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1、PHOTOSMCEventGeneratorSimulatingQEDradiativecorrectionindecays徐庆君XuQingjun杭州师范大学理学院CollaborationwithZ.Was中国高能物理学会第十次会议，2010年4月19日，南昌OutlineRecentDevelopmentofPHOTOSMCIntroductionPHOTOSMCEventGeneratorSummaryandOutlook2MCEventGenerator,徐庆君IntroductionTheoryσ,Γ,BrandD
2、istributionsVeryImportant!!TelltheexperimentwheretogoEventswrittenin4-momentumMCSimulationwithdetectoreffectsMCEventsin4-momentumExp.ComparePhenomenologyTheoryExp.=Ornot!!Conclusion:MCIntegrationFurtherdiscussions3MCEventGenerator,徐庆君Introduction:MCIntegrationvs.Sim
3、ulationForanintegral:MCIntegrationMCSimulationUseapproximationInsteadof,followingstepsofMCIntegration,eventsaresavedforfutureuseCalculateweightEventsareacceptedifWisthemaximumweight,Otherwisewerejectthem.StatisticalerrorRejectiondensity4MCEventGenerator,徐庆君Introduct
4、ionPHOTOSMCEventGeneratorPHOTOSisusedtosimulateQEDeffectsindecaysItiswidelyused(LEP.LHC,DESY,KEK,SLAC,BEPC,BELLE,BARBAR)andhas300+citationsPHOTOScanbecombinedwithothermainprocessgeneratorsProcessindependentkernelisusedinPHOTOSSystematicerrorneedstobecontrolledproces
5、sbyprocess5MCEventGenerator,徐庆君PHOTOSMC:simulateQEDeffectsUsingFeynmanrules,calculateCalculatevirtualQEDcorrectionsCalculatesoftandcollinearphotoncontribution++freeofIRandcollineardivergences=Calculatenon-collinearphotoncontribution,addcorrectionsofvirtualandrealpho
6、tontogether,wegetone-looplevelresultNormalwaytostudyQEDradiativecorrection(1+)+non-collinear6MCEventGenerator,徐庆君PHOTOSMC:simulateQEDeffectsPHOTOSMCsimulateshardphotonemissionfromfinalstatesAprocessindependentkernelisusedinsteadofexactmatrixelement,itsatisfies:insof
7、tandcollinearlimits,Lim==remainingpart+Phasespaceisexact,factorizedintoBornlevelAmplitudeandphasespaceProcessindependentkernelandexactphasespaceEvents(supposetobeeventswithandwithouthardphoton)EventswithhardphotonAffectstheprecisionAffectstheprecision7MCEventGenerat
8、or,徐庆君PHOTOSMC:studytheprecisionHowtoincreasetheprecision(importantforexp.systematicerror)Writeitintotwoparts,oneissameasthekernelinPHOTOS
