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1、BudkerInstituteofNuclearPhysicsA.G.GrozinIntroductiontotheHeavyQuarkE ectiveTheoryPart1BUDKERINP92-97NOVOSIBIRSK1992arXiv:hep-ph/9908366v116Aug1999IntroductiontotheHeavyQuarkE ectiveTheoryPart1A.G.Grozin1;2BudkerInstituteofNuclearPhysics,630090Novosibirsk90,RussiaABSTRACTHeavyQuar
2、kE ectiveTheory(HQET)isanewapproachtoQCDproblemsinvolvingaheavyquark.Intheleadingapprox-imation,theheavyquarkisconsideredasastaticsourceofthegluon eld;1=mcorrectionscanbesystematicallyincludedintheperturbationtheory.NewsymmetrypropertiesnotapparentinQCDappearinHQET.Theyareused,inp
3、articular,toobtainre-lationsamongheavyhadronformfactors.HQETalsosimpli eslatticesimulationandsumrulesanalysisofheavyhadrons.Part1containsdiscussionofthee ectivelagrangian,mesons,baryons,andrenormalization.Part2willcontain1=mcorrec-tions,nonleptonicdecays,andinteractionwithsoftpion
4、s.cBudkerInstituteofNuclearPhysics1SupportedinpartbygrantfromtheSorosfund2Internetaddress:GROZIN@INP.NSK.SU1.E ectiveLagrangianRecentlyaninterestingnewapproachtoQCDproblemsinvolvingaheavyquarkwasproposed,namelytheHeavyQuarkE ectiveTheory(HQET).Intheleadingapproximation,theheavyqua
5、rkisconsideredasastaticsourceofthegluon eld;1=mcorrectionscanbesystematicallyincludedintheperturbationtheory.Thissimpli cationissimilartoconsideringahydrogenatominsteadofapositronium.NewsymmetrypropertiesnotapparentinQCDappearinHQET.Theyareused,inparticular,toobtainrelationsamongh
6、eavyhadronformfactors.However,inQCDevensuchasimpli edproblemisunsolvable.Approximatemethodssuchaslatticesimulationorsumrulesarenecessarytoobtainquantitativeresults.HereagainHQETallowstoproceedmuchfurtherthanQCD.ThereareseveralgoodreviewsofHQET[1,2,3]towhichweaddressthereaderforana
7、dditionalinformation.Herewewidelyusethepropertiesofcurrents'correlatorstoobtaingeneralresults.Thisapproachisinspiredbysumrules,thoughweshallnotconsiderdetailsofsumrulescalculations.WeshallstartfromaverysimplethoughapproximatepictureintheSections1{3;somecomplicationsarediscussedlat
8、er.Let'sstartfromtheQCDLagrangian
