J/psi and psi(2S) Radiative Transitions to eta_c
High Energy Physics - Experiment
2011-04-20 v2
Abstract
Using 24.5 million psi(2S) decays collected with the CLEO-c detector at CESR we present the most precise measurements of magnetic dipole transitions in the charmonium system. We measure B(psi(2S)->gamma eta_c) = (4.32+/-0.16+/-0.60)x10^-3, B(J/psi->gamma eta_c)/B(psi(2S)->gamma eta_c) = 4.59+/-0.23+/-0.64, and B(J/psi->gamma eta_c) = (1.98+/-0.09+/-0.30)%. We observe a distortion in the eta_c line shape due to the photon-energy dependence of the magnetic dipole transition rate. We find that measurements of the eta_c mass are sensitive to the line shape, suggesting an explanation for the discrepancy between measurements of the eta_c mass in radiative transitions and other production mechanisms.
Keywords
Cite
@article{arxiv.0805.0252,
title = {J/psi and psi(2S) Radiative Transitions to eta_c},
author = {CLEO Collaboration and R. E. Mitchell},
journal= {arXiv preprint arXiv:0805.0252},
year = {2011}
}
Comments
11 pages, 3 figures