We present our study on B→πlν semileptonic decay form factors with NRQCD action for heavy quark from a quenched lattice QCD simulation at β=5.9 on a 163×48 lattice. We obtain form factors defined in the context of heavy quark effective theory by Burdman et al. and find that their 1/mB correction is small. The limit of physical heavy and light quark masses can be performed without introducing any model function, and we obtain a prediction for the differential decay rate dΓ/dq2. We also discuss the soft pion limit of the form factors.
@article{arxiv.hep-lat/0011008,
title = {Differential decay rate for $B \to \pi l \nu$ semileptonic decays},
author = {JLQCD Collaboration and S. Aoki and R. Burkhalter and M. Fukugita and S. Hashimoto and K-I. Ishikawa and N. Ishizuka and Y. Iwasaki and K. Kanaya and T. Kaneko and Y. Kuramashi and M. Okawa and T. Onogi and S. Tominaga and N. Tsutsui and A. Ukawa and N. Yamada and T. Yoshie},
journal= {arXiv preprint arXiv:hep-lat/0011008},
year = {2009}
}