Detailed Study of the KL -> 3pi0 Dalitz Plot

TL;DR

This paper analyzes the Dalitz plot density of 68 million KL -> 3pi0 decays, revealing interference effects and measuring the quadratic slope parameter while accounting for pion rescattering effects.

Contribution

First observation of interference from KL->pi+pi-pi0 decays with pi+pi- rescattering to 2pi0, and the first measurement of the KL-> 3pi0 quadratic slope parameter considering rescattering.

Findings

Observation of interference effects in KL -> 3pi0 decays.

First measurement of the quadratic slope parameter with rescattering.

Quantitative analysis of pion scattering length differences.

Abstract

Using a sample of 68 million KL -> 3pi0 decays collected in 1996-1999 by the KTeV (E832) experiment at Fermilab, we present a detailed study of the KL -> 3pi0 Dalitz plot density. We report the first observation of interference from KL->pi+pi-pi0 decays in which pi+pi- rescatters to 2pi0 in a final-state interaction. This rescattering effect is described by the Cabibbo-Isidori model, and it depends on the difference in pion scattering lengths between the isospin I=0 and I=2 states, a0-a2. Using the Cabibbo-Isidori model, we present the first measurement of the KL-> 3pi0 quadratic slope parameter that accounts for the rescattering effect.