K¯Λ molecular explanation to the newly observed Ξ(1620)0

Abstract

The newly observed Ξð1620Þ 0 by the Belle Collaboration inspires our interest in performing a systematic study on the interaction of an antistrange meson ðK ðÃÞ Þ with a strange or doubly strange ground octet baryon B (Λ, Σ, and Ξ), where the spin-orbit force and the recoil correction are considered in the adopted one-boson-exchange model. Our results indicate that Ξð1620Þ 0 can be explained as aKΛ molecular state with IðJ P Þ ¼ 1=2ð1=2 − Þ and the intermediate force from σ exchange plays an important role. Additionally, we also predict several other possible molecular candidates, i.e., theKΣ molecular state with IðJ P Þ ¼ 1=2ð1=2 − Þ and the triply strangeKΞ molecular state with IðJ P Þ ¼ 0ð1=2 − Þ.

Tritonlike Molecules of Three Identical Baryons

“…We should consider the distortion created by the ℧ c while calculating the BO potential between the ℧ a and ℧ b . After solving the three-body Schrödinger equation as Equation (21), we obtain the distorted wave functions Φð r (11). Therefore, we should use Φð r !…”

“…The analog of deuteron as well as the largely accumulated experimental data on the exotic states arouses interest in the explorations on two-body hadronic systems. Currently, lots of effort has been spent on searching for the bound states of two-hadron systems [13][14][15][16][17][18][19][20][21][22][23][24][25][26]. In nuclear physics, triton and helium-3 nucleus can be understood as trihadron molecules, where the three nucleons bind together via colorless strong interactions with the binding energy 8.…”

Radiative decay of the $Ξ(1620)$ in a hadronic molecule picture

“…A molecular state with a narrow width and a mass around 1606 MeV was predicted in the unitarized coupled channels approach [8][9][10][11]. However, a Ξ bound state with a mass about 1620 MeV and J P = 1/2 − is predicted by studying the KΛ interaction in the framework of the One-Boson-Exchange (OBE) model [14]. In other words, the Ref.…”

“…As indicated in Refs. [8][9][10][11][12][13][14][15], the Ξ(1620) can be understood as a molecular state in comparison with the Belle data [2]. A molecular state with a narrow width and a mass around 1606 MeV was predicted in the unitarized coupled channels approach [8][9][10][11].…”

“…In other words, the Ref. [14] consider Ξ(1620) as a pure molecular state composes of KΛ component. A possible explanation for these results of Refs.…”