Lattice study of B→π semileptonic decay using nonrelativistic lattice QCD

Hashimoto Shoji

Ishikawa Ken-Ichi

Matsufuru Hideo

Onogi Tetsuya

Yamada Norikazu

Physical Review D

We present an exploratory lattice study of B→π semileptonic decay form factors using nonrelativistic lattice QCD for a heavy quark with a Wilson light quark on a 163×32 quenched lattice at β=5.8. The matrix elements are calculated at eight values of the heavy quark mass in the range of 1.5–8 GeV and with three values of light quark mass. The 1/mB corrections to the matrix elements are found to be fairly small except for the spatial component proportional to the B-meson momentum. We find that the q2 dependence of the form factor f+(q2) near q2 max becomes much stronger for a larger heavy quark mass, which may suggest an increase in the pole contribution. We perform a model independent fit of the form factors and study whether the q2 dependence is consistent with the pole contribution. Although the soft pion theorem predicts f0(q2 max) =fB / fπ in the chiral limit, we observe a significant violation of this relation.

eng

American Physical Society

Copyright (c) 1998 The American Physical Society.

[ISSN] 1550-7998

[DOI] 10.1103/PhysRevD.58.014502

[NCID] AA00773624

[DOI] http://dx.doi.org/10.1103/PhysRevD.58.014502