Electron-positron annihilation into phi f_{0}(980) and clues for a new 1^{--} resonance

TL;DR

This paper investigates the e^{+}e^{-} to phi pi pi reaction, modeling the interactions with unitarized chiral perturbation theory and vector mesons, revealing a peak at f_{0}(980) and evidence for a new 1^{--} resonance.

Contribution

It introduces a detailed theoretical analysis combining unitarized chiral perturbation theory and vector meson effects to explain experimental data and suggest a new resonance.

Findings

Observed a peak around f_{0}(980) in dipion mass

Reproduced experimental data for e^{+}e^{-} to phi pi pi

Supported the existence of a new 1^{--} resonance

Abstract

We study the e^{+}e^{-} to phi pi pi reaction for pions in an isoscalar s-wave which is dominated by loop mechanisms. For kaon loops we start from the conventional RCHPT, but use the unitarized amplitude for KbarK-pipi scattering and the full kaon form factor instead of the lowest order terms. We study also effects of vector mesons using RCHPT supplemented with the conventional anomalous term for VVP interactions and taking into account the effects of heavy vector mesons in the K*K transition form factor. We find a peak in the dipion invariant mass around the f_{0}(980) as in the experiment. Selecting the phi f_{0}(980) contribution as a function of the e^{+}e^{-} energy we also reproduce the experimental data except for a narrow peak, yielding support to the existence of a 1^{--} resonance above the phi f_{0}(980) threshold, coupling strongly to this state.