Double-Peakedlogtan12θDistributions and Their Relation to Fireballs

Abstract

The double-peaked feature of the $logtan\frac{1}{2}\ensuremath{\theta}$ distribution of secondary particles in a cosmicray jet is predicted not only by the two-fireball model, but also by a number of other phenomenological and empirical models. It is shown that in these models there is also a simple explanation for the occurrence of the two peaks, namely, the independence of ${p}_{\ensuremath{\parallel}}$ from ${p}_{t}$ in the c.m. system. Infinite-fireball models do not lead to the double-peaked distribution even when two groups (or clouds) of fireballs are considered.