Spectroscopic parameters of Bc meson
Abstract
We study the spectroscopy and decays of the Bc meson in a nonrelativistic quark model in which all observables follow from a single set of wave functions, with spin-dependent effects included directly in the bound-state equation. With parameters calibrated to the measured Bc(1S) and Bc(2S) masses, we predict the S-, P-, and D-wave spectrum up to n=5, the pseudoscalar and vector decay constants with one-loop QCD corrections, the E1 and M1 radiative widths, and the radial Regge trajectories of ten spin-parity families. The 1P multiplet is predicted at 6692--6746~MeV with the normal fine-structure ordering, compatible with lattice QCD and located in the region of the two structures observed by LHCb in the Bc+γ spectrum. The 1D states lie near 7008~MeV, below the BD threshold, and all four D-wave families are provided. The decay constant fBc=507.1~MeV is consistent with recent QCD sum-rule results and corresponds to ℬ(Bc→τντ)≈3%. The E1 widths follow the expected angular weights, while their magnitudes are governed mainly by the radial overlap. The 1P→1S (81--112~keV) and 1D→1P (71--93~keV) widths suggest the 1D→1P→1S cascade as a promising route toward the first D-wave Bc state. The Regge trajectories are nearly linear, with slopes decreasing from about 5.8~GeV2 for the S-wave to 4.7--4.8~GeV2 for the D-wave states. These results may guide forthcoming measurements at the LHC and future e+e- facilities.
Related
- Resolving the ϕ-meson directed-flow puzzle by multi-step meson--baryon dynamics
- Meson photoproduction at Jefferson Lab: from two-meson final states to meson-baryon spin-density matrices
- Non-monotonicity of pT correlations from meson-baryon mixing
- Electroweak baryogenesis from charged current anomalies in B meson decays
- Meson spectroscopy of exotic symmetries of Ising criticality in Rydberg atom arrays
BibTeX
@misc{kucukyılmaz2026spectroscopic,
title = {{Spectroscopic parameters of $B_c$ meson}},
author = {Sinem Küçükyılmaz and Halil Mutuk},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2609.24536},
eprint = {2609.24536},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.24536},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Spectroscopic parameters of B_c meson
AU - Sinem Küçükyılmaz
AU - Halil Mutuk
PY - 2026
DA - 2026/10/07
PB - arXiv
DO - 10.48550/arxiv.2609.24536
UR - https://arxiv.org/abs/2609.24536
AB - We study the spectroscopy and decays of the B_c meson in a nonrelativistic quark model in which all observables follow from a single set of wave functions, with spin-dependent effects included directly in the bound-state equation. With parameters calibrated to the measured B_c(1S) and B_c(2S) masses, we predict the S-, P-, and D-wave spectrum up to n=5, the pseudoscalar and vector decay constants with one-loop QCD corrections, the E1 and M1 radiative widths, and the radial Regge trajectories of ten spin-parity families. The 1P multiplet is predicted at 6692--6746~MeV with the normal fine-structure ordering, compatible with lattice QCD and located in the region of the two structures observed by LHCb in the B_c^+γ spectrum. The 1D states lie near 7008~MeV, below the BD threshold, and all four D-wave families are provided. The decay constant f_B_c=507.1~MeV is consistent with recent QCD sum-rule results and corresponds to ℬ(B_c→τν_τ)≈3%. The E1 widths follow the expected angular weights, while their magnitudes are governed mainly by the radial overlap. The 1P→1S (81--112~keV) and 1D→1P (71--93~keV) widths suggest the 1D→1P→1S cascade as a promising route toward the first D-wave B_c state. The Regge trajectories are nearly linear, with slopes decreasing from about 5.8~GeV^2 for the S-wave to 4.7--4.8~GeV^2 for the D-wave states. These results may guide forthcoming measurements at the LHC and future e^+e^- facilities.
ER -