Abstract
Recently, for the first time, the BESIII Collaboration reported the strange hidden charm tetraquark states $Z_{cs}(3985)^-$ in the $K^+$ recoil-mass spectrum near the $D_{s}^{-}D^{*0}/ D_{s}^{*-}D^{0}$ mass thresholds in the processes of $e^{+}e^{-}\to K^{+}(D_{s}^{-}D^{*0}+D_{s}^{*-}D^{0})$ at $\sqrt{s}=4.681$ GeV. The significance was estimated to be 5.3 $\sigma$. We show that the newly observed $Z_{cs}(3985)^-$ state is the $U$-spin partner of $Z_c(3900)^{-}$ as a resonance within coupled-channel calculation in the $\text{SU(3)}_F$ symmetry and heavy quark spin symmetry (HQSS). In the $\text{SU(3)}_F$ symmetry, we introduce the $G_{U/V}$ parity to construct the flavor wave functions of the $Z_{cs}$ states. In a unified framework, we consider the $J/\psi\pi(K)$, $\bar{D}_{(s)}{D}^*/\bar{D}_{(s)}^*{D}$ coupled-channel effect with the contact interaction. With the masses and widths of $Z_c(3900)$ and $Z_c(4020)$, we determine all the unknown coupling constants. We obtain mass and width of $Z_{cs}(3985)$ in good agreement with the experimental results, which strongly supports the $Z_{cs}$ states as the $U/V$-spin partner states of the charged $Z_c(3900)$. We also calculate the ratio of the partial decay widths of $Z_{cs}(3985)$, which implies that the $\bar{D}_sD^*/\bar{D}^*_s D$ decay modes are dominant. We also predict the $Z_{cs}^\prime$ states with a mass around $4130$ MeV and width around $30$ MeV, which are the $U/V$-spin partner states of the charged $Z_c(4020)$ and HQSS partner states of the $Z_{cs}(3985)$. In the hidden bottom sector, we predict the strange tetraquark states $Z_{bs}$ and $Z_{bs}^\prime$ with a mass around 10700 MeV and 10750 MeV, which are the $U/V$-spin partner states of $Z_{b}(10610)^{\pm}$ and $Z_b(10650)^{\pm}$, respectively.
Highlights
Very recently, the BESIII Collaboration reported a novel structure Zcsð3985Þ− in the Kþ recoil-mass spectrum near the D−s DÃ0=DÃs−D0 eþe− → KþðD−s DÃ0mþaDssÃs−tDhr0eÞshaotldps ffisiffin1⁄4th4e.68p1roGceesVses[1o]f.The pole mass and width were determined with a massdependent-width Breit-Wigner line shape, MpZocsle 1⁄4 ð3982.5þ−21..68 Æ 2.1Þ MeV; ΓpZocsle 1⁄4 ð12.8þ−45..43 Æ 3.0Þ MeV; ð1Þ where the first and the second uncertainties are statistical and systematic, respectively
We further extend the calculation to the hidden bottom sector with heavy quark flavor symmetry (HQFS)
We predict the Z0cs with the mass around 4130 MeV, which are the heavy quark spin symmetry (HQSS) partner states of the Zcsð3985Þ and U=V-spin partner states of the Zcð4020Þ
Summary
The BESIII Collaboration reported a novel structure Zcsð3985Þ− in the Kþ recoil-mass spectrum near the D−s DÃ0=DÃs−D0 eþe− → KþðD−s DÃ0mþaDssÃs−tDhr0eÞshaotldps ffisiffin1⁄4th4e.68p1roGceesVses[1o]f.The pole mass and width were determined with a massdependent-width Breit-Wigner line shape, MpZocsle 1⁄4 ð3982.5þ−21..68 Æ 2.1Þ MeV; ΓpZocsle 1⁄4 ð12.8þ−45..43 Æ 3.0Þ MeV; ð1Þ where the first and the second uncertainties are statistical and systematic, respectively. The BESIII Collaboration reported a novel structure Zcsð3985Þ− in the Kþ recoil-mass spectrum near the D−s DÃ0=DÃs−D0 eþe− → KþðD−s DÃ0. The pole mass and width were determined with a massdependent-width Breit-Wigner line shape, MpZocsle 1⁄4 ð3982.5þ−21..68. Æ 3.0Þ MeV; ð1Þ where the first and the second uncertainties are statistical and systematic, respectively.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.