Wavelet analysis of angular distributions of secondary particles in high-energy nucleus-nucleus interactions: Irregularity of particle pseudorapidity distributions

Experimental data on interactions of sulfur and oxygen nuclei with photoemulsion nuclei at energies of 200 and 60 GeV/nucleon are analyzed with the help of a continuous wavelet transform. Irregularities in pseudorapidity distributions of narrow groups of the secondary shower particles in these interactions are observed upon application of the second-order derivative of a Gaussian as a wavelet. The irregularities can be interpreted as the existence of preference emission angles of groups of particles. Such an effect is expected during emission of Cherenkov gluons in nucleus-nucleus collisions. Some of the positions of the observed peculiarities on the pseudorapidity axis coincide with those found by Dremin et al. (I. M. Dremin et al., Phys. Lett. B 499, 97 (2001)).