Abstract
Inspired by the discovery of two pentaquarks $P_{c}(4380)$ and $P_{c}(4450)$ at the LHCb detector, we study possible hidden-charm molecular pentaquarks in the framework of quark delocalization color screening model. Our results suggest that both $N\eta_{c}$ with $IJ^{P}=\frac{1}{2}\frac{1}{2}^{-}$ and $NJ/\psi$ with $IJ^{P}=\frac{1}{2}\frac{3}{2}^{-}$ are bounded by channels coupling. However, $NJ/\psi$ with $IJ^{P}=\frac{1}{2}\frac{3}{2}^{-}$ may be a resonance state in the $D-$wave $N\eta_{c}$ scattering process. Moreover, $P_{c}(4380)$ can be explained as the molecular pentaquark of $\Sigma^{*}_{c}D$ with quantum numbers $IJ^{P}=\frac{1}{2}\frac{3}{2}^{-}$. The state $\Sigma^{*}_{c}D^{*}$ with $IJ^{P}=\frac{1}{2}\frac{5}{2}^{-}$ is a resonance, it may not be a good candidate of the observed $P_{c}(4450)$ because of the opposite parity of the state to $P_{c}(4380)$, although the mass of the state is not far from the experimental value. In addition, the calculation is extended to the hidden-bottom pentaquarks, the similar properties as that of hidden-charm pentaquarks system are obtained.
Highlights
In the past decade, many near-threshold charmoniumlike states have been observed at Belle, BaBar, BESIII, and LHCb, triggering lots of studies on the molecule-like hadrons containing heavy quarks
In the heavy quark sector, the large masses of the heavy quarks reduce the kinetic of the system, which makes it easier to form bound states or resonances
There is a stable state, the mass of which is lower than the threshold of N J/ψ, and the main channel of this state is N J/ψ, with the ratio of 80.8
Summary
Many near-threshold charmoniumlike states have been observed at Belle, BaBar, BESIII, and LHCb, triggering lots of studies on the molecule-like hadrons containing heavy quarks. Quarks confined in one nucleon are allowed to delocalize to a nearby nucleon and the confinement interaction between quarks in different baryon orbits is modified to include a color screening factor The latter is a model description of the hidden color channel-coupling effect [23]. The resonating-group method (RGM) is employed to study the possible hidden-charm molecular pentaquarks in QDCSM, and the channel-coupling effect are considered. All other parameters are taken from our previous work [31], except for the charm and bottom quark masses mc and mb, which are fixed by a fitting to the masses of the charmed and bottom baryons and mesons. It has been used to explain the cross-over transition between hadron phase and quark–gluon plasma phase [35]
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