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 $T_{c\bar{s}0}^a(2900{)}^{++}$ and its neutral partner $T_{c\bar{s}0}^a(2900{)}^0$ 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 $T_{c\bar{s}0}^a(2900{)}^{++/0}$ have been suggested to be a compact multi-quark state or a hadron molecule. In order to distinguish the various interpretations of the $T_{c\bar{s}0}^a(2900{)}^{++/0}$, we investigate the possibility to study the ${\bar{T}}_{c\bar{s}0}^a(2900)$ [the antiparticle of $T_{c\bar{s}0}^a(2900)$] 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 ${\bar{T}}_{c\bar{s}0}^a(2900)$ can be either a $K^{\ast }{D}^{\ast }-D_s^{\ast }\rho$ molecule or a compact tetraquark state. Using the coupling constants of the ${\bar{T}}_{c\bar{s}0}^a(2900)$ to $KD$ channel obtained from molecule or compact tetraquark picture of the ${\bar{T}}_{c\bar{s}0}^a(2900)$, we compute the cross-sections for the process $K^{-}n\to {\bar{T}}_{c\bar{s}0}^a(2900{)}^{--}{\Lambda }_c^{+}$. The $\bar{K}N$ initial state interaction mediated by Pomeron and Reggeon exchanges is also included, which reduces the production of the ${\bar{T}}_{c\bar{s}0}^a(2900)$. Our calculations show that whether ${\bar{T}}_{c\bar{s}0}^a(2900)$ is a molecule or a compact tetraquark state, the cross-sections for the $K^{-}n\to {\bar{T}}_{c\bar{s}0}^a(2900{)}^{--}{\Lambda }_c^{+}$ reaction are of similar magnitude, ranging from approximately 0.075 nb to 0.270 nb.