Regimes of the Pomeron and its Intrinsic Entropy

TL;DR

This paper explores the dual descriptions of the Pomeron as perturbative and non-perturbative phases, linking entropy, string dynamics, and saturation phenomena, with implications for high-energy collisions and future experiments.

Contribution

It proposes a unified phase diagram for the Pomeron, connecting string theory, entropy, and saturation, and introduces the concept of string balls as a phase boundary.

Findings

Intrinsic entropy of the Pomeron matches perturbative entanglement entropy.

Large multiplicity distributions resemble those in LHC pp collisions.

Low-x saturation linked to Bekenstein bound and string density.

Abstract

We suggest that the perturbative and non-perturbative descriptions of the Pomeron can be viewed as complementary descriptions of different phases in the Pomeron phase diagram, with a phase boundary where the proper description of the produced systems are "string balls". Their intrinsic entropy is calculated and turned out to be the same, as the recently reported perturbative entanglement entropy. The distribution of large multiplicities stemming from the string balls is also wide, with its moments close to those reported for hadrons in $pp$ collisions at the LHC. At low-x, the quantum string is so entangled that sufficiently weak string self-attraction can cause it to turn to a string ball dual to a black hole. We suggest that low-x saturation occurs when the density of wee-strings reaches the Bekenstein bound, with a proton size that freezes with increasing rapidity. Some of these observations maybe checked at the future eIC.