First measurement of direct $f_0(980)$ photoproduction on the proton

TL;DR

This paper presents the first experimental measurement of the $f_0(980)$ meson produced by photon interactions with protons, revealing its properties and cross sections in a novel photoproduction context.

Contribution

It provides the first measurement of $f_0(980)$ photoproduction on protons, using partial wave analysis to identify the meson and quantify its production cross section.

Findings

Clear evidence of $f_0(980)$ in interference patterns at 1 GeV

The $f_0(980)$ cross section is 50 times smaller than the $ ho$ meson

First measurement of $f_0(980)$ in a photoproduction experiment

Abstract

We report on the results of the first measurement of exclusive $f_0(980)$ meson photoproduction on protons for $E_\gamma=3.0 - 3.8$ GeV and $-t = 0.4-1.0$ GeV$^2$. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. The resonance was detected via its decay in the $\pi^+ \pi^-$ channel by performing a partial wave analysis of the reaction $\gamma p \to p \pi^+ \pi^-$. Clear evidence of the $f_0(980)$ meson was found in the interference between $P$ and $S$ waves at $M_{\pi^+ \pi^-}\sim 1$ GeV. The $S$-wave differential cross section integrated in the mass range of the $f_0(980)$ was found to be a factor of 50 smaller than the cross section for the $\rho$ meson. This is the first time the $f_0(980)$ meson has been measured in a photoproduction experiment.