# QCD isospin breaking in meson masses, decay constants and quark mass ratios

Abstract : The procedure to calculate masses and matrix-elements in the presence of mixing of the basis states is explained in detail. We then apply this procedure to the two-loop calculation in Chiral Perturbation Theory of pseudoscalar masses and decay constants including quark mass isospin breaking. These results are used to update our analysis of $K_{\ell4}$ done previously and obtain a value of $m_u/m_d$ in addition to values for the low-energy-constants $L_i^r$.
Document type :
Journal articles

http://hal.in2p3.fr/in2p3-00018858
Contributor : Suzanne Robert Connect in order to contact the contributor
Submitted on : Tuesday, July 10, 2001 - 12:02:34 PM
Last modification on : Wednesday, September 16, 2020 - 4:06:48 PM

### Identifiers

• HAL Id : in2p3-00018858, version 1

### Citation

G. Amoros, J. Bijnens, P. Talavera. QCD isospin breaking in meson masses, decay constants and quark mass ratios. Nuclear Physics B, Elsevier, 2001, 602, pp.87-108. ⟨in2p3-00018858⟩

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