The mass of the two lightest quarks

Abstract

The problems encountered in the determination of m_u and m_d are discussed. While their sum is known quite well, the difference m_d-m_u, which measures the breaking of isospin symmetry in the QCD Lagrangian, is still subject to significant uncertainties. I focus on recent work based on the dispersive analysis of the decay eta -> 3 pi, which offers a good handle on isospin breaking, because in that transition, the contributions from the e.m. interaction are suppressed.

Contribution to the proceedings of the workshop "Determination of the Fundamental Parameters of QCD", Nanyang Technological University, Singapore, March 2013

References in corpus (9)

• Review of lattice results concerning low energy particle physics
• $\eta \to 3\pi$ at Two Loops In Chiral Perturbation Theory
• Cusps in K --> 3 pi decays
• Radiative corrections in K --> 3 pi decays
• Analytical dispersive construction of $\eta \to 3\pi$ amplitude: First order in isospin breaking
• Cusps in K_L --> 3 pi decays
• Cusps in K --> 3pi decays: a theoretical framework
• Analysis of discrepancies in Dalitz plot parameters in eta to 3 pion decay
• Eta --> 3 pi and quark masses

Cited by in corpus (5)

• QCD and strongly coupled gauge theories: challenges and perspectives
• Etaprime and Eta Mesons with Connection to Anomalous Glue
• $\eta$-${\eta }^{\prime }$ Mixing in Large-$N_c$ Chiral Perturbation Theory
• Status of chiral perturbation theory for light mesons
• $\eta$-${\eta }^{\prime }$ mixing in large-$N_c$ chiral perturbation theory: discussion, phenomenology, and prospects