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Study of Pentaquark and $Λ(1405)$

H. Nemura·C. Nakamoto
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Abstract

We perform a five-body calculation for pentaquark $(q^4\bar{q})$ state of $Λ(1405)$ as well as the three-body calculations for the ground state baryons and the $Λ(1405)$, and two-body calculations for mesons. The hamiltonian, which reproduces reasonably well the energies of ground state baryons ($N,Λ,Σ,Ξ$ and $Δ$) and mesons ($π,K,ρ,K^\ast$), includes kinetic energy of semi-relativistic form, linear confinement potential, and the simplest form of color-magnetic interaction with Gaussian form factor. Flavor symmetry breaking ($m_s> m_{u,d}$) is taken into account. The energy calculated for $(q^4\bar{q})$ state of $Λ(1405)$ is lower than the energy for the $(q^3)$ state. The present result suggests that the $Λ(1405)$ is a pentaquark-dominated state if the color-magnetic potential plays a leading role of the quark-quark and quark-antiquark interactions.

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H. Nemura, C. Nakamoto. 2006-02-27. Study of Pentaquark and $Λ(1405)$. https://doi.org/10.1063/1.2220305

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