Cluster Mass Distribution in Multiperipheral Cluster Emission Model

Abstract

It is shown that dynamics of the multiperipheral cluster em1ss1on model uniquely determines the cluster mass (M) distribution. In particular, the mass distribution is dynamically suppressed by the output factor (M')-Po(fi,>g'(p.), p.: final hadron mass) in addition to a possible decreasing effect due to the input factors of the cluster emission (g'(M)) and decay (JJ(M)) vertices. A dynamical equation for solving fio is derived. Some quantitative estimates are also presented. Since proposed in 1962 by ABFST,l> a multiperipheral model has been a continuing laboratory of physical interest when the multiple production of hadrons is studied. Incorporation of Regge exchanges 2>·8> along the multiperipheral chain makes the model more suitable for analyzing a high-energy multiparticle production. Quite recently, an idea that hadrons are produced in clusters 4> has provided a popular interpretation of several features of multiparticle production data. In particular, the postulates of (A) independent emission of clusters along th.e multiperipheral chain and (B) their isotropic decay via a Gaussian distribution in rapidity give a facile imitation of data on two-particle inclusive rapidity cor­ relations in the central regioit. 6> It is not clear whether clusters have any intrinsic dynamical significance (e.g., generalized resonances) or whether they are primarily of phenomenological convenience. Experimentally we still have to wajt for eve~t-by-event data on an exclusive rapidity distribution in order to observe directly the cluster formation and its detailed properties. On the other hand, the observed high multiplicity in rapidity space suggests that final hadrons should be produced more preferably through cluster (or resonance) formation along the multiperipheral chain to through factorized Regge exchanges between the final hadrons. It is a reasonable guess that due to a small average spacing of .dy~0.3 to 0.5 between the final hadrons, there will be a strong correlation among the produced particles, which is better represented by the above postulates (A) and (B). The purpose of this paper is to show that the postulates (A) and (B) just mentioned uniquely determine the mass distribution of produced clusters which is usually assumed to take a certain form as a third input. What is important, the predicted mass distribution can be checked experimentally when the exclusive