Decay constants of B-mesons from non-perturbative HQET with two light dynamical quarks

Abstract

We present a computation of B-meson decay constants from lattice QCD simulations within the framework of Heavy Quark Effective Theory for the b-quark. The next-to-leading order corrections in the HQET expansion are included non-perturbatively. Based on Nf=2 gauge field ensembles, covering three lattice spacings a (0.08-0.05)fm and pion masses down to 190MeV, a variational method for extracting hadronic matrix elements is used to keep systematic errors under control. In addition we perform a careful autocorrelation analysis in the extrapolation to the continuum and to the physical pion mass limits. Our final results read fB=186(13)MeV, fBs=224(14)MeV and fBs/fB=1.203(65). A comparison with other results in the literature does not reveal a dependence on the number of dynamical quarks, and effects from truncating HQET appear to be negligible.

16 pages including figures and tables

References in corpus (12)

• On the generalized eigenvalue method for energies and matrix elements in lattice field theory
• Critical slowing down and error analysis in lattice QCD simulations
• Evidence for B- -> tau- nu_tau-bar with a Hadronic Tagging Method Using the Full Data Sample of Belle
• Relativistic treatment of the decay constants of light and heavy mesons
• Evidence for B- -> tau- nu_bar with a Semileptonic Tagging Method
• Decay constants of the heavy-light mesons from the field correlator method
• Decay constants of heavy pseudoscalar mesons from QCD sum rules
• Parameters of Heavy Quark Effective Theory from Nf=2 lattice QCD
• Heavy Quark Effective Theory computation of the mass of the bottom quark
• HQET at order $1/m$: II. Spectroscopy in the quenched approximation
• HQET at order 1/m: III. Decay constants in the quenched approximation
• O(a) improvement of the HYP static axial and vector currents at one-loop order of perturbation theory

Cited by in corpus (11)

• FLAG Review 2021
• FLAG Review 2024
• Exclusive Radiative Decays of W and Z Bosons in QCD Factorization
• Neutral $B$ meson mixings and $B$ meson decay constants with static heavy and domain-wall light quarks
• Analysis of Charmless Two-body B decays in Factorization Assisted Topological Amplitude Approach
• B-meson decay constants from 2+1-flavor lattice QCD with domain-wall light quarks and relativistic heavy quarks
• Precision lattice QCD computation of the $B^{\ast }B\pi$ coupling
• $SU(3)$ breaking effects in $B$ and $D$ meson lifetimes
• Recent Developments on the CKM Matrix
• Testing the Standard Model under the weight of heavy flavors
• Lattice QCD Study of $B$-meson Decay Constants from ETMC