Speaker
Blazenka Melic
(Rudjer Boškovic Institute, Theoretical Physics Division P.O.Box 180, HR-10002 Zagreb, Croatia)
Description
We compute the decay constants of the lowest ccbar-states with quantum numbers J(PC)=0(-+) [eta_c], 1(--) [J/psi], and 1(+-) [hc] by using lattice QCD and QCD sum rules. We consider the coupling of J/psi to both the vector and tensor currents. Lattice QCD results are obtained from the unquenched (Nf=2) simulations using twisted mass QCD at four lattice spacings, allowing us to take the continuum limit. On the QCD sum rule side we use the moment sum rules.
The results are then used to discuss the rate of eta_c --> gamma gamma decay, and to comment on the factorization in B --> X K decays, with X being either eta_c or J/psi.
Primary author
Damir Becirevic
(Laboratoire de Physique Théorique (Bât. 210) 1 Université Paris Sud, F-91405 Orsay-Cedex, France)
Co-authors
Blazenka Melic
(Rudjer Boškovic Institute, Theoretical Physics Division P.O.Box 180, HR-10002 Zagreb, Croatia)
Bruno Klajn
(Rudjer Boškovic Institute, Theoretical Physics Division P.O.Box 180, HR-10002 Zagreb, Croatia)
Francesco Sanfilippo
(School of Physics and Astronomy, University of Southampton, Highfield, Southampton, SO171 BJ, UK)
Goran Duplancic
(Rudjer Boškovic Institute, Theoretical Physics Division P.O.Box 180, HR-10002 Zagreb, Croatia)
