QCD sum rule calculation for P-wave bottom baryons

Understand

We study the P-wave bottom baryons using the method of QCD sum rule and heavy quark effective theory.

• Our results suggest that Lambda_b(5912) and Lambda_b(5920) can be well described by the baryon doublet [3F_bar, 1, 1, rho], and they belong to the SU(3) 3F_bar multiplets of J(P)=1/2(-) and 3/2(-).
• Their SU(3) flavor partners, Xi_b(1/2-) and Xi_b(3/2-), have masses 6.06 \pm 0.13 GeV and 6.07 \pm 0.13 GeV, respectively, with mass splitting 9 \pm 4 MeV.
• The results obtained using baryon doublet [3F_bar, 1, 0, lambda] are similar and also consistent with the experimental data.