Coherent States in High-Energy Physics

TL;DR

This paper explores how emission amplitudes of bosons factorize in high-energy physics, revealing new quasi-particle structures in non-abelian sources and enabling advanced calculations in QCD and cross section bounds.

Contribution

It introduces the concept of quasi-particles in non-abelian sources, extending factorization and coherence principles to complex boson emission processes.

Findings

Factorization holds for abelian sources, simplifying emission amplitude calculations.

Non-abelian sources involve quasi-particles, enabling new computational approaches.

Application to large-N_c QCD solves the baryon problem and respects Froissart bound.

Abstract

The amplitude for emitting $n$ bosons factorizes into the product of $n$ single-boson emission amplitudes, if the source is energetic and abelian. If it is energetic but {\it non-abelian}, the amplitude is given by a sum of factorized {\it quasi-particle} amplitudes. A quasi-particle is made up of an arbitrary number of bosons, but couples to the source like a single one. Factorization is related to coherence, and it allows computation of subleading contributions not obtainable by usual means. Its importance is illustrated in two applications: to solve the baryon problem in large-$N_c$ QCD, and to obtain a total cross section satisfying the Froissart bound.