Interference Effect betweenϕandΛ(1520)Production Channels in theγp

Abstract

The ϕ-Λ(1520) interference effect in the γp→K^{+}K^{-}p reaction has been measured for the first time in the energy range from 1.673 to 2.173 GeV. The relative phases between ϕ and Λ(1520) production amplitudes were obtained in the kinematic region where the two resonances overlap. The measurement results support strong constructive interference when K^{+}K^{-} pairs are observed at forward angles but destructive interference for proton emission at forward angles. Furthermore, the observed interference effect does not account for the sqrt[s]=2.1 GeV bump structure in forward differential cross sections for ϕ photoproduction. This fact suggests possible exotic structures such as a hidden-strangeness pentaquark state, a new Pomeron exchange, or rescattering processes via other hyperon states.

ϕ meson self-energy in nuclear matter from ϕN resonant interactions

“…The emergence of resonances in the region near 2 GeV from vector-meson baryon interactions has been found crucial to correctly interpret the data shape and energy dependence of the γp → K 0 Σ + reaction by the CBELSA/TAPS Collaboration [50]. Claims for the need of a N * resonant state in that energy region have also been made from the analysis of Λ(1520) photoproduction data by the LEPS Collaboration [51].…”

Photoproduction and electroproduction of Λ(1405) via γ(*)p→K*Nam1 2019Phys. Rev. C0000View full textAdd to dashboardCite

“…such as (1405). As observed in the γ p → K + K − p reaction process [26], such interference effects are not significant and become negligible, when the decay width of the resonance is considerably wide. Moreover, the coupling constants for K * N * are rarely determined experimentally, resulting in the increase of theoretical uncertainties.…”