Landscape of pentaquark bound states with neural-network Variational Monte Carlo
Abstract
We present a systematic study of the ground states of pentaquark systems using the neural network variational Monte Carlo method within the constituent quark potential model. We investigate all manifestly exotic pentaquark systems with negative parity, which cannot mix with the conventional baryons through the creation and annihilation of light or strange quark pair. We exhaust 387 color, spin, and isospin configurations and identify 21 pentaquark bound state candidates with binding energies ranging from $2$ to $15$ MeV. A striking observation is that all of the bound states are shallowly bound molecular states, and a deeply bound pentaquark state does not exist. The QQqqQ̅, ssqqQ̅, QsqqQ̅ and QqqqQ̅ bound states are composed of a heavy vector meson and a baryon, while the QQqqs̅ and Qqqqs̅ bound states are composed of a K meson and a heavy baryon. As a cross-validation, the ground-state energies of the unbound systems converge to the baryon--meson thresholds from above, which are consistent with the S-wave scattering states and provide a reliable baseline for the bound-state criterion. Especially, we reproduce the lowest scattering states ηc N and ηc Λ in the qqqcc̅ and qqscc̅ channels respectively, where the hidden-charm pentaquark resonances were observed experimentally. We also find that all fully heavy pentaquark states are unbound. Our results provide valuable guidance for future pentaquark searches at LHCb, Belle II, and other experiments.
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BibTeX
@misc{song2026landscape,
title = {{Landscape of pentaquark bound states with neural-network Variational Monte Carlo}},
author = {Jing-Zhe Song and Wei-Lin Wu and Shi-Lin Zhu},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.32624},
eprint = {2609.32624},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.32624},
}
RIS
TY - UNPB
TI - Landscape of pentaquark bound states with neural-network Variational Monte Carlo
AU - Jing-Zhe Song
AU - Wei-Lin Wu
AU - Shi-Lin Zhu
PY - 2026
DA - 2026/09/26
PB - arXiv
DO - 10.48550/arxiv.2609.32624
UR - https://arxiv.org/abs/2609.32624
AB - We present a systematic study of the ground states of pentaquark systems using the neural network variational Monte Carlo method within the constituent quark potential model. We investigate all manifestly exotic pentaquark systems with negative parity, which cannot mix with the conventional baryons through the creation and annihilation of light or strange quark pair. We exhaust 387 color, spin, and isospin configurations and identify 21 pentaquark bound state candidates with binding energies ranging from $2$ to $15$ MeV. A striking observation is that all of the bound states are shallowly bound molecular states, and a deeply bound pentaquark state does not exist. The QQqqQ̅, ssqqQ̅, QsqqQ̅ and QqqqQ̅ bound states are composed of a heavy vector meson and a baryon, while the QQqqs̅ and Qqqqs̅ bound states are composed of a K meson and a heavy baryon. As a cross-validation, the ground-state energies of the unbound systems converge to the baryon--meson thresholds from above, which are consistent with the S-wave scattering states and provide a reliable baseline for the bound-state criterion. Especially, we reproduce the lowest scattering states η_c N and η_c Λ in the qqqcc̅ and qqscc̅ channels respectively, where the hidden-charm pentaquark resonances were observed experimentally. We also find that all fully heavy pentaquark states are unbound. Our results provide valuable guidance for future pentaquark searches at LHCb, Belle II, and other experiments.
ER -