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

$B\to\pi$ semileptonic decay form factors with NRQCD/HISQ quarks

29 Jul 2016, 17:30

20m

Building 67 Room 1003 (Highfield Campus, University of Southampton)

Talk Weak Decays and Matrix Elements Weak Decays and Matrix Elements

Speaker

Dr Chris Bouchard (William & Mary)

Description

We report on our ongoing calculation of the $B\to\pi$ semileptonic decay form factors using NRQCD/HISQ valence quarks with MILC's $N_f=2+1$ asqtad ensembles.  The use of HISQ light quarks allows simulation at large pion momenta, corresponding to $q^2\approx 0$, with controlled $(ap)^2$ errors.  We perform a simultaneous chiral, continuum, and kinematic extrapolation using the Hard Pion ChPT modified $z$ expansion developed in Phys. Rev. D 90, 054506 (2014).  This approach permits lattice simulation in a kinematic region previously considered inaccessible to lattice QCD and promises significant reduction in form factor uncertainties at low $q^2$.