arXiv subjects

Benoît Blossier

Publications and source records attributed to Benoît Blossier.

24 records · Page 2Linked to original sources

arXiv2013

On the B*' --> B transition

We present a first Nf=2 lattice estimate of the hadronic coupling g_12 which parametrises the strong decay of a radially excited B* meson into the ground state B meson at zero recoil. We work in the static limit of Heavy Quark Effective Theory (HQET) and solve a Generalised Eigenvalue Problem (GEVP), which is necessary for the extraction of excited state properties. After an extrapolation to the continuum limit and a check of the pion mass dependence, we obtain g_12 = -0.17(4).

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arXiv2011

M_b and f_B from non-perturbatively renormalized HQET with Nf=2 light quarks

We present an updated analysis of the non-perturbatively renormalized b-quark mass and B meson decay constant based on CLS lattices with two dynamical non-perturbatively improved Wilson quarks. This update incorporates additional light quark masses and lattice spacings in large physical volume to improve chiral extrapolations and to reach the continuum limit. We use Heavy Quark Effective Theory (HQET) including 1/m_b terms with non-perturbative coefficients based on the matching of QCD and HQET developed by the ALPHA collaboration during the past years.

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arXiv2010

HQET at order 1/m: III. Decay constants in the quenched approximation

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 contributions to be very small. The results are extrapolated to the continuum limit, the main systematic error affecting the computation is therefore the quenched approximation used here. The Generalized Eigenvalue Problem and the use of all-to-all propagators are important technical ingredients of our approach that allow to keep statistical and systematic errors under control. We also report on the decay constant $f_{B'_s}$ of the first radially excited state in the $B_s$ sector, computed in the static limit.

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arXiv2010

HQET at order $1/m$: II. Spectroscopy in the quenched approximation

Using Heavy Quark Effective Theory with non-perturbatively determined parameters in a quenched lattice calculation, we evaluate the splittings between the ground state and the first two radially excited states of the $B_s$ system at static order. We also determine the splitting between first excited and ground state, and between the $B_s^*$ and $B_s$ ground states to order $1/m_b$. The Generalized Eigenvalue Problem and the use of all-to-all propagators are important ingredients of our approach.

hep-lat↗

arXiv2010

HQET at order 1/m: I. Non-perturbative parameters in the quenched approximation

We determine non-perturbatively the parameters of the lattice HQET Lagrangian and those of the time component of the heavy-light axial-vector current in the quenched approximation. The HQET expansion includes terms of order 1/m. Our results allow to compute, for example, the heavy-light spectrum and B-meson decay constants in the static approximation and to order 1/m in HQET. The determination of the parameters is separated into universal and non-universal parts. The universal results can be used to determine the parameters for various discretizations. The computation reported in this paper uses the plaquette gauge action and the "HYP1/2" action for the b-quark described by HQET. The parameters of the current also depend on the light-quark action, for which we choose non-perturbatively O(a)-improved Wilson fermions.

hep-lat↗

arXiv2007

Heavy-light decay constant at the 1/m order of HQET

Following the strategy developed by the ALPHA collaboration, we present a method to compute non-perturbatively the decay constant of a heavy-light meson in HQET including the 1/m corrections. We start by a matching between HQET and QCD in a small volume to determine the parameters of the effective theory non-perturbatively. Observables in the effective theory are then evolved to larger volumes. In two steps a large enough volume is reached to determine the physical decay constant. Some preliminary results in the quenched approximation are shown.

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