Search for hidden-charm tetraquark with strangeness in $e^{+}{e}^{-}\to K^{+}{D}_s^{\ast -}{D}^{\ast 0}+c.c.$

Abstract

We report a search for a heavier partner of the recently observed $Z_{cs}(3985{)}^{-}$ state, denoted as $Z_{cs}^{\prime -}$, in the process $e^{+}{e}^{-}\to K^{+}{D}_s^{\ast -}{D}^{\ast 0}+c.c.$, based on $e^{+}{e}^{-}$ collision data collected at the center-of-mass energies of $\sqrt{s}=4.661$, 4.682 and 4.699 GeV with the BESIII detector. The $Z_{cs}^{\prime -}$ is of interest as it is expected to be a candidate for a hidden-charm and open-strange tetraquark. A partial-reconstruction technique is used to isolate $K^{+}$ recoil-mass spectra, which are probed for a potential contribution from $Z_{cs}^{\prime -}\to D_s^{\ast -}{D}^{\ast 0}$ ($c.c.$). We find an excess of $Z_{cs}^{\prime -}\to D_s^{\ast -}{D}^{\ast 0}$ ($c.c.$) candidates with a significance of $2.1\sigma$, after considering systematic uncertainties, at a mass of $(4123.5\pm 0.7_{stat.}\pm 4.7_{syst.})\mathrm{MeV}/c^2$. As the data set is limited in size, the upper limits are evaluated at the 90\% confidence level on the product of the Born cross sections (${\sigma }^{\mathrm{Born}}$) and the branching fraction ($\mathcal{B}$) of $Z_{cs}^{\prime -}\to D_s^{\ast -}{D}^{\ast 0}$, under different assumptions of the $Z_{cs}^{\prime -}$ mass from 4.120 to 4.140 MeV and of the width from 10 to 50 MeV at the three center-of-mass energies. The upper limits of ${\sigma }^{\mathrm{Born}}\cdot \mathcal{B}$ are found to be at the level of $\mathcal{O}(1)$ pb at each energy. Larger data samples are needed to confirm the $Z_{cs}^{\prime -}$ state and clarify its nature in the coming years.

17 pages, 7 figures

References in corpus (21)

• Heavy quarkonium: progress, puzzles, and opportunities
• An updated review of the new hadron states
• Method for detector description transformation to Unity and application in BESIII
• Observation of a near-threshold structure in the $K^{+}$ recoil-mass spectra in $e^{+}{e}^{-}\to K^{+}(D_s^{-}{D}^{\ast 0}+D_s^{\ast -}{D}^0)$
• Explaining the Many Threshold Structures in the Heavy-Quark Hadron Spectrum
• Luminosities and energies of $e^{+}{e}^{-}$ collision data taken between $\sqrt{s}$=4.612 GeV and 4.946 GeV at BESIII
• $Z_{cs}(3985{)}^{-}$ as the $U$-spin partner of $Z_c(3900{)}^{-}$ and implication of other states in the ${\text{SU(3)}}_F$ symmetry and heavy quark symmetry
• Hidden charm tetraquark states in a diquark model
• Decoding the nature of $Z_{cs}(3985)$ and establishing the spectrum of charged heavy quarkoniumlike states in chiral effective field theory
• The strange partner of the $Z_c$ structures in a coupled-channels model
• A combined analysis of the $Z_c(3900)$ and the $Z_{cs}(3985)$ exotic states
• Hidden and doubly heavy molecular states from interactions $D_{(s)}^{(\ast )}{\bar{D}}_s^{(\ast )}$/$B_{(s)}^{(\ast )}{\bar{B}}_s^{(\ast )}$ and $D_{(s)}^{(\ast )}{D}_s^{(\ast )}$/$B_{(s)}^{(\ast )}{B}_s^{(\ast )}$
• Hidden-charm tetraquarks with strangeness in the chiral quark model
• Determination of quantum numbers for several excited charmed mesons observed in $B^{-}\to D^{\ast +}{\pi }^{-}{\pi }^{-}$ decays
• Is $Z_{cs}(3982)$ a molecular partner of $Z_c(3900)$ and $Z_c(4020)$ states?
• Evidence for a neutral near-threshold structure in the $K_{\mathrm{S}}^0$ recoil-mass spectra in $e^{+}{e}^{-}\to K_{\mathrm{S}}^0{D}_s^{+}{D}^{\ast -}$ and $e^{+}{e}^{-}\to K_{\mathrm{S}}^0{D}_s^{\ast +}{D}^{-}$
• $Z_{cs}$ states from the $D_s^{\ast }{\bar{D}}^{\ast }$ and $J/\psi K^{\ast }$ coupled channels: Signal in $B^{+}\to J/\psi \varphi K^{+}$ decay
• The strange cousin of the $Z_c(4020/4025)$ as tetraquark state
• Measurements of Born Cross Sections of $e^{+}{e}^{-}\to D_s^{\ast +}{D}_{sJ}^{-}+c.c.$
• Spectrum of Hidden-Charm, Open-Strange Exotics in the Dynamical Diquark Model
• Observation of ${\chi }_{cJ}\to 4K_S^0$

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