Eur. Phys. J. C (2003) 29: 383-395
https://doi.org/10.1140/epjc/s2003-01245-x

Original Paper

$M_\pi^2$ versus m_q: comparing CP-PACS and UKQCD data to Chiral Perturbation Theory

¹ DESY Zeuthen, 15738, Zeuthen, Germany
² INT, University of Washington, WA 98195-1550, Seattle, USA

Abstract

I present a selection of CP-PACS and UKQCD data for the pseudo-Goldstone masses in N _f =2 QCD with doubly degenerate quarks. At least the more chiral points should be consistent with Chiral Perturbation Theory for the latter to be useful in an extrapolation to physical masses. I find consistency with the chiral prediction but no striking evidence for chiral logs. Nonetheless, the consistency guarantees that the original estimate, by Gasser and Leutwyler, of the N _f =2 QCD low-energy scale $\Lambda_3$ was not entirely wrong.