The Quenched Approximation in Health and in Sickness

TL;DR

This paper compares quenched and unquenched chiral perturbation theory results, highlighting a potential theoretical issue with the quenched approximation in the context of physical quantity calculations.

Contribution

It provides a detailed comparison between quenched and unquenched theories and discusses a theoretical problem associated with the quenched approximation.

Findings

Quenched results differ from unquenched ones for certain physical quantities.

Identification of an apparent theoretical problem in the quenched approximation.

Comparison highlights limitations of the quenched approach.

Abstract

We present results for physical quantities computed in quenched chiral perturbation theory and compare them with the corresponding unquenched expressions. We also point out an apparent theoretical problem of the quenched approximation. latex, file espcrc2.sty needed (appended at the end: search for espcrc2.sty).