Radiative transitions in charmonium from lattice QCD

Journal Article · Sat Apr 01 04:00:00 EST 2006 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.73.074507· OSTI ID:20782826

Dudek, Jozef J; Edwards, Robert G; Richards, David G ^[1]

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1. Jefferson Laboratory Mail-Stop 12H2, 12000 Jefferson Avenue, Newport News, Virginia 23606 (United States)

Radiative transitions between charmonium states offer an insight into the internal structure of heavy-quark bound states within QCD. We compute, for the first time within lattice QCD, the transition form factors of various multipolarities between the lightest few charmonium states. In addition, we compute the experimentally unobservable, but physically interesting vector form factors of the {eta}{sub c}, J/{psi}, and {chi}{sub c0}. To this end we apply an ambitious combination of lattice techniques, computing three-point functions with heavy domain-wall fermions on an anisotropic lattice within the quenched approximation. With an anisotropy {xi}=3 at a{sub s}{approx}0.1 fm we find a reasonable gross spectrum and a hyperfine splitting {approx}90 MeV, which compares favorably with other improved actions. In general, after extrapolation of lattice data at nonzero Q{sup 2} to the photopoint, our results agree within errors with all well-measured experimental values. Furthermore, results are compared with the expectations of simple quark models where we find that many features are in agreement; beyond this we propose the possibility of constraining such models using our extracted values of physically unobservable quantities such as the J/{psi} quadrupole moment. We conclude that our methods are successful and propose to apply them to the problem of radiative transitions involving hybrid mesons, with the eventual goal of predicting hybrid meson photoproduction rates at the GlueX experiment.

• OSTI ID: 20782826
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 7 Vol. 73; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANISOTROPY
APPROXIMATIONS
B QUARKS
BAG MODEL
BOUND STATE
C QUARKS
COMPARATIVE EVALUATIONS
ERRORS
ETA MESONS
EXTRAPOLATION
FORM FACTORS
J PSI-3097 MESONS
LATTICE FIELD THEORY
MEV RANGE
MULTIPOLARITY
PHOTOPRODUCTION
QUADRUPOLE MOMENTS
QUANTUM CHROMODYNAMICS
T QUARKS
VECTORS