Nuclei as Probes of Meson-Nucleon Interactions at High and Low Energy

TL;DR

This paper investigates color transparency effects in meson and vector meson electroproduction reactions at high-energy experiments and assesses the feasibility of measuring the J/psi-nucleon scattering parameters.

Contribution

It provides new theoretical predictions for color transparency detection in pion and rho meson electroproduction and evaluates the potential to measure J/psi-nucleon scattering at JLab energies.

Findings

Color transparency should be detectable in pion knockout reactions at CERN energies.

Color transparency effects are predicted in rho meson electroproduction at small Q^2 and large t.

Feasibility of measuring J/psi-nucleon scattering amplitude at JLab energies is demonstrated.

Abstract

This dissertation explores two main topics: 1) Color Transparency and quasi-elastic knockout reactions involving pions and $\rho$ mesons; and 2) determination of the $J/\psi$-nucleon scattering amplitude and scattering length via $J/\psi$ electroproduction on the deuteron. It is shown that at the energies available at the COMPASS experiment at CERN, Color Transparency should be detectable in the reaction $\pi+A\to \pi+p+(A-1)^*$ (proton knockout). It is also shown that Color Transparency should be detectable in the electroproduction reaction $\gamma^*+A\to\rho+p+(A-1)^*$ at small $Q^2$ (where $Q^2$ is the virtuality of the photon) but large $t$ (4-momentum transfer squared to the knocked out proton), which represents an as-yet unexplored kinematic region in the search for CT effects in electroproduction of vector mesons. Calculations are also presented for the reaction $\gamma^*+D\to J/\psi+p+n$ at JLab energies in order to determine the feasibility of measuring the elastic $J/\psi$-nucleon scattering amplitude and/or scattering length. It is found that it may be possible to measure the $J/\psi$-nucleon scattering amplitude at lower energies than previous measurements, but the scattering length cannot be measured.