Prediction of beauty particle masses with the heavy quark effective theory (II)

Abstract

The effective theory for heavy quarks has additional symmetries with respect to QCD, which relate charm and beauty hadron masses. Assuming the spectrum of charmed particles, we predicted in a previous work the masses of some beauty particles. The predictions of the Lambda_b mass, M(Lambda_b)=5630 MeV, and of the B_s mass, M(B_s)=5379 MeV, are in agreement with present experimental data. We continue this work using recent experimental data on charm hadron masses. The results are: M(Sigma_b)=5822+-6 MeV, M(Sigma_b*)-M(Sigma_b)=33+-3 MeV, M(Omega_b)=6080+-7 MeV, M(Omega_b*)-M(Omega_b)=32+-3 MeV, M(Lambda_b*)=5945+-3 MeV, M(Lambda_b**)-M(Lambda_b*)=15+-1 MeV. When experimental data for beauty hadron masses are available, a comparison with the theoretical values allows a quantitative estimate of the corrections to the static theory, which contain informations on hadron dynamics at low energy.