New $X_{0,1}(2900)$-like exotic states in $b$-baryon decays

Abstract: In the $B^+\to D^+ D^-K^+$ decay, LHCb has reported the observation of the open-charm exotic states $X_{0,1}^0\equiv X_{0,1}(2900)^0$ with four different quark flavors~$(ud\bar s \bar c)$, where the subscripts (0,1) denote the spins. To confirm the discovery, we propose $\Lambda_b\to \Sigma_c^{0(++)} X_{0,1}^{\prime\,0(--)}$ in the final state interaction, where $X_{0,1}^{\prime\,0(--)}$ with $s u\bar d \bar c$ ($ds\bar u \bar c$) are the new $X_{0,1}$-like exotic states. More specifically, $\Lambda_c^+D_s^-$ in $\Lambda_b\to \Lambda_c^+D_s^-$ are transformed as $\Sigma_c^{0(++)} X_{0,1}^{\prime\,0(--)}$, by exchanging $\pi^{+(-)}$. As the order of magnitude estimates, we calculate ${\cal B}(\Lambda_b\to \Sigma_c^{0(++)} X_{0,1}^{\prime\,0(--)}) =(2.3\pm 0.6,4.3\pm 0.8^{+3.3}_{-2.5})\times 10^{-4}$. In addition, we estimate other $b$-baryon decays with the $X_{0,1}$-like states, such as ${\cal B}(\Xi_{b}^{0(-)}\to \Xi_{c}^{0(+)}(2645)X_{0}^{\prime\,0(--)}, \Lambda_{b}\to \Xi_{c}^{\prime\,0}X_{0,1}^{0})\sim 10^{-5}$. While one needs $\Lambda_b\to \Sigma_c^{0(++)}M_c M$ to observe $X_{0,1}^{\prime\,0(--)}\to M_c M$ with $M_c M=D_s^-\pi^+$, $\bar D^0 \bar K^0$ $(D_s^-\pi^-$, $D^-K^-)$, ${\cal B}(\Lambda_b\to \Sigma_c^{0(++)} X_{0,1}^{\prime\,0(--)}, X_{0,1}^{\prime\,0(--)}\to M_c M)\sim 10^{-4}$ are accessible to the LHCb experiment.