Possible interpretation of the newly observed Ω(2012) state

Abstract

Inspired by the newly observed Ωð2012Þ state at Belle II, we investigate the two-body strong decays of Ω baryons up to N ¼ 2 shell within the chiral quark model. Our results indicate that (i) the newly observed Ωð2012Þ state could be assigned to the spin-parity J P ¼ 3=2 − state j70; 2 10; 1; 1; 3 2 − i and the experimental data can be reasonably described. However, the spin-parity J P ¼ 1=2 − state j70; 2 10; 1; 1; 1 2 − i and spin-parity J P ¼ 3=2 þ state j56; 4 10; 2; 0; 3 2 þ i cannot be completely excluded.(ii) The D-wave states in the N ¼ 2 shell are most likely to be narrow states with a width of dozens of MeV and have a good potential to be observed in the ΞK and/or Ξð1530ÞK channels in future experiments. The Ωð2250Þ resonance listed in PDG may be a good candidate for the J P ¼ 5=2 þ 1D wave state j56; 4 10; 2; 2; 5=2 þ i.

Understanding the newly observed Ωc states through their decays

“…Moreover, the possibility of the broad structure arising from the overlapping of Ξ ′ c |1P λ 1/2 − 1 and Ξ ′ c |1P λ 1/2 − 2 cannot be ruled out as well. Finally it should be mentioned that combining our previous study [49] of the newly observed Ω * b states at LHCb [50], we find that the Ξ c (2923) 0 , Ξ c (2939) 0 , and Ξ c (2965) 0 may be flavour partners of Ω b (6330), Ω b (6340), and Ω b (6350), respectively. The missing mixed state Ξ ′ c |1P λ 1/2 − 1 may be a flavour partner of Ω b (6316).…”

Interpretation of the newly discovered Ω(2012)

“…To identify the properties of the Ωð2012Þ baryon, it would also be helpful to investigate its other properties besides the mass. Its strong decay was studied recently in [15], using the chiral quark model, and as a result, the possibility of Ωð2012Þ being J P ¼ 3=2 − was underlined; however, it also stated that the results obtained for the possibility of it being J P ¼ 1=2 − or J P ¼ 3=2 þ are consistent with the results of the Belle Collaboration within the uncertainties. There are also some studies on the radiative decays [16] and magnetic moments of negative parity baryons [17,18].…”

Ω baryon spectrum and their decays in a constituent quark model

“…They are determined by fitting the masses of four Ω resonances: (i) The ground state Ω(1672) [2], which is well established in experiments. (ii) The newly observed Ω(2012) resonance at Belle [15], which is interpreted as the first orbital excited state Ω(1 2 P 3/2 − ) [16,17]. (iii) The other first orbital excited state Ω(1 2 P 1/2 − ) whose mass is predicted to be ∼ 1950 MeV within the Lattice QCD [13] and the relativized quark models [5,6].…”

“…The Ω(2250) resonance listed in RPP [2] which is assigned as the Ω(1 4 D 5/2 + ) state according to our previous studies [16]. The determined parameter set is listed in Table IV.…”

“…The masses of the mesons and baryons in the final states are taken from the RPP [2] and have been collected in Table V. The decay constants for K and η mesons are taken as f K = f η = 160 MeV. For the global parameter δ, we fix its value the same as the previous study of the strong decays of Ξ and Ω baryons [16,37], i.e., δ = 0.576. The strong and radiative decay widths of Ω baryons up to N = 2 shell are listed in Table VI and Table VII, respectively.…”