Investigation of Λ (1405)as a molecular pentaquark state



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The European Physical Journal C


Λ(1405) is one of the interesting particles with its unclear structure and distinct properties. It has a light mass compared to its non-strange counterpart, despite the strange quark it carries. This situation puts the investigation of this resonance among the hot topics in hadron physics and collects attention to clarify its properties. In this study, we focus on the calculation of the mass and residue of the Λ(1405) resonance within the framework of QCD sum rules. We assign a structure in the form of a molecular pentaquark composed from admixture of K− meson-proton and K¯ 0 meson neutron. Using an interpolating current in this form, the masses and the current coupling constant are attained as m = 1406±128 MeV and λ = (3.35±0.35)×10−5 GeV6 for /q and m = 1402±141 MeV and λ = (4.08 ± 1.08) × 10−5 GeV6 for I Lorentz structures entering the calculations, respectively. The obtained mass values agree well with the experimental data supporting the plausibility of the considered structure.


Open Access; Published by The European Physical Journal C;; K. Azizi, Department of Physics, University of Tehran, North Karegar Avenue, Tehran, 14395-547, Iran, Department of Physics, Doǧuş University, Dudullu-Ümraniye, 34775, Istanbul, Turkey, School of Particles and Accelerators, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran, Iran; Y. Sarac, Electrical and Electronics Engineering Department, Atilim University, 06836 Ankara, Turkey,; H. Sundu, Department of Physics Engineering, Istanbul Medeniyet University, 34700, Istanbul, Turkey.