Classical and quantum entropy of parton distributions

TL;DR

This paper introduces a semiclassical entropy measure for nucleons to analyze their internal structure, compares it with quantum entropy, and discusses entropy growth and saturation at small-x due to Pomeron loops.

Contribution

It presents the Wehrl entropy as a new tool for nucleon tomography and compares it with von Neumann entropy, highlighting entropy saturation mechanisms.

Findings

Wehrl entropy provides a new phase space complexity measure for nucleons.

Entropy grows at small-x and saturates due to Pomeron loop effects.

Comparison between semiclassical and quantum entropies offers new insights into nucleon structure.

Abstract

We introduce the semiclassical Wehrl entropy for the nucleon as a measure of complexity of the multiparton configuration in phase space. This gives a new perspective on the nucleon tomography. We evaluate the entropy in the small-$x$ region and compare with the quantum von Neumann entropy. We also discuss the growth of entropy at small-$x$ and argue that it eventually saturates due to the Pomeron loop effect.