Pentaquark as Kaon-Nucleon Resonance

Abstract

Several recent experiments have reported evidence for a narrow feature in the K(+)-neutron system, an apparent resonant state ~ 100 MeV above threshold and with a width < 25 MeV. This state has been labelled as Theta(+) (previously as Z(*)), and because of the implied inclusion of a anti-strange quark, is referred to as a pentaquark, that is, five quarks within a single bag. We present an alternative explanation for such a structure, as a higher angular momentum resonance in the isospin zero K(+) -N system. One might call this an exit channel or a molecular resonance. In a non-relativistic potential model we find a possible candidate for the kaon-nucleon system with relative angular momentum L=3, while L=1 and 2 states possess centrifugal barriers too low to confine the kaon and nucleon in a narrow state at an energy so high above threshold. A rather strong state-dependence in the potential is essential, however, for eliminating an observable L=2 resonance at lower energies.

4 pages

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Cited by in corpus (10)

• Chiral-Soliton Predictions for Exotic Baryons
• Search for the exotic ${\Xi }^{--}(1860)$ Resonance in 340GeV/c ${\Sigma }^{-}$-Nucleus Interactions
• Present status on experimental search for pentaquarks
• A comprehensive search for the Θ^+ pentaquark on the lattice
• Phenomenology of spin 3/2 baryons with pentaquarks
• Spin asymmetries in gamma + N --> K*bar + Theta^+
• Absence of evidence for pentaquarks on the lattice
• Mixing of Pentaquark and Molecular States
• Production of the pentaquark ${\Theta }^{+}$ in $np$ scattering
• LHCb $P_c^{+}$ Resonances as Molecular States