John Bulava

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 N f = 2 gauge field ensembles, covering three lattice spacings a ≈ ( 0.08 – 0.05 ) fm and pion masses down to 190 MeV , 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 f B = 186 ( 13 ) MeV , f B s = 224 ( 14 ) MeV and f B s / f B = 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.

I = 1 and I = 2 π–π scattering phase shifts from Nf = 2 + 1 lattice QCD

The

Improvement of Nf=3 lattice QCD with Wilson fermions and tree-level improved gauge action

I=1

N_f

p

=3 lattice QCD with Wilson fermions and tree-level improved gauge action

-wave and

The b-quark mass from non-perturbative

I=2

Heavy Quark Effective Theory at

s

O(1/m_h)

-wave elastic