Unitarity corrections to short-range order: Long-range rapidity correlations

Althougha the effective hadronic forces have short range in rapidity space, one nevertheless expects long-range dynamical correlations induced by unitarity constraints. This paper contains a thorough discussion of long-range rapidity correlations in high-multiplicity events. In particular, we analyze in detail the forward-backward multiplicity correlations, measured recently in the whole CERN ISR energy range. We find from these data that the normalized variance of the number $n$ of exchanged cut Pomerons, $〈{(\frac{n}{〈n〉}-1)}^2〉$, is most probably in the range 0.32 to 0.36. We show that such a number is obtained from Reggeon theory in the eikonal approximation. We also predict a very specific violation of local compensation of charge in multiparticle events: The violation should appear in the fourth-order zone correlation function and is absent in the second-order correlation function, the only one measured until now.