2023年12月9日发(作者：无缝液晶拼接屏)

HBTInterferometry:InstitutodeF´ısicaTe´orica-UNESP,RuaPamplona145,01405-900S˜aoPaulo,BrazilIreviewthehistoryofHBTinterferometry,sinceitsdiscoveryinthemid50’s,uptotherecentdevelopmentsandresultsfromBNL/thediscussionUCTION002Iwilldiscussherethefascinatingmethodinvented

decadesago,whichturnedintoaveryactivefiar,wearecelebrat-Fingthe50thanniversaryofthefirstpublicationofthe

sec-71tion,Iwillbrieflytellthestoryaboutthephenomenon

inradio-astronomy,thesubsequentobservationofasim-

2ilaroneoutsideitsoriginalrealm,andmanyaposteriorivdevelopmentsinthefield,uptothepresent.301I.1HBT2140/th-lcu:nviXraFIG.1:vebeenextractedfromRef.[1].HBTinterferometry,alsoknownastwo-identical-particlecorrelation,wasidealizedinthe1950sbyRobertHanbury-Brown,asameanstomeasuringstellarradiithroughtheanglesubtendedbynearbystars,asseenfromtheEarth’actuallyperformingtheFIG.2:figurewasextractedfromRef.[1].experiment,odevelopthemathematicaltheoryofintensityinter-ference(second-orderinterference)[2].Averyinterest-ingaspectofthisexperimentisthatitwasconceivedbybothphysicists,whoalsobuilttheapparatusthem-selves,madetheexperimentinNarrabri,Australia,andfinally,ys,theexperimentsdoingHBTattheRHIC/dbrieflysummarizetheexperi-mentbyinformingthatitconsistedoftwomirrors,,anelectronury-Brownhimselfdescribedit,they“...”,therewasnoneedtoformaconventionalimage:the(paraboloidal)telescopesusedforradio-astronomywouldbeenough,butwithlight-reflessaryprecisionofthesur-faceswasgovernedbymaximumpermissiblefiw-backtheyhadtofaceinthefirstyeaientistsconsideredthattheity,in1956,helpedbyPurcell[3],theymanagedtoshowthatitwastheotherwayround:notonlythephenomenonexisted,butitalsofollowedfromthefactthatphotonstendedtoarriveinpairsatthetwocorrelators,nterestingreviewabouttheseearlyyearswaswrittenbyGersonGoldhaber[1],oneoftheexperimen-talistsresponsiblefordiscoveringtheidenticalparticlecorrelationintheoppositerealmofHBT:themicrocos-mosofhighenergycollisions.I.2GGLPIn1959,Goldhaber,Goldhaber,LeeandPaisper-formedanexperimentattheBevalac/LBL,inBerkeley,CA,USA,aimingatthediscoveryoftheρ0resonance[4].Intheexperiment,theyconsideredp¯pcollisions,at1.05GeV/researchingfortheresonancebymeansofthedecayρ0,mass-distribution→π+π−,bymeasuringtheunlikepair,π+π−andcomparingitwiththeonesforlikepairs,π±π±.Afterwards,theyconcludedthattherewasnotenoughstatisticsforestablishingtheexis-tenceofρheless,theyobservedanunexpectedangularcorrelationamongidenticalpions!Later,in1960,theysuccessfullyreproducedtheempiricalangulardistri-butionbyadetailedmulti-πphase--ingso,theyconcludedtheeffectwasaconsequenceoftheBose-Einsteinnatureofπ+π+andπ−π−.Theywerenot,theyhaddiscovered,bychance,thecounterpartoftheHBTefframeterizedtheobservedcorrelationas:C(Q2)=1+e−Q2r2=1+e(q02−q2)r2(1)Q2=−q2=−(k1−k2)2=M122−(m1+m2)ssianformintheaboveequation,andseveralofitsvariantoptions,wouldbewidelyusedintheyearstocome,mainlybytheexperimentalists,duetothesimplic-ityoftheemissionsourceandanalyticalresultsallowedbythisprofiseewhicharetheparametersandinterpretationsderivedfromitinawhile.I.3SIMPLEPICTUREAtthispoint,itisnaturaltoaskthequestion:Howtounderstandinterferometry,ortwo-particlecorrela-tion,inasimpleway?Firstofall,weshouldantici-patethatitfollowsfromconsideringtwoessentialpoints:theadequatequantumstatisticsandchaoticallyemittingsources,whichwasalreadyemphasizedbyBartknikandRz¸az˙ewski[5].Letmeillustrateitbyasimpleexampleofonlytwopointsources,asshowninFig.3:2(xµA)