SU(3) mass-splittings of the heavy-baryons octet in QCD

R. A. Albuquerque , Stephan Narison (1) , M. Nielsen

1 LPTA - Laboratoire de Physique Théorique et Astroparticules

We directly extract (for the first time) the heavy-baryons octetmass-splittings due to SU(3) breaking using double ratios of QCD spectral sumrules(QSSR), which are less sensitive to the exact value and definition of theheavy quark mass and to the QCD continuum contributions than the simple ratioscommonly used in the current literature for determining the heavy baryonmasses. As a result, we can provide relatively accurate predictions of the Xi_Qand Omega_Q masses once the ones of the associated non-strange Lambda_Q andSigma_Q baryons are known from the data. It is remarkable to notice that theleading term controlling the mass-splittings is the ratio ss/dd of the quarkcondensate rather than the running mass m_s. The optimal choice of theinterpolating currents for the spin 1/2 baryons octet is the same as in thecase of light baryons with the mixing parameter b=-1/5 and confirms the firstQSSR results obtained in [1-3] for the non-strange Lambda_Q and Sigma_Qbaryons.

Domaines: Physique des Hautes Energies - Phénoménologie [hep-ph]

R. A. Albuquerque, Stephan Narison, M. Nielsen. SU(3) mass-splittings of the heavy-baryons octet in QCD. Physics Letters B, 2010, 684 (4-5), pp.236-245. ⟨10.1016/j.physletb.2010.01.011⟩. ⟨hal-00378611⟩