Application of the Two-Scale Model to the HERMES Data on Nuclear Attenuation

Abstract

The Two-Scale Model and its improved version were used to perform the fit to the HERMES data for $\hat{I}½$ (the virtual photon energy) and z (the fraction of $\hat{I}½$ carried by hadron) dependencies of nuclear multiplicity ratios for $\ddot{I}{€}^{+}$ and $\ddot{I}{€}^{-}$ mesons electro-produced on two nuclear targets (${}^{14}$N and ${}^{84}$Kr). The quantitative criterium $\ddot{I}{‡}^2$ was used for the first time to analyse the results of the model fit to the nuclear multiplicity ratios data. The two-parameter's fit gives satisfactory agreement with the HERMES data. Best values of the parameters were then used to calculate the $\hat{I}½$- and $z$ - dependencies of nuclear attenuation for $\ddot{I}{€}^0$, K${}^{+}$, K${}^{-}$ and $\bar{p}$ produced on ${}^{84}$Kr target, and also make a predictions for $\hat{I}½$, z and the Q${}^2$ (the photon virtuality) - dependencies of nuclear attenuation data for those identified hadrons and nuclea, that will be published by HERMES.