Sound waves in hadronic matter

Abstract

Abstract. We argue that recent high energy CERN LHC experiments on transverse momenta distributions of produced particles provide us new, so far unnoticed and not fully appreciated, information on the underlying production processes. To this end we concentrate on the small (but persistent) log-periodic oscillations decorating the observed p T spectra and visible in the measured ratios R = σ data (p T ) /σ f it (p T ). Because such spectra are described by quasi-power-like formulas characterised by two parameters: the power index n and scale parameter T (usually identified with temperature T ), the observed logperiodic behaviour of the ratios R can originate either from suitable modifications of n or T (or both, but such a possibility is not discussed). In the first case n becomes a complex number and this can be related to scale invariance in the system, in the second the scale parameter T exhibits itself log-periodic oscillations which can be interpreted as the presence of some kind of sound waves forming in the collision system during the collision process, the wave number of which has a so-called self similar solution of the second kind. Because the first case was already widely discussed we concentrate on the second one and on its possible experimental consequences.

From Tsallis Scheme of high-energy pp collisions to Generalized Multiplicity Distribution with Modified Combinants

“…The combinants (C ′ j s) of GMD show an oscillatory behaviour which appear to be dependent on k ′ parameter. The oscillatory C ′ j s have been discussed and verified experimentally [9]. However using a single NBD does not allow us to get this oscillatory behaviour.…”

“…Modified combinants, (C ′ j s) are defined in terms of generating functions of a given distribution i.e., By taking data to fit ratio, a wiggly structure as shown in Figs. 2a and 2b is obtained suggesting some additional information hidden in P(n) and C ′ j s may provide a way to retrieve this information [9]. The generating functions G(z) of NBD and GMD and their corresponding C ′ j s are given as:…”