ATLAS探測器上雙玻色子WZ產(chǎn)生截面的精確測量.pdf

1、中國科學技術大學碩士學位論文ATLAS探測器上雙玻色子WZ產(chǎn)生截面的精確測量姓名：張沛申請學位級別：碩士專業(yè)：粒子物理與原子核物理指導教師：蔣一20090401ABSTRACTThisdissertationdescribesatestoftheStandardModel(SM)ofparticlephysicsbymeasuringtheprobability，orCROSSsection，ofsimultaneouslyproduc

2、ingaWbosonandaZbosonfromMonteCarlosimulateddataofprotonprotoncollisionsTheSMpredictsthetotal玎一ZproductioncrosssectiontObe294pbandthe阿廠ZproductionCROSSsectiontobe184pbThe14TeVcenter。ofmassenergyprotonprotoncollisionsarepr

3、ovidedbytheCERN(EuropeanOrganizationforNuclearResearch)LHC(LargeHadronCollider)TheWandZparticlesaredetectedusingtheATLAS(AToroidaiLHCApparatus)detectorThestudiesusetheATLASComputerSystemCommissioning(CSC)MonteCarlodatase

4、ts，whichincludetriggerinformationanddetectorcalibrationandalignmentcorrectionsThemeasurementusesthetrilepton(eeveee／zvlt／tevand／u／#zv)decaychannels，inwhicha∥decaystoachargedleptonplusaneutrinoandaZdecaystoapairofchargedl

5、eptonsThe形andZparticleselectioncriteria，detectionefficiency，andbackgrounddeterminationarepresentedindetailForthedataof1fb—integratedluminosity，weexpecttoobserve53曠Zsignaleventsand8backgroundevents，givingasignaltobackgrou

6、ndratioofabout67TheWZdibosonproductionCROSSsectionforpp一眩Xat、／S=14TeVismeasuredtobe仃木Br=5343。10，oyb(includeeventselectionefficiency)ThisisinagreementwiththepredictedSMcrosssection。Meanwhile，anewdataanalysistechnique，Boos