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1、REVIEWSOFMODERNPHYSICS,VOLUME82,APRIL–JUNE2010BaryonspectroscopyEberhardKlempt*Helmholtz-InstitutfürStrahlen-undKernphysikderRheinischenFriedrich-WilhelmsUniversität,Nußallee14-16,D-53115Bonn,Germany†Jean-MarcRichardLaboratoiredePhysiqueSubatomiqueetCosmologie,UniversitéJosephFourier-CNRS-IN2P3
2、-INPG,Grenoble,France,andInstitutdePhysiqueNucléairedeLyon,UniversitédeLyon,CNRS-IN2P3-UniversitéClaudeBernard,4,rueEnricoFermi,F-69622Villeurbanne,FrancePublished8April2010About120baryonsandbaryonresonancesareknown,fromtheabundantnucleonwithuandd−light-quarkconstituentsuptothe=bsd,whichco
3、ntainsonequarkofeachgenerationandtotheb−recentlydiscovered=bss.Inspiteofthisimpressivelylargenumberofstates,theunderlyingbmechanismsleadingtotheexcitationspectrumarenotyetunderstood.Heavy-quarkbaryonssufferfromalackofknownspinparities.Inthelight-quarksector,quark-modelcalculationshavemetwith
4、considerablesuccessinexplainingthelow-massexcitationsspectrumbutsomeimportantaspectssuchasthemassdegeneracyofpositive-parityandnegative-paritybaryonexcitationsremainunclear.Athighmasses,above1.8GeV,quarkmodelspredictaveryhighdensityofresonancespermassintervalwhichisnotyetobserved.Inthisreview,i
5、ssuesareidentifieddiscriminatingbetweendifferentviewsoftheresonancespectrum;prospectsarediscussedonhowopenquestionsinbaryonspectroscopymayfindanswersfromphotoproductionandelectroproductionexperimentswhicharepresentlycarriedoutinvariouslaboratories.DOI:10.1103/RevModPhys.82.1095PACSnumbers:12.39
6、.x,13.60.r,13.75.n,14.20.cCONTENTS4.Thecstates1105a.c1105b.*1105I.Introduction1096c5.Double-charmbaryons1106A.Whybaryons?1096E.Beautifulbaryons1106B.Thestructureofbaryons10971.Thebstates1106C.Namingscheme10972.Thebstates1106D.Guidetotheliterature1098a.band*1106E.Outline1098b3.Thebst
7、ates1107II.Heavy-QuarkBaryons1098a.b1107A.Thelifetimeofcharmedparticles10994.Theb1107B.Summaryofheavybaryons1099F.AfutureatLHC1108C.Majorexperimentsinheavy-baryonspectroscopy1100III.Light-QuarkBaryonResonances1108D.Charmedbaryon