Note on two-particle correlations in two-component models

Abstract

the elastic slope (R*' 1 . 5-6 G~v-'),"The fact that R* is distinct f r o m R means that the inclusive p r o c e s s A + B -B + X gives no direct information on the hypothetical increase of R with increasing m a s s . Such information may be forthcoming when one adopts a specific model for the decay of the l a r g e radius excitations. It is plausible that the momentum distribution of the decay products of these unusual objects may be rather different f r o m that observed f r o m objects of lower m a s s . In particular one can argue that the effective temperature of these states may grow with their radii, leading perhaps to an energy-dependent component in the production of particles at large t r a n s v e r s e momenta. Further discussion of these ideas-and their implementation in a specific model-is reserved to a separate publication. A. S. Carroll et al., Phys. Rev. Lett. 2, 928 (1974) ; 33, 932 (1974) ; M. J. Eongo et a l . , ibid. 33, 725 (1974). 'M. F r o i s s a r t , Phys. Rev. 123, 1053 (1961). 3~e e , f o r example, H. Cheng and T. T . Wu, Phys. Rev. Phys. Rev. 170, 1591 (1968). 5~. Durand III and R. Lipes, Phys. Rev. Lett. 20, 637 (1968); B. T. C a r r e r a s and J. N. J. White, Nucl. Phys. B42, 95 (1972).' h r~l i t z u r and R. Lipes, Phys. Rev. D 1, 1420 (1973).The two-particle correlation function f, = (An)' -( n ) is calculated for the case where two independent incoherent mechanisms simultaneously contribute to high-energy particle production. It is pointed out that a possible discrepancy between f, values observed in pp collisions and in pure Fp annihilation events could be explained in terms of the phase-space description of the pionization component.Many correlation phenomena in high-energy hadronic particle production a r e easily understood in t e r m s of a two-component picture, i.e., by the idea that particle production proceeds via two distinct dynamical mechanisms o r processes. Consider, f o r example, the fully integrated inclusive two-particle correlation function for undiscriminated particles f , = ( n ( n -1)) -(n)' =(an)' -( n ) .Experimentally, a s a function of ( n ) , f , f i r s t dec r e a s e s and then increase^."^ This increase i n f , can be obtained by the superposition of two p a rticle-number distributions either of which can have a r b i t r a r y (within their possible range) values f J,,, respectively. The only requirement is that the distributions yield different average numb e r s ( n ) , # ( t~) , . ' -~ However, this only works if one excludes the possibility that both mechanisms a c t only simultaneously. Moreover, the derivations of the twocomponent formula f o r f , s o f a r excluded not only this case but in fact considered only the c a s e where either the f i r s t o r the second mechanism acts, but never both simultaneously, i n a collision.5a Besides the theoretical interest i n the general c a s e t h e r e