Numerical modelling of correlations

Bose-Einstein correlations(BEC)between identicalbosonsare supposed toprovideinform ation on space-tim edevelopm entofm ultiparticleproduction processes.TheusualM onteCarloeventgeneratorsm odellingsuch processes ,because their probabilistic structure,excludes a priorithe genuine BEC, which areofpurelyquantum statisticalorigin.O necan onlym odelBEC by(i) suitablychangingoutputofthesegenerators orby(ii)buildinggenerator, which properly incorporatesthebosoniccharacterofproduced particles.In both casesthe goalisto reproduce the experim entaltwo-particlecorrelation function C2(Q = jpi pjj)= N 2(pi;pj)=N 1(pi)N 1(pj).In (i)thisisachieved by suitablebunching ofthe nally produced identicalparticlesin phase-space perform ed using specialweights constructed from the output of the event generator.In (ii)theparticlesarealreadybeingproduced in properlybunched way by m eansofspecialgeneratorconstructed using speci cstatisticalm odel (providingBose-Einstein orgeom etricaldistribution ofparticlesin each bunch which isidenti ed with a single em itting cellin phase space ). W hereas(i) can be applied only foralleventsand is(via weights)sensitive to the spacetim e structure ofthe production process provided by event generator,the (ii)appliesalready on a single eventlevelbutitsgeneratorbearsno a priori inform ation on the space-tim e structure ofthe production process,it uses instead nonstatisticalcharacterof uctuationsitproduces. W e propose generalization ofthe second approach to m ake itapplicable also to othergenerators. To betterunderstand ourreasoning letusrem ind