Measurement of neutral pion pair production in two-photon collisions

TL;DR

This paper reports measurements of the differential cross section for neutral pion pair production in two-photon collisions, revealing multiple resonant structures and evidence for chi_{c0} production, advancing understanding of meson interactions.

Contribution

It provides the first detailed measurement of gamma gamma -> pi^0 pi^0 cross sections over a broad energy range, identifying resonant features and comparing with charged pion production.

Findings

Observation of at least four resonant structures including f_0(980)

Evidence for chi_{c0} production in gamma gamma collisions

Preliminary analysis of angular dependence and cross section ratios

Abstract

The differential cross section of the process gamma gamma -> pi^0 pi^0 has been measured in the kinematical range 0.6 GeV < W < 4.0 GeV and |cos theta*|<0.8 in energy and pion scattering angle, respectively, in the gamma gamma center-of-mass system. We find at least four resonant structures including a peak from f_0(980). In addition, there is evidence for chi_{c0} production. We also make a preliminary discussion of the angular dependence and cross section ratio to gamma gamma -> pi^+ pi^-.