Spectra and nonleptonic decays of multiply heavy baryons in a finite-size quark-diquark model
Abstract
We investigate the mass spectra and two-body nonleptonic weak decays of ground-state doubly and triply heavy baryons in a nonrelativistic quark-diquark model. To account for the finite size of the diquark, we generalize the convoluted quark-diquark interaction to unequal-mass diquarks using mass-weighted constituent coordinates and distinct pairwise spin-spin couplings. The resulting Schr{ö}dinger equations provide the baryon masses and wave functions used consistently in the decay calculation. The predicted masses differ from existing lattice QCD results by less than 1.5%, and our calculated mass of Ωcc+ is consistent with recent LHCb observations. The calculated hyperfine splittings are systematically slightly smaller than the lattice values, indicating a residual uncertainty in the spin-dependent interaction. Within the factorization approximation, we evaluate the c→ s and b→ c transitions with pion or kaon emission. At leading nonrelativistic order, the vector contribution vanishes for the 3/2+→1/2+ transitions, while both vector and axial contributions enter the 3/2+→3/2+ channels. The b→ c spatial overlaps are substantially smaller than their c→ s counterparts. Together with the Cabibbo-Kobayashi-Maskawa hierarchy, this reduces the corresponding b → c width by approximately two orders of magnitude. In the 3/2+→1/2+ charm transitions, the leading |k|3 dependence enhances the suppression of kaon emission. In bottom transitions with a larger energy release, the smaller relative phase-space difference brings the ratios close to the scaling determined by the Cabibbo-Kobayashi-Maskawa elements and meson decay constants. These results provide benchmark estimates for future studies of multiply heavy baryons and quantify the role of recoil dynamics within the finite-size quark-diquark framework.
Related
- λ-ρ mode mixing and radial Regge trajectories for triply heavy baryons Ωccc and Ωbbb in the diquark picture
- Nonleptonic decays of the double-charmed baryon Ξcc+ with dynamically determined baryon wave functions
- Electromagnetic form factors of singly charmed baryons Σc and Λc in a covariant quark-diquark model
- Phenomenological study of diquark effects in B̅(s)0 → D(s)(*)+ L- decays
- The semileptonic decays of Ωb*, Σb* and Ξb′* baryons
BibTeX
@misc{yu2026spectra,
title = {{Spectra and nonleptonic decays of multiply heavy baryons in a finite-size quark-diquark model}},
author = {Yongtao Yu and Tao Guo},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.05721},
eprint = {2610.05721},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.05721},
note = {CC0},
}
RIS
TY - UNPB
TI - Spectra and nonleptonic decays of multiply heavy baryons in a finite-size quark-diquark model
AU - Yongtao Yu
AU - Tao Guo
PY - 2026
DA - 2026/10/05
PB - arXiv
DO - 10.48550/arxiv.2610.05721
UR - https://arxiv.org/abs/2610.05721
AB - We investigate the mass spectra and two-body nonleptonic weak decays of ground-state doubly and triply heavy baryons in a nonrelativistic quark-diquark model. To account for the finite size of the diquark, we generalize the convoluted quark-diquark interaction to unequal-mass diquarks using mass-weighted constituent coordinates and distinct pairwise spin-spin couplings. The resulting Schr{ö}dinger equations provide the baryon masses and wave functions used consistently in the decay calculation. The predicted masses differ from existing lattice QCD results by less than 1.5%, and our calculated mass of Ω_cc^+ is consistent with recent LHCb observations. The calculated hyperfine splittings are systematically slightly smaller than the lattice values, indicating a residual uncertainty in the spin-dependent interaction. Within the factorization approximation, we evaluate the c→ s and b→ c transitions with pion or kaon emission. At leading nonrelativistic order, the vector contribution vanishes for the 3/2^+→1/2^+ transitions, while both vector and axial contributions enter the 3/2^+→3/2^+ channels. The b→ c spatial overlaps are substantially smaller than their c→ s counterparts. Together with the Cabibbo-Kobayashi-Maskawa hierarchy, this reduces the corresponding b → c width by approximately two orders of magnitude. In the 3/2^+→1/2^+ charm transitions, the leading |k|^3 dependence enhances the suppression of kaon emission. In bottom transitions with a larger energy release, the smaller relative phase-space difference brings the ratios close to the scaling determined by the Cabibbo-Kobayashi-Maskawa elements and meson decay constants. These results provide benchmark estimates for future studies of multiply heavy baryons and quantify the role of recoil dynamics within the finite-size quark-diquark framework.
ER -