A new way to perform partial wave decompositions of few-nucleon forces

TL;DR

This paper introduces an exact, automated method for partial wave decomposition of nucleon-nucleon and three-nucleon forces, streamlining calculations and enabling future complex nuclear force analyses.

Contribution

It presents a general, symbolic algebra-based approach for PWD applicable to any NN or 3N potential, improving efficiency and accuracy over traditional methods.

Findings

Excellent agreement with traditional PWD methods.

Demonstrated applicability to BonnB and chiral forces.

Facilitates future complex three-nucleon force calculations.

Abstract

We formulate a general and exact method of partial wave decomposition (PWD) of any nucleon-nucleon (NN) potential and any three-nucleon (3N) force. The approach allows one to efficiently use symbolic algebra software to generate the interaction dependent part of the program code calculating the interaction. We demonstrate the feasibility of this approach for the one-boson exchange BonnB potential, a recent nucleon-nucleon chiral force and the chiral two-pion-exchange three-nucleon force. In all cases very good agreement between the new and the traditional PWD is found. The automated PWD offered by the new approach is of the utmost importance in view of future applications of numerous chiral N3LO contributions to the 3N force in three nucleon calculations.