We present results for the form factor f+Kπ(0), needed to extract the CKM matrix element ∣Vus∣ from experimental data on semileptonic K decays, on the HISQ Nf=2+1+1 MILC configurations. The HISQ action is also used for the valence sector. The data set used for our final result includes three different values of the lattice spacing and data at the physical light quark masses. We discuss the error budget and how this calculation improves on our previous determination of f+Kπ(0) on the asqtad Nf=2+1 MILC configurations.
@article{arxiv.1311.7264,
title = {K semileptonic form factor with HISQ fermions at the physical point},
author = {E. Gámiz and A. Bazavov and C. Bernard and C. Bouchard and C. DeTar and D. Du and A. X. El-Khadra and J. Foley and E. D. Freeland and Steven Gottlieb and U. M. Heller and J. Kim and A. S. Kronfeld and J. Laiho and L. Levkova and P. B. Mackenzie and E. T. Neil and M. B. Oktay and Si-Wei Qiu and J. N. Simone and R. Sugar and D. Toussaint and R. S. Van de Water and Ran Zhou},
journal= {arXiv preprint arXiv:1311.7264},
year = {2014}
}
Comments
7 pages, 1 figure, presented at the 31st International Symposium on Lattice Field Theory (Lattice 2013), 29 July - 3 August 2013, Mainz, Germany; v2: minor changes