Production of the newly observed $\bar{T}_{c\bar{s}0}$ by kaon-induced reactions on a proton/neutron target

Abstract: Recently, a new doubly charged tetraquark $T^{a}_{c\bar{s}0}(2900)^{++}$ and its neutral partner $T^{a}_{c\bar{s}0}(2900)^0$ at the invariant mass spectrum of $\pi{}D_s$ were observed by the LHCb Collaboration. According to its properties, such as the mass and decay width, the $T^{a}_{c\bar{s}0}(2900)^{++/0}$ have been suggested to be a compact multi-quark state or a hadron molecule. In order to distinguish the various interpretations of the $T^{a}_{c\bar{s}0}(2900)^{++/0}$, we investigate the possibility to study the $\bar{T}^{a}_{c\bar{s}0}(2900)$ [the antiparticle of $T^{a}_{c\bar{s}0}(2900)$] by kaon-induced reactions on a proton target in an effective Lagrangian approach. The production mechanism is characterized by the $t$-channel $D$ meson exchange. Our theoretical approach is based on the assumption that $\bar{T}^{a}_{c\bar{s}0}(2900)$ can be either a $K^{}D^{}-D_s^{*}\rho$ molecule or a compact tetraquark state. Using the coupling constants of the $\bar{T}^{a}_{c\bar{s}0}(2900)$ to $KD$ channel obtained from molecule or compact tetraquark picture of the $\bar{T}^{a}_{c\bar{s}0}(2900)$, we compute the cross-sections for the process $K^{-}n\to{}\bar{T}^{a}_{c\bar{s}0}(2900)^{--}\Lambda^{+}_c$. The $\bar{K}N$ initial state interaction mediated by Pomeron and Reggeon exchanges is also included, which reduces the production of the $\bar{T}^{a}_{c\bar{s}0}(2900)$. Our calculations show that whether $\bar{T}^{a}_{c\bar{s}0}(2900)$ is a molecule or a compact tetraquark state, the cross-sections for the $K^{-}n\to{}\bar{T}^{a}_{c\bar{s}0}(2900)^{--}\Lambda^{+}_c$ reaction are of similar magnitude, ranging from approximately 0.075 nb to 0.270 nb.