Dependence of soft pion jet properties in the space of relative four-dimensional velocities on initial energy. International Journal of Modern Physics A Volume 28, Issue 30, 10 December 2013, Article number 1350150

In this 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 ± 0.6) GeV.
Author keywords
Quark degrees of freedom; Soft jets