paper

-wave coupled channel effects in electron-positron annihilation

arXiv:1608.02537 · doi:10.1103/PhysRevD.94.096006

Abstract

-wave coupled channel effects arising from the , , and thresholds in annihilations are systematically studied. We provide an exploratory study by solving the Lippmann-Schwinger equation with short-ranged contact potentials obtained in the heavy quark limit. These contact potentials can be extracted from the -wave interactions in the annihilations, and then be employed to investigate possible isosinglet -wave hadronic molecules. In particular, such an investigation may provide information about exotic candidates with quantum numbers . In the mass region of the , , and thresholds, there are two quark model bare states, i.e. the and , which are assigned as and states, respectively. By an overall fit of the cross sections of , , , we determine the physical coupling constants to each channel and extract the pole positions of the and . The deviation of the ratios from that in the heavy quark spin symmetry (HQSS) limit reflects the HQSS breaking effect due to the mass splitting between the and the . Besides the two poles, we also find a pole a few MeV above the threshold which can be related to the so-called observed earlier by BABAR and Belle. This scenario can be further scrutinized by measuring the angular distribution in the channel with high luminosity experiments.

15 pages, 2 figures

References in corpus (20)

Cited by in corpus (1)