| |
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 P-3(0) model, which has only one free parameter, the pair creation strength gamma(0); this is the first time that the Lambda(b)eta, Sigma(b rho), Sigma(b)*rho, Lambda(b)eta', Lambda(b)omega, Xi K-b, Xi(b)'K, Xi(b)*K, Xi K-b*, Xi(b)'K*, and Xi(b)*K* channels have been considered in the calculation of the strong decay widths of the excited Lambda b states; the Sigma(b)eta, Xi K-b, Sigma(b)rho, Sigma(b)*rho, Lambda(b)rho, Sigma(b)*eta, Sigma(b)eta', Sigma(b)eta', Xi(b)'K , Xi(b)*K , Xi K-b*, Xi(b)'K*, Xi(b)*K*, Sigma(b)omega, Sigma(b)*omega, Sigma B-8(s), Delta B, 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 Sigma(b) states; the Lambda K-b*, Xi(b)rho, Xi(b)'rho , Xi(b)*rho, Sigma K-b*, Sigma(b)*K*, Xi(b)eta', Xi(b)eta', Xi(b)*eta', Xi(b)omega , Xi(b)'omega, Xi(b)*omega, Xi(b)phi , Xi(b)'phi, Xi(b)*phi, Xi B-8(s), Sigma B-8*, and Sigma(10) B channels in the calculation of the strong decay widths of the excited Xi(b) and Xi(b)' states; the Xi K-b*, Xi K-b*, Xi(b)*K*, Omega(b)eta, Omega(b)*eta, Omega(b)phi, Omega(b)*phi, Omega(b)eta', Omega b*eta' , Xi B-8, and Xi B-10 channels in the calculation of the strong decay widths of the Omega(b) 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 Lambda(b) (6146)(0) and Lambda(b) (6152)(0) states are consistent with our mass and width predictions for the D-lambda excitations with quantum numbers J(P) = 3/2+ and J(P) = 5/2+, respectively. Moreover, the masses and widths of the new Xi(b) (6327)(0) and Xi(b)(6333)(0) states 2 agree with our calculations for the D-lambda excitations with quantum numbers J(P) = 3/2+ and J(P) = 5/2+, 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 Omega(-)(b) missing spin excitation, with J(P) = 3/2+, which cannot decay strongly, but has a nonvanishing predicted electromagnetic decay width in the Omega(-)(b)gamma channel. Therefore, we suggest the Omega(-)(b)gamma 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. |
|
