0000000000514702
AUTHOR
Ken C. Bowler
Improved B ->pi l nu(iota) form factors from the lattice
We present the results of a lattice computation of the form factors for B-0 --> pi(-)l(+)nu(l) decays near zero-recoil. These results will allow a determination of the CKM matrix element \V-ub\ when measurements of the differential decay rate become available. We also provide models for extrapolation of the form factors and rate to the full recoil range. Our computation is performed in the quenched approximation to QCD on a 24(3) x 48 lattice at beta = 6.2, using a non-perturbatively O(a)-improved action. The masses of all light valence quarks involved are extrapolated to their physical values.
Lattice study of the decay (B)over-bar(0)->p(+)l(-)(v)over-bar(l): Model-independent determination of vertical bar V-ub vertical bar
We present results of a lattice computation of the vector and axial-vector current matrix elements relevant for the semileptonic decay (B) over bar(0) --> rho(+)l(-)(l). The computations are performed in the quenched approximation of lattice QCD on a 24(3) x 48 lattice at beta = 6.2, using an O(a) improved fermionic action. Our principal result is for the differential decay rate, d Gamma/dq(2), for the decay (B) over bar(0) --> rho(+)l(-)(l), in a region beyond the charm endpoint, allowing a model-independent extraction of \V-ub\ from experimental measurements. Heavy quark symmetry relations between radiative and semileptonic decays of (B) over bar mesons into light vector mesons are also d…
Lattice study of semileptonic b-decays - (b)over-bar-]dl(nu)over-bar decays
We present a study of semileptonic ($) over bar B --> Dl ($) over bar v decays in quenched lattice QCD through a calculation of the matrix element [D\($) over bar c gamma(mu)b\($) over bar B] on a 24(3) x 48 lattice at beta = 6.2, using an O(alpha)-improved fermion action. We perform the calculation for several values of the initial and final heavy-quark masses around the charm mass, and three values of the light-(anti)quark mass around the strange mass. Because the charm quark has a bare mass which is almost 1/3 the inverse lattice spacing, we study the ensuing mass-dependent discretization errors, and propose a procedure for subtracting at least some of them nonperturbatively. We extract …
First lattice study of semileptonic decays of Lambda(b) and Xi(b) baryons
We present the results of the first lattice study of semileptonic decays of baryons containing a b quark. Predictions for the decay distributions are given and the Isgur-Wise functions for heavy baryons are computed for values of the velocity transfer up to about omega = 1.2. The computations are performed on a 24(3) x 48 lattice at beta = 6.2 using the Sheikholeslami-Wohlert action in the quenched approximation.