The Status and Future of Color Transparency and Nuclear Filtering

TL;DR

This paper reviews the current state of color transparency research, discusses experimental evidence and controversies, and advocates for new measurements to clarify the phenomenon's role in nuclear physics and related theories.

Contribution

It provides a comprehensive review of color transparency evidence and proposes specific new experimental directions involving GPD and TDA physics.

Findings

Experimental evidence for color transparency is mixed and controversial.

Nuclear transparency experiments can indicate dominance of short-distance processes.

The paper calls for new measurements in various kinematic regimes.

Abstract

40 years after its introduction, the phenomenon of color transparency remains a domain of controversial interpretations of experimental data. We review present evidence for or against its manifestation in various exclusive hard scattering reactions. The nuclear transparency experiments reveal whether short distance processes dominate a scattering amplitude at some given kinematical point. We plead for a new round of nuclear transparency measurements in a variety of experimental set-ups, including near-forward exclusive reactions related to generalized parton distribution (GPD) physics and near-backward exclusive reactions related to transition distribution amplitudes (TDA) physics.