Systematic investigation of hadronic-resonance effects in pseudoscalar electroproduction

Investigate systematically whether hadronic resonances account for the substantial discrepancies between the theoretical predictions and measured cross sections for the processes e^+e^- -> eta' + rho^0 and e^+e^- -> eta + rho^0, particularly at low and high energies and near 2 GeV.

Background

The paper calculates the electron-positron annihilation processes e+e- -> etaprime + rho0, with rho0 -> pi+pi-, and compares the predicted cross sections with BESIII and CLEO data. Although the prediction agrees with the eta' channel around 3 GeV, the authors report substantial deviations at both lower and higher energies, especially near 2 GeV. They suggest that hadronic-resonance contributions may be responsible, but do not perform a systematic analysis of those effects, leaving their role unresolved.

References

We give the final results in Fig.~\ref{fig:crosssection}, where our theoretical predictions for $e+ e- \to \eta'+\rho0(\to \pi++\pi-)$ are well agreement with experimental data around 3GeV, however, large deviates at both low and high energies, especially near 2GeV. We consider that hadronic resonances might play a crucial role, however, a systematic investigation of this issue is deferred to future studies.

— Probing Glueball content of X(2370) through heavy quarkonium radiative decays and electron-positron annihilation  (2608.23428 - Zhu et al., 24 Aug 2026) in Section “Pseudoscalar production in heavy quarkonium radiative decays and electron-positron annihilation processes,” discussion following Fig. 2