Using coherent dipion photoproduction to image gold nuclei

TL;DR

This paper demonstrates how coherent dipion photoproduction can be used to image the shape of gold nuclei by analyzing the Fourier transform of the cross section, revealing details about nuclear structure and gluon shadowing effects.

Contribution

It introduces a method to image nuclear shape using dipion photoproduction data and analyzes systematic uncertainties in the process.

Findings

Successful extraction of nuclear shape information from dipion photoproduction data

Evidence of sensitivity to gluon shadowing in the nuclear interaction

Quantitative analysis of systematic uncertainties in the imaging process

Abstract

Vector meson photoproduction offers the opportunity to image target nuclei. The two-dimensional Fourier transform $d\sigma_{\rm coherent}/dt$ of coherent vector meson photoproduction gives the two-dimensional distribution of interaction sites in the target. Since vector meson photoproduction occurs, at lowest order, via two-gluon exchange, this is sensitive to gluon shadowing. We present an analysis of $\pi^+\pi^-$ photoproduction using data from the STAR detector and a study of $d\sigma_{\rm coherent}/dt$, with an emphasis on probing the nuclear shape and its systematic uncertainties.