Eur. Phys. J. A (2009) 42: 237-241
https://doi.org/10.1140/epja/i2009-10879-1

Regular Article - Theoretical Physics

Charmonium rescattering effects in (2S) decay

¹ School of Physical Science and Technology, Southwest University, 400715, Chongqing, PRC
² Institute of High Energy Physics, Chinese Academy of Sciences, P.O. Box 918(1), 100049, Beijing, PRC

^* e-mail: chenh@swu.edu.cn

Received: 12 July 2009
Revised: 10 August 2009
Accepted: 20 September 2009
Published online: 4 October 2009

Abstract

Charmonium rescattering effects in the M1 transition of (2S) are investigated by modeling a or J/ rescattering into a final state. The absorptive and dispersive part of the transition amplitudes for the rescattering loops of () and () are separately evaluated. The numerical results show that the contribution from the () rescattering process is negligible. Compared with the virtual D (D ^*) rescattering processes, the () process may be regarded as the next-leading order of the hadronic loop mechanism, which only offers the partial decay width of ∼ 0.045 keV to the (2S) .