NΩ interaction: Meson exchanges, inelastic channels, and quasibound state

Abstract

Based on a baryon-baryon interaction model with meson exchanges, we investigate the origin of the strong attraction in the N Ω( 5 S2) interaction, which was indicated by recent lattice QCD simulations. The long range part of the potential is constructed by the conventional mechanisms, the exchanges of the η meson and of the correlated two mesons in the scalar-isoscalar channel, denoted by "σ" in the literature. The short range part is represented by the contact interaction. We find that the meson exchanges do not provide sufficient attraction. This means that most of the attraction is attributed to the short range contact interaction. We then evaluate the effect of the coupled channels to the N Ω( 5 S2) interaction. We find that, while the D-wave mixing of the N Ω channel is negligible, the inelastic ΛΞ, ΣΞ, and ΛΞ(1530) channels via the K meson exchange give the attraction of the N Ω( 5 S2) interaction to the same level with the elastic meson exchanges. Although the elimination of these channels induces the energy dependence of the single-channel N Ω interaction, this effect is not significant. With the present model parameters fitted to reproduce the scattering length of the HAL QCD result of the nearly physical quark masses, we obtain the N Ω( 5 S2) quasibound state with its eigenenergy 2611.3−0.7i MeV, which corresponds to the binding energy 0.1 MeV and width 1.5 MeV for the decay to the ΛΞ and ΣΞ channels. From the analysis of the spatial structure and the compositeness, the quasibound state is shown to be the molecular state of N Ω. We also construct an equivalent local potential for the N Ω( 5 S2) system which is useful for various applications.

Baryon Interactions from Lattice QCD

“…4 (Left) is the 1 S 0 potential V LO 0 (r) for t/a = 11−14. These potentials are consistent with each other within statistical errors, which is an indirect evidence of the small coupling with the D-wave octet-octet states below the NΩ threshold in the spin-2 channel as suggested in [23]. (Such a stability of the potential in the same range of t is not found for the spin-1 NΩ system which can couple to the S-wave octet-octet states below threshold.)…”

HAL QCD method and Nucleon-Omega interaction with physical quark masses

“…The statistics are slightly improved from the result at the conference 2. The effect of these coupling channels is found to be small from the phenomenological study in Ref [11],. nevertheless, the coupled channel analysis would be required to confirm this assumption in the future[3].…”

“…Recently, the model-independent studies of the H-dibaryon are reported from lattice QCD calculations [2,3,4]. Due to the absence of the Pauli blocking effect, another promising candidate for the dibaryon is NΩ(uudsss or uddsss), which is claimed to be bound from the studies based on the phenomenological models [5,6,7,8,9,10,11]. This dibaryon is also reported from the (2+1)-flavor lattice QCD study for the heavier pion mass at m π 875 MeV [12].…”

Masses and strong decays of open charm hexaquark states $$\Sigma _{c}^{(*)}{\Sigma }_{c}^{(*)}$$

“…However, the existence of the dibaryon is still controversial. In recent years, the theoretical and experimental studies of dibaryon states have been extended to systems containing more strangeness quarks [60][61][62][63][64][65][66][67][68][69][70][71][72].Experimental searches for dibaryons containing charm quarks is challenging because of the high energy required and the low production of charmed baryons. On the other hand, many theoretical studies have been performed.…”

“…However, the existence of the dibaryon is still controversial. In recent years, the theoretical and experimental studies of dibaryon states have been extended to systems containing more strangeness quarks [60][61][62][63][64][65][66][67][68][69][70][71][72].…”