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S-wave flavor-singlet meson mixing in QCD with light and charm quarks

Juan Andrés Urrea-Niño*

Roman Höllwieser, Francesco Knechtli, and Tomasz Korzec

Jacob Finkenrath

Michael Peardon

  • CERN, Esplanade des Particules 1, 1211 Geneva 23, Switzerland

  • *Contact author: urrea.nino@tcd.ie
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Phys. Rev. D 112, 074502 – Published 10 October, 2025

DOI: https://doi.org/10.1103/tcbk-x4f1

Abstract

We investigate the mixing between flavor-singlet light meson and charmonium operators in the S-wave channels, i.e., pseudoscalar and vector channel, at two different pion masses. We measure statistically significant nonzero correlations between operators with different quark content corresponding to off-diagonal entries of a flavor-singlet mixing correlation matrix. By solving a Generalized Eigenvalue Problem (GEVP) we extract the low-lying energy spectrum and compare it with the one obtained by the different types of operators separately. We also calculate the overlaps between the states created by different operators and the energy eigenstates of the theory and find that all types of operators contribute to resolve the states of interest.

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Phys. Rev. D 112, 074502– Published 10 October, 2025
  • Received 9 July 2025
  • Accepted 2 September 2025
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