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1、SHEP–96–33DEVELOPMENTINLATTICEQCDJONATHANMFLYNNDepartmentofPhysics,UniversityofSouthampton,Highfield,Southampton,SO171BJ,UKAfterabriefdiscussionofthepromiseandlimitationsofthelatticetechnique,IreviewlatticeQCDresultsforseveralquantitiesofphenomenologicalinterest.Theseare:matri
2、xelementsforheavy-to-lightmesondecays,leptonicdecayconstantsfBandfD,theparametersBBandBKforneutralBandKmesonmixingrespectively,thestrongcouplingconstant,lightquarkmassesandthelightestscalarglueballmass.1Introductiondynamics.Continuumresultsshouldbeobtainedinthelimita→0:thisco
3、ntinuumextrapolationisnowInthisreviewIconcentrateonlatticeQCDresultsfeasibleformanyquantities.Latticesshouldbelargeforaselectionofquantitiesdirectlyrelevantforphe-enoughthathadronswillcomfortablyfitonthem.nomenology,someofwhichwerenototherwisere-Currentspatialsizesareoforder2f
4、morso,thoughportedatthisconference.Iapologisetopresenterssomepractitionersadvocateatleast2.5fm.1oflatticestudieswhichIdonothavespacetoreportBecausetheQCDactionisquadraticinthequarkonhereandrefertheinterestedreaderdirectlytothefields,matrixelementsofquarkscanbeevaluatedus-paral
5、lelsessionreports.ingquarkpropagatorsinthegluonbackgroundto-LatticeQCDisanimportanttoolforthenon-getherwiththegluon-field-dependentdeterminantofperturbativeevaluationofstronginteractioneffects,thefermionoperator.Thedeterminantisextremelybutawaryconsumershouldkeepinmindthemainde
6、mandingtocalculatesoitisoftensettoitsaveragesourcesoferror,whichIwillbrieflymentionbelow,valueinthegaugefieldbackground—thequenchedwhenusinglatticeresults.Onebeautyofthelatticeapproximation—whichcorrespondstoneglectingin-approachisthattheseerrorscanbesystematicallyternalquarklo
7、ops.Inpractice,muchoftheeffectinvestigatedandreduced.ofinternalloopsistochangetherunningofthecou-Thepresentationbeginswithformfactorsforplingconstantandthiscanbecompensatedbychang-B¯0→π+l−ν¯,B¯0→ρ+l−ν¯andB¯→K∗γ.Thesemilep-llingthevalueofβ,thebarecouplingwhichisinput.tonicdecay
8、sareimportantfordetermining
9、Vub
10、;theQuenchingisoneofthesystematiceffe