Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 0710.1553

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

Benoît Blossier·Michele Della Morte·Nicolas Garron·Rainer Sommer
View original source ↗Read source document ↗Export metadata ↓

Abstract

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.

Explore related subjects

hep-lat

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Benoît Blossier, Michele Della Morte, Nicolas Garron, Rainer Sommer. 2007-10-08. Heavy-light decay constant at the 1/m order of HQET. https://arxiv.org/abs/0710.1553

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Extraction of spectral densities from lattice correlators: decoupling signal from noise

We expand the treatment of the problem of the extraction of smeared spectral densities from Euclidean correlators introduced in [Phys. Rev. D 99, 094508], providing an alternative which does not rely on the Backus-Gilbert regularization. This is possible due to the observation that the solution can be decomposed into a sum of terms, in the spirit of the singular value decomposition, where those with the largest contribution to the statistical noise happen to contribute the least to the central value of the smeared spectral density. The analysis of the systematics of the inverse problem is then shifted to finding the optimal truncation of such summation, so that the signal is saturated before the noise explodes. We scrutinise the performance and systematics of this approach either as a standalone procedure, or to complement the stability analysis required to extrapolate the unbiased result in the Backus-Gilbert regulated version of the solution.

hep-lat↗
arXiv2026

Excited-State Effects in Nucleon Sigma Terms from a Variational Analysis

We investigate excited-state effects in nucleon sigma-terms in lattice QCD using twisted-mass clover-improved fermion ensembles. We study correlation functions with nucleon and multihadron nucleon-$σ$-meson interpolating operators. The analysis is performed using three gauge ensembles, including one ensemble simulated with two degenerate light, a strange, and a charm quark with quark masses tuned to approximately their physical value. We solve the generalized eigenvalue problem that arises from the matrix of correlators and show that the three-point function for the light sigma-term obtained using the optimal linear combination of interpolating operators has substantially reduced time dependence without loss of statistical precision. We apply Laplace filtering and investigate residual excited-state contributions in the extraction of $σ_{πN}$. Using the same optimal linear combination of correlators as for $σ_{πN}$ for the strange sigma-term we also observe suppressed excited state contributions over an extended range of source--sink time separations. For the charm sigma-term, we observe negligible time dependence within the large statistical uncertainties, and these improvements show no significant effect.

hep-lat↗
arXiv2026

Isotensor $πππ$ scattering with a $ρ$ resonant subsystem from QCD

This work presents a lattice quantum chromodynamics (QCD) determination of $πππ$ scattering amplitudes for the isospin-2 channel with angular momentum and parity $J^{P} = 1^+$. The calculation is performed using unphysically heavy light-quark masses, corresponding to a pion mass of $m_π \approx 400$~MeV, for which the $ρ$ meson manifests as a narrow resonance. The analysis employs a previously developed formalism that non-perturbatively relates the finite-volume spectra of two- and three-pion systems to their infinite-volume scattering amplitudes. We combine earlier lattice QCD results for $ππ$ systems with isospins 1 and 2 with new determinations of the isospin-2 three-pion finite-volume spectrum, obtained for three cubic, periodic lattice volumes with box lengths ranging from $\approx 4/m_π$ to $6/m_π$. These combined data constrain the low-lying partial waves of the infinite-volume three-pion K matrix, from which we solve a set of coupled integral equations to extract the corresponding scattering amplitudes.

hep-lat↗