p-Wave pion production from nucleon-nucleon collisions

TL;DR

This paper uses chiral effective field theory to analyze p-wave pion production in nucleon-nucleon collisions, demonstrating a unified description of multiple reaction channels by tuning a single parameter.

Contribution

It shows that p-wave amplitudes in various nucleon-nucleon to nucleon-nucleon pion reactions can be simultaneously described at NNLO by adjusting one low-energy constant.

Findings

Successful simultaneous description of multiple channels

Validation of chiral EFT for NN to NNπ reactions

Adjustment of a single low-energy constant suffices

Abstract

We investigate p-wave pion production in nucleon-nucleon collisions up to next-to-next-to-leading order in chiral effective field theory. In particular, we show that it is possible to describe simultaneously the p-wave amplitudes in the $pn\to pp\pi^-$, $pp\to pn\pi^+$, $pp\to d\pi^+$ channels by adjusting a single low-energy constant accompanying the short-range operator which is available at this order. This study provides a non-trivial test of the applicability of chiral effective field theory to reactions of the type $NN\to NN\pi$.