Title: D-s -> eta,eta \' semileptonic decay form factors with disconnected quark loop contributions
Authors: Bali, Gunnar S.
Collins, Sara
Duerr, Stephan
Kanamori, Issaku
Institute of Physics
Issue Date: 14-Jan-2015
Abstract: We calculate for the first time the form factors of the semileptonic decays of the D-s meson to eta and eta \' using lattice techniques. As a by-product of the calculation we obtain the masses and leading distribution amplitudes of the eta and eta\' mesons. We use N-f = 2 + 1 nonperturbatively improved clover fermions on configurations with a lattice spacing a similar to 0.075 fm. We are able to obtain clear signals for relevant matrix elements, using several noise reduction techniques, for both the connected and the disconnected contributions. This includes a new method for reducing the variance of pseudoscalar disconnected two-point functions. At zero momentum transfer, we obtain for the scalar form factors, vertical bar f(0)(Ds ->eta)vertical bar = 0.564(11) and vertical bar f(0)(Ds ->eta\')vertical bar = 0.437(18) at M-pi approximate to 470 MeV, as well as vertical bar f(0)(Ds ->eta)vertical bar = 0.542(13) and vertical bar f(0)(Ds ->eta\')vertical bar = 0.404(25) at M-pi approximate to 370 MeV, w here the errors are statistical only.
URI: http://dx.doi.org/10.1103/PhysRevD.91.014503
ISSN: 1550-7998
DOI: 10.1103/PhysRevD.91.014503
Volume: 91
Appears in Collections:Articles