Search

Abstract The methods of QCD sum rules and light-cone sum rules within the framework of heavy quark effective theory have been widely applied to study the singly heavy baryons, and especially, we have applied these methods to predict not only the mass and width of the $$\varXi _b(6087)^0$$ Ξ b ( 6087 ) 0 recently discovered by LHCb, but also its observation channel and its mass difference from the $$\varXi _b(6100)^-$$ Ξ b ( 6100 ) - . We apply the same approach to perform a complete study on the P-wave bottom baryons of the SU(3) flavor $${\bar{\textbf{3}}}_F$$ 3 ¯ F and investigate their fine structure. Besides the $$\varLambda _b(5912)^0$$ Λ b ( 5912 ) 0 , $$\varLambda _b(5920)^0$$ Λ b ( 5920 ) 0 , $$\varXi _b(6087)^0$$ Ξ b ( 6087 ) 0 , and $$\varXi _b(6100)^-$$ Ξ b ( 6100 ) - , our results suggest the existence of the other two $$\varLambda _b$$ Λ b and two $$\varXi _b$$ Ξ b baryons, whose widths are limited. They are the $$\varLambda _b(J^P = 3/2^-)$$ Λ b ( J P = 3 / 2 - ) with the mass and width about $$(5.93^{+0.13}_{-0.13}~\textrm{GeV},\,0.0^{+12.0}_{-~0.0}~\textrm{MeV})$$ ( 5 . 93 - 0.13 + 0.13 GeV , 0 . 0 - 0.0 + 12.0 MeV ) , the $$\varLambda _b(5/2^-)$$ Λ b ( 5 / 2 - ) with $$(5.94^{+0.13}_{-0.13}~\textrm{GeV},\,\approx 0~\textrm{MeV})$$ ( 5 . 94 - 0.13 + 0.13 GeV , ≈ 0 MeV ) , the $$\varXi _b(3/2^-)$$ Ξ b ( 3 / 2 - ) with $$(6.10^{+0.15}_{-0.10}~\textrm{GeV},\, 1.4{^{+11.6}_{-~1.4}}~\textrm{MeV})$$ ( 6 . 10 - 0.10 + 0.15 GeV , 1.4 - 1.4 + 11.6 MeV ) , and the $$\varXi _b(5/2^-)$$ Ξ b ( 5 / 2 - ) with $$(6.11^{+0.15}_{-0.10}~\textrm{GeV},\,1.0{^{+7.4}_{-1.0}}~\textrm{MeV})$$ ( 6 . 11 - 0.10 + 0.15 GeV , 1.0 - 1.0 + 7.4 MeV ) . Their mass splittings are calculated to be $$M_{\varLambda _b(5/2^-)} - M_{\varLambda _b(3/2^-)} = 17\pm 7~\textrm{MeV}$$ M Λ b ( 5 / 2 - ) - M Λ b ( 3 / 2 - ) = 17 ± 7 MeV and $$M_{\varXi _b(5/2^-)} - M_{\varXi _b(3/2^-)} = 14\pm 7~\textrm{MeV}$$ M Ξ b ( 5 / 2 - ) - M Ξ b ( 3 / 2 - ) = 14 ± 7 MeV . All these baryons are explained as the P-wave bottom baryons of the $$\rho $$ ρ -mode, where the orbital excitation is between the two light quarks. However, the existence of this mode is still controversial, so their experimental searches can verify both our approach and the existence of the $$\rho $$ ρ -mode, which can significantly improve our understanding on the internal structure of hadrons.

Abstract The heavy baryon system bounded by the strong interaction has a rich internal structure, so its mass spectra can have the fine structure similar to the line spectra of atom bounded by the electromagnetic interaction. We systematically study the internal structure of P-wave $$\varOmega _b$$ Ωb baryons and calculate their D-wave decay properties. The present study, together with our previous studies on their mass spectra and S-wave decay properties, suggest that all the four excited $$\varOmega _b$$ Ωb baryons recently discovered by LHCb can be well explained as P-wave $$\varOmega _b$$ Ωb baryons, and their beautiful fine structure is directly related to the rich internal structure of P-wave $$\varOmega _b$$ Ωb baryons.

Abstract We use the method of light-cone sum rules to study decay properties of P-wave bottom baryons belonging to the SU(3) flavor $$\mathbf {6}_F$$ 6F representation. In Cui et al. (Phys Rev D 99:094021, 2019) we have studied their mass spectrum and pionic decays, and found that the $$\varSigma _{b}(6097)$$ Σb(6097) and $$\varXi _{b}(6227)$$ Ξb(6227) can be well interpreted as P-wave bottom baryons of $$J^P = 3/2^-$$ JP=3/2- . In this paper we further study their decays into ground-state bottom baryons and vector mesons. We propose to search for a new state $$\varXi _b({5/2}^-)$$ Ξb(5/2-) , that is the $$J^P = 5/2^-$$ JP=5/2- partner state of the $$\varXi _{b}(6227)$$ Ξb(6227) , in the $$\varXi _b({5/2}^-) \rightarrow \varXi _b^{*}\rho \rightarrow \varXi _b^{*}\pi \pi $$ Ξb(5/2-)→Ξb∗ρ→Ξb∗ππ decay process. Its mass is $$12 \pm 5$$ 12±5 MeV larger than that of the $$\varXi _{b}(6227)$$ Ξb(6227) .

Abstract We apply the method of QCD sum rules to study the structure X newly observed by the BESIII Collaboration in the $$\phi \eta ^\prime $$ ϕη′ mass spectrum in 2.0–2.1 GeV region in the $$J/\psi \rightarrow \phi \eta \eta ^\prime $$ J/ψ→ϕηη′ decay. We construct all the $$s s {\bar{s}} {\bar{s}}$$ sss¯s¯ tetraquark currents with $$J^{PC} = 1^{+-}$$ JPC=1+- , and use them to perform QCD sum rule analyses. One current leads to reliable QCD sum rule results and the mass is extracted to be $$2.00^{+0.10}_{-0.09}$$ 2.00-0.09+0.10 GeV, suggesting that the structure X can be interpreted as an $$s s {\bar{s}} {\bar{s}}$$ sss¯s¯ tetraquark state with $$J^{PC} = 1^{+-}$$ JPC=1+- . The Y(2175) can be interpreted as its $$s s {\bar{s}} {\bar{s}}$$ sss¯s¯ partner having $$J^{PC} = 1^{--}$$ JPC=1-- , and we propose to search for the other two partners, the $$s s {\bar{s}} {\bar{s}}$$ sss¯s¯ tetraquark states with $$J^{PC} = 1^{++}$$ JPC=1++ and $$1^{-+}$$ 1-+ , in the $$\eta ^\prime f_0(980)$$ η′f0(980) , $$\eta ^\prime K {\bar{K}}$$ η′KK¯ , and $$\eta ^\prime K {\bar{K}}^*$$ η′KK¯∗ mass spectra.