Journal of High Energy Physics (May 2024)

Radiative transitions in charmonium from lattice QCD

  • James Delaney,
  • Christopher E. Thomas,
  • Sinéad M. Ryan,
  • for the Hadron Spectrum collaboration

DOI
https://doi.org/10.1007/JHEP05(2024)230
Journal volume & issue
Vol. 2024, no. 5
pp. 1 – 35

Abstract

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Abstract The coupling of various charmonium mesons to a photon is studied using lattice QCD, giving access to radiative form factors and transitions, and probing the mesons’ structure. Methods are developed which allow the robust determination of amplitudes, including those involving an excited state as well as multiple form factors, for a range of kinematics. These are applied in dynamical lattice QCD calculations using the distillation technique to compute the underlying three-point correlation functions. Form factors and amplitudes involving the low-lying charmonia, η c , J/ψ, χ c0 and η c ′ $$ {\eta}_c^{\prime } $$ , are calculated, demonstrating the methods and providing the first dynamical lattice QCD results for some quantities.

Keywords