# Status of isospin splittings in mesons and baryons

## TL;DR

This paper reviews recent precise measurements of isospin splittings in mesons and baryons, highlighting their role in estimating up-down quark mass differences and emphasizing the need for improved future measurements.

## Contribution

It updates previous results on isospin splittings based on new data and discusses the importance of more accurate measurements of specific meson and baryon mass differences.

## Key findings

- Updated estimates of quark mass differences from new measurements.
- Identification of key observables needing more precise data.
- Recognition of the impact of current measurement uncertainties.

## Abstract

Current measurements of isospin splittings in mesons and baryons are sufficiently precise that they allow estimates of the mass difference between constituent up and down quarks. Some previous results are updated in the light of these new measurements, and the importance of better measurements of some observables such as $M(K^{*\pm})$, $M(B^{*0})-M(B^0)$, and isospin splittings in bottom baryons is noted.