相关论文: $B^0$-$\bar{B}^0$ mixing: matching to HQET at NNLO

We compute perturbative corrections to matching coefficients of QCD to HQET for the matrix element of the $\Delta B=2$ operator that determines the mass difference in $B^0-\bar{B}^0$ system of states. This involves the technical point of…

We compute the perturbative corrections to the HQET sum rules for the matrix element of the \Delta B=2 operator that determines the mass shift of $B^0$, $\bar{B}^0$ states. Technically, we obtain analytically the non-factorizable…

We present our analysis of B physics quantities using non-perturbatively matched Heavy Quark Effective Theory (HQET) in Nf= 2 lattice QCD on the CLS ensembles. Using all-to-all propagators, HYP-smeared static quarks, and the Generalized…

We analyse matrix elements of Delta B=2 operators by combining QCD results with the ones obtained in the static limit of HQET. The matching of all the QCD operators to HQET is made at NLO order. To do that we have to include the anomalous…

In this work we address the issue of large perturbative uncertainties in the theory prediction for $\Delta \Gamma_s$, the width difference in the $B^0_s - \bar{B}^0_s$ mixing process. To this aim we complete important steps towards the full…

In this work, we find the expressions of continuum HQET four-fermion operators in terms of lattice operators in perturbation theory. To do so, we calculate the one--loop continuum--lattice HQET matching for the complete basis of $\Delta…

We present analytical next-to-leading order results for the correlator of baryonic currents at the three-loop level with one finite mass quark. We obtain the massless and the HQET limits of the correlator as particular cases from the…

We explain how the strategy of solving renormalization problems in HQET non-perturbatively by a matching to QCD in finite volume can be implemented to include dynamical fermions. As a primary application, some elements of an HQET…

Heavy--light QCD currents are matched with HQET currents at two loops and leading order in $1/m$. A single formula applies to all current matchings. As a by--product, a master formula for the two--loop anomalous dimension of the QCD current…

HQET is an effective theory for QCD with N_f light quarks and a massive valence quark if the mass of the latter is much bigger than Lambda_QCD. As any effective theory, HQET is predictive only when a set of parameters has been determined…

We discuss the renormalisation properties of parity-odd Delta B=2 operators with the heavy quark treated in the static approximation. Via twisted mass QCD (tmQCD), these operators provide the matrix elements relevant for the B0-B0bar mixing…

We consider the currents formed by a heavy and a light quark within Quantum Chromodynamics and compute the matching to Heavy Quark Effective Theory to three-loop accuracy. As an application we obtain the third-order perturbative corrections…

The QCD/HQET matching coefficient for the heavy-quark field is calculated up to four loops. It must be finite; this requirement produces analytical results for some terms in the four-loop on-shell heavy-quark field renormalization constant…

We present a perturbative calculation of the renormalization constants for the $\Delta B=2$ four-quark operators, which is needed to evaluate the bag parameters $B_B$ and $B_S$ in lattice QCD. The one-loop coefficients are calculated for…

We present a fully non-perturbative computation of the mass of the b-quark in the quenched approximation. Our strategy starts from the matching of HQET to QCD in a finite volume and finally relates the quark mass to the spin averaged mass…

Heavy Quark Effective Theory (HQET) is a new approach to QCD problems involving a heavy quark. In the leading approximation, the heavy quark is considered as a static source of the gluon field; 1/m corrections can be systematically included…

We compute on the lattice the ``bag'' parameters of the five (Delta B = 2) operators of the supersymmetric basis, by combining their values determined in full QCD and in the static limit of HQET. The extrapolation of the QCD results from…

The use of Heavy Quark Effective Theory (HQET) on the lattice as an approach to B-physics phenomenology is based on a non-perturbative matching of HQET to QCD in finite volume. As a first step to apply the underlying strategy in the…

In this talk I report on the results of a recent calculation of the \alpha_s corrections to a three-point correlation function at the three-loop level in QCD perturbation theory, which allows one to extract the matrix element of B^0 -\bar…

We report on the status of an ALPHA Collaboration project to extract quantities for B physics phenomenology from Nf=2 lattice simulations. The framework is Heavy Quark Effective Theory (HQET) expanded up to the first order of the inverse…