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arXiv · 1212.3188

Kaon semileptonic decays near the physical point

Peter A. Boyle·Jonathan M. Flynn·Andreas Jüttner·Christopher Sachrajda·Karthee Sivalingam·James M. Zanotti
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Abstract

The CKM matrix element $|V_{us}|$ can be extracted from the experimental measurement of semileptonic $K\toπ$ decays. The determination depends on theory input for the corresponding vector form factor in QCD. We present a preliminary update on our efforts to compute it in $N_f=2+1$ lattice QCD using domain wall fermions for several lattice spacings and with a lightest pion mass of about $170\,\mathrm{MeV}$. By using partially twisted boundary conditions we avoid systematic errors associated with an interpolation of the form factor in momentum-transfer, while simulated pion masses near the physical point reduce the systematic error due to the chiral extrapolation.

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Peter A. Boyle, Jonathan M. Flynn, Andreas Jüttner, Christopher Sachrajda, Karthee Sivalingam, James M. Zanotti. 2012-12-13. Kaon semileptonic decays near the physical point. https://arxiv.org/abs/1212.3188

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