τ-→l-pp稀有衰变中的代非普适z’玻色子效应研究

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1、ABSTRACTTosomeextent，thestandardmodel(SM)hasbeenexcellentlysuccessfulintheoreticalpredictions，mostofwhichareconfirmedbyexperimem．However,itstillexistsmanydeficiencies，forexample，theleptonflavorviolating(LFV)problempredictedbytheneutrinooscillations．Itisexpectedthattheremustexistmorebas

2、ictheoryinhighenergyscale．Sincethechargedleptonflavorviolatingprocesseshavetheadvantagesofsmallhadronicuncertainty,cleanbackground，etc．，theobservationoftheseprocessesinexperimentswillbeasignalofnewphysicsbeyondtheSM．Comparedwiththeeand∥leptons，therleptonhasamoreheavymassandmoredecays，r

3、UiVprocessesbecomegoodplacetOprobenewphysics．StudingthefLFVprocessesinthenewscenariosishelpfultoobtainthemodelinformation．andprovidereferencestOtheLFVmechanism．Intheexperiment，Belle，BabarandLHCbexperimentalgroupshavemeasuredfLFVprocesses，suchasradiativedecaysr专，，，，semi—leptonicdecays_『

4、斗驴(驴P)，pureleptonicdecaysf专31．Belle’SintegratedluminosRyhasreached1041fb～，andwillreached50ab～inthefuture．LHCb’scurrentintegratedluminosityis3．2fb～，willimprovedtoSfb～．Theoretically，physicistshavestudiedT·ly，tjlP(1P玲，≮÷3ldecaysinvariousDewphysicsmodelsandpresentedtheirtheoreticalpredicti

5、ons．Theresultsshowthattheirdecaysbranchingratioscanbeimprovedto000。8)～000“)．Thisthesisstudiesthez一·l“PP@P=KK，兀+芤一、)decaysintheUn—universalzmodel．IntheSM．thisprocessisforbidden．WhileintheUn—universalZmodel，whentheleptonsandquarksexistmixing，theextranewboson’Sflavorchangingcouplingwillpr

6、oduceIII万方数据off-diagonalflavorchangingneutralcurrent，andthenf’专l—PP∽P=KK，死+7／"一、)decayscanoccurinthetreelevelthroughthenewneutralboson．Intheprocessofcalculation，ignoringthemixingbetweenZandZboson，andconsideringthecontributionsofresonanceandnon—resonantformfactorstothehadronicmatrixelem

7、ents，westudytheT一_l—PP(、PP=KK，死+兀一、)branchingratiosandtheinvariablemassspectrumofthefinalstatemesons．Theresultsshowthat：themodelparametersg慕)areconstrainedattheorderofo(10。)bythecurrentexperimentalupperlimits．Forthedi．kaonfinalstates，thecontributionofresonantformfactorF?isdominatedam