English

Charmonium Spectroscopy in Strong Magnetic Fields by QCD Sum Rules: S-Wave Ground States

High Energy Physics - Phenomenology 2015-02-25 v2 High Energy Physics - Lattice Nuclear Experiment Nuclear Theory

Abstract

We investigate quarkonium mass spectra in external constant magnetic fields by using QCD sum rules. We first discuss a general framework of QCD sum rules necessary for properly extracting meson spectra from current correlators computed in the presence of strong magnetic fields, that is, a consistent treatment of mixing effects caused in the mesonic degrees of freedom. We then implement operator product expansions for pseudoscalar and vector heavy-quark current correlators by taking into account external constant magnetic fields as operators, and obtain mass shifts of the lowest-lying bound states ηc\eta_c and J/ψJ/\psi in the static limit with their vanishing spatial momenta. Comparing results from QCD sum rules with those from hadronic effective theories, we find that the dominant origin of mass shifts comes from a mixing between ηc\eta_c and J/ψJ/\psi with a longitudinal spin polarization, accompanied by other subdominant effects such as mixing with higher excited states and continua.

Keywords

Cite

@article{arxiv.1411.7675,
  title  = {Charmonium Spectroscopy in Strong Magnetic Fields by QCD Sum Rules: S-Wave Ground States},
  author = {Sungtae Cho and Koichi Hattori and Su Houng Lee and Kenji Morita and Sho Ozaki},
  journal= {arXiv preprint arXiv:1411.7675},
  year   = {2015}
}

Comments

24 pages, 12 figures. Comments inserted in the last paragraph of Sec. II; One reference added; Published in PRD; Title slightly changed upon request by PRD