TY  - JOUR
AU  - Bali, Gunnar S.
AU  - Collins, Sara
AU  - Dürr, Stephan
AU  - Kanamori, Issaku
TI  - D s → η , η ′ semileptonic decay form factors with disconnected quark loop contributions
JO  - Physical review / D
VL  - 91
IS  - 1
SN  - 1550-7998
CY  - [S.l.]
PB  - Soc.
M1  - FZJ-2015-05042
SP  - 014503
PY  - 2015
AB  - We calculate for the first time the form factors of the semileptonic decays of the Ds meson to η and η′ using lattice techniques. As a by-product of the calculation we obtain the masses and leading distribution amplitudes of the η and η′ mesons. We use Nf=2+1 nonperturbatively improved clover fermions on configurations with a lattice spacing a∼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, |fDs→η0|=0.564(11) and |fDs→η′0|=0.437(18) at Mπ≈470  MeV, as well as |fDs→η0|=0.542(13) and |fDs→η′0|=0.404(25) at Mπ≈370  MeV, where the errors are statistical only.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000348157800005
DO  - DOI:10.1103/PhysRevD.91.014503
UR  - https://juser.fz-juelich.de/record/202895
ER  -