Nuclear attenuation at low energies

Abstract

Nuclear attenuation of the single hadron at low energies of the virtual photon $\ensuremath{\nu}$ ($\ensuremath{\nu}l5\phantom{\rule{0.16em}{0ex}}\phantom{\rule{4.pt}{0ex}}\text{GeV}$) is considered in the framework of the improved two-scale model, which is one of the versions of the string model. The model is used for a description of the ratio of the multiplicities of pions electroproduced on nuclear and deuterium targets as a function of the energy of virtual photons and the fractional energy of the pions. The final state interactions, which are essential in this energy range, are taken into account. A comparison with two sets of the experimental data obtained at JLab is performed. A satisfactory agreement of the theoretical calculations with the first set of data for the ratio of the multiplicities of positively charged pions on carbon, iron, and lead targets to that on the deuterium one is obtained. However, agreement with the second set of data for the ratio of the multiplicities of positively and negatively charged pions on the aluminum target to those on the deuterium one is poor. Possible reasons for this situation are discussed.