Compositeness of the strange, charm, and beauty odd parityΛstates

Abstract

We study the dependence on the quark mass of the compositeness of the lowest-lying odd parity hyperon states. Thus, we pay attention to Λ−like states in the strange, charm and beauty, sectors which are dynamically generated using a unitarized meson-baryon model. In the strange sector we use an SU(6) extension of the Weinberg-Tomozawa meson-baryon interaction, and we further implement the heavy-quark spin symmetry to construct the meson-baryon interaction when charmed or beauty hadrons are involved. In the three examined flavor sectors, we obtain two J P = 1/2 − and one J P = 3/2 − Λ states. We find that the Λ states which are bound states (the three Λ b ) or narrow resonances (one Λ(1405) and one Λc(2595)) are well described as molecular states composed of s-wave meson-baryon pairs. The

Compositeness of Hadrons and Near-Threshold Dynamics

“…References Result Λ(1405), lower pole [23], [30], [10], [31], [11] πΣ dominance Λ(1405), higher pole [23], [30], [10], [31], [11], [12]KN dominance N(1535) [10] small meson-baryon components Λ(1670) [10] half KΞ Ξ(1690)…”

“…[32]KΣ dominance ∆(1232), Σ(1385), Ξ(1535), Ω [22] small meson-baryon components Λ(1520) [33], [31] d-waveKN and πΣ dominance Λ c (2595) [9], [31], [11] small πΣ c Λ c (2625) [31] small meson-baryon components Λ b (5912)…”

“…Similar conclusion is drawn in the quantitative evaluations in Refs. [11,31] while the importance of the isospin breaking effect is pointed out [11]. The meson-baryon components in Λ c (2625) is also found to be small [31].…”

“…by the chiral approach with the next-to-leading order interaction [10][11][12], and by the SU(6) extension of the Weinberg-Tomozawa interaction [31]. In all cases, it is found that the higher pole is dominated by theKN component, and the main component of the lower pole comes from the πΣ state.…”

“…[11,31] while the importance of the isospin breaking effect is pointed out [11]. The meson-baryon components in Λ c (2625) is also found to be small [31]. On the other hand, the negative parity Λ b states are dominated by the SU(6) meson-baryon channels [31].…”