Related papers: Nonspectator Effects and B Meson Lifetimes
The mass spectrum of $c \bar b$ meson is investigated with an effective quark-antiquark potential of the form $\frac{-\alpha_c}{r}$ + $A r^{\nu}$ with $\nu$ varying from 0.5 to 2.0. The S and P-wave masses, pseudoscalar decay constant, weak…
I review the status of theoretical aspects of B-decays. The principal difficulty in interpreting the wealth of experimental data is the control of non-perturbative QCD effects, and the talk is focused on attempts to control these effects.…
The light quarks inside $B$ mesons are usually treated as spectators and do not affect the decay rates which are assumed to be purely due to b quark decays. In this paper we calculate the non-spectator contributions to inclusive charmless…
\Lambda_b matrix element of four-quark operator relevant to its lifetime is reanalyzed by QCD sum rule. The new ingredients introduced are that (1) more vacuum condensates are considered; (2) different quark-hadron duality is adopted; and…
In the framework of potential models for heavy quarkonium the mass spectrum for the system ($\bar b c$) is considered. Spin-dependent splittings, taking into account a change of a constant for effective coulomb interaction between the…
We describe a theoretical approach to compute inclusive widths of heavy hadrons, based on a systematic expansion in the inverse powers of the heavy quark mass. The method reproduces quite well the experimental ratios of $B$ mesons…
We calculate penguin contributions to the lifetime splitting between the B_s and the B_d meson. In the Standard Model the penguin effects are found to be opposite in sign, but of similar magnitude as the contributions of the current-current…
We discuss the problem of the large discrepancy between the observed lifetime ratio of $\Lambda_b$ to $B_d$ and the theoretical prediction obtained by the heavy quark effective theory. A new possibility of solving this problem is proposed…
We investigate the semileptonic and nonleptonic decays of $B_s$ mesons. We work within the context of nonrelativistic constituent quark models. We calculate the different form factors that parameterize the hadron matrix elements.
In this talk we review the theoretical status of the lifetime ratios of heavy hadrons and of the B-mixing quantities $\Delta M_s$, $\Delta \Gamma_s$ and $\phi_s$. While $\Delta M_s$ and $\Delta \Gamma_s$ suffer from large uncertainties due…
We study the time evolution and decay of the neutral B-meson system using quantum dynamical semigroups. New, nonstandard terms appear in the expression of relevant observables; they can be parametrized in terms of six phenomenological…
We present a calculation of 1/m^2_b corrections to the lifetime differences of B_s mesons \Delta \Gamma_s in the heavy-quark expansion. We find that they are small to significantly affect \Delta \Gamma_s and present the result for lifetime…
We compute by QCD sum rules the matrix elements of the relevant four-quark operators appearing in the expression of the $\Lambda_b$ inclusive decay rates at the order $1/m_b^3$. The results suggest that $1/m_b^3$ corrections are not…
Semileptonic and nonleptonic decays of the B_c meson to B_s and B mesons, caused by the c\to s,d quark transitions, are studied in the framework of the relativistic quark model. The heavy quark expansion in inverse powers of the active c…
We present a two-flavor dynamical QCD calculation of the B meson B parameters and decay constant. We use NRQCD for heavy quark and the nonperturbatively O(a)-improved Wilson action for light quark at $\beta$=5.2 on a $20^3\times 48$…
We review the current status of theoretical predictions for mixing quantities and lifetimes in the $B$-sector. In particular, due to the first non-zero measurement of the decay rate difference in the neutral $B_s$-system, $\Delta \Gamma_s/…
In the heavy quark expansion (HQE) of the total decay rates of $B_s$ and $D_s^+$ mesons non-perturbative matrix elements of four quark operators are arising as phase space enhanced contributions. We present the first determination of $m_s$…
A phenomenological analysis of lifetimes of bottom and charmed hadrons within the framework of the heavy quark expansion is performed. The baryon matrix element is evaluated using the bag model and the nonrelativistic quark model. We find…
The hadronic matrix elements of dimension-six $\Delta F=0,2$ operators are crucial inputs for the theory predictions of mixing observables and lifetime ratios in the $B$ and $D$ system. We determine them using HQET sum rules for three-point…
The ratio of the \Lambda b baryon lifetime to that of the B0 meson is measured using 1.0/fb of integrated luminosity in 7 TeV center-of-mass energy pp collisions at the LHC. The \Lambda b baryon is observed for the first time in the decay…