Related papers: Width difference in the Bs system from lattice HQE…
The relation between the heavy-quark field in QCD and the corresponding field in HQET is derived up to three loops, and to all orders in the large-$\beta_0$ limit. The corresponding relation between the QED electron field and the…
Quantum mechanics predicts deviations from exponential decay at short and long times, yet experimental evidence is limited. We report a power-law tail after $\sim$10 lifetimes in erythrosine~B fluorescence, confirmed by two detectors…
We present predictions based on the heavy quark expansion in QCD. We find SU(3) breaking in B mesons suppressed in the framework of the HQE. B_s is expected to have the semileptonic width about 1% lower and Lambda_b about 3% higher when…
We present a lattice QCD calculation of the parameters \alpha and \beta which are necessary in the theoretical estimation of the proton lifetime in grand unified theories (GUTs) using chiral lagrangian approach. The simulation is carried…
We compute the \alpha_s^2\beta_0 part of the two-loop QCD corrections to the charged lepton spectrum in b \to c \ell \bar\nu_\ell decays and find them to be about 50\% of the first order corrections at all lepton energies, except those…
We study the light-quark mass and spatial volume dependence of the matrix elements of $\Delta B=0$ four-quark operators relevant for the determination of $V_{ub}$ and the lifetime ratios of single-$b$ hadrons. To this end, one-loop diagrams…
Theoretical estimates for the lifetimes of several isotopes of heavy elements with Z=102-120 are presented by calculating the quantum mechanical tunneling probability in a WKB framework and using microscopic nucleus-nucleus potential…
We report on the computation of the $B_s$ meson decay constant in Heavy Quark Effective Theory on the lattice. The next to leading order corrections in the HQET expansion are included non-perturbatively. We estimate higher order…
We present results of the first lattice QCD calculations of $B_c \to B_s$ and $B_c \to B_d$ weak matrix elements. Results are derived from correlation functions computed on MILC Collaboration gauge configurations with lattice spacings…
We derive a QCD sum rule for the inverse moment of the $B_s$-meson light-cone distribution amplitude in HQET. Within this method, the $SU(3)_{fl}$ symmetry violation is traced to the strange quark mass and to the difference between strange…
We give a review of the theoretical status of the lifetime predictions in the standard model. In case of $(\Delta \Gamma/ \Gamma)_{B_s}$ we are already in a rather advanced stage. We obtain…
Computational and theoretical developments in lattice QCD calculations of B and D mesons are surveyed. Several topical examples are given: new ideas for calculating the HQET parameters \bar{\Lambda} and \lambda_1; form factors needed to…
We use QCD sum rules to compute matrix elements of the Delta B=2 operators appearing in the heavy-quark expansion of the width difference of the B_s mass eigenstates. Our analysis includes the leading-order operators Q and Q_S, as well as…
By means of a heavy-top-quark effective Lagrangian, we calculate the three-loop corrections of O(alpha_s^2 G_F M_t^2) to the H->bb-bar partial decay width of the standard-model Higgs boson with intermediate mass M_H<<2M_t. We take advantage…
A lattice computation of the B-meson decay constant and the mass of the b-quark to leading order in the heavy quark effective theory is presented. The involved renormalization problems are solved non-perturbatively, and the continuum limit…
We compute the mass of the b-quark and the B_s meson decay constant in quenched lattice QCD using a combination of HQET and the standard relativistic QCD Lagrangian. We start from a small volume, where one can directly deal with the…
We calculate perturbative renormalization constants for the \Delta B=2 four-quark operators in lattice NRQCD. Continuum operators \bar{b}\gamma_{\mu}(1-\gamma_5)q~ \bar{b}\gamma_{\mu}(1-\gamma_5)q and…
We extract the total width of the top quark, Gamma_t, from the partial decay width Gamma(t -> W b) measured using the t-channel cross section for single top quark production and from the branching fraction B(t -> W b) measured in ttbar…
We consider QCD with one massless quark and one heavy quark in a finite volume of linear extent L_0 ~ 0.2 fm. In this situation, HQET represents an expansion in terms of 1/z=1/(m L_0), which we test by a non-perturbative computation of…
We point out that there exist two different formulations of the Heavy Quark Effective Theory (HQET). One formulation of HQET was mostly developed at Harvard and involves the use of the equation of motion to eliminate the small components of…