Effects of multipion correlations on the source distribution in ultrarelativustic heavyi.pdfVIP

Effects of multi-pion correlations on the source distribution in ultra-relativistic heavy-ion collisions Q.H. Zhang Institut f¨ur Theoretische Physik, Universit¨at Regensburg, D-93040 Regensburg, Germany 8 9 9 Abstract 1 n a Multi-pion correlation effect on the source distribution is studied. It is shown J 0 that multi-pion Bose-Einstein correlation make the average radius of the pion 2 1 source become smaller. The isospin effect on the pion multiplicity distribution v 7 and the source distribution is also discussed. 5 3 PACS number(s): 11.38 Mh, 11.30 Rd,25.75 Dw 1 0 8 Ultrarelativistic hadronic and nuclear collisions provide a unique environment to create 9 / dozens, and in some cases hundreds, of pions [1–3]. To study the pion source distributions in h p - these processes, therefore, one must take into account the effects of multi-pion Bose-Einstein p e h (BE) correlations [4–14]. Among others, Lam and Lo [4] suggested that the larger isospin : v i fluctuations were due to the Bose nature of the emitted pions. Pratt [7] suggested that if X r the number of bosons in a unit value of phase space is large enough, bosons may condense a into the same quantum state and a pion laser could be created. Considering isospin effect, Pratt and Zelevinsky [8] used the method in Ref. [7] to explain Centauro events [15,16]. Zajc [6] first used Monte-Carlo method to analyse multi-pion Bose-Einstein correlation effects on two-pion interferometry. Detail derivation of multi-pion Bose-Einstein correlation can be found in Ref. [12]. The bosonic nature and isospin of the pion should affe