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Updated: Jun 8, 2026

Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
Published on: July 19, 2019
Novel interpretation of the "θ+ (1540) pentaquark" peak
1Departamento de Física Teórica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigación de Paterna, Apartado 22085, 46071 Valencia, Spain.
Abstract:
We use a theoretical model of the γd→K+ K- np reaction adapted to the experiment done at LEPS where a peak was observed and associated with the Θ+ (1540) pentaquark. The study shows that the method used in the experiment to assign momenta to the undetected proton and neutron, together with the chosen cuts, necessarily creates an artificial broad peak in the assumed K+ n invariant mass in the region of the claimed Θ+ (1540), such that the remaining strength seen for the experimental peak is compatible with a fluctuation of 2σ significance.
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