Computation of the O(p^6) order low-energy constants: an update

TL;DR

This paper updates the calculation of low-energy constants in chiral perturbation theory to the O(p6) order, comparing results across different orders and literature, highlighting the improved reliability of O(p4) results.

Contribution

The paper provides an updated set of low-energy constants at the O(p6) order for two and three flavors, including normal and anomalous terms, with a comparative analysis of different orders.

Findings

O(p4) results are more reliable than O(p6)

Most O(p6) results align with existing literature

Some O(p6) results are less accurate than previous estimates

Abstract

We update our original low-energy constants to the O(p6) order, including two and three flavours, the normal and anomalous ones. Following a comparative analysis, the O(p4) results are considered better. In the O(p6) order, most of our results are consistent or better with those we have found in the literature, although several are worse.