An analysis is made of the results of a recent polarization correlation experiment by Bovino (unpublished) where about 60,000 data have been obtained. I assume that the state of the photon pairs produced in the source (a non-linear crystal) are in a (sligh
Eqs.(10)and(13)mayberewrittentakingaccountofthe rsttwotermsofδ(φ)bymeansofsmallchangesintheparametersR0andV,thatPLHV(φ)≡16R′f=1
03π2η2
that,thediscriminationbetweenquantumand |φ| π2LHVpredictions + is.(15)Afterwillconsistofcheckingwhetherthequantumeq.(11)(withR0andVasfreepa-rameters)ortheLHVeq.(15)(withR′0,V′andηasfreeparameters)maybe ttedtothedataoftheexperiment.Inpracticeweshouldmakechi-square tsoftheexperimentaldataintoeq.(15)with3freeparameters,namelyR′0,V′andη.TheparameterεisrelatedtoηandV′byeq.(14).Ifη<<1eq.(14)maybe
ε solvedtoorderε2giving[4]2 1 sin2(πη/2)21
(πη/2)2 ,(16)
+
wherethesecondequalityisvalidforV′closetounity,asisusuallythecase.Iguessthatfairlygood tsexistforsomesetofvaluesofη.Ifagood tispossibleforη=0(inthiscasetheLHVeq.(15)becomeidenticaltothequantumeq.(11))thentheexperimentiscompatiblewithstandardquantummechanics(“standard”meansacceptingtheanalysisleadingtoeqs.(6)and
(7)).Ifgood tsarepossibleforη≥0.17thentheexperimentiscompatiblewiththefamilyoflocalmodelsde nedin[4],afamilylabelledLHV1in
[5].Iftherearegood tsforη≥0.55thentheexperimentwouldbealsocompatiblewiththefamilyde nedasLHV2in[5],whichismorerestrictivethanLHV1.HoweverIdonotthinkthelatterwillbethecaseinviewoftheresultsoftheroughanalysismadeatthebeginningofthispaper.
The tofthedataintotheequationsshouldbemadeforeveryoneofthe46setsofdatacorrespondingtooneBob´spolarizerpositioneach,ratherthana tofthewholesetofdata.ThereasonisthatinBelltestsitisessentialthatthemeasuredratescorrespondtothesameproductionrateinthesource.IsupposethatintheBovinoexperimentitismucheasiertoguaranteetheconstancyoftheproductionrateforeveryBob´spolarizerpositionthanforthewholesetofdata.
InordertomakeapreliminaryanalysisoftheexperimentIhaveusesafewdataof“fiBob”=90o.Asimpleconsequenceofthe(LHV)eq.(13)is,assumingη≤1/2,
ν≡f(0)+f(π/2) 2f(π/4)
4+16ε3/(3πη) 4ε3