Dependence of soft pion jet properties in the space of relative four-dimensional velocities on initial energy

TL;DR

This study investigates how soft pion jet properties depend on initial energy in the 2-20 GeV range, revealing fractal characteristics and the energy threshold (~2.8 GeV) where quark degrees of freedom become significant.

Contribution

It provides the first quantitative estimate of the energy boundary (~2.8 GeV) for quark degrees of freedom in soft pion jet production at intermediate energies.

Findings

Pion jets exhibit fractal-like properties with fractional cluster dimensions.

Mean kinetic energy and jet structure parameters increase with energy.

Quark degrees of freedom start to manifest around 2.8 GeV.

Abstract

In the paper experimental results obtained by studying of collective and fractal properties of soft pion jets in the space of relative four-dimensional velocities in intermediate energy domain 2 - 20 GeV are presented. Fractional values of cluster dimension are indicated on manifestation of fractal-like properties by pion jets. The changes of the mean square of the distance between secondary particles and jet axis, the mean kinetic energy of particles in jets and the cluster dimension with increasing of collision energy agree with the hypothesis of manifestation of quark degrees of freedom in processes of pion jet production at intermediate energies. For the first time the quantitative estimations are obtained for the low boundary energy at which quark degrees of freedom start to display itself in production of soft pion jets experimentally. The value of estimation for this parameter derived with taking into account of all used collective parameters is (2.8 \pm 0.6) GeV.