Single - particle correlations in events with the total disintegration of nuclei

New experimental data on the behaviour of the single-particle two-dimensional correlation functions R versus Q (Q is the number of nucleons emitted from nuc- lei) and Ap (Ap is the mass of projectile nuclei) are presented in this paper. The interactions of protons, d, 4He and 12C nuclei with carbon nuclei (at a momentum of 4.2 A GeV/c) are considered.The values of R are obtained separately for pi minus mesons and protons.In so doing,the values of R are normalized so that -1=<R=<1.The value of R=0 corresponds to the case of the absence of corre- lations.It has been found that the Q- and Ap-dependence of R takes place only for weak correlations (R< 0.3).In the main (90 %),these correlations are con- nected with the variable pt and have a nonlinear character, that is the regi- ons with different characters of the Q-dependence of R are separated: there is a change of regimes in the Q-dependences of R.The correlations weaken with increasing Ap, and the variable R gets the least values of all the considered ones in 12CC interactions.Simultaneously with weakening the correlations in the region of large Q, the character of the Q-dependence of R changes.Comment: 17 pages, submitted to Phys. Rew.

Some Properties of the Central pi--Meson Carbon Interactions at 40 Gev/C

We discuss some properties of the central pi--meson carbon reactions at 40 GeV/c. While these results were obtained many years ago they have not been explained completely. We attempt to interpret following: results regime change on the behavior of some characteristics of the events as a function of the centrality; anomaly peak on the angular distributions of the slow protons emitted in these reactions; charge asymmetry on the pi--mesons production in the back hemisphere in lcs. Understanding of the results could help to explain the new ones coming from the modern central experiments at high and ultrarelativistic energies.Comment: To appear in the proceedings of the 10th nternational Workshop on Meson Production, Properties and Interaction (MESON 2008), Krakow, Poland, 6 - 10 June 2008. 4 pages and 4 figure