The opportunity to find ${\bar{d}}^{\ast }(2380)$ in the ${\rm Y}(nS)$ decay

Abstract

$d^{\ast }(2380)$ was observed by WASA-at-COSY collaborations in the nuclear reaction recently. Its particularly narrow width may indicate the new QCD-allowed hadronic structure. To further confirm the existence of this peculiar particle in a totally different kind of reaction, we study the opportunity for searching ${\bar{d}}^{\ast }$ in the ${\rm Y}(nS)$ (with n=1, 2, 3) decay. As a phenomenological study, our framework is based on SU(3) chiral quark model. By virtue of the unitarity of $S$-matrix and crossing symmetry, we study the imaginary part of the forward scattering amplitudes between ${\rm Y}(nS)$ and $d^{\ast }$. The scattering process is mainly governed by the quark-meson interaction. We examine both the pseudoscalar and vector meson contribution in the intermediate state. Hopefully, our results show that it's quite possible to find ${\bar{d}}^{\ast }$ in this decay mode in the future.

Comments: 7 pages, 3 figures, 1 table