A resonance interpretation for the nonmonotonic behavior of the phi-photoproduction cross section near threshold

TL;DR

This paper proposes that a specific resonance with J^P=3/2^- near 2.10 GeV explains the nonmonotonic behavior of phi-photoproduction cross sections near threshold, improving theoretical data agreement.

Contribution

It introduces a new resonance hypothesis to explain phi-photoproduction data and compares its effects with existing models, providing a novel interpretation of the observed phenomena.

Findings

Resonance with mass 2.10 GeV and width 0.465 GeV fits data well.

Helicity amplitude ratio differs from known D13(2080).

Adding the resonance improves omega photoproduction predictions.

Abstract

We study whether the nonmonotonic behavior found in the differential cross section of the phi-meson photoproduction near threshold can be described by a resonance. The resonant contribution is evaluated by using an effective Lagrangian approach. We find that, with the assumption of a J^P=3/2^- resonance with mass of 2.10 \pm 0.03 GeV and width of 0.465 \pm 0.141 GeV, LEPS data can indeed be well described. The ratio of the helicity amplitudes A_1/2/A_3/2 calculated from the resulting coupling constants differs in sign from that of the known D13(2080). We further find that the addition of this postulated resonance can substantially improve the agreement between the existing theoretical predictions and the recent omega photoproduction data if a large value of the OZI evading parameter x_OZI = 12 is assumed for the resonance.