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

24-30 July 2016
Highfield Campus, University of Southampton
Europe/London timezone

## Chiral Perturbation Theory at finite volume or with twisted boundary conditions

28 Jul 2016, 14:00
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

Prof. Johan Bijnens (Lund University)

### Description

Recent progress in mesonic Chiral Perturbation Theory at finite volume and/or with twisted boundary conditions will be discussed. Topics include the finite volume at two-loop order calculations of masses and decay constants for the pseudoscalar of the normal case for two and three flavours [1], partially quenched three flavour [2] and the case for different patterns of spontaneous symmetry breaking [3]. Twisted boundary conditions lead to extra terms in Ward identities and form-factors which affects finite volume corrections and relations often used. This will be discussed for a number of cases, the older work [4] and the application to $K_{\ell3}$ for staggered partially quenched [5]. Vector two-point functions relevant for the $g-2$ HVP calculation will be treated at two-loop order [6] allowing a better estimnate of twisting and finite volume corrections. [1] Finite Volume at two-loops in Chiral Perturbation Theory, J. Bijnens and T. Rössler,[arXiv:1411.6384] JHEP 1501 (2015) 034 [2] Finite Volume for Three-Flavour Partially Quenched Chiral Perturbation Theory through NNLO in the Meson Sector, J. Bijnens and T. Rössler, [arXiv:1508.07238] JHEP 1511 (2015) 097 [3] Finite Volume and Partially Quenched QCD-like Effective Field Theories, J. Bijnens and T. Rössler, [arXiv:1509.04082] JHEP 1511 (2015) 017 [4] Masses, Decay Constants and Electromagnetic Form-factors with Twisted Boundary Conditions, J. Bijnens and J. Relefors, [arXiv:1402.1385] JHEP 05 (2014) 015 [5] C. Bernard, J. Bijnens, E. Gamiz and J. Relefors, work in progress [6] J. Bijnens and J. Relefors, work in progress

### Primary author

Prof. Johan Bijnens (Lund University)

 Slides