Strong decay widths and mass spectra of the 1D , 2P and 2S singly bottom baryons

Abstract

We calculate the 1D, 2P, and 2S mass spectra of the singly bottom baryons and their strong decay widths. The calculations are performed within a harmonic oscillator quark model that incorporates the spin, spin-orbit, isospin, and flavor interactions. To obtain the model parameters, we conducted a fit using only 13 of the 22 experimentally observed states. Our predictions align well with the observed states, showing a root-mean-square deviation of 9.6 MeV. We calculate the three-quark strong decay widths within the P03 model, which has only one free parameter, the pair creation strength γ0; this is the first time that the Λbη, Σbρ, Σb*ρ, Λbη′, Λbω, ΞbK, Ξb′K, Ξb*K, ΞbK*, Ξb′K*, and Ξb*K* channels have been considered in the calculation of the strong decay widths of the excited Λb states; the Σbη, ΞbK, Σbρ, Σb*ρ, Λbρ, Σb*η, Σbη′, Σb*η′, Ξb′K,Ξb*K, ΞbK*, Ξb′K*, Ξb*K*, Σbω, Σb*ω, Σ8Bs, ΔB, N(1520)B, N(1535)B, N(1680)B, and N(1720)B channels in the calculation of the strong decay widths of the excited Σb states; the ΛbK*, Ξbρ, Ξb′ρ, Ξb*ρ, ΣbK*, Σb*K*, Ξbη′, Ξb′η′, Ξb*η′, Ξbω, Ξb′ω, Ξb*ω, Ξbϕ, Ξb′ϕ, Ξb*ϕ, Ξ8Bs, Σ8B*, and Σ10B channels in the calculation of the strong decay widths of the excited Ξb and Ξb′ states; the ΞbK*, Ξb′K*, Ξb*K*, Ωbη, Ωb*η, Ωbϕ, Ωb*ϕ, Ωbη′, Ωb*η′, Ξ8B, and Ξ10B channels in the calculation of the strong decay widths of the Ωb states. Moreover, in Appendix D, we give the flavor couplings that can be useful for other articles. In Appendix E, our partial decay widths are reported for each open flavor channel; these may be useful to the LHCb, ATLAS, and CMS experimentalists in order to plan in which particular channels to look for missing bottom baryons. The experimental masses and widths of the discovered Λb(6146)0 and Λb(6152)0 states are consistent with our mass and width predictions for the Dλ excitations with quantum numbers JP=32+ and JP=52+, respectively. Moreover, the masses and widths of the new Ξb(6327)0 and Ξb(6333)0 states agree with our calculations for the Dλ excitations with quantum numbers JP=32+ and JP=52+, respectively. Finally, we calculate the electromagnetic decay widths from P-wave states to ground states. We give the exact analytical expressions of the spin-flip and orbit-flip transition amplitudes, both of which are functions of the photon-transferred momentum. The electromagnetic decays are dominant when the strong decays are suppressed. A relevant case is the Ωb− missing spin excitation, with JP=32+, which cannot decay strongly, but has a nonvanishing predicted electromagnetic decay width in the Ωb−γ channel. Therefore, we suggest the Ωb−γ electromagnetic decay channel as a golden channel in which to search for this state. In all of our calculations, we report the uncertainties related to the experimental and model errors by means of the Monte Carlo bootstrap method. Published by the American Physical Society 2024