中性top介子與高能噴注在LHC上的聯(lián)合產(chǎn)生.pdf

1、遼寧師范大學(xué)碩士學(xué)位論文中性top介子與高能噴注在LHC上的聯(lián)合產(chǎn)生姓名：朱世海申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：粒子物理與原子核物理指導(dǎo)教師：岳崇興20090501中性top介子與高能噴注在L日a上的聯(lián)合產(chǎn)生Abstract：Themechanismofelectroweaksymmetrybreaking(EWSB)remainsanopenquestionincurrentphysicsdespitetheSUCCESSofthestand

2、ardmodel(SM)testedbythehighenergyexperimentaldataIntheSM，elementaryHiggsfieldisassumedtoberesponsibletobreaktheelectrowcaksymmetrybutthescalarsectorsuffersfromtheproblemsoftrivialityandunnaturalnessTherefore，SMisnotafund

3、amentaltheory，itCanonlybeeffectivefieldtheoryTheremustbenewphysicsbeyondtheSMSopeopleprovidedsomenewphysicsmodelsForexample，thesupersymmetry(SUSY)theorytopcolorassistedtechnicolor(TC2)modelandSOonNowTC2modelisveryprevail

4、Weintroducetheelementaryideathemaintheoreticalbranchings，phenomenologyandthenowadaydevelopmentofthetechnicolormodelWestudythesignalsofneutraltop—pionatthehighenergycolliders，andsummarizeandclassifytherelevantworksofOUrsi

5、ndetailinordertoexplainthesignificanceofourworkpresentexlinthispaperWestudytheproductionoftheneutraltoppion磚associatedwithahigh—PTjetintheframeworkofTC2modelandcompareournumericalresultswiththosefortheHiggsbosoninthesMor

6、theMSSMWestudytheproductionoftheneutraltoppion7rPinassociationwithahigh—PTjetattheLHC，whichproceedsviathepartonicprocessesgg_7rP9，gq_礙q，qCt_程夕，gb(b)_7r知(5)and65_7r踟Weseethattheproductionoftheneutraltop—pion7rinassociatio

7、nwithahigh一冊(cè)jetisdominatedbythepartonicprocessgg_磚g。whichissimilartotheHiggsbosonproductionassociatedwithahigh—PTjetintheSMandtheMSSM。HoweverfortheMSSMmodel，thecontributionsofthebbchannelcanbesignificantlylarge，depending

8、onthefreeparametersWhile，thisisnotthecasefortheTC2modelFor002≤￡≤008and200GeV≤mr≤500GeV，thehadronicCROSSsectionforthepartonicprocessbb醒9isonlyintherangeof16fb一46fb，whichisseveralordersofmagnitudesmallerthanthatfortheparto

9、nicprocessgg一磚9Fortheneutraltoppion丌o，itsmaindecaymodesare玩云cCte)，6，gg，and“／7For仇t≤mWP≤2mr，磚mainlydecaysto如andt己IthasbeenshownthatthevalueofthebranchingratioBr(磚一琵re)islargerthan90％for“t霄P=250GeVand￡≥002Thus，formtm丌2≤2mr

10、，theproductionofneutraltop—pion7rPassociatedwithahighpThadronicjetCaneasilytransfertothetcjeteventThisfinalStategeneratescharacteristicsignalsattheLHCexperimentsWefindthatitisverychallengingtodetecttheneutraltoppion磚viat