Color coherence effects in the reaction H2(p,2p)n

Abstract

The hard proton knock-out by the proton from the deuteron at relativistic energies is considered with a focus on the color transparency (CT) effect which influences the initial- and final-state interactions. The calculations are performed in the framework of the generalized eikonal approximation supplemented by the quantum diffusion model of CT. The main results of the previous calculations [Frankfurt et al., Phys. Rev. C 56, 2752 (1997)] at the beam momentum below 20 $\mathrm{GeV}/\mathrm{c}$ are confirmed, including the dependence of the nuclear transparency on the transverse momentum of the spectator neutron, ${p}_{st}$, and on the relative azimuthal angle $\ensuremath{\phi}$ between proton and neutron: absorption at ${p}_{st}<0.2\phantom{\rule{0.28em}{0ex}}\mathrm{GeV}/\mathrm{c}$ and enhancement at ${p}_{st}>0.3\phantom{\rule{0.28em}{0ex}}\mathrm{GeV}/\mathrm{c}$ due to rescattering on the neutron, the change of $\ensuremath{\phi}$ dependence between these two regions, and the enhancement of CT effects with ${p}_{\mathrm{lab}}$. The study is then generalized to higher beam momenta, up to 75 $\mathrm{GeV}/\mathrm{c}$. It is shown that such behavior of the transparency is mainly preserved up to ${p}_{\mathrm{lab}}\ensuremath{\simeq}50\phantom{\rule{0.28em}{0ex}}\mathrm{GeV}/\mathrm{c}$, but changes significantly at higher beam momenta due to the interference of valence quark configurations of small and large sizes. As a result, the transparency at small ${p}_{st}$ exhibits oscillations as a function of the beam momentum (the nuclear filtering effect). The tensor analyzing power due to the longitudinal polarization of the deuteron is calculated. The event rate at Nuclotron-based Ion Collider fAcility (NICA) is estimated.