# The 34th International Symposium on Lattice Field Theory (Lattice 2016)

Jul 24 – 30, 2016
Highfield Campus, University of Southampton
Europe/London timezone

## Towards a determination of the ratio of the kaon to pion decay constants

Jul 28, 2016, 3:00 PM
20m
Building 67 Room 1003 (Highfield Campus, University of Southampton)

### Building 67 Room 1003

#### Highfield Campus, University of Southampton

Highfield Campus, Southampton SO17 1BJ, UK
Talk Weak Decays and Matrix Elements

### Speaker

Dr Roger Horsley (University of Edinburgh)

### Description

The SU(3) flavour symmetry breaking expansion in up, down and strange quark masses is extended from hadron masses to meson decay constants. This allows a determination of the ratio of kaon to pion decay constants in QCD. Furthermore when using partially quenched valence quarks the expansion is such that SU(2) isospin breaking effects can also be determined. It is found that the lowest order SU(3) flavour symmetry breaking expansion (Gell-Mann-Okubo) works very well. Simulations are performed for 2+1 flavours of clover fermions at 4 lattice spacings.

### Primary author

Dr Roger Horsley (University of Edinburgh)

 Slides