Charmed baryon semileptonic decays in a relativistic three-quark model
Abstract
We study the spin-1/2→1/2 semileptonic decays of singly charmed baryons (Λc+, Ξc0,+, and Ωc0) into the light baryon octet within a relativistic three-quark model. The constituent quark masses and spatial wave functions are determined by the baryon mass spectrum. For the physical Ξc states, the light flavor SU(3) breaking (ms > mu,d) naturally induces a coherent mixing between the flavor antitriplet and flavor sextet configurations, which is completely fixed by the mass eigenstates. Consequently, no adjustable parameters are introduced in calculating the weak transition amplitudes. Using these wave functions, we calculate the c→ s,d helicity amplitudes with the Bakamjian--Thomas boost, including the spatial Jacobian and the Wigner rotations of the constituent spins. The branching fractions, q2 distributions, longitudinal polarizations, and form factors are then obtained from these amplitudes. For the Λc+→Λℓ+νℓ and Λc+→ nℓ+νℓ modes, our branching fractions and form factors are in good agreement with the experimental data and Lattice QCD results. For Ξc0→Ξ-e+νe, we obtain branch ratio ℬℓ ≃ 4.0 %, which is consistent with recent Lattice QCD calculations but lies well above the current experimental average. Clarifying the origin of this discrepancy calls for further dedicated efforts from both experimental and theoretical sides. For the Ωc0→Ξ-ℓ+νℓ decay, the spin-$1$ ss spectator yields a positive longitudinal polarization of the final Ξ-, in contrast to the negative polarizations in the predominantly antitriplet decay modes. Our predictions for the q2 spectra, angular asymmetries, and final baryon polarizations may provide useful references for future measurements of singly charmed baryon semileptonic decays.
Related
- Unified study of hyperon semileptonic decays in a relativistic three-quark model
- U-spin sum rules in charmed baryon decays beyond the U-spin limit
- Charmed baryon decays at BESIII
- Nonleptonic decays of the double-charmed baryon Ξcc+ with dynamically determined baryon wave functions
- Exclusive production of doubly charmed baryon pair at B Factories
BibTeX
@misc{ni2026charmed,
title = {{Charmed baryon semileptonic decays in a relativistic three-quark model}},
author = {Ru-Hui Ni and Zhen-Yang Wang and Jia-Jun Wu and Bing-Song Zou},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.09802},
eprint = {2609.09802},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.09802},
}
RIS
TY - UNPB
TI - Charmed baryon semileptonic decays in a relativistic three-quark model
AU - Ru-Hui Ni
AU - Zhen-Yang Wang
AU - Jia-Jun Wu
AU - Bing-Song Zou
PY - 2026
DA - 2026/09/09
PB - arXiv
DO - 10.48550/arxiv.2609.09802
UR - https://arxiv.org/abs/2609.09802
AB - We study the spin-1/2→1/2 semileptonic decays of singly charmed baryons (Λ_c^+, Ξ_c^0,+, and Ω_c^0) into the light baryon octet within a relativistic three-quark model. The constituent quark masses and spatial wave functions are determined by the baryon mass spectrum. For the physical Ξ_c states, the light flavor SU(3) breaking (m_s > m_u,d) naturally induces a coherent mixing between the flavor antitriplet and flavor sextet configurations, which is completely fixed by the mass eigenstates. Consequently, no adjustable parameters are introduced in calculating the weak transition amplitudes. Using these wave functions, we calculate the c→ s,d helicity amplitudes with the Bakamjian--Thomas boost, including the spatial Jacobian and the Wigner rotations of the constituent spins. The branching fractions, q^2 distributions, longitudinal polarizations, and form factors are then obtained from these amplitudes. For the Λ_c^+→Λℓ^+ν_ℓ and Λ_c^+→ nℓ^+ν_ℓ modes, our branching fractions and form factors are in good agreement with the experimental data and Lattice QCD results. For Ξ_c^0→Ξ^-e^+ν_e, we obtain branch ratio ℬ_ℓ ≃ 4.0 %, which is consistent with recent Lattice QCD calculations but lies well above the current experimental average. Clarifying the origin of this discrepancy calls for further dedicated efforts from both experimental and theoretical sides. For the Ω_c^0→Ξ^-ℓ^+ν_ℓ decay, the spin-$1$ ss spectator yields a positive longitudinal polarization of the final Ξ^-, in contrast to the negative polarizations in the predominantly antitriplet decay modes. Our predictions for the q^2 spectra, angular asymmetries, and final baryon polarizations may provide useful references for future measurements of singly charmed baryon semileptonic decays.
ER -