The $P$-wave $[cs][\bar{c}\bar{s}]$ tetraquark state: Y(4260) or Y(4660)?

Abstract

The mass of $P$-wave $cs$-scalar-diquark $\bar{c}\bar{s}$-scalar-antidiquark state is computed in the framework of QCD sum rules. The result $4.69\pm 0.36GeV$ is in good agreement with the experimental value of Y(4660) but higher than Y(4260)'s, which supports the $P$-wave $[cs][\bar{c}\bar{s}]$ configuration for Y(4660) while disfavors the interpretation of Y(4260) as the $P$-wave $[cs][\bar{c}\bar{s}]$ state. In the same picture, the mass of $P$-wave $[bs][\bar{b}\bar{s}]$ is predicted to be $11.19\pm 0.49GeV$.

Comments: Variations of continuum thresholds have been enlarged following the Referee's suggestions; the revised version accepted for publication in PRD; 7 pages 6 figures