πp碰撞Drell-Yan過程的色偶極模型.pdf

1、河北師范大學碩士學位論文πp碰撞DrellYan過程的色偶極模型姓名：趙洪明申請學位級別：碩士專業(yè)：理論物理指導教師：段春貴2002.4.1，’AbstractWestudyDrell—Yan(DY、dileptonproductionin，rprotoncollisionswithinthelight—cone(LC)colordipolepicture，whichisdescribedinthetargetrestframeItwa

2、spointedoutthatinthetargetrestframe，DYdileptonproductionlookslikebremsstrahlung，ratherthanpartonannihilationAquark(oranantiquark)fromtheprojectilehadronradiatesavirtualphotononimpactonthetarget，thephotonsubsequentlydecay

3、sintoaleptonpairThevirtualofthismodelisthatthehighenergycollisionisstudiedinthetargetrestframe，SOitisnotonlyconvenienttocomparewiththeexperimentdata，butalsoeasytounderstandthephysicmechanic，neoh口n：每。hThebasicblocksinthec

4、olordipolemethodaretheLCwavefunctionandthedipolecrosssectionTheLCwavefunctioniscalculatedfromperturbationtheoryWehaveshownthattheLCwavefunctionfortheyqconfigurationplaystheroleofaweightforthedifferenttransverseseparation

5、PcontributiontotheprocessNamely，smalltransverseseparmionsareselectedbyboththetransverseandlongitudinalpiecesHowever，thetransverseonecanselectnon—negligiblelargesizesPInaddition，largerinvariantmassMscanssmalleryqseparatio

6、nsMoreover，thelongitudinalpieceishighertwist(suppressedbyafactor1／M2)Thedipolecrosssectionislargelyunknown，onlyatsmalldistancePitcanbeexpressedintermsofgluondensityHowever，severalparameterizationsexistintheliterature，des