High-statistics measurement of the eta->3pi^0 decay at the Mainz Microtron

TL;DR

This study presents a high-statistics measurement of the eta->3pi^0 decay, providing detailed insights into its dynamics, including the second-order term and cusp structure, based on a large dataset from the Mainz Microtron.

Contribution

It offers the first measurement of the second-order term in eta->3pi^0 decay and enhances understanding of its nonlinear dynamics and cusp features.

Findings

Measurement of the second-order term in decay dynamics

Observation of the cusp structure in the decay

Comparison with recent theoretical models

Abstract

The largest, at the moment, statistics of 7x10^6 eta->3pi^0 decays, based on 6.2x10^7 eta mesons produced in the gamma p -> eta p reaction, has been accumulated by the A2 Collaboration at the Mainz Microtron, MAMI. It allowed a detailed study of the eta->3pi^0 dynamics beyond its conventional parametrization with just the quadratic slope parameter alpha and enabled, for the first time, a measurement of the second-order term and a better understanding of the cusp structure in the neutral decay. The present data are also compared to recent theoretical calculations that predict a nonlinear dependence along the quadratic distance from the Dalitz-plot center.