Diffractive SUSY particle production at the LHC

We give detailed predictions for diffractive SUSY Higgs boson and top squark associated productions at the LHC via the exclusive double pomeron exchange mechanism. We study how the SUSY Higgs cross section and the signal over background ratio are enhanced

Di ractiveSUSYparticleproductionattheLHC

M.Boonekamp

Servicedephysiquedesparticules,CEA/Saclay,91191Gif-sur-Yvettecedex,France

J.Cammin

UniversityofRochester,NY,USA

Servicedephysiqueth´eorique,CEA/Saclay,91191Gif-sur-Yvettecedex,France¶http://doc.xuehai.netvignac andR.Peschanski§

C.Royon

Servicedephysiquedesparticules,CEA/Saclay,91191Gif-sur-Yvettecedex,France,andFermilab,Batavia,USA

Wegivedetailedpredictionsforthedi ractiveassociatedproductionofSUSYHiggsbosonsand

topsquarksattheLHCviaexclusivedoublepomeronexchangemechanism.WestudyhowtheSUSY

Higgsproductioncross-sectionandthesignal-over-backgroundratioareenhancedasafunctionof

tanβindi erentregimes.Theprospectsareparticularlypromisinginthe“anti-decoupling”regime,

whichwestudyindetail.Wealsogiveprospectsforaprecisemeasurementofthetopsquarkmass

usingthethresholdscanofcentraldi ractiveassociatedtopsquarkeventsattheLHC.

arXiv:hep-ph/0506275v2 8 Aug 2006I.INTRODUCTIONThequestforsupersymmetry(SUSY)isoneofthemajorgoalsinhighenergyparticlephysics,andisanimportanttaskfortheexperimentsattheupcomingLHC.ThediscoveryofSUSYHiggsscalar(s)andothernewSUSYparticles,amongwhichthesuperpartnersofthetopquarkaregoodcandidates,wouldbeanimportantachievement.StandardproductionmechanismsbasedonQCDarenowwellexplored,atleastforthemainchannels.However,duetoboththegeneralinterestoftheproblemandsomespeci cfeaturesoftheSUSYHiggsandtopsquarksectors,oneshouldseekforalternativewaysofSUSYproduction.Inthispaperweinvestigatetheprospectsfordi ractiveproductionofSUSYHiggsbosonsandassociatedsparticles(stops)inthecentralregionofthedetectors.StandardModelHiggsbosonproductionindoubledi raction(denotedDPE,forDoublePomeronExchange)hasalreadybeenstudiedinrecentyears[1,2,3],[4,5,6,7,8].Manyapproacheshavebeenpursued,consideringdi ractivescattering,asintheReggepicture[1,2,3], nalstatesoftcolourinteractions[6],orfullyperturbativeexchangeofgluonpairs[7].WeextendthesestudiestotheSUSYHiggsandsparticlesectorintheframeworkoftheMinimalSupersymmetricStandardModel(MSSM)[9].Thissubjecthasalreadybeeninvestigatedintheliterature[12,13]1,andwewillinparticularfocusoncentraldi ractiveproductionofthelightestMSSMHiggsbosoninthe“anti-decoupling”regimewhichhasnotyetbeenstudiedintheproposedframework.The“decoupling”and“intensecoupling”regimeshavebeenstudiedinRef.[11],whereitisshownthatdi ractiveHiggsbosonproductioncanhelpdistinguishingbetweenhandHintheintensecouplingregime.A.Centraldi ractiveproductionofaheavystate

OnegenerallyconsiderstwotypesofDPEeventsfortheproductionofaheavystate,namely“exclusive”DPE

[1,2,3],wherethecentralheavyobjectisproducedalone,separatedfromtheoutgoinghadronsbyrapiditygaps:

pp→p+heavyobject+p,

(1)

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