PHOTOS MC Event GeneratorSimulating QED radiative correction indecays徐庆君XuQingjunCollaborationwithZWas中国高能物理学会第十次会议，2010年4月19日，南昌
PHOTOS MC Event Generator Simulating QED radiative correction in decays 徐庆君 Xu Qingjun Collaboration with Z.Was 中国高能物理学会第十次会议，2010年4月19日，南昌
OutlineIntroductionPHOTOS MC Event GeneratorRecent Development of PHOTOS MC*→+()K→ee()K±→πeve ()Summary and OutlookMCEventGenerator，徐庆君
MC Event Generator, 徐庆君 2 Outline Recent Development of PHOTOS MC Introduction PHOTOS MC Event Generator Summary and Outlook
IntroductionFurther discussionsMC Integrationg,,Brand DistributionsTheoryMVeryImportant!!Tell theexperiment where to goPhenomenologyS>S>Z>d2MC SimulationMCEvents in4-momentumwithdetectoreffectsCompareExpEventswrittenin 4-momentum=ExpConclusion:TheoryOr not!!MCEventGenerator,徐庆君3
MC Event Generator, 徐庆君 3 Introduction Theory σ,Γ, Br and Distributions Events written in 4-momentum MC Simulation with detector effects MC Events in 4-momentum Exp.Phenomenology Conclusion: Theory = Exp. Or not!! MC Integration Further discussions
Introduction: MC Integration vs. SimulationFor an integral: R = Jo p(a)dncMC Integration1,I =1,2, ...N generated according to p()p(α)shouldhavesimilarpeaksandsingularitiesasp()Np(ar)p(a)1ZR= limRatiow(aiscalledweightofeventNp(aI)paN-I-(w-(w))2）densitystatisticalerrorRVNVNMCSimulationUse approximation p(1) Instead of P , following steps of MC Integration,eventsaresavedforfutureusp(ci)Calculate weight w(r) =Rejectionp(1)(r)Events are accepted if rW < w, Wis the maximum weight, 0 < r < 1Otherwisewerejectthem.StatisticalerrorMCEventGenerator,徐庆君
MC Event Generator, 徐庆君 4 Introduction: MC Integration vs. Simulation For an integral: MC Integration MC Simulation Use approximation Instead of , following steps of MC Integration, events are saved for future use Calculate weight Events are accepted if W is the maximum weight, Otherwise we reject them. Statistical error density
IntroductionMC Event GeneratorQCDQEDNewPhysicsPHOTOSMCEventGeneratorPHOTOSis usedtosimulateQEDeffects indecaysIt is widelyused (LEP.LHC,DESY,KEK,SLAC,BEPC,BELLE,BARBAR)andhas300+citationsPHOTOScanbecombinedwithothermainprocessgeneratorsProcessindependentkernelisusedinPHOTOSSystematic error needs to be controlled process byprocessMCEventGenerator,徐庆君
MC Event Generator, 徐庆君 5 Introduction MC Event Generator QCD QED New Physics PHOTOS MC Event Generator PHOTOS is used to simulate QED effects in decays It is widely used (LEP. LHC, DESY, KEK, SLAC, BEPC, BELLE, BARBAR) and has 300+ citations PHOTOS can be combined with other main process generators Process independent kernel is used in PHOTOS Systematic error needs to be controlled process by process