Differential decay rate for $B \to \pi l \nu$ semileptonic decays
  We present our study on $B \to \pi l \nu$ semileptonic decay form factors with NRQCD action for heavy quark from a quenched lattice QCD simulation at $\beta$=5.9 on a $16^3\times 48$ lattice. We obtain form factors defined in the context of heavy quark effective theory by Burdman et al. and find that their $1/m_B$ 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 $d\Gamma/dq^2$. We also discuss the soft pion limit of the form factors. 
JLQCD Collaboration: S.Aoki, R.Burkhalter, M.Fukugita, S.Hashimoto,   K-I.Ishikawa, N.Ishizuka, Y.Iwasaki, K.Kanaya, T.Kanek...