Hadron attenuation in deep inelastic lepton-nucleus scattering

Abstract

We present a detailed theoretical investigation of hadron attenuation in deep inelastic scattering off complex nuclei in the kinematic regime of the HERMES experiment. The analysis is carried out in the framework of a probabilistic coupled-channel transport model based on the Boltzmann-Uehling-Uhlenbeck equation, which allows for a treatment of the final-state interactions beyond simple absorption mechanisms. Furthermore, our event-by-event simulations account for the kinematic cuts of the experiments as well as the geometrical acceptance of the detectors. We calculate the multiplicity ratios of charged hadrons for various nuclear targets relative to deuterium as a function of the photon energy $\ensuremath{\nu}$, the hadron energy fraction ${z}_{h}={E}_{h}∕\ensuremath{\nu}$, and the transverse momentum ${p}_{T}$. We also confront our model results on double-hadron attenuation with recent experimental data. Separately, we compare the attenuation of identified hadrons (${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$, ${\ensuremath{\pi}}^{0}$, ${K}^{\ifmmode\pm\else\textpm\fi{}}$, $p$, and $\overline{p}$) on $^{20}\mathrm{Ne}$ and $^{84}\mathrm{Kr}$ targets with the data from the HERMES Collaboration and make predictions for a $^{131}\mathrm{Xe}$ target. At the end we turn towards hadron attenuation on $^{63}\mathrm{Cu}$ nuclei at EMC energies. Our studies demonstrate that (pre-)hadronic final-state interactions play a dominant role in the kinematic regime of the HERMES experiment while our present approach overestimates the attenuation at EMC energies.