Possible scaling behaviour of the multiplicities ratio in leptoproduction of charged pions in nuclear medium

Abstract

In this paper it is demonstrated that based on two-dimensional distributions in semi-inclusive deep inelastic scattering (SIDIS) data, obtained recently by the HERMES experiment at DESY on different nuclei, which contains data for charged pions produced in $z$ slices as a function of $\hat{I}½$, and in a $\hat{I}½$ slices as a function of $z$, it it is possible to parametrise a ratio of multiplicities on nucleus and deuterium (per nucleon) $R_M^h$ in a form of a function of a single variable $\ddot{I}„$, which has the physical meaning of the formation time of hadron. We call this effect $\ddot{I}„$ scaling. $\ddot{I}„$ is a function of two variables $\hat{I}½$ and $z$. It is also shown that $R_M^h$ can be presented in a form of a linear polynomial of $\ddot{I}„$, $a_{11}$ + $\ddot{I}„a_{12}$, where parameters $a_{11}$ and $a_{12}$ do not depend on $\hat{I}½$ and $z$.