Probing new types of $P_c$ states inspired by the interaction between an $S$-wave charmed baryon and an anticharmed meson in a $\bar{T}$ doublet state

Abstract

Inspired by the observations of three $P_c$ states, we systematically investigate interactions between an $S$-wave charmed baryon ${\mathcal{B}}_c^{(\ast )}={\Lambda }_c/{\Sigma }_c/{\Sigma }_c^{\ast }$ and an anticharmed meson $\bar{T}={\bar{D}}_1/{\bar{D}}_2^{\ast }$ with the one-pion-exchange potential model and the one-boson-exchange potential model, and search for possible new types of $P_c$ states with the structures of ${\mathcal{B}}_c^{(\ast )}\bar{T}$. Both $S$-$D$ wave mixing and coupled channel effects are considered. Our results suggest that in some ${\mathcal{B}}_c^{(\ast )}\bar{T}$ systems there are ideal candidates of new types of $P_c$ states, i.e., the ${\Sigma }_c{\bar{D}}_1$ state with $I(J^P)=1/2(1/2^{+})$, the ${\Sigma }_c{\bar{D}}_2^{\ast }$ state with $I(J^P)=1/2(3/2^{+})$, the ${\Sigma }_c^{\ast }{\bar{D}}_1$ state with $I(J^P)=1/2(1/2^{+})$, and the ${\Sigma }_c^{\ast }{\bar{D}}_2^{\ast }$ states with $I(J^P)=1/2(1/2^{+},3/2^{+})$, and we suggest that these predicted new types of $P_c$ states can be detected in the process ${\Lambda }_b^0\to \psi (2S)p{\pi }^{-}$. Meanwhile, we also extend our study to the interactions between an $S$-wave charmed baryon and a charmed meson in a $T$ doublet, and we predict a series of double-charm molecular pentaquarks.

14 pages, 1 figure