Related papers: Upsilon Spectrum from NRQCD with Improved Action
We extend our previous studies to calculate the B meson B parameters B_B and B_S on the lattice, and present an update of the results for the B_s meson width difference. We perform an extensive study of systematic errors in the quenched…
We examine the electronic width ratios of Upsilon resonances below the BBbar threshold by means of an effective (Cornell-type) QCD potential incorporating 1/m_b corrections obtained from a prior fit to the bottomonium spectrum. From our…
While electromagnetic and up-down quark mass difference effects on octet baryon masses are very small, they have important consequences. The stability of the hydrogen atom against beta decay is a prominent example. Here we include these…
We present a lattice calculation of the B meson B-parameter B_B using the NRQCD action. The heavy quark mass dependence is explicitly studied over a mass range between m_b and 4m_b with the $O(1/m_Q)$ and $O(1/m_Q^2)$ actions. We find that…
Theoretical predictions for B decay rates are rewritten in terms of the Upsilon(1S) meson mass instead of the b quark mass, using a modified perturbation expansion. The theoretical consistency of this expansion is shown both at low and high…
We present a model-independent analysis of the mass spectrum of nonstrange l=1 baryons in large N_c QCD. The 1/N_c expansion is used to select and order a basis of effective operators that spans the nine observables (seven masses and two…
We determine the decay rate to leptons of the ground-state $\Upsilon$ meson and its first radial excitation in lattice QCD for the first time. We use radiatively-improved NRQCD for the $b$ quarks and include $u$, $d$, $s$ and $c$ quarks in…
We investigate higher order effects in the nonrelativistic expansion of lattice QCD on the heavy-light meson decay constants and some other quantities in order to understand the truncation error of NRQCD. While our numerical results have…
The leading order coefficients of the beta-function of QCD are computed in a large N_f expansion. They are in agreement with the three loop MSbar calculation. The method involves computing the anomalous dimension of the operator (G^2_{mu…
We present new values for the $\bar{MS}$ masses of $b$ and $c$ quarks based on lattice NRQCD simulations of the $\Upsilon (b\bar{b})$ and $\psi (c\bar{c})$ systems. These include three measurements of the $b$ mass based on quenched…
For the first time, we compute non-perturbatively, i.e. without lattice perturbation theory, the renormalization constants of two-fermion operators in the quenched approximation at $\beta=6.0$, 6.2 and 6.4 using the Wilson and the…
Recent results on the QCD analysis of bound states of heavy $\bar{q}q$ quarks are reviewed, paying attention to what can be derived from the theory with a reasonable degree of rigour. We report a calculation of $\bar{b}c$ bound states; a…
We present an update of our NRQCD calculation of $B_B$ at $\beta$=5.9 with increased statistics. We also discuss a calculation of $B_S$, which is relevant to the width difference in the $B_s-\bar{B}_s$ mixing.
Triply heavy baryons are very interesting systems analogous to heavy quarkonia, but are difficult to access experimentally. Lattice QCD can provide precise predictions for these systems, which can be compared to other theoretical…
First results are obtained for B mesons using a heavy propagator calculated using NRQCD, and a light Wilson propagator. Results from 13 quenched configurations of size 16^3 x 48 at \beta = 6.0 give a value for f_{B} of less than 200 Mev and…
We show how string breaking on the lattice, treated as a mixing effect, can be related to decay rates for heavy quark systems. We use this to make a preliminary calculation of the energy split at maximum mixing for static quarks in QCD from…
We present our results of lattice calculations of $B$ parameters, which parameterize $\Delta B$=2 transition amplitudes together with the leptonic decay constant. Calculations are made in the quenched approximation at $\beta$=5.7, 5.9, 6.0…
In a recent paper, we included two loop, relativistic one loop and second order relativistic tree level corrections, plus leading nonperturbative contributions, to obtain a calculation of the lower states in the heavy quarkonium spectrum…
We compare the light hadron spectrum and decay constants for quenched QCD at $\beta=6.2$ using an $O(a)$-improved nearest-neighbour Wilson fermion action with those obtained using the standard Wilson fermion action on the same set of 18…
We present lattice results on the meson spectrum and decay constants in large-N QCD. The results are obtained in the quenched approximation for N = 2, 3, 4, 5, 6, 7 and 17 and extrapolated to infinite N.