In the context of the observed decay B → Kγ the applicability of the Heavy Quark Effective Theory (HQET), treating both b and s as heavy quarks, is examined. We show that the heavy s-quark approximation, as can be found in the literature, is not reliable. Electronic address: [email protected]

B → πlν decay is studied in the effective theory of heavy quark with infinite mass limit. The leading order heavy flavor-spin independent universal wave functions which parameterize the relevant matrix elements are evaluated via light cone sum rule method in the effective theory. The important quark mixing matrix element |V ub | is then extracted via B → πlν decay mode.

Applications of HQET and NRQCD to fragmentation are briefly reviewed. The special role of the b-quark in applications of heavy quark symmetry is discussed. Predictions of HQET for semileptonic B decays to excited charmed mesons are considered. Work supported in part by the U.S. Dept. of Energy under Grant No. DE-FG03-92-ER40701.

The semileptonic decay B → πl ¯ ν l is studied starting from a simple quark model and taking into account the effect of the B * resonance. A novel, multiply subtracted, Omnès dispersion relation has been implemented to extend the predictions of the quark model to all physical q 2 values. We find |V ub | = 0.0034 ± 0.0003(exp.)± 0.0007(theory), in good agreement with experiment.

We studied the hadronic decays of excited states of heavy mesons (D, Ds, B and Bs) to lighter states by emission of π, η or K. Wavefunctions and energy levels of these excited states are determined using a Dirac equation for the light quark in the potential generated by the heavy quark (including first order corrections in the heavy quark expansion). Transition amplitudes are computed in the co...

We present a lattice investigation of heavy-light mesons in the quenched approximation, using non-relativistic QCD for the heavy quark and a clover improved Wilson formulation for the light quark. A comprehensive calculation of the heavy-light spectrum has been performed for various heavy quark masses around the b. Our results for the Bs−Bd splitting agree well with the experimental value. We f...

We reexamine contributions of higher K-resonances to the radiative rare decays b → sγ in the limit where both band s-quark are considered heavy. Using the non-relativistic quark model, and the form factor definitions consistent with the HQET covariant trace formalism, we find significant disagreement with previous work which also used heavy quark symmetry, and excellent agreement with experimen...

The study of the semileptonic B-meson decays is the most accessible and cleanest way to determine the CKM matrix elements |Vcb| and Vub. These decays also provide experimental access to study the QCD form-factors, heavy quark masses, and HQE parameters. The theoretical description of semileptonic B-meson decays at the parton level is very simple because there is no interaction between leptonic ...

Flavor changing interactions of the gluino allow the b quark to decay into the strange quark plus a gluino pair if the gluino is in the ultra low mass window below 1 GeV. In this case the enhancement of the nonleptonic b decay could explain the anomalous semileptonic branching ratio. 14.80.Ly, 13.25.+m, 11.30.Pb Typeset using REVTEX

* The talk presents an update of the bottom quark mass determination from QCD moment sum rules for the Υ system by the authors [1]. Employing the M S scheme, we find m b (m b) = 4.19 ± 0.06 GeV. The differences to our previous analysis will be discussed and we comment on the determination of the pole mass for the bottom quark.