FIRST STUDY OF B-]PI SEMILEPTONIC DECAY FORM-FACTORS USING NRQCD

We present a quenched calculation of the form factors of the semilepto nic weak decay B --> pi I<(nu)over bar> with O(1/M-Q) NRQCD heavy quar k and Wilson light quark on a 16(3) x 32 lattice at beta = 5.8. The fo rm factors are evaluated at six heavy quark masses, in the range of m( Q) similar to 1.5 - 8 GeV. 1/m(Q) dependence of matrix elements are in vestigated and compared with HQET predictions. We observe clear signal for the form factors near q(max)(2), even at the b-quark mass range. f(0)(q(max)(2)) is compared with f(B)/f(pi) based on the soft pion the orem and significant difference is observed.