Lattice QCD and QCD sum rule determination of the decay constants of ηc, J/ψ and hc states
Abstract
We compute the decay constants of the lowest ccbar-states with quantum numbers J=0 (ηc), 1 (J/ψ), and 1 (hc) by using lattice QCD and QCD sum rules. We consider the coupling of J/ψ 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 ηc→γγ decay, and to comment on the factorization in B→XK decays, with X being either ηc or J/ψ.
- Publication:
-
Nuclear Physics B
- Pub Date:
- June 2014
- DOI:
- 10.1016/j.nuclphysb.2014.03.024
- arXiv:
- arXiv:1312.2858
- Bibcode:
- 2014NuPhB.883..306B
- Keywords:
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- High Energy Physics - Phenomenology;
- High Energy Physics - Experiment;
- High Energy Physics - Lattice
- E-Print:
- 25 pages (published version)