Structure of parton showers including quantum interference

TL;DR

This paper formulates a quantum interference-inclusive evolution equation for leading order parton showers, emphasizing the importance of color, spin, and interference effects, and discusses initial steps toward numerical implementation.

Contribution

It introduces a comprehensive evolution equation for parton showers that includes quantum interference effects, extending beyond traditional strong ordering approximations.

Findings

Formulated a linear evolution equation including quantum interference

Outlined initial approaches for numerical implementation

Highlighted the importance of color and spin in parton shower evolution

Abstract

It is useful to describe a leading order parton shower as the solution of a linear equation that specifies how the state of the partons evolves. This description involves an essential approximation of a strong ordering of virtualities as the shower progresses from a hard interaction to softer interactions. If this is to be the only approximation, then the partons should carry color and spin and quantum interference graphs should be included. We explain how the evolution equation for this kind of a shower can be formulated. We discuss briefly our efforts to implement this evolution equation numerically.