Light flavor baryon spectrum with higher order hyperfine interactions

Abstract

We study the spectrum of light flavor baryons in a quark-model framework by taking into account the order $\mathrm{O}(\alpha_s^2)$ hyperfine interactions due to two-gluon exchange between quarks. The calculated spectrum agree better with the experimental data than the results from hyperfine interactions with only one-gluon exchange. It is also shown that two-gluon exchange hyperfine interactions bring a significantly improved correction to the Gell-Mann--Okubo mass formula. Two-gluon exchange corrections on baryon excitations (including negative parity baryons) are also briefly discussed.Comment: 31 latex pages, final version in journal publicatio

Ω baryon spectrum and their decays in a constituent quark model

“…The masses of the J P = 3/2 + D-wave states Ω(1 4 D 3/2 + ) and Ω(1 2 D 3/2 + ) and their mass splitting ∆m ≃ 60 MeV predicted in this work are close to those predicted in Refs. [7,8]. The masses of the J P = 5/2 + D-wave states Ω(1 4 D 5/2 + ) and Ω(1 2 D 5/2 + ) and their mass splitting ∆m ≃ 50 MeV predicted in this work are close to those predicted in Refs.…”

“…Ω(2 2 S 1/2 + ) The J P = 1/2 + state Ω(2 2 S 1/2 + ) (|70, 2 10, 2, 0, 1/2 + ) has a mass of ∼ 2232 MeV according to our predictions, which is close to the predictions in Refs. [5,7,8,12]. The Ω(2 2 S 1/2 + ) state might be narrow state with a width of…”

“…Before 2018, except for the ground state Ω(1672) only three Ω resonances Ω(2250), Ω(2380) and Ω(2470) were listed in the Review of Particle Physics (RPP) [2]. Due to the slow development in experiments, most of the theoretical studies are limited in the calculations of the mass spectrum of the Ω baryon with various methods, such as the Skyrme model [3], the relativistic quark models [4][5][6], the nonrelativistic quark model [7][8][9][10][11][12], the lattice gauge theory [13,14], and so on.…”

Possible interpretation of the newly observed Ω(2012) state

“…In various models and methods, such as the Skyrme model [3], quark model [4][5][6][7][8][9][10][11][12][13], lattice gauge theory [14,15] and so on [16][17][18][19][20][21], the masses of the first orbital excitations of Ωð1672Þ are predicted to be ∼2.0 GeV. Thus, the newly observed Ωð2012Þ may be a good candidate for the first orbital (1P) excitations of Ωð1672Þ.…”

Newly observed Ω(2012) state and strong decays of the low-lying Ω excitations

“…More excited Ω baryons should exist as well according to SUð6Þ × Oð3Þ symmetry. In theory, the mass spectrum of Ω hyperon has been predicted within many models, such as the Skyrme model [2], various constituent quark models [3][4][5][6][7][8][9][10][11][12], the lattice gauge theory [13,14], and so on. However, in experiments there are only a few information of the excited Ω baryons.…”