Journal of High Energy Physics (Mar 2024)
The three-pion K-matrix at NLO in ChPT
Abstract
Abstract The three-particle K-matrix, K $$ \mathcal{K} $$ df,3, is a scheme-dependent quantity that parametrizes short-range three-particle interactions in the relativistic-field-theory three-particle finite-volume formalism. In this work, we compute its value for systems of three pions in all isospin channels through next-to-leading order in Chiral Perturbation Theory, generalizing previous work done at maximum isospin. We obtain analytic expressions through quadratic order (or cubic order, in the case of zero isospin) in the expansion about the three-pion threshold.
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