Pionic color transparency

Abstract

We use a semi-classical approximation to investigate the effects of color transparency on pion electroproduction reactions. The resulting reduced nuclear interactions produce significant, but not dominating, differences with the results of conventional distorted-wave, Glauber-type treatments at kinematics accessible to Jefferson Laboratory. Nuclear effects that could mimic the influence of color transparency are also discussed.

Color transparency: Past, present and future

“…This simplifies interpretation of the Q 2 dependence of the transparency as compared to the case of small x where l in becomes comparable to the nucleus size. The experimental results agree well with predictions of [76] and [77] where CT was calculated based on the quantum diffusion modelEq. (9).…”

“…The measured pion nuclear transparencies are compared to three different calculations. The calculations of Larson, et al [76], use a semi-classical formula based on the eikonal approximation and a parametrization of the effects of final state interactions (FSI) in terms of an effective interaction. The effective interaction is based on the quantum diffusion model [15], where the interaction of the small transverse size object PLC is approximately proportional to the propagation distance z for z < l c .…”

“…In RMSGA, the wave function of the spectator nucleon and the outgoing pion is taken to be a convolution of a relativistic plane wave and a Glauber-type eikonal phase operator that parametrizes the effects of FSI. CT was incorporated by replacing the total cross section with an effective one based on the quantum diffusion model [15], similar to the effective interaction parameter of Larson, et al [76]. Finally, Kaskulov, et al [85,86] use a model built around a microscopic description [87] of the elementary [76], with and without CT, respectively.…”

“…CT was incorporated by replacing the total cross section with an effective one based on the quantum diffusion model [15], similar to the effective interaction parameter of Larson, et al [76]. Finally, Kaskulov, et al [85,86] use a model built around a microscopic description [87] of the elementary [76], with and without CT, respectively. Similarly, the dotshort dash and dot-long dash lines (blue) are Glauber calculations with and without CT from Cosyn, et al [77].…”

Time dependent hadronization via HERMES and EMC data consistency

“…Finally, we implement the 'quantum diffusion' picture of Farrar et al (5) proposed by these authors to describe the time-development of the interactions of a point-like configuration produced in a hard initial reaction (see also (6)). This picture combines the linear increase with the assumption that the cross section for the leading particles does not start at zero, but at a finite value connected with Q 2 of the initial interaction,…”