# Light meson decay constants beyond the quenched approximation

## TL;DR

This paper investigates how including dynamical fermion loops in lattice QCD calculations affects light meson decay constants, showing that uncorrected values increase compared to quenched approximations for moderately light quarks.

## Contribution

It introduces a method to estimate dynamical fermion effects by extrapolating from negative flavour numbers with mass matching, advancing beyond quenched approximations.

## Key findings

- Decay constants increase when dynamical fermion effects are included.
- Uncorrected decay constants are higher than quenched values for moderate quark masses.
- Method provides a way to incorporate dynamical effects in lattice QCD estimates.

## Abstract

We calculate the effects of including dynamical fermion loops in the lattice QCD estimates of meson decay constants, by extrapolating the results from negative flavour numbers after a suitable matching of the pion and rho mass. For moderately light quarks, the values of the decay constants not corrected for the renormalization constants increase with respect to their quenched values.

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Source: https://tomesphere.com/paper/hep-lat/9510048