| 摘要: |
The Y(4260) has been one of the most puzzling pieces among the so-called XYZ states. In this paper, we try to gain insights into the structure of the Y(4260) from the light-quark perspective. We study the dipion invariant mass spectrum of the e(+) e(-) -> Y(4260) -> J/psi pi(+)pi(-) process and the ratio of the cross sections sigma(e(+)e(-) -> J/psi K+ K-)/sigma(e(+)e(-) -> J/psi pi(+)pi(-)). In particular, we consider the effects of different light-quark SU(3) eigenstates inside the Y(4260). The strong pion-pion final-state interactions as well as the K (K) over bar coupled channel in the S-wave are taken into account in a model-independent way using dispersion theory. We find that the SU(3) octet state plays a significant role in these transitions, implying that the Y(4260) contains a large light-quark component. Our findings suggest that the Y(4260) is neither a hybrid nor a conventional charmonium state, and they are consistent with the Y(4260) having a sizeable (D) over barD(1) component which, however, is not completely dominant. |
