相关论文: |Vcb| and |Vub|: Theoretical Developments
We point out that current experimental data for partial B --> pi l nu branching fractions reduce the theoretical input required for a precise extraction of |V_ub| to the form factor normalization at a single value of the pion energy. We…
Decays of B mesons to states involving tau leptons can be used as a tool to search for the effects of new physics, such as those involving a charged Higgs boson. The experimental status of the decays B -> tau nu and B -> D^(*) tau nu is…
We discussed the impact of the existence of B -> D' l nu decays to radially excited D' mesons on various long-standing puzzles in the experimental data of semileptonic b -> c ell nu decays, as summarized in our recent article…
Numerous recent measurements of kaon decays are described, with an emphasis on results offering constraints on chiral perturbation theory calculations. An up-to-date estimate of |Vus|f+(0) based on semileptonic kaon decay rates is…
A reliable determination of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{cb}|$ is mandatory for precision flavor physics and for the search for CP violating phases from new, heavy particles. In this article, we review the theory of the…
The status of heavy-quark decays as of summer 1999 is reviewed. New measurements of semileptonic B decays from LEP and from CLEO are reported and the status of determining the CKM parameters |Vcb| and |Vub| is assessed. Rare charmless…
We explore the theoretical feasibility of extracting V_ub from two ratios built from B meson inclusive partial decays, R_1 = Gamma(b-> u cbar s)/3Gamma(b -> c l nu), and R_2 = [Gamma(b -> c X) - Gamma(b -> cbar X)]/Gamma(b -> c ubar d). We…
Recent measurements of kaon decays contributing to the determination of |V_us| are summarized, and up-to-date evaluations of |V_us|f+(0) and |V_us| are presented.
Bauer, Ligeti and Luke have recently proposed a new method for measuring |V_{ub}| in inclusive semileptonic B decays, using a cut on the lepton invariant mass to discriminate against b->c transitions. We investigate the structure of the…
I review the status of lattice simulations relevant for phenomenological studies of B-physics. Results for much-studied quantities such as f_B, B_B and form-factors for semileptonic decays are presented as well as those for quantities which…
Recent progress in the theoretical description of inclusive B to X_u l nu decays in the shape-function region is reported. Finite moments of the shape function are related to HQET parameters. Event fractions for several experimental cuts…
Semileptonic ${B}$ meson decays involving low-mass charged leptons ${e}$ or ${\mu}$ are expected to be free of non-Standard Model contributions and therefore play a critical role in determinations of ${\vert V_{ub} \vert}$ and ${\vert…
Moments of B -> X l nu and B -> Xs gamma decays can determine nonperturbative QCD parameters that relate the semileptonic decay width to Vcb. CLEO pioneered measurement of these moments, determined the relevant QCD parameters from the…
To start the $b$-decay session we briefly introduce and comment some important theoretical tools which are currently used in $b$ physics. Heavy Quark Symmetry and its consequences for heavy to heavy and heavy to light semi-leptonic decays,…
The recent experimental results on leptonic $D^+_{(s)}$ decays, semileptonic $D$ decays, determinations of decay constants and form factors, as well as extractions of $|V_{cd}|$ and $|V_{cs}|$ are briefly reviewed. Global analysis of all…
Aspects of the OPE-based QCD theory of B decays are discussed. We have at least one nontrivial precision check of the OPE at the nonperturbative level in inclusive decays. The data suggest proximity to the `BPS' limit for B mesons. Its…
We present a brief discussion about expressions of decay widths of exclusive nonleptonic and semileptonic B decays at tree level including $l=0$ and $l=1$ mesons in final state. Our analysis is carried out assuming factorization hypothesis…
Recent results in leptonic and semileptonic D decays by BaBar, Belle, CLEO, and FOCUS are reviewed and compared with theoretical predictions.
We discuss our ongoing effort to calculate form factors for several B and Bs semileptonic decays. We have recently completed the first unquenched calculation of the form factors for the rare decay B -> K ll. Extrapolated over the full…
Motivated by the anomalies present in $b \to u$ and $b \to c$ semileptonic decays, we study the corresponding $B_s \to (K,K^*) \tau \nu$ and $B \to \pi \tau \nu$ decays within an effective field theory formalism. Our analysis is based on a…