Search

This study explores the production of open-charm pentaquark molecular states, specifically $N\bar{D}^*$ and $\bar{N}\bar{D}^*$, within the $B^0 \rightarrow \bar{D}^0 p \bar{p}$ decay process. We analyze the invariant mass spectrum of $p\bar{D}^0$ and $\bar{p}\bar{D}^0$, incorporating the rescattering process calculated using a quasipotential Bethe-Salpeter equation approach. Our findings suggest the potential identification of the isoscalar $\bar{N}\bar{D}^*$ molecule with $3/2^+$, serving as the antiparticle partner of the $\Lambda_c(2940)$, in the $\bar{p}\bar{D}^0$ mass distribution. Additionally, distinctive signals of the isovector $N\bar{D}^*$ molecule with $1/2^-$ may emerge in the $p\bar{D}^0$ invariant mass distribution. We highlight the significance of the three-body decay of the bottom meson as a valuable avenue for studying open-charm molecules and advocate for increased attention and more precise experimental measurements of the $B^0 \rightarrow \bar{D}^0 p \bar{p}$ process., Comment: 8 pages, 3 figures

In this work, we systematically investigate the charmed-strange dibaryon systems with $csssqq$ quarks and their baryon-antibaryon partners from the interactions $\Xi^{(',*)}_{c}\Xi^{(*)}$, $\Omega^{(*)}_c\Lambda$, $\Omega^{(*)}_c\Sigma^{(*)}$, $\Lambda_c\Omega$ and $\Sigma^{(*)}_c\Omega$ and their baryon-antibaryon partners from interactions $\Xi^{(',*)}_{c}\bar{\Xi}^{(*)}$, $\Omega^{(*)}_c\bar{\Lambda}$, $\Omega^{(*)}_c\bar{\Sigma}^{(*)}$, $\Lambda_c\bar{\Omega}$ and $\Sigma^{(*)}_c\bar{\Omega}$. The potential kernels are constructed with the help of effective Lagrangians under SU(3), heavy quark, and chiral symmetries to describe these interactions. To search for possible molecular states, the kernels are inserted into the quasipotential Bethe-Salpeter equation, which is solved to find poles from scattering amplitude. The results suggest that 36 and 24 bound states can be found in the baryon-baryon and baryon-antibaryon interactions, respectively. However, much large values of parameter $\alpha$ are required to produce the bound states from the baryon-antibaryon interactions, which questions the existence of these bound states. Possible coupled-channel effect are considered in the current work to estimate the couplings of the molecular states to the channels considered., Comment: 13 pages, 5 figures. arXiv admin note: text overlap with arXiv:2208.11962

Recently, the LHCb Collaboration has reported two strange hidden-charm pentaquark states named $P^\Lambda_{\psi s}(4459)$ and $P^\Lambda_{\psi s}(4338)$ in the $ J/\psi \Lambda$ invariant mass spectra of decays $\Xi_b^-$$\to$$ J/\psi \Lambda K^-$ and $B^-$$\to$$J/\psi \Lambda \bar{p}$,respectively. In this work, we perform a coupled-channel study of the interactions $\Xi_c^*\bar{D}^*$, $\Xi'_c\bar{D}^*$, $\Xi^*_c\bar{D}$, $\Xi_c\bar{D}^*$, $\Xi'_c\bar{D}$, $\Lambda_c\bar{D}_s^{*}$, $\Xi_c\bar{D}$, $\Lambda_c\bar{D}_s$, and $\Lambda J/\psi$ in the quasipotential Bethe-Salpeter equation approach to estimate the $ J/\psi \Lambda$ invariant mass spectra. With the help of effective Lagrangians, the potential kernel can be constructed by meson exchanges to obtain the scattering amplitudes, from which the poles of the bound states and the invariant mass spectra can be reached. The coupled-channel calculation results in that the width of state $\Xi_c\bar{D}^{*}(1/2^-)$ is about $18$~MeV and that of state $\Xi_c\bar{D}^{*}(3/2^-)$ is only about $1.6$~MeV. By comparison with experimental data, it indicates that the structure $P^{\Lambda}_{\psi s}(4459)$ is mainly from the contribution from the $\Xi_c \bar{D}^{*}(1/2^-)$ state while the role of state $\Xi_c \bar{D}^{*}(3/2^-)$ cannot be excluded. The line shape of the structure $P^{\Lambda}_{\psi s}(4338)$ can be reproduced roughly by a narrow molecular state from the $\Xi_c \bar{D}$ interaction with $J^P$=$1/2^-$, which is extremely close to the threshold, with a large interference effect. Besides, an additional state $\Xi'_c \bar{D}(1/2^-)$ is suggested to be observed as a dip structure in the $J/\psi \Lambda$ invariant mass spectrum., Comment: 8 pages, 5 figures

In this work, we systematically investigate the dibaryons with charm number $C$=1 and strangeness number $S$=$\pm$ 1 from the interactions of a charmed baryon and a strange baryon $\Lambda_c\Lambda$, $\Lambda_c\Sigma^{(*)}$, $\Sigma_c^{(*)}\Lambda$, and $\Sigma^{(*)}_c\Sigma^{(*)}$, and corresponding interactions of a charmed baryon and an antistrange baryon $\Lambda_c\bar{\Lambda}$, $\Lambda_c\bar{\Sigma}^{(*)}$, $\Sigma^{(*)}_c\bar{\Lambda}$, and $\Sigma^{(*)}_c\bar{\Sigma}^{(*)}$. With the help of the effective Lagrangians with $SU(3)$, heavy quark, and chiral symmetries, the potentials of the interactions considered are constructed by light meson exchanges. To search for the possible molecules, the quasipotential Bethe-Salpeter equation with the interaction potential kernel is solved to find poles from scattering amplitude. The results suggest that attractions widely exist in charmed-strange system with $C$=1 and $S$=$-1$. The $S$-wave bound states can be produced from most of the channels. Few bound states are also produced from the charmed-antistrange interactions. Couple-channel effect are considered in the current work to discuss the couplings of the molecular states to the channels considered. More experimental research for these charmed-strange dibaryons are suggested., Comment: 11 pages, 6 figures

In this work, a study of possible molecular states from the $\Lambda_c\bar{\Lambda}_c$ interaction and their productions in nucleon-antinucleon collision is performed in a quasipotential Bethe-Salpeter equation approach. Two bound states with quantum numbers $J^{PC}=0^{-+}$ and $1^{--}$ are produced with almost the same binding energy from the $\Lambda_c\bar{\Lambda}_c$ interaction which is described by the light meson exchanges. However, the result does not support the assignment of experimentally observed $Y(4630)$ as a $\Lambda_c\bar{\Lambda}_c$ molecular state because it is hard to obtain a peak near experimental mass of the $Y(4630)$ which is far above the $\Lambda_c\bar{\Lambda}_c$ threshold. The possibility to search these states in nucleon-antinucleon collision is studied by including couplings to $N\bar{N}$ and $D^{(*)}\bar{D}^{(*)}$ channels. The peaks can be found obviously near the $\Lambda_c\bar{\Lambda}_c$ threshold in the $D^*\bar{D}^*$ channel at an order of amplitude of 10 $\mu$b. Too small width of state with $0^{-+}$ may lead to the difficulty to be observed in experiment. Based on the results in the current work, search for the $\Lambda_c\bar{\Lambda}_c$ molecular state with $1^{--}$ is suggested in process $N\bar{N}\to D^*\bar{D}^*$, which is accessible at $\rm \bar{P}ANDA$., Comment: 4 pages, 4 figures

In this work, the $\Omega_c$-like molecular states are systematically investigated in a quasipotential Bethe-Salpeter equation approach. The relevant interactions $\Xi_c^{(*,')}\bar{K}^{(*)}$, $\Xi^{(*)}D^{(*)}$, and $\Omega^{(*)}_c(\pi/\eta/\rho/\omega)$ are described by light meson exchanges with the help of the effective Lagrangians with SU(3), chiral, and heavy quark symmetries. The obtained potential kernels of considered interactions are inserted into the quasipotential Bethe-Salpeter equation, and coupled-channel calculations are performed to find possible molecular states and its couplings to the channels considered. The results suggest that an isoscalar state can be produced from the $\Xi^*_c\bar{K}$ interaction with spin parity $3/2^-$, which can be related to state $\Omega_c(3120)$. And its isoscalar partner is predicted with a dominant decay in the $\Omega_c^*\pi$ channel. The isoscalar and isovector states with $1/2^-$ can be produced from the $\Xi'_c\bar{K}$ interaction with a threshold close to the mass of the $\Omega_c(3050)$ and $\Omega_c(3065)$. Their couplings to the $\Xi_c \bar{K}$ channel are very weak, and the isovector one has strong coupling to $\Omega_c\pi$. High precision measurement is helpful to confirm or search such molecular states. Experimental search of states with higher masses generated from interactions $\Xi^{(*,')}_c \bar{K}^*$ and $\Xi^* D^{(*)}$ are also suggested by the current results., Comment: 11 pages, 3 figures

In this work, we systematically investigate the heavy-strange meson systems, $D^{(*)}K^{(*)}/\bar{B}^{(*)}K^{(*)}$ and $\bar{D}^{(*)}K^{(*)}/B^{(*)}K^{(*)}$, to study possible molecules in a quasipotenial Bethe-Salpter equation approach together with the one-boson exchange model. The potential is achieved with the help of the hidden-gauge Lagrangians. Molecular states are found from all six $S$-wave isoscalar interactions of $D^{(*)}K^{(*)}$ or $\bar{B}^{(*)}K^{(*)}$. The charmed-strange mesons $D^*_{s0}(2317)$ and $D_{s1}(2460)$ can be related to the ${D}K$ and $D^*K$ states with spin parities $0^+$ and $1^+$, respectively. In the current model, the $\bar{B}K^*$ molecular state with $1^+$ is the best candidate of the recent observed $B_{sJ}(6158)$. Four molecular states are produced from the interactions of $\bar{D}^{(*)}K^{(*)}$ or $B^{(*)}K^{(*)}$. The relation between the $\bar{D}^*{K}^*$ molecular state with $0^+$ and the $X_0(2900)$ is also discussed. No isovector molecular states are found from the interactions considered. The current results are helpful to understand the internal structure of $D^*_{s0}(2317)$, $D_{s1}(2460)$, $X_0(2900)$, and new $B_{sJ}$ states. The experimental research for more heavy-strange meson molecules is suggested., Comment: 8 pages,5 figure

Recently, the LHCb Collaboration reported a new structure $P_{cs}(4459)$ with a mass of 19 MeV below the $\Xi_c \bar{D}^{*} $ threshold. It may be a candidate of molecular state from the $\Xi_c \bar{D}^{*} $ interaction. In the current work, we perform a coupled-channel study of the $\Xi_c^*\bar{D}^*$, $\Xi'_c\bar{D}^*$, $\Xi^*_c\bar{D}$, $\Xi_c\bar{D}^*$, $\Xi'_c\bar{D}$, and $\Xi_c\bar{D}$ interactions in the quasipotential Bethe-Salpeter equation approach. With the help of the heavy quark chiral effective Lagrangian, the potential is constructed by light meson exchanges. Two $\Xi_c \bar{D}^{*} $ molecular states are produced with spin parities $ J^P=1/2^-$ and $3/2^- $. The lower state with $3/2^-$ can be related to the observed $P_{cs}(4450)$ while two-peak structure cannot be excluded. Within the same model, other strange hidden-charm pentaquarks are also predicted. Two states with spin parities $1/2^-$ and $3/2^-$ are predicted near the $\Xi'_c\bar{D}$, $\Xi_c\bar{D}$, and $\Xi_c^*\bar{D}$ thresholds, respectively. As two states near $\Xi_c \bar{D}^{*}$ threshold, two states are produced with $1/2^-$ and $3/2^-$ near the $\Xi'_c\bar{D}^*$ threshold. The couplings of the molecular states to the considered channels are also discussed. The experimental research of those states are helpful to understand the origin and internal structure of the $P_{cs}$ and $P_c$ states., Comment: 7 pages, 2 figures

In this work, we study possible hidden-bottom molecular pentaquarks $P_b$ from coupled-channel $\Sigma^{(*)}_bB^{(*)}-\Lambda_bB^{(*)}$ interaction in the quasipotential Bethe-Salpeter equation approach. In isodoublet sector with $I=1/2$, with the same reasonable parameters the interaction produces seven molecular states, a state near $ \Sigma_bB$ threshold with spin parity $J^P=1/2^-$, a state near $\Sigma^*_bB$ threshold with $3/2^-$, two states near $\Sigma_bB^*$ threshold with $1/2^-$ and $3/2^-$, and three states near $\Sigma_b^*B^*$ threshold with $1/2^-$, $3/2^-$, and $5/2^-$. The results suggest that three states near $\Sigma_b^* B^*$ threshold and two states near $\Sigma_b B^*$ threshold are very close, respectively, which may be difficult to distinguish in experiment without partial wave analysis. Compared with the hidden-charm pentaquark, the $P_b$ states are relatively narrow with widths at an order of magnitude of 1 MeV or smaller. The importance of each channel considered is also discussed, and it is found that the $\Lambda_b B^*$ channel provides important contribution for the widths of those states. In isoquartet sector with $I=3/2$, cutoff should be considerably enlarged to achieve bound states from the interaction, which makes the existence of such states unreliable. The results in the current work are helpful for searching for hidden-bottom molecular pentaquarks in future experiments, such as the COMPASS, J-PARC, and the Electron Ion Collider in China (EicC)., Comment: 8 pages, 3 figures

Recently, a new structure $Y(4626)$ was reported by the Belle Colloboration in the process $e^+e^-\to D_s^+D_{s1}(2536)^-$. In this work, we propose an assignment of the $Y(4626)$ as a ${D}^*_s\bar{D}_{s1}(2536)$ molecular state, which decays into the $D_s^+D_{s1}(2536)^-$ channel through a coupling between ${D}^*_s\bar{D}_{s1}(2536)$ and ${D}_s\bar{D}_{s1}(2536)$ channels. With the help of the heavy quark symmetry, the potential of the interaction ${D}^*_s\bar{D}_{s1}(2536)-{D}_s\bar{D}_{s1}(2536)$ is constructed within the one-boson-exchange model, and inserted into the quasipotential Bethe-Salpeter equation. The pole of obtained scattering amplitude is searched for in the complex plane, which corresponds to a molecular state from the interaction ${D}^*_s\bar{D}_{s1}(2536)-{D}_s\bar{D}_{s1}(2536)$. The results suggest that a pole is produced near the ${D}^*_s\bar{D}_{s1}(2536)$ threshold, which exhibits as a peak in the invariant mass spectrum of the ${D}_s\bar{D}_{s1}(2536)$ channel at about 4626 MeV. It obviously favors the $Y(4265)$ as a ${D}^*_s\bar{D}_{s1}(2536)$ molecular state. In the same model, other molecular states from the interaction ${D}^*_s\bar{D}_{s1}(2536)-{D}_s\bar{D}_{s1}(2536)$ are also predicted, which can be checked in future experiments., Comment: 7 pages, 2 figures

In this work, we propose a possible assignment of the newly observed $X(2239)$, as well as the $\eta(2225)$, as a molecular state from the interaction of a baryon $\Lambda$ and an antibaryon $\bar{\Lambda}$. With the help of effective Lagrangians, the $\Lambda\bar{\Lambda}$ interaction is described within the one-boson-exchange model with $\eta$, $\eta'$, $\omega$, $\phi$, and $\sigma$ exchanges considered. After inserting the potential kernel into the quasipotential Bethe-Salpeter equation, the bound states from the $\Lambda\bar{\Lambda}$ interaction can be studied by searching for the pole of the scattering amplitude. Two loosely bound states with spin parities $I^G(J^{PC})=0^+(0^{-+})$ and $0^-(1^{--})$ appear near the threshold almost with the same parameter. The $0^-(1^{--})$ state can be assigned to the $X(2239)$ observed at BESIII, which is very close to the $\Lambda\bar{\Lambda}$ threshold. The scalar meson $\eta(2225)$ can be interpreted as a $0^+(0^{-+})$ state from the $\Lambda\bar{\Lambda}$ interaction. The annihilation effect is also discussed through a coupled-channel calculation plus a phenomenological optical potential. It provides large widths to two bound states produced from the $\Lambda\bar{\Lambda}$ interaction. The mass of the $1^-$ state is a little larger than the mass of the $0^-$ state after including the annihilation effect, which is consistent with our assignment of these two states as $X(2239)$ and $\eta(2225)$, respectively. The results suggest that further investigation is expected to understand the structures near the $\Lambda\bar{\Lambda}$ threshold, such as $X(2239)$, $\eta(2225)$, and $X(2175)$., Comment: 2 figures, 6 pages