K∗ vector and tensor couplings from Nf=2 twisted mass QCD

Abstract

The mass m K ∗ and vector coupling f K ∗ of the K ∗ meson, as well as the ratio of the tensor to vector couplings f T f V | K ∗ , are computed in lattice QCD. Our simulations are performed in a partially quenched setup, with two dynamical (sea) Wilson quark flavors, having a maximally twisted mass term. Valence quarks are either of the standard or the Osterwalder-Seiler maximally twisted variety. Results obtained at three values of the lattice spacing are extrapolated to the continuum, giving m K ∗ = 981 ( 33 ) MeV , f K ∗ = 240 ( 18 ) MeV , and f T ( 2 GeV ) f V | K ∗ = 0.704 ( 41 ) .