedbySCOAP3.
1. Introduction
The raredecay into the γ final state of the Higgsboson is a rich source of information that can enhance our understand-ing of its basic properties and probe novel couplings predicted by extensionsof thestandard model (SM) ofparticle physics. As illustratedinFig. 1,thisdecayinSMhascontributionsfrom loop-inducedH→γ∗γ andH→Zγ diagrams(a, b,c),tree-level pro-cessH→ with final-stateradiation (d),and higher-order pro-cesses,knownasboxdiagrams(e,f,g)[1–4].Other contributions include H→V(qq¯)γ → γ, shown in Fig. 2, where V denotes a vector meson (J/ψ or ϒ) that decays to [5–7]. The Higgs boson branching fraction to γ is dominated by the H→γ∗γ
andH→Zγ modes,whilethecontributionfromtheboxdiagrams isnegligible [1]. Inthe muon channel, whenthe dilepton invari-ant mass, m, is greater than 100 GeV, final-state radiation in
H→μμstartstodominate[8].Inthethree-bodydecay,H→ γ, it is possible to investigate non-SM couplings by examining the angulardistributions, andforward–backwardasymmetry variables reconstructedfromthe γ finalstate[8,9].
TheexpectedratesoftheH→ (Z/γ∗)γ→ γ processes com-paredtothe rateofH→γ γ decay,foraHiggsbosonwithmass mH=125 GeV,are[10,11]:
E-mail address:cms-publication-committee-chair@cern.ch.
(H→γ∗γ→eeγ) (H→γ γ) ∼3.5%, (H→γ∗γ→μμγ) (H→γ γ) ∼1.7%, (H→Zγ→ γ) (H→γ γ) ∼2.3%.
TheH→γ∗γ→eeγ decayisdistinctfromH→γ γ followed byaconversionofaphotontoane+e−pairinthedetector,which canbecomeabackgroundforH→γ∗γ ifphotonconversionsare not properly identified. Experimentally, the various contributions shown inFigs. 1 and 2 can be disentangled to some extent. Re-quirementsonm andthetransversemomentum(pT)ofthe pho-tonareusedtoseparateH→γ∗γ andH→Zγ.Eventswith final-stateradiationareremovedbyrequiringthephotontobeisolated fromeitheroftheleptons.ContributionsfromH→ (J/ψ)γ→ γ
andotherresonancesareidentifiedandrejectedorselectedbased onthevalueofm.
TheATLASandCMSCollaborationsattheCERNLHChaveboth performed a search for H→Zγ → γ decay with m above
50 GeV[12,13].As anaturalextension ofthoseanalyses,the cur-rent paper describes the first search for a Higgs boson Dalitz decay, H→γ∗γ, where the γ∗ decaysinto a muon oran elec-tronpair.The searchisperformedfora Higgs-likeparticlewithin themass rangebetween120and150 GeV.Inorderto selectthe
http://dx.doi.org/10.1016/j.physletb.2015.12.039
0370-2693/©2015CERNforthebenefitoftheCMSCollaboration.PublishedbyElsevierB.V.ThisisanopenaccessarticleundertheCCBYlicense (http://creativecommons.org/licenses/by/4.0/).FundedbySCOAP3.
Fig. 1. DiagramscontributingtoH→ γ.Thecontributionsfromdiagrams(a),(b),and(c)dominate.Thefinal-stateradiationofH→μμdecay,shownindiagram(d),is importantathighdileptoninvariantmass.Higherordercontributionsfromdiagrams(e),(f)and(g)arenegligible.
Fig. 2. Diagrams contributing to H→Vγ→ γ decay.
contribution fromtheDalitz decay,we requirem<20 GeV.The
μμγ topologyisacleanfinalstatewithamassresolutionofabout 1.6%, as measured from the simulated signal samples. The eeγ
channel is challenging dueto the low m that results ina pair
of merged electron showers in the electromagnetic calorimeter (ECAL).Nevertheless,whenthemergedshowersarereconstructed intheECAL,amassresolutionof1.8%isachieved.Important back-groundsincludetheirreduciblecontributionsfromtheinitial- and final-statephotonradiationinDrell–Yanproduction,andDrell–Yan eventswithadditionaljetswhereajet ismisidentified asa pho-ton.
In addition, a search is performed for H→ (J/ψ)γ →μμγ
decay for mH=125 GeV, which is sensitive to the Higgs boson couplingtocharmquark andapromising wayto accessthe cou-plingsof theHiggsbosonto thesecond generationquarksatthe LHC.IntheSMthisdecayoccursthroughtwomainprocesses: di-rectcouplingoftheHiggsbosontocharm(Fig. 2a),andtheusual t/W loop, where the radiated γ∗ converts to a cc in¯ a resonant state(Fig. 2b).Thetwoamplitudesinterferedestructively andthe second one dominates [6,7]. Forthe SM Higgs boson withmH= 125 GeV,the branching fractionis predictedto be 2.8×10−6. A search by the ATLAS Collaboration for thisdecay is described in Ref.[14].
Theresultspresentedinthispaperarebasedonproton–proton collisiondatarecordedin2012withtheCMSdetectorata centre-of-massenergy√s=8 TeV,correspondingto anintegrated lumi-nosityof19.7 fb−1.
2. CMSdetectorandtrigger
AdetaileddescriptionoftheCMSdetector,togetherwitha def-inition of thecoordinatesystemused andtherelevant kinematic variables,canbefoundinRef.[15].ThecentralfeatureoftheCMS apparatusisasuperconductingsolenoid, 13 minlengthand6 m indiameter,whichprovidesanaxialmagneticfieldof3.8 T.Within thesolenoidvolumeareasiliconpixelandstriptracker,theECAL, andahadroncalorimeter(HCAL).Charged-particletrajectoriesare measured bysiliconpixelandstrip trackers,covering0≤ φ ≤2π
inazimuthand|η|<2.5 inpseudorapidity.Aleadtungstatecrystal ECAL surrounds the tracking volume. It is comprised of a bar-rel region|η| <1.48 and two endcaps that extendup to |η| =3. A brass andscintillatorHCALsurroundsECALandalsocovers the region |η| <3.Iron forward calorimeterswithquartz fibers, read out by photomultipliers, extend the calorimetric coverage up to |η|=5. Alead and silicon-strip preshowerdetectoris located in front of the ECAL endcaps. Muons are identified and measured ingas-ionizationdetectorsembeddedinthesteelflux-returnyoke outsidethesolenoid.Thedetectorisnearlyhermetic,allowing en-ergy balance measurements inthe plane transverseto the beam direction.
Atwo-tiertriggersystemselectscollisioneventsofinterestfor physics analysis. Twotriggersare usedin thecurrentanalysis. In themuon channel,thetriggerrequiresa singlemuon anda pho-ton, both with pT greater than 22 GeV. In the electron channel the γ∗→ee process at low dielectron invariant mass mimics a photon at thetrigger level. Forthisreason, adiphoton trigger is usedintheelectronchannel,for γ+γ∗ finalstate.Thetrigger re-quires a leading (subleading)photon with pT>26(18)GeV. The diphoton trigger is inefficientforevents withhigh dielectron in-variantmass(mee>2 GeV)duetotheisolationandshowershape requirements. The available dielectrontriggers cannot be used to selecteventswith2<mee<20 GeV becausetheyalsorequire iso-lation,andthe pT requirementmadeon thesubleadinglepton is toohigh.
3. Eventreconstruction
The photon energy is reconstructed from a sum of signals in the ECAL crystals [16]. The ECAL signals are calibrated and corrected [17], and a multivariate regression technique, devel-oped for the H→γ γ analysis [18], is used to determine the final energy of the photon [16]. The neighboring ECAL crystals withenergy deposition are combined into clusters, and the col-lection of clusters that contain the energy of a photon or an electroniscalledasupercluster. Identificationcriteriaare applied to distinguish photons from jets and electrons. The observables used in the photon identification criteriaare: the isolation vari-ables, the ratio of the energy in the HCAL towers behind the supercluster to the electromagnetic energy in the supercluster; the transverse width in η of the electromagnetic shower; and the number of charged tracks matched to the supercluster. The efficiency of the photon identification is measured using Z→ ee data by reconstructing the electron showers as photons, and found to be 80 (88%) at a transverse energy >30(50)GeV and |η| <1.44.
Muon candidates are reconstructed inthe tracker and identi-fiedbytheparticle-flowglobaleventreconstructionalgorithm[19, 20] using hits in the tracker and the muon systems. This ap-proach allows us to maintain a high efficiency independent of the dimuon invariant mass and to reconstruct muons with pT as low as 4 GeV. Muons from γ∗→μμ internal conversions are expected to be isolated from other particles. A cone of size
R≡(η)2+ (φ)2=0.4 is constructed around the momen-tumdirectionofeachmuon candidate[21]. Therelative isolation of the muon is quantified by summing the pT of all photons, charged and neutral hadrons within this cone, and then divid-ing by the muon pT. The resulting quantity, corrected for addi-tionalunderlying eventactivity dueto pileup events, isrequired to be less than 0.4for the leading muon. The isolation require-ment rejects misidentified leptons and background arising from hadronic jets. The R(μμ) separation between the two muons is small due to their low invariant mass (as shown in Fig. 3) andhigh pT of the γ∗ in H→γ∗γ decays. Hence, no isolation requirement is applied to the subleading muons as they are al-ready within the isolation cone of the leading muons in most events.Dimuonidentificationandisolationefficiencyofabout80% isobtained.
IntheelectronchanneloftheH→γ∗γ→ γ decay,thetwo electronsproducedinthe γ∗→ee processareevenclosertoeach otherthaninthemuonchannel, sincethem issmaller (Fig. 3).
Therefore,theirenergydeposits intheECALaremerged intoone supercluster giving rise to a unique signature. To identify these merged electrons, two tracks associated to the supercluster are required. A Gaussian sum filter (GSF) algorithm is used to re-constructthe electron tracks [22]. The supercluster energy must correspond to pT>30 GeV and be located in the ECAL barrel (|η| <1.44). The scalar sum pe1
T +p
e2
T of thecorresponding two GSFtracks must exceed 44 GeV.Both GSFtracks are required to have no more than one missing hit in the pixel detector in or-der to reduce the background from photons converting to e+e− in the detector material. A multivariate discriminator is trained to separate the γ∗→ee objects from jets or single electrons. The input variables forthe training include lateral shower shape variables,themedianenergydensityintheeventtotake into ac-countthepileupdependence,andthekinematicinformationfrom thesuperclusterandtracks.Acombinedreconstructionand selec-tion efficiency of ∼40% is achieved for the signal. For compari-son,theefficiencyforasingleisolatedelectron withsimilar pT is ∼88%[23].
Fig. 3. Theinvariant massofthedileptonsysteminsignalsimulationfor mH=
125 GeV.Distributionsareshownformuonandelectronchannels,beforeandafter selection.Theinvariantmassbeforeselectionisobtainedfromtheleptonsatthe generatorlevel,whileafterselectionthereconstructedinvariantmassisused.
4. Simulatedsamples
The description of the Higgs boson signal used in the search isobtainedfromsimulatedevents.ThesamplesfortheDalitz sig-nalare producedatleading-orderusingthe MadGraph 5 matrix-elementgenerator[24]withtheANO-HEFTmodel[25],interfaced with pythia 6.426 [26], for the gluon and vector boson fusion processes,andforassociatedproductionwitha vectorboson. As-sociated productionwithat¯t pairisignored becauseofits small contribution. The sample for H→ (J/ψ)γ process is produced with the pythia 8.153 generator [27], and reweighted to simu-late100%polarizationoftheJ/ψ.Thepartondistributionfunction (PDF)setusedtoproducethesesamplesisgivenbyCTEQ6L1[28]. The SM Higgs boson production cross sections are taken from Ref. [11].Thebranching fractionsforH→γ∗γ areestimated us-ing MCFM 6.6 [29] andfor H→ (J/ψ)γ are taken fromRef. [6]. For the SM Higgs boson in the mass range of 120–150 GeV, the H→γ∗γ →μμγ(eeγ) branching fraction is expected to be between 2.0(4.5) ×10−5 and 3.3(7.5) ×10−5 for m
be-low 20 GeV. The expectedbranching fractionfor H→ (J/ψ)γ is
(2.8±0.2) ×10−6 form
H=125 GeV,whichisfurthersuppressed duetotheJ/ψmesondecaytomuons, B(J/ψ→μμ) =0.059.
Thesimulationaimstoincludeallknowneffectsandthe condi-tionsofrealdatatakinginCMS.Someresidualdifferencesbetween the data and simulation are taken into account by reweighting the simulated events with scale factors. Systematic uncertainties areassignedtocoverimperfect knowledgeofresidualdifferences. Scalefactorsareimplementedtomatchthedistributionofprimary vertices,thephotonidentificationandisolation efficiency,andthe muonisolation efficiency.Nocorrectionsareappliedtothemuon and electron identificationand trigger efficiencies, but an uncer-taintyisassignedasdescribedinSection7.
Theenergyandmomentumresolutionofmuonsandphotonsin simulatedeventsare correctedto matchthatindata.The energy scaleofmuons(photons)iscorrectedtothatfoundinZ→μμ(ee)
events. For the electrons, no resolution or scale corrections are applied because of their unique topology, and the absence of a data-drivenmethodtoderivethosecorrections.Therefore,werely on the simulation ofthe γ∗→ee processand assign uncertain-ties sufficientto cover anypossible discrepancy inthe scale and resolutionbetweendataandsimulation.
Table 1
Theexpectedsignalyieldandthenumberofeventsindata,foranintegratedluminosityof19.7 fb−1.Signaleventsarepresentedbeforeandafterapplyingthefullselection
criteriadescribedinthetext.Inthe(J/ψ)γ sub-categoryonlytheJ/ψ→μμdecayisconsidered,andthesignalyieldisasumoftwocontributions:H→ (J/ψ)γ→μμγ andH→γ∗γ→μμγ,wherethedimuonmassdistributionisnon-resonant.
Sample Signal events before selection Signal events after selection Number of events in data
mH=125 GeV mH=125 GeV 120<mγ<130 GeV
μμγ 13.9 3.3 151
eeγ 25.8 1.9 65
(J/ψ→μμ)γ 0.065(J/ψ)+0.32 (non-res.) 0.014(J/ψ)+0.078 (non-res.) 12
5. Eventselection
Events are required to pass the muon plus photon trigger in the μμγ final state andthe diphoton triggers in the eeγ final state.Thetriggerefficiencyforsignaleventsaftertheselection re-quirementsdescribed below is85% (90%) in themuon (electron) channel,asmeasuredfromthesimulatedsamples.
Themuons(electrons)arerequiredtobewithin|η| <2.4(1.44), while the photon is required to be within |η| <1.44. The in-variant mass of the γ system, mγ , is required to satisfy 110 <mγ <170 GeV. The photon and dilepton momenta both must satisfy pT>0.3·mγ requirement, whichis optimized for highsignalefficiencyandbackgroundrejection.
Onaverage,thereare21ppinteractionswithinthesamebunch crossing in the 8 TeV data, which result in about 16 collision verticesreconstructed ineach event. Thevertexwiththe highest scalarsumofthep2T ofitsassociatedtracksistakentocorrespond to the primary interaction vertex. The primary vertexmust have thereconstructedlongitudinalposition(z)within24 cmofthe ge-ometric centreof the detector andthe transverse position (x– y) within2 cmofthebeaminteractionregion.Theleptontracksfrom
γ∗→μμ (ee)arerequiredto originatefromtheprimary vertex, andto havetransverse andlongitudinal impact parameters with respecttothatvertexsmallerthan2.0(0.2)mm and5(1)mm, re-spectively.
The muons must be oppositely charged, and have pT >
23(4)GeV for the leading (subleading) lepton. The pT require-mentontheleadingmuonisdrivenby thetriggerthreshold,and onthesubleadingmuonbytheminimumenergyneededtoreach themuonsystem,whilemaintaininghighreconstructionefficiency. Inthe electronchannel, noadditionalselection on pT ofthe GSF tracks is necessary, beyond those described in Section 3. Finally, inbothmuonandelectronchannels,theseparationbetweeneach lepton andthe photon is requiredto satisfy R >1 in orderto suppressDrell–Yanbackgroundeventswithfinal-stateradiation.
Thedileptoninvariantmassinthemuonchannelisrequiredto belessthan20 GeVtorejectcontributions frompp→γZ andto suppressinterferenceeffectsfromtheH→γZ processandthebox diagramsshowninFig. 1.Eventswithadimuonmassintheranges 2.9 <mμμ<3.3 GeV and 9.3 <mμμ<9.7 GeV are rejected to avoidtheJ/ψ→μμand ϒ→μμcontamination.Intheelectron channelthe invariantmass,constructed fromthe twoGSFtracks, isrequiredtosatisfymee<1.5 GeV.Them distributionsfor
sim-ulatedsignaleventsareshowninFig. 3inthemuonandelectron channels.
In the search for the H→ (J/ψ)γ →μμγ, both pγT and pμμT >40 GeV are required, and the events are selected with 2.9 <mμμ<3.3 GeV.
The observed yields after theevent selection described above arelisted inTable 1.Inthe electronchannel, thereisalsoa con-tribution from the H→γ γ process due to unidentified conver-sions, which isabout 15% of the H→γ∗γ signal (0.2 events at mH=125 GeV).Thiscontributionisconsideredasabackgroundto H→γ∗γ,andnegligiblecomparedtothecontinuum background estimatedfromthefittodatadescribedinthenextsection.
Fig. 4. The mμμγ(top)and meeγ (bottom)spectrafor8 TeVdata(pointswitherror
bars),togetherwiththeresultofabackground-onlyfittothedata.The1σ and2σ uncertaintybandsrepresenttheuncertaintyintheparametersofthefittedfunction. Theexpectedcontributionfromthe SMHiggsboson signalwith mH=125 GeV,
scaledupbyafactorof 10,isshownasahistogram.
6. Backgroundandsignalmodeling
Thebackgroundismodeledbyfittingapolynomial functionto the γ massdistributionsindata.Anunbinnedmaximum likeli-hoodfitisperformedovertherange110 <mγ<170 GeV.Fig. 4 shows the mγ spectra, which are fitted withpolynomial func-tions offourthdegree.Thereduced χ2 ofthefits are0.5and0.7 forthemuonandelectronchannels,respectively.Eventhoughthe searchislimitedto120 <mH<150 GeV,thefitstothemγ spec-tra areperformedoverawiderrange,givingabettermodelingof thebackground,particularlyattheedgesofthesearchrange.The degree of the polynomialsis chosen following a procedure simi-larto theone described inRef.[30].Thisprocedure ensures that thepotential biasdueto thebackgroundmodeling isatleastfive timessmallerthanstatisticaluncertainty.
FortheH→ (J/ψ)γ search,whereonlythesingleHiggsboson mass hypothesismH=125 GeV is investigated, afit toa polyno-mial of second degree is performedover the110–150 GeV mass range(Fig. 5).
Fig. 5. The mμμγdistributionforeventswith2.9<mμμ<3.3 GeV for8 TeVdata (pointswitherrorbars),togetherwiththeresultofabackground-onlyfit tothe data.The1σand2σuncertaintybandsrepresenttheuncertaintyintheparameters ofthe fittedfunction.Theexpectedcontributionfromthe H→ (J/ψ)γ→μμγ processoftheSMHwith mH=125 GeV,scaledupbyafactorof 500,isshownas
ahistogram.
Table 2
Systematicuncertaintiesaffectingthesignal.
Source Uncertainty
Integrated luminosity (Ref.[37]) 2.6% Theoretical uncertainties: PDF 2.6–7.5% Scale 0.2–7.9% H→γ∗γ→ γbranching fraction 10% Experimental uncertainties: Pileup reweighting 0.8%
Trigger efficiency,μ(e) channel 4 (2)%
Muon reconstruction efficiency 11%
Electron reconstruction efficiency 3.5%
Photon reconstruction efficiency 0.6%
mγ scale,μ(e) channel 0.1 (0.5)%
mγ resolution,μ(e) channel 10 (10)%
The signal model in all three cases is obtained from an un-binned fit to the mass distribution of the corresponding sample ofsimulatedeventstoaCrystalBallfunction[31]plusaGaussian function.
7.Results
The data are used to derive upper limitson the Higgs boson crosssectiontimesbranchingfraction, σ(pp→H) B(H→γ∗γ →
γ) divided by that expected fora SM Higgs boson, for m<
20 GeV.Nosignificantexcessabovebackgroundisobservedinthe fullmassrange,120 <mH<150 GeV,witha maximumexcessof lessthantwo standard deviations. Inthe electron channel a cor-rectionismadetoaccountfortheeventsthatareremovedbythe requirementofmee<1.5 GeV due to thetrigger and reconstruc-tioninefficienciesdescribedabove.
Theexclusionlimitsarecalculatedusingthemodified frequen-tistCLsmethod[32–36].Anunbinnedevaluationoverthefullmass rangeofdataisused.Theuncertaintyinthelimitisdominatedby the size of the data sample and systematicuncertainties have a smallimpact.
Thesystematicuncertainty inthe limitsresultsonly fromthe uncertaintyinthesignaldescription,asthebackgroundisobtained fromdataandbiasesinthefittingprocedurehavebeenfound to benegligible.Asummary ofthesystematicuncertainties isgiven inTable 2.The uncertaintycanbe separatedintotheuncertainty resultingfromtheoreticalpredictionsandfromtheuncertaintyin detectorreconstructionandselectionefficiency.
Fig. 6. The95%CLexclusion limit,asafunctionofthe masshypothesis, mH,on
σ/σS M,thecrosssectiontimesthebranchingfractionofaHiggsbosondecaying
intoaphotonandaleptonpairwith m<20 GeV,dividedbytheSMvalue.(Top)
muon,(middle)electronchannels, (bottom)statisticalcombinationoftheresultsin thetwochannels.
Theoretical uncertainties come from the effects of the PDF choice on signal cross section, the missing higher-order calcula-tions (scale) [38–42], and the uncertainty in the prediction on the Higgsboson decay branching fraction[4,11]. The uncertainty dueto the muon reconstruction efficiency,11%, is obtainedfrom data using J/ψ→μμ events. It is dominated by the statistical uncertainty ofthe data sample. In theelectron channel, the cor-respondinguncertainty,3.5%,isobtainedfromsimulation.The11% uncertaintyestimatedforthemuonidentificationefficiencyis suf-ficientlysmallandit hasnoimpact onour result,thus no simu-lation studywas attempted, although itcould greatly reduce the uncertainty.
Theexpectedandobservedindividualandcombined μμγ and eeγ limitsareshowninFig. 6.Thelimitsare calculatedat1 GeV
Fig. 7. The95%CLexclusionlimitonσ(pp→H)B(H→μμγ),with mμμ<20 GeV,
foraHiggs-likeparticle,asafunctionofthemasshypothesis, mH.
intervals in the 120–150 GeV mass range.The median expected exclusionlimitsat95%confidencelevel(CL)arebetween6and10 times the SM prediction and the observed limit ranges between about5 and11 timesthe SM. The observed (expected) limit for mH=125 GeV is6.7(5.9+−21..88)timestheSMprediction.
The 95% CL exclusion limits on σ(pp→H) B(H→μμγ) for a narrow scalar particle without assuming the decay kinematics ofa SM Higgsboson, inthe muon channel, are shownin Fig. 7. Theobserved(expected)limitformH=125 GeV is7.3(5.2+−21..46) fb. The total signal efficiency is 24% andalmost independentof the dimuoninvariantmass.Intheelectronchannel,however,this effi-ciencydependsonthedielectronmass,sinceitisstronglyshaped by the selection. For this reason the corresponding limit in the electronchannelisnotevaluated.
Additionally, forthe SM Higgsboson withmH=125 GeV, we placeanupperlimitfora2.9 <m<3.3 GeV regioninthemuon
channel: σ(pp→H) B(H→μμγ) <1.80 fb, while the expected limit is 1.90±0.97 fb. One can interpret thisresultasan upper limit on σ(pp→H) B(H→ (J/ψ)γ →μμγ) and obtain for the branchingfraction, B(H→ (J/ψ)γ) <1.5×10−3 at95%CL,which is about 540 times the prediction in Ref. [6]. The limit on the branchingfractionat90%CL is B(H→ (J/ψ)γ) <1.2×10−3.The numberofeventspresentinthismμμ masswindowcomingfrom the H→γ∗γ →μμγ is large compared to the H→ (J/ψ)γ → μμγ (as shownin Table 1). On theother handit issmall com-paredtothetotalbackground,henceitisconsidered asa partof thebackgroundwhenextractingthelimiton B(H→ (J/ψ)γ).
8. Summary
AsearchforaHiggsbosondecayH→γ∗γ → γ ispresented. Noexcessabovethebackgroundpredictionshasbeenfoundinthe three-bodyinvariantmassrange120<mγ<150 GeV.Limitson theHiggs bosonproduction crosssection timesthe H→γ∗γ →
γ branching fraction divided by the SM values have been de-rived.TheobservedlimitformH=125 GeV isabout6.7timesthe SMprediction.Limitsat95%CLon σ(pp→H) B(H→μμγ)fora narrowresonancearealsoobtainedinthemuonchannel.The ob-servedlimitformH=125 GeV is7.3 fb.Eventsconsistentwiththe J/ψ in dimuoninvariant mass are usedto set a 95% CLlimit on thebranching fraction B(H→ (J/ψ)γ) <1.5×10−3,that is, 540 timestheSMpredictionformH=125 GeV.
Acknowledgements
WecongratulateourcolleaguesintheCERNaccelerator depart-ments for the excellent performance of the LHC and thank the
technical andadministrativestaffs atCERNand atother CMS in-stitutes for their contributions to the success of the CMS effort. Inaddition,wegratefullyacknowledgethecomputingcentresand personneloftheWorldwideLHCComputingGridfordeliveringso effectively thecomputinginfrastructure essentialto our analyses. Finally, we acknowledge the enduring support for the construc-tion andoperationofthe 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 andCNRS/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 of Korea); 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);TUBITAK andTAEK (Turkey);NASU andSFFR (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 MinistryofEducation, Youth andSports(MEYS) of theCzechRepublic;theCouncilofScienceandIndustrialResearch, India;theHOMING PLUSprogrammeoftheFoundationforPolish Science, cofinanced from European Union, Regional Development Fund; theCompagniadi SanPaolo (Torino);the Consorzioper la Fisica (Trieste); MIURproject20108T4XTM (Italy); theThalisand Aristeia programmes cofinanced by EU-ESF and the Greek NSRF; theNationalPrioritiesResearchProgrammeby QatarNational Re-search Fund;theRachadapisekSompot Fund forPostdoctoral Fel-lowship,ChulalongkornUniversity(Thailand);andtheWelch Foun-dation.
References
[1] A. Abbasabadi, D. Bowser-Chao, D.A. Dicus, W.W. Repko, Radiative Higgs boson decays H→ f fγ, Phys. Rev. D 55 (1997) 5647, http://dx.doi.org/ 10.1103/PhysRevD.55.5647,arXiv:hep-ph/9611209.
[2] L.B.Chen,C.F.Qiao,R.L. Zhu,Reconstructingthe 125 GeVSM Higgsboson through ¯γ,Phys.Lett.B726(2013)306,http://dx.doi.org/10.1016/j.physletb. 2013.08.050,arXiv:1211.6058.
[3] D.A.Dicus, W.W.Repko,CalculationofthedecayH→eeγ¯ ,Phys.Rev.D87 (2013)077301,http://dx.doi.org/10.1103/PhysRevD.87.077301,arXiv:1302.2159. [4] G.Passarino,Higgsbosonproductionanddecay:Dalitzsector,Phys.Lett.B727 (2013)424,http://dx.doi.org/10.1016/j.physletb.2013.10.052,arXiv:1308.0422. [5] G.T.Bodwin,F.Petriello,S.Stoynev,M.Velasco,Higgsbosondecaysto
quarko-niaand theHcc coupling, ¯ Phys.Rev.D88(2013)053003,http://dx.doi.org/ 10.1103/PhysRevD.88.053003,arXiv:1306.5770.
[6] G.T.Bodwin,H.S.Chung,J.-H.Ee,J.Lee,F.Petriello,Relativisticcorrectionsto Higgsbosondecaystoquarkonia,Phys.Rev.D90(2014)1130,http://doi.org/ 10.1103/PhysRevD.90.113010,arXiv:1407.6695.
[7] M. König,M. Neubert, Exclusive radiative higgs decays as probesof light-quarkYukawa couplings,J. HighEnergyPhys.08(2015)012,http://doi.org/ 10.1007/JHEP08(2015)012,arXiv:1505.03870.
[8] Y. Sun,H. Chang, D. Gao, Higgsdecays to γ+− in the standard model, J. HighEnergyPhys.05(2013)061,http://dx.doi.org/10.1007/JHEP05(2013)061, arXiv:1303.2230.
[9] A.Korchin, V.Kovalchuk, Angulardistributionand forward–backward asym-metryofthehiggs-bosondecaytophotonandleptonpair,Eur.Phys.J.C74 (2014),http://dx.doi.org/10.1140/epjc/s10052-014-3141-7,arXiv:1408.0342.
[10] A.Firan,R.Stroynowski,InternalconversionsinHiggsdecaystotwophotons, Phys.Rev.D76(2007)057301,http://dx.doi.org/10.1103/PhysRevD.76.057301, arXiv:0704.3987.
[11] S.Heinemeyer,etal.,HandbookofLHCHiggscrosssections:3.Higgs prop-erties, CERN Report CERN-2013-004, 2013, http://dx.doi.org/10.5170/CERN-2013-004,arXiv:1307.1347.
[12] ATLASCollaboration,SearchforHiggsbosondecaystoaphotonandaZboson inppcollisionsat√s=7 and 8 TeV withtheATLASdetector,Phys.Lett.B732 (2014)8,http://dx.doi.org/10.1016/j.physletb.2014.03.015,arXiv:1402.3051. [13] CMSCollaboration,Searchfor aHiggsbosondecaying intoaZ anda
pho-ton in pp collisions at √s=7 and 8 TeV, Phys. Lett. B 726 (2013) 587,
http://dx.doi.org/10.1016/j.physletb.2013.09.057,arXiv:1307.5515.
[14] ATLASCollaboration,SearchforHiggsandZbosondecaystoJ/ψγandϒ(nS)γ withtheATLASdetector,Phys.Rev.Lett.114(2015)121801,http://dx.doi.org/ 10.1103/PhysRevLett.114.121801,arXiv:1501.03276.
[15] CMSCollaboration,TheCMSexperimentattheCERNLHC,J.Instrum.3(2008) S08004,http://dx.doi.org/10.1088/1748-0221/3/08/S08004.
[16] CMSCollaboration, Performanceofphoton reconstruction and identification with the CMS detector in proton–proton collisions at √s=8 TeV, J. In-strum. 10(2015) P08010,http://dx.doi.org/10.1088/1748-0221/10/08/P08010, arXiv:1502.02702.
[17] CMSCollaboration,EnergycalibrationandresolutionoftheCMS electromag-neticcalorimeterinppcollisionsat√s=7 TeV,J.Instrum.8(2013)P09009,
http://dx.doi.org/10.1088/1748-0221/8/09/P09009,arXiv:1306.2016.
[18] CMS Collaboration, Observation of the diphoton decay of the Higgs bo-son and measurement of its properties, Eur. Phys. J. C 74 (2014) 3076,
http://dx.doi.org/10.1140/epjc/s10052-014-3076-z,arXiv:1407.0558.
[19] CMSCollaboration,Particle-floweventreconstructioninCMSandperformance forjets,taus,and Emiss
T ,CMSPhysicsAnalysisSummaryCMS-PAS-PFT-09-001,
CERN,2009,http://cdsweb.cern.ch/record/1194487.
[20] CMSCollaboration,Commissioningoftheparticle–flow eventreconstruction withthefirstLHCcollisionsrecordedintheCMSdetector,CMSPhysics Anal-ysis Summary CMS-PAS-PFT-10-001, CERN, 2010, https://cds.cern.ch/record/ 1247373.
[21] CMSCollaboration,PerformanceofCMSmuonreconstructioninppcollision eventsat√s=7 TeV,J.Instrum.7(2012)P10002,http://dx.doi.org/10.1088/ 1748-0221/7/10/P10002,arXiv:1206.4071.
[22] W.Adam,R.Frühwirth,A.Strandlie,T.Todor,Reconstructionofelectronswith theGaussian-sumfilterintheCMStrackerattheLHC,TechnicalReport CMS-NOTE-2005-001,CERN,2005,http://cds.cern.ch/record/815410.
[23] CMS Collaboration, Performance of electron reconstruction and selection with the CMS detector in proton–proton collisions at √s=8 TeV, J. In-strum. 10(2015) P06005,http://dx.doi.org/10.1088/1748-0221/10/06/P06005, arXiv:1502.02701.
[24] J.Alwall,M.Herquet,F.Maltoni,O.Mattelaer,T.Stelzer,MadGraph5:going beyond,J.HighEnergyPhys.06(2011)128,http://dx.doi.org/10.1007/JHEP06 (2011)128,arXiv:1106.0522.
[25] T. Corbett, O.J.P. Éboli, J. Gonzalez-Fraile, M.C. Gonzalez-Garcia, Constrain-ing anomalous higgs boson interactions, Phys. Rev. D 86 (2012) 075013,
http://dx.doi.org/10.1103/PhysRevD.86.075013,arXiv:1207.1344.
[26] T.Sjöstrand,S.Mrenna,P.Z.Skands,PYTHIA 6.4physicsandmanual,J.High EnergyPhys.05(2006)026,http://dx.doi.org/10.1088/1126-6708/2006/05/026,
arXiv:hep-ph/0603175.
[27] T.Sjöstrand,S.Mrenna,P.Z.Skands,AbriefintroductiontoPYTHIA8.1,Comput. Phys. Commun. 178 (2008) 852, http://dx.doi.org/10.1016/j.cpc.2008.01.036, arXiv:0710.3820.
[28] J. Pumplin, D.R. Stump, J. Huston,H.-L. Lai, P. Nadolsky, W.-K. Tung, New generationofpartondistributionswithuncertaintiesfromglobalQCD analy-sis,J.HighEnergyPhys.07(2002)012,http://dx.doi.org/10.1088/1126-6708/ 2002/07/012,arXiv:hep-ph/0201195.
[29] J.M.Campbell,R.Ellis,MCFMfortheTevatronandtheLHC,Nucl.Phys.Proc. Suppl.205–206(2010)10,http://dx.doi.org/10.1016/j.nuclphysbps.2010.08.011, arXiv:1007.3492.
[30] CMS Collaboration, Observation of anew boson with mass near125 GeV in pp collisions at √s=7 and 8 TeV, J.High Energy Phys. 06 (2013) 081,
http://dx.doi.org/10.1007/JHEP06(2013)081,arXiv:1303.4571.
[31] M.J.Oreglia,Astudyofthereactionsψ→γ γψ,PhDthesis,Stanford Univer-sity,1980,http://www.slac.stanford.edu/pubs/slacreports/slac-r-236.html,SLAC ReportSLAC-R-236,seeAppendixD.
[32] A.L.Read,Presentationofsearchresults:theCLstechnique,J.Phys.G28(2002)
2693,http://dx.doi.org/10.1088/0954-3899/28/10/313.
[33] T.Junk,Confidencelevelcomputationforcombiningsearcheswithsmall statis-tics, Nucl.Instrum.Meth.,Sect.A434(1999)435,http://dx.doi.org/10.1016/ S0168-9002(99)00498-2,arXiv:hep-ex/9902006.
[34] ATLAS and CMSCollaborations, Procedure for the LHCHiggsboson search combinationinsummer2011,TechnicalReportATL-PHYS-PUB-2011-011, CMS-NOTE-2011/005,CERN,2011,https://cds.cern.ch/record/1375842.
[35] G.Cowan,K.Cranmer,E.Gross,O.Vitells,Asymptoticformulaefor likelihood-based testsofnewphysics,Eur.Phys.J.C71(2011)1554,http://dx.doi.org/ 10.1140/epjc/s10052-011-1554-0,arXiv:1007.1727.
[36] L.Moneta,K.Belasco,K.Cranmer,A.Lazzaro,D.Piparo,G.Schott,W. Verk-erke,M.Wolf,TheRooStatsProject,in:13thInternationalWorkshopon Ad-vanced Computingand Analysis TechniquesinPhysics Research,ACAT2010, SISSA,2010,http://pos.sissa.it/archive/conferences/093/057/ACAT2010_057.pdf, arXiv:1009.1003.
[37] CMSCollaboration,CMSluminositybasedonpixelclustercounting,Summer 2013 update, CMS Physics Analysis SummaryCMS-PAS-LUM-13-001, CERN, 2013,https://cds.cern.ch/record/1598864.
[38] A.D. Martin,W.J. Stirling,R.S. Thorne, G.Watt, Partondistributionsfor the LHC,Eur.Phys.J.C63(2009)189, http://dx.doi.org/10.1140/epjc/s10052-009-1072-5,arXiv:0901.0002.
[39] H. Lai, M. Guzzi, J. Huston, Z. Li, P.M. Nadolsky, J. Pumplin, C.-P. Yuan, Newpartondistributionsforcolliderphysics,Phys.Rev.D82(2010)74024,
http://dx.doi.org/10.1103/PhysRevD.82.074024,arXiv:1007.2241.
[40]S.Alekhin,etal.,ThePDF4LHCWorkingGroupInterimReport,arXiv:1101.0536, 2011.
[41]M. Botje,J.Butterworth, A.Cooper-Sarkar,A.deRoeck,J. Feltesse,S.Forte, A. Glazov,J.Huston,R.McNulty,T.Sjöstrand,R.S.Thorne,ThePDF4LHC Work-ingGroupInterimRecommendations,arXiv:1101.0538,2011.
[42] R.D.Ball,V.Bertone,F.Cerutti,L. DelDebbio, S.Forte,A. Guffanti,J.I. La-torre,J.Rojo,M.Ubiali,NNPDFCollaboration,Impactofheavyquarkmasses onpartondistributionsandLHCphenomenology,Nucl.Phys.B849(2011)296,
http://dx.doi.org/10.1016/j.nuclphysb.2011.03.021,arXiv:1101.1300.
CMSCollaboration
V. Khachatryan,A.M. Sirunyan, A. Tumasyan
Yerevan Physics Institute, Yerevan, Armenia
W. Adam, E. Asilar,T. Bergauer, J. Brandstetter, E. Brondolin, M. Dragicevic, J. Erö,M. Flechl, M. Friedl, R. Frühwirth1, V.M. Ghete, C. Hartl, N. Hörmann, J. Hrubec,M. Jeitler1,V. Knünz, A. König,
M. Krammer1, I. Krätschmer,D. Liko, T. Matsushita,I. Mikulec, D. Rabady2,B. Rahbaran, H. Rohringer, J. Schieck1, R. Schöfbeck, J. Strauss, W. Treberer-Treberspurg,W. Waltenberger, C.-E. Wulz1
Institut für Hochenergiephysik der OeAW, Wien, Austria
V. Mossolov,N. Shumeiko,J. Suarez Gonzalez
National Centre for Particle and High Energy Physics, Minsk, Belarus
R. Rougny, M. Van De Klundert,H. Van Haevermaet, P. Van Mechelen, N. Van Remortel,A. Van Spilbeeck
Universiteit Antwerpen, Antwerpen, Belgium
S. Abu Zeid,F. Blekman, J. D’Hondt, N. Daci, I. De Bruyn, K. Deroover, N. Heracleous,J. Keaveney, S. Lowette,L. Moreels, A. Olbrechts,Q. Python, D. Strom, S. Tavernier, W. Van Doninck, P. Van Mulders, G.P. Van Onsem,I. Van Parijs
Vrije Universiteit Brussel, Brussel, Belgium
P. Barria, C. Caillol, B. Clerbaux, G. De Lentdecker, H. Delannoy, D. Dobur, G. Fasanella, L. Favart, A.P.R. Gay, A. Grebenyuk,T. Lenzi, A. Léonard,T. Maerschalk,A. Marinov, L. Perniè, A. Randle-conde, T. Reis,T. Seva, C. Vander Velde, P. Vanlaer, R. Yonamine,F. Zenoni, F. Zhang3
Université Libre de Bruxelles, Bruxelles, Belgium
K. Beernaert,L. Benucci, A. Cimmino, S. Crucy, A. Fagot,G. Garcia, M. Gul, J. Mccartin, A.A. Ocampo Rios, D. Poyraz, D. Ryckbosch,S. Salva, M. Sigamani, N. Strobbe, M. Tytgat,W. Van Driessche, E. Yazgan, N. Zaganidis
Ghent University, Ghent, Belgium
S. Basegmez, C. Beluffi4,O. Bondu,S. Brochet, G. Bruno, R. Castello, A. Caudron, L. Ceard,
G.G. Da Silveira,C. Delaere, D. Favart,L. Forthomme,A. Giammanco5,J. Hollar, A. Jafari,P. Jez,M. Komm, V. Lemaitre, A. Mertens, C. Nuttens, L. Perrini, A. Pin, K. Piotrzkowski,A. Popov6,L. Quertenmont,
M. Selvaggi,M. Vidal Marono
Université Catholique de Louvain, Louvain-la-Neuve, Belgium
N. Beliy, G.H. Hammad
Université de Mons, Mons, Belgium
W.L. Aldá Júnior, G.A. Alves,L. Brito, M. Correa Martins Junior,T. Dos Reis Martins, C. Hensel, C. Mora Herrera,A. Moraes, M.E. Pol,P. Rebello Teles
Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil
E. Belchior Batista Das Chagas, W. Carvalho,J. Chinellato7,A. Custódio, E.M. Da Costa,
D. De Jesus Damiao,C. De Oliveira Martins, S. Fonseca De Souza, L.M. Huertas Guativa, H. Malbouisson, D. Matos Figueiredo, L. Mundim,H. Nogima, W.L. Prado Da Silva, A. Santoro, A. Sznajder,
E.J. Tonelli Manganote7,A. Vilela Pereira
Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
S. Ahujaa, C.A. Bernardesb, A. De Souza Santosb,S. Dograa, T.R. Fernandez Perez Tomeia,
E.M. Gregoresb, P.G. Mercadanteb,C.S. Moona,8,S.F. Novaesa,Sandra S. Padulaa,D. Romero Abad, J.C. Ruiz Vargas
aUniversidade Estadual Paulista, São Paulo, Brazil bUniversidade Federal do ABC, São Paulo, Brazil
A. Aleksandrov, V. Genchev†, R. Hadjiiska,P. Iaydjiev, S. Piperov,M. Rodozov, S. Stoykova, G. Sultanov, M. Vutova
Institute for Nuclear Research and Nuclear Energy, Sofia, Bulgaria
A. Dimitrov, I. Glushkov,L. Litov, B. Pavlov,P. Petkov
University of Sofia, Sofia, Bulgaria
S.M. Shaheen,J. Tao, C. Wang, Z. Wang, H. Zhang
Institute of High Energy Physics, Beijing, China
C. Asawatangtrakuldee, Y. Ban,Q. Li, S. Liu, Y. Mao,S.J. Qian, D. Wang, Z. Xu,W. Zou
State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, China
C. Avila,A. Cabrera, L.F. Chaparro Sierra, C. Florez,J.P. Gomez, B. Gomez Moreno, J.C. Sanabria
Universidad de Los Andes, Bogota, Colombia
N. Godinovic, D. Lelas,D. Polic, I. Puljak
University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, Split, Croatia
Z. Antunovic,M. Kovac
University of Split, Faculty of Science, Split, Croatia
V. Brigljevic,K. Kadija, J. Luetic,S. Micanovic, L. Sudic
Institute Rudjer Boskovic, Zagreb, Croatia
A. Attikis, G. Mavromanolakis,J. Mousa, C. Nicolaou, F. Ptochos,P.A. Razis, H. Rykaczewski
University of Cyprus, Nicosia, Cyprus
M. Bodlak,M. Finger10, M. Finger Jr.10
Charles University, Prague, Czech Republic
R. Aly11, S. Aly11,E. El-khateeb12, A. Lotfy13,A. Mohamed14,A. Radi15,12, E. Salama12,15,A. Sayed12,15
Academy of Scientific Research and Technology of the Arab Republic of Egypt, Egyptian Network of High Energy Physics, Cairo, Egypt
B. Calpas,M. Kadastik, M. Murumaa, M. Raidal, A. Tiko,C. Veelken
National Institute of Chemical Physics and Biophysics, Tallinn, Estonia
P. Eerola,J. Pekkanen, M. Voutilainen
Department of Physics, University of Helsinki, Helsinki, Finland
J. Härkönen,V. Karimäki, R. Kinnunen, T. Lampén, K. Lassila-Perini,S. Lehti, T. Lindén,P. Luukka, T. Mäenpää,T. Peltola, E. Tuominen, J. Tuominiemi, E. Tuovinen,L. Wendland
Helsinki Institute of Physics, Helsinki, Finland
J. Talvitie,T. Tuuva
Lappeenranta University of Technology, 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, M. Machet,J. Malcles, J. Rander, A. Rosowsky,M. Titov, A. Zghiche
DSM/IRFU, CEA/Saclay, Gif-sur-Yvette, France
I. Antropov,S. Baffioni, F. Beaudette, P. Busson, L. Cadamuro, E. Chapon,C. Charlot,T. Dahms, O. Davignon,N. Filipovic, A. Florent, R. Granier de Cassagnac,S. Lisniak, L. Mastrolorenzo, P. Miné, I.N. Naranjo,M. Nguyen, C. Ochando, G. Ortona, P. Paganini,S. Regnard, R. Salerno, J.B. Sauvan, Y. Sirois, T. Strebler, Y. Yilmaz,A. Zabi
J.-L. Agram16, J. Andrea, A. Aubin, D. Bloch,J.-M. Brom, M. Buttignol,E.C. Chabert, N. Chanon, C. Collard, E. Conte16, X. Coubez, J.-C. Fontaine16,D. Gelé, U. Goerlach,C. Goetzmann, A.-C. Le Bihan, J.A. Merlin2, K. Skovpen, P. Van Hove
Institut Pluridisciplinaire Hubert Curien, Université de Strasbourg, Université de Haute Alsace Mulhouse, CNRS/IN2P3, Strasbourg, France
S. Gadrat
Centre de Calcul de l’Institut National de Physique Nucleaire et de Physique des Particules, CNRS/IN2P3, Villeurbanne, France
S. Beauceron,C. Bernet, G. Boudoul, E. Bouvier, C.A. Carrillo Montoya, J. Chasserat, R. Chierici, D. Contardo, B. Courbon, P. Depasse, H. El Mamouni, J. Fan, J. Fay, S. Gascon, M. Gouzevitch, B. Ille, I.B. Laktineh,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
Université de Lyon, Université Claude Bernard Lyon 1, CNRS-IN2P3, Institut de Physique Nucléaire de Lyon, Villeurbanne, France
T. Toriashvili17
Georgian Technical University, Tbilisi, Georgia
Z. Tsamalaidze10
Institute of High Energy Physics and Informatization, Tbilisi State University, Tbilisi, Georgia
C. Autermann, S. Beranek,M. Edelhoff,L. Feld, A. Heister, M.K. Kiesel, K. Klein, M. Lipinski, A. Ostapchuk, M. Preuten,F. Raupach, J. Sammet,S. Schael, J.F. Schulte, T. Verlage,H. Weber, B. Wittmer, V. Zhukov6
RWTH Aachen University, I. Physikalisches Institut, Aachen, Germany
M. Ata, M. Brodski,E. Dietz-Laursonn, D. Duchardt, M. Endres, M. Erdmann,S. Erdweg, T. Esch, 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, T. Pook,M. Radziej, H. Reithler,M. Rieger, F. Scheuch,L. Sonnenschein, D. Teyssier, S. Thüer
RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany
V. Cherepanov, Y. Erdogan,G. Flügge, H. Geenen, M. Geisler, F. Hoehle, B. Kargoll, T. Kress, Y. Kuessel, A. Künsken, J. Lingemann2,A. Nehrkorn, A. Nowack,I.M. Nugent,C. Pistone, O. Pooth,A. Stahl
RWTH Aachen University, III. Physikalisches Institut B, Aachen, Germany
M. Aldaya Martin,I. Asin, N. Bartosik, O. Behnke, U. Behrens,A.J. Bell, 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,E. Gallo, J. Garay Garcia, A. Geiser, A. Gizhko,
P. Gunnellini, J. Hauk, M. Hempel18, H. Jung,A. Kalogeropoulos, O. Karacheban18, M. Kasemann, P. Katsas, J. Kieseler, C. Kleinwort,I. Korol, W. Lange, J. Leonard, K. Lipka,A. Lobanov, W. Lohmann18, R. Mankel, I. Marfin18,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,M.Ö. Sahin, P. Saxena,T. Schoerner-Sadenius, M. Schröder,C. Seitz, S. Spannagel, K.D. Trippkewitz, C. Wissing
Deutsches Elektronen-Synchrotron, Hamburg, Germany
V. Blobel, M. Centis Vignali, A.R. Draeger,J. Erfle, E. Garutti, K. Goebel, D. Gonzalez, M. Görner, J. Haller, M. Hoffmann,R.S. Höing, A. Junkes, R. Klanner, R. Kogler,T. Lapsien, T. Lenz, I. Marchesini, D. Marconi, D. Nowatschin, J. Ott, F. Pantaleo2,T. Peiffer, A. Perieanu, N. Pietsch, J. Poehlsen,D. Rathjens, C. Sander, H. Schettler, P. Schleper, E. Schlieckau,A. Schmidt, J. Schwandt, M. Seidel, V. Sola,H. Stadie,
G. Steinbrück, H. Tholen, D. Troendle,E. Usai, L. Vanelderen, A. Vanhoefer
M. Akbiyik, C. Barth, C. Baus,J. Berger,C. Böser, E. Butz, T. Chwalek, F. Colombo, W. De Boer, A. Descroix, A. Dierlamm,M. Feindt, F. Frensch, M. Giffels,A. Gilbert, F. Hartmann2,U. Husemann, F. Kassel2,
I. Katkov6,A. Kornmayer2,P. Lobelle Pardo, M.U. Mozer,T. Müller, Th. Müller, M. Plagge, G. Quast, K. Rabbertz,S. Röcker, F. Roscher,H.J. Simonis, F.M. Stober,R. Ulrich, J. Wagner-Kuhr, S. Wayand, T. Weiler, C. Wöhrmann, R. Wolf
Institut für Experimentelle Kernphysik, Karlsruhe, Germany
G. Anagnostou,G. Daskalakis, T. Geralis,V.A. Giakoumopoulou, A. Kyriakis, D. Loukas,A. Psallidas, I. Topsis-Giotis
Institute of Nuclear and Particle Physics (INPP), NCSR Demokritos, Aghia Paraskevi, Greece
A. Agapitos,S. Kesisoglou, A. Panagiotou,N. Saoulidou, E. Tziaferi
University of Athens, Athens, Greece
I. Evangelou,G. Flouris, C. Foudas, P. Kokkas, N. Loukas, N. Manthos,I. Papadopoulos, E. Paradas, J. Strologas
University of Ioánnina, Ioánnina, Greece
G. Bencze,C. Hajdu, A. Hazi,P. Hidas, D. Horvath19, F. Sikler,V. Veszpremi, G. Vesztergombi20, A.J. Zsigmond
Wigner Research Centre for Physics, Budapest, Hungary
N. Beni,S. Czellar, J. Karancsi21,J. Molnar, Z. Szillasi
Institute of Nuclear Research ATOMKI, Debrecen, Hungary
M. Bartók22,A. Makovec,P. Raics, Z.L. Trocsanyi, B. Ujvari
University of Debrecen, Debrecen, Hungary
P. Mal, K. Mandal, N. Sahoo, S.K. Swain
National Institute of Science Education and Research, Bhubaneswar, India
S. Bansal,S.B. Beri, V. Bhatnagar, R. Chawla, R. Gupta,U. Bhawandeep, A.K. Kalsi, A. Kaur, M. Kaur, R. Kumar,A. Mehta,M. Mittal, N. Nishu, J.B. Singh, G. Walia
Panjab University, Chandigarh, India
Ashok Kumar,Arun Kumar, A. Bhardwaj, B.C. Choudhary, R.B. Garg,A. Kumar, S. Malhotra, M. Naimuddin,K. Ranjan, R. Sharma, V. Sharma
University of Delhi, Delhi, India
S. Banerjee, S. Bhattacharya, K. Chatterjee,S. Dey,S. Dutta, Sa. Jain, Sh. Jain,R. Khurana,N. Majumdar, A. Modak, K. Mondal,S. Mukherjee, S. Mukhopadhyay, A. Roy,D. Roy, S. Roy Chowdhury, S. Sarkar, M. Sharan
Saha Institute of Nuclear Physics, Kolkata, India
A. Abdulsalam,R. Chudasama, D. Dutta, V. Jha, V. Kumar, A.K. Mohanty2,L.M. Pant, P. Shukla, A. Topkar
Bhabha Atomic Research Centre, Mumbai, India
T. Aziz,S. Banerjee, S. Bhowmik23, R.M. Chatterjee, R.K. Dewanjee,S. Dugad, S. Ganguly, S. Ghosh, M. Guchait,A. Gurtu24, G. Kole, S. Kumar, B. Mahakud, M. Maity23, G. Majumder,K. Mazumdar, S. Mitra, G.B. Mohanty, B. Parida,T. Sarkar23,K. Sudhakar, N. Sur, B. Sutar, N. Wickramage25
S. Sharma
Indian Institute of Science Education and Research (IISER), Pune, India
H. Bakhshiansohi,H. Behnamian, S.M. Etesami26, A. Fahim27, R. Goldouzian, M. Khakzad,
M. Mohammadi Najafabadi, M. Naseri, S. Paktinat Mehdiabadi, F. Rezaei Hosseinabadi, B. Safarzadeh28, M. Zeinali
Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
M. Felcini,M. Grunewald
University College Dublin, Dublin, Ireland
M. Abbresciaa,b, C. Calabriaa,b,C. Caputoa,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, G. Minielloa,b, S. Mya,c, S. Nuzzoa,b,A. Pompilia,b,G. Pugliesea,c, R. Radognaa,b, A. Ranieria,G. Selvaggia,b,L. Silvestrisa,2, R. Vendittia,b,P. Verwilligena
aINFN Sezione di Bari, Bari, Italy bUniversità di Bari, Bari, Italy cPolitecnico di Bari, Bari, Italy
G. Abbiendia,C. Battilana2, 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
aINFN Sezione di Bologna, Bologna, Italy bUniversità di Bologna, Bologna, Italy
G. Cappelloa,M. Chiorbolia,b,S. Costaa,b,F. Giordanoa, R. Potenzaa,b,A. Tricomia,b, C. Tuvea,b
aINFN Sezione di Catania, Catania, Italy bUniversità di Catania, Catania, Italy cCSFNSM, Catania, Italy
G. Barbaglia, V. Ciullia,b,C. Civininia, R. D’Alessandroa,b,E. Focardia,b,S. Gonzia,b,V. Goria,b, P. Lenzia,b,M. Meschinia,S. Paolettia, G. Sguazzonia,A. Tropianoa,b,L. Viliania,b
aINFN Sezione di Firenze, Firenze, Italy bUniversità di Firenze, Firenze, Italy
L. Benussi, S. Bianco, F. Fabbri,D. Piccolo
INFN Laboratori Nazionali di Frascati, Frascati, Italy
V. Calvellia,b, F. Ferroa, M. Lo Veterea,b, M.R. Mongea,b,E. Robuttia,S. Tosia,b
aINFN Sezione di Genova, Genova, Italy bUniversità di Genova, Genova, Italy
L. Brianza,M.E. Dinardoa,b, S. Fiorendia,b,S. Gennaia,R. Gerosaa,b,A. Ghezzia,b, P. Govonia,b,
S. Malvezzia, R.A. Manzonia,b,B. Marzocchia,b,2,D. Menascea,L. Moronia, M. Paganonia,b,D. Pedrinia, S. Ragazzia,b, N. Redaellia,T. Tabarelli de Fatisa,b
aINFN Sezione di Milano-Bicocca, Milano, Italy bUniversità di Milano-Bicocca, Milano, Italy
S. Buontempoa, N. Cavalloa,c, S. Di Guidaa,d,2, M. Espositoa,b, F. Fabozzia,c,A.O.M. Iorioa,b,G. Lanzaa, L. Listaa,S. Meolaa,d,2,M. Merolaa,P. Paoluccia,2,C. Sciaccaa,b,F. Thyssen
aINFN Sezione di Napoli, Napoli, Italy bUniversità di Napoli ‘Federico II’, Napoli, Italy cUniversità della Basilicata, Potenza, Italy dUniversità G. Marconi, Roma, Italy
N. Bacchettaa, D. Biselloa,b,A. Bolettia,b,R. Carlina,b, A. Carvalho Antunes De Oliveiraa,b,P. Checchiaa, M. Dall’Ossoa,b,2,F. Fanzagoa, F. Gasparinia,b, U. Gasparinia,b, F. Gonellaa,A. Gozzelinoa,
K. Kanishcheva,c,M. Margonia,b,G. Marona,29, A.T. Meneguzzoa,b,F. Montecassianoa,M. Passaseoa, J. Pazzinia,b, N. Pozzobona,b, P. Ronchesea,b,F. Simonettoa,b, E. Torassaa,M. Tosia,b, M. Zanetti, P. Zottoa,b, A. Zucchettaa,b,2,G. Zumerlea,b
aINFN Sezione di Padova, Padova, Italy bUniversità di Padova, Padova, Italy cUniversità di Trento, Trento, Italy
A. Braghieria, A. Magnania,P. Montagnaa,b, S.P. Rattia,b,V. Rea,C. Riccardia,b,P. Salvinia, I. Vaia, P. Vituloa,b
aINFN Sezione di Pavia, Pavia, Italy bUniversità di Pavia, Pavia, Italy
L. Alunni Solestizia,b, 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
aINFN Sezione di Perugia, Perugia, Italy bUniversità di Perugia, Perugia, Italy
K. Androsova,30,P. Azzurria,G. Bagliesia,J. Bernardinia, T. Boccalia,G. Broccoloa,c,R. Castaldia, M.A. Cioccia,30,R. Dell’Orsoa, S. Donatoa,c,2,G. Fedi, L. Foàa,c,†,A. Giassia, M.T. Grippoa,30,
F. Ligabuea,c,T. Lomtadzea,L. Martinia,b, A. Messineoa,b, F. Pallaa,A. Rizzia,b,A. Savoy-Navarroa,31, A.T. Serbana, P. Spagnoloa,P. Squillaciotia,30, R. Tenchinia,G. Tonellia,b, A. Venturia,P.G. Verdinia
aINFN Sezione di Pisa, Pisa, Italy bUniversità di Pisa, Pisa, Italy
cScuola Normale Superiore di Pisa, Pisa, Italy
L. Baronea,b, F. Cavallaria,G. D’imperioa,b,2, D. Del Rea,b,M. Diemoza, S. Gellia,b,C. Jordaa,E. Longoa,b, F. Margarolia,b, P. Meridiania,F. Michelia,b, G. Organtinia,b,R. Paramattia, F. Preiatoa,b,S. Rahatloua,b, C. Rovellia,F. Santanastasioa,b,P. Traczyka,b,2
aINFN Sezione di Roma, Roma, Italy bUniversità di Roma, Roma, Italy
N. Amapanea,b,R. Arcidiaconoa,c,2,S. Argiroa,b,M. Arneodoa,c,R. Bellana,b, C. Biinoa, N. Cartigliaa, M. Costaa,b,R. Covarellia,b, A. Deganoa,b, N. Demariaa,G. Dugheraa,L. Fincoa,b,2,C. Mariottia, S. Masellia,E. Migliorea,b, V. Monacoa,b, E. Monteila,b, M. Musicha, M.M. Obertinoa,b,L. Pachera,b, N. Pastronea,M. Pelliccionia,G.L. Pinna Angionia,b, F. Raveraa,b,A. Romeroa,b, M. Ruspaa,c,R. Sacchia,b, A. Solanoa,b,A. Staianoa, U. Tamponia
aINFN Sezione di Torino, Torino, Italy bUniversità di Torino, Torino, Italy
cUniversità del Piemonte Orientale, Novara, 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. Schizzia,b, T. Umera,b,A. Zanettia
aINFN Sezione di Trieste, Trieste, Italy bUniversità di Trieste, Trieste, Italy
S. Chang,A. Kropivnitskaya, S.K. Nam
Kangwon National University, Chunchon, Republic of Korea
D.H. Kim,G.N. Kim, M.S. Kim, D.J. Kong, S. Lee, Y.D. Oh,A. Sakharov, D.C. Son
Kyungpook National University, Daegu, Republic of Korea
J.A. Brochero Cifuentes,H. Kim, T.J. Kim, M.S. Ryu
S. Song
Chonnam National University, Institute for Universe and Elementary Particles, Kwangju, Republic of Korea
S. Choi, Y. Go, D. Gyun,B. Hong,M. Jo, H. Kim, Y. Kim,B. Lee, K. Lee, K.S. Lee, S. Lee,S.K. Park, Y. Roh
Korea University, Seoul, Republic of Korea
H.D. Yoo
Seoul National University, Seoul, Republic of Korea
M. Choi,H. Kim, J.H. Kim, J.S.H. Lee, I.C. Park, G. Ryu
University of Seoul, Seoul, Republic of Korea
Y. Choi,Y.K. Choi, J. Goh,D. Kim, E. Kwon, J. Lee, I. Yu
Sungkyunkwan University, Suwon, Republic of Korea
A. Juodagalvis,J. Vaitkus
Vilnius University, Vilnius, Lithuania
I. Ahmed,Z.A. Ibrahim, J.R. Komaragiri, M.A.B. Md Ali32,F. Mohamad Idris33,W.A.T. Wan Abdullah
National Centre for Particle Physics, Universiti Malaya, Kuala Lumpur, Malaysia
E. Casimiro Linares, H. Castilla-Valdez, E. De La Cruz-Burelo,I. Heredia-de La Cruz34, A. Hernandez-Almada,R. Lopez-Fernandez, A. Sanchez-Hernandez
Centro de Investigacion y de Estudios Avanzados del IPN, Mexico City, Mexico
S. Carrillo Moreno, F. Vazquez Valencia
Universidad Iberoamericana, Mexico City, Mexico
S. Carpinteyro, I. Pedraza, H.A. Salazar Ibarguen
Benemerita Universidad Autonoma de Puebla, Puebla, Mexico
A. Morelos Pineda
Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
D. Krofcheck
University of Auckland, Auckland, New Zealand
P.H. Butler,S. Reucroft
University of Canterbury, Christchurch, New Zealand
A. Ahmad, M. Ahmad, Q. Hassan,H.R. Hoorani, W.A. Khan, T. Khurshid,M. Shoaib
National Centre for Physics, Quaid-I-Azam University, Islamabad, Pakistan
H. Bialkowska, M. Bluj,B. Boimska, T. Frueboes,M. Górski, M. Kazana, K. Nawrocki, K. Romanowska-Rybinska, M. Szleper,P. Zalewski
National Centre for Nuclear Research, Swierk, Poland
G. Brona, K. Bunkowski, K. Doroba, A. Kalinowski, M. Konecki,J. Krolikowski, M. Misiura, M. Olszewski, M. Walczak
P. Bargassa,C. Beirão Da Cruz E Silva, A. Di Francesco, P. Faccioli,P.G. Ferreira Parracho, M. Gallinaro, N. Leonardo,L. Lloret Iglesias, F. Nguyen, J. Rodrigues Antunes, J. Seixas,O. Toldaiev, D. Vadruccio, J. Varela, P. Vischia
Laboratório de Instrumentação e Física Experimental de Partículas, Lisboa, Portugal
S. Afanasiev,P. Bunin,M. Gavrilenko,I. Golutvin, I. Gorbunov, A. Kamenev,V. Karjavin, V. Konoplyanikov, A. Lanev,A. Malakhov,V. Matveev35, P. Moisenz, V. Palichik,V. Perelygin, S. Shmatov, S. Shulha,
N. Skatchkov,V. Smirnov, A. Zarubin
Joint Institute for Nuclear Research, Dubna, Russia
V. Golovtsov,Y. Ivanov, V. Kim36,E. Kuznetsova, P. Levchenko, V. Murzin, V. Oreshkin, I. Smirnov, V. Sulimov,L. Uvarov, S. Vavilov, A. Vorobyev
Petersburg Nuclear Physics Institute, Gatchina (St. Petersburg), Russia
Yu. Andreev,A. Dermenev,S. Gninenko, N. Golubev, A. Karneyeu, M. Kirsanov,N. Krasnikov, A. Pashenkov,D. Tlisov, A. Toropin
Institute for Nuclear Research, Moscow, Russia
V. Epshteyn,V. Gavrilov, N. Lychkovskaya,V. Popov, I. Pozdnyakov,G. Safronov, A. Spiridonov, E. Vlasov, A. Zhokin
Institute for Theoretical and Experimental Physics, Moscow, Russia
A. Bylinkin
National Research Nuclear University ‘Moscow Engineering Physics Institute’ (MEPhI), Moscow, Russia
V. Andreev,M. Azarkin37,I. Dremin37, M. Kirakosyan, A. Leonidov37,G. Mesyats, S.V. Rusakov, A. Vinogradov
P.N. Lebedev Physical Institute, Moscow, Russia
A. Baskakov,A. Belyaev, E. Boos,M. Dubinin38,L. Dudko, A. Ershov, A. Gribushin, V. Klyukhin, O. Kodolova,I. Lokhtin,I. Myagkov, S. Obraztsov,S. Petrushanko, V. Savrin, A. Snigirev
Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, 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
State Research Center of Russian Federation, Institute for High Energy Physics, Protvino, Russia
P. Adzic39,M. Ekmedzic, J. Milosevic,V. Rekovic
University of Belgrade, Faculty of Physics and Vinca Institute of Nuclear Sciences, Belgrade, Serbia
J. Alcaraz Maestre,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
Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain
C. Albajar, J.F. de Trocóniz,M. Missiroli, D. Moran
H. Brun, J. Cuevas,J. Fernandez Menendez, S. Folgueras, I. Gonzalez Caballero, E. Palencia Cortezon, J.M. Vizan Garcia
Universidad de Oviedo, Oviedo, Spain
I.J. Cabrillo, A. Calderon, J.R. Castiñeiras De Saa, P. De Castro Manzano, 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
Instituto de Física de Cantabria (IFCA), CSIC-Universidad de Cantabria, 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, G.M. Berruti, G. Bianchi, P. Bloch,A. Bocci, A. Bonato,C. Botta, H. Breuker, T. Camporesi, G. Cerminara, S. Colafranceschi40,M. D’Alfonso, D. d’Enterria, A. Dabrowski, V. Daponte, A. David,M. De Gruttola, F. De Guio, A. De Roeck, S. De Visscher, E. Di Marco, M. Dobson, M. Dordevic, T. du Pree,N. Dupont, 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, H. Kirschenmann,M.J. Kortelainen, K. Kousouris, K. Krajczar,P. Lecoq,C. Lourenço, M.T. Lucchini,N. Magini, L. Malgeri,M. Mannelli, A. Martelli,L. Masetti, F. Meijers, S. Mersi, E. Meschi, F. Moortgat, S. Morovic, M. Mulders, M.V. Nemallapudi,H. Neugebauer, S. Orfanelli41, L. Orsini, L. Pape, E. Perez,A. Petrilli, G. Petrucciani, A. Pfeiffer,D. Piparo, A. Racz,G. Rolandi42,M. Rovere, M. Ruan, H. Sakulin, C. Schäfer, C. Schwick,A. Sharma,P. Silva, M. Simon, P. Sphicas43, D. Spiga,J. Steggemann, B. Stieger, M. Stoye,Y. Takahashi, D. Treille, A. Tsirou, G.I. Veres20,N. Wardle, H.K. Wöhri,
A. Zagozdzinska44,W.D. Zeuner
CERN, European Organization for Nuclear Research, Geneva, Switzerland
W. Bertl,K. Deiters, W. Erdmann, R. Horisberger, Q. Ingram, H.C. Kaestli, D. Kotlinski,U. Langenegger, D. Renker, T. Rohe
Paul Scherrer Institut, Villigen, Switzerland
F. Bachmair, L. Bäni, L. Bianchini, M.A. Buchmann,B. Casal, G. Dissertori, M. Dittmar, M. Donegà, M. Dünser,P. Eller, C. Grab,C. Heidegger, D. Hits, J. Hoss, G. Kasieczka, W. Lustermann,B. Mangano, A.C. Marini,M. Marionneau, P. Martinez Ruiz del Arbol,M. Masciovecchio, D. Meister, P. Musella, F. Nessi-Tedaldi, F. Pandolfi, J. Pata, F. Pauss,L. Perrozzi,M. Peruzzi, M. Quittnat, M. Rossini, A. Starodumov45,M. Takahashi, V.R. Tavolaro, K. Theofilatos,R. Wallny, H.A. Weber
Institute for Particle Physics, ETH Zurich, Zurich, Switzerland
T.K. Aarrestad, C. Amsler46, L. Caminada,M.F. Canelli, V. Chiochia,A. De Cosa, C. Galloni, A. Hinzmann, T. Hreus, B. Kilminster,C. Lange, J. Ngadiuba, D. Pinna,P. Robmann, F.J. Ronga,D. Salerno, S. Taroni, Y. Yang
Universität Zürich, Zurich, Switzerland
M. Cardaci, C.P. Chang, K.H. Chen, T.H. Doan,C. Ferro, M. Konyushikhin, C.M. Kuo, W. Lin, Y.J. Lu, R. Volpe, S.S. Yu
National Central University, Chung-Li, Taiwan
R. Bartek, P. Chang, Y.H. Chang,Y.W. Chang, Y. Chao, K.F. Chen, P.H. Chen, C. Dietz,F. Fiori, U. Grundler, W.-S. Hou,Y. Hsiung, Y.F. Liu, R.-S. Lu,M. Miñano Moya, E. Petrakou,J.F. Tsai, Y.M. Tzeng
National Taiwan University (NTU), Taipei, Taiwan
B. Asavapibhop, K. Kovitanggoon, G. Singh, N. Srimanobhas,N. Suwonjandee
A. Adiguzel, S. Cerci47,C. Dozen, S. Girgis, G. Gokbulut, Y. Guler,E. Gurpinar, I. Hos, E.E. Kangal48, A. Kayis Topaksu,G. Onengut49, K. Ozdemir50,S. Ozturk51, B. Tali47, H. Topakli51, M. Vergili, C. Zorbilmez
Cukurova University, Adana, Turkey
I.V. Akin,B. Bilin, S. Bilmis, B. Isildak52,G. Karapinar53,U.E. Surat, M. Yalvac, M. Zeyrek
Middle East Technical University, Physics Department, Ankara, Turkey
E.A. Albayrak54, E. Gülmez,M. Kaya55,O. Kaya56, T. Yetkin57
Bogazici University, Istanbul, Turkey
K. Cankocak,S. Sen58, F.I. Vardarlı
Istanbul Technical University, Istanbul, Turkey
B. Grynyov
Institute for Scintillation Materials of National Academy of Science of Ukraine, Kharkov, Ukraine
L. Levchuk,P. Sorokin
National Scientific Center, Kharkov Institute of Physics and Technology, Kharkov, Ukraine
R. Aggleton,F. Ball, L. Beck, 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. Newbold59, S. Paramesvaran,A. Poll, T. Sakuma,S. Seif El Nasr-storey, S. Senkin, D. Smith,V.J. Smith
University of Bristol, Bristol, United Kingdom
K.W. Bell,A. Belyaev60,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,L. Thomas, I.R. Tomalin, T. Williams, W.J. Womersley, S.D. Worm
Rutherford Appleton Laboratory, Didcot, United Kingdom
M. Baber,R. Bainbridge, O. Buchmuller, A. Bundock,D. Burton, S. Casasso,M. Citron, D. Colling, L. Corpe, N. Cripps,P. Dauncey,G. Davies, A. De Wit, M. Della Negra,P. Dunne, A. Elwood, W. Ferguson, J. Fulcher, D. Futyan,G. Hall, G. Iles, G. Karapostoli,M. Kenzie, R. Lane, R. Lucas59,L. Lyons, A.-M. Magnan,
S. Malik,J. Nash, A. Nikitenko45, J. Pela, M. Pesaresi,K. Petridis, D.M. Raymond, A. Richards,A. Rose, C. Seez,A. Tapper, K. Uchida, M. Vazquez Acosta61, T. Virdee,S.C. Zenz
Imperial College, London, United Kingdom
J.E. Cole, P.R. Hobson,A. Khan, P. Kyberd,D. Leggat, D. Leslie,I.D. Reid, P. Symonds, L. Teodorescu, M. Turner
Brunel University, Uxbridge, United Kingdom
A. Borzou,J. Dittmann, K. Hatakeyama,A. Kasmi, H. Liu, N. Pastika
Baylor University, Waco, USA
O. Charaf,S.I. Cooper, C. Henderson, P. Rumerio
The University of Alabama, Tuscaloosa, USA
A. Avetisyan, T. Bose,C. Fantasia, D. Gastler, P. Lawson, D. Rankin, C. Richardson, J. Rohlf, J. St. John, L. Sulak,D. Zou
J. Alimena,E. Berry, S. Bhattacharya, D. Cutts, N. Dhingra, A. Ferapontov, A. Garabedian,U. Heintz, E. Laird,G. Landsberg, Z. Mao, M. Narain, S. Sagir, T. Sinthuprasith
Brown University, 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,M. Mulhearn, D. Pellett, J. Pilot, F. Ricci-Tam, S. Shalhout, J. Smith, M. Squires, D. Stolp, M. Tripathi, S. Wilbur,R. Yohay
University of California, Davis, Davis, USA
R. Cousins,P. Everaerts,C. Farrell, J. Hauser, M. Ignatenko, G. Rakness, D. Saltzberg, E. Takasugi, V. Valuev,M. Weber
University of California, Los Angeles, USA
K. Burt, R. Clare,J. Ellison, J.W. Gary, G. Hanson,J. Heilman, M. Ivova Paneva, P. Jandir, E. Kennedy, F. Lacroix,O.R. Long, A. Luthra, M. Malberti, M. Olmedo Negrete, A. Shrinivas,H. Wei, S. Wimpenny
University of California, Riverside, Riverside, USA
J.G. Branson, G.B. Cerati,S. Cittolin, R.T. D’Agnolo, A. Holzner, R. Kelley, D. Klein, J. Letts, I. Macneill, D. Olivito, S. Padhi, M. Pieri, M. Sani,V. Sharma, S. Simon, M. Tadel,A. Vartak, S. Wasserbaech62, C. Welke,F. Würthwein,A. Yagil, G. Zevi Della Porta
University of California, San Diego, La Jolla, USA
D. Barge, J. Bradmiller-Feld, C. Campagnari, A. Dishaw, V. Dutta,K. Flowers, M. Franco Sevilla, P. Geffert, C. George, F. Golf, L. Gouskos,J. Gran, J. Incandela, C. Justus,N. Mccoll, S.D. Mullin, J. Richman, D. Stuart, I. Suarez,W. To, C. West,J. Yoo
University of California, Santa Barbara, Santa Barbara, USA
D. Anderson,A. Apresyan, A. Bornheim,J. Bunn, Y. Chen, J. Duarte, A. Mott, H.B. Newman,C. Pena, M. Pierini,M. Spiropulu, J.R. Vlimant, S. Xie, R.Y. Zhu
California Institute of Technology, Pasadena, USA
V. Azzolini,A. Calamba, B. Carlson, T. Ferguson, Y. Iiyama, M. Paulini,J. Russ, M. Sun, H. Vogel, I. Vorobiev
Carnegie Mellon University, Pittsburgh, USA
J.P. Cumalat, W.T. Ford,A. Gaz, F. Jensen, A. Johnson, M. Krohn,T. Mulholland, U. Nauenberg, J.G. Smith, K. Stenson,S.R. Wagner
University of Colorado Boulder, Boulder, USA
J. Alexander, A. Chatterjee, J. Chaves,J. Chu, S. Dittmer, N. Eggert, N. Mirman, G. Nicolas Kaufman, J.R. Patterson,A. Rinkevicius, A. Ryd, L. Skinnari,L. Soffi, W. Sun, S.M. Tan, W.D. Teo, J. Thom, J. Thompson, J. Tucker, Y. Weng,P. Wittich
Cornell University, Ithaca, USA
S. Abdullin,M. Albrow, J. Anderson, G. Apollinari, L.A.T. Bauerdick, A. Beretvas, J. Berryhill,P.C. Bhat, G. Bolla,K. Burkett,J.N. Butler, H.W.K. Cheung, F. Chlebana, S. Cihangir, V.D. Elvira,I. Fisk, J. Freeman, E. Gottschalk,L. Gray, D. Green, S. Grünendahl, O. Gutsche,J. Hanlon, D. Hare, R.M. Harris, J. Hirschauer, B. Hooberman, Z. Hu, S. Jindariani, M. Johnson, U. Joshi, A.W. Jung,B. Klima, B. Kreis,S. Kwan†,
S. Lammel,J. Linacre, D. Lincoln,R. Lipton, T. Liu,R. Lopes De Sá, J. Lykken, K. Maeshima, J.M. Marraffino, V.I. Martinez Outschoorn, S. Maruyama,D. Mason, P. McBride, P. Merkel,K. Mishra, S. Mrenna, S. Nahn, C. Newman-Holmes,V. O’Dell, O. Prokofyev,E. Sexton-Kennedy, A. Soha, W.J. Spalding, L. Spiegel,