Exploring bottom-charmed molecular tetraquarks with the complex scaling method

Abstract

In this work, we adopt the one-boson exchange model to analyze the $D_{(s)}^{(\ast )}{B}_{(s)}^{(\ast )}$ interactions from a coupled-channel perspective. For the $I(J^P)=1(1^{+})$ $D{B}^{\ast }/D^{\ast }B/D^{\ast }{B}^{\ast }$ system, employing the complex scaling method, we obtain a loosely bound state and two resonant states located below the $D{B}^{\ast }$, $D^{\ast }B$, and $D^{\ast }{B}^{\ast }$ thresholds, respectively. Assuming that the charmonium-like states $T_{c\bar{c}1}(3900)$ and $T_{c\bar{c}1}(4020)$, as well as the bottomonium-like states $T_{b\bar{b}1}(10610)$ and $T_{b\bar{b}1}(10650)$, are molecular states near their respective thresholds, we suggest that the predicted states in the $I(J^P)=1(1^{+})$ $D_{(s)}^{(\ast )}{B}_{(s)}^{(\ast )}$ system could be their bottom-charmed analogues. In addition, we extend our analysis to other $D_{(s)}^{(\ast )}{B}_{(s)}^{(\ast )}$ combinations with various quantum numbers. Our results suggest that some exotic structures may exist in the bottom-charmed sector. Finally, we collect the possible decay channels for future experimental observations. The $B_c/B_c^{\ast }$ plus a light meson are the ideal final state to search for the bound states, while the $D_{(s)}^{(\ast )}{B}_{(s)}^{(\ast )}$ channels are suitable for the resonances. We highly recommend that the future experiments hunt for these bottom-charmed exotic particles.