Lattice QCD and QCD Sum Rule determination of the decay constants of eta_c, J/psi and hc states

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...

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Bibliographic Details
Published in:arXiv.org 2014-04
Main Authors: Becirevic, Damir, Duplancic, Goran, Klajn, Bruno, Melic, Blazenka, Sanfilippo, Francesco
Format: Article
Language:English
Subjects:
Computer simulation
Decay rate
Gamma emission
Personal computers
Quantum chromodynamics
Quantum numbers
Sum rules
Tensors
Online Access:Get full text
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Summary: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.
ISSN:2331-8422
DOI:10.48550/arxiv.1312.2858