A search for decay $\eta' \rightarrow 4 \pi^{0}$ with GAMS-$4\pi$ Setup

TL;DR

This paper reports a search for the rare decay of eta prime mesons into four neutral pions, setting a new upper limit on its branching ratio based on data from the GAMS-4π experiment at IHEP U-70.

Contribution

The study provides the first upper limit on the decay $ ext{eta'} ightarrow 4 ext{pi}^0$, improving constraints on this rare process.

Findings

Established upper limit for decay BR < 3.2 x 10^{-4} at 90% CL

Analyzed 1.3 million eta' mesons produced in charge-exchange reactions

Used GAMS-4π setup at IHEP U-70 for the search

Abstract

A search for rare decay $\eta' \rightarrow 4 \pi^{0}$ has been performed with GAMS-4$\pi$ Setup. The new upper limit for decay was established $BR(\eta' \rightarrow 4 \pi^{0}) < 3.2 \cdot 10^{-4}$ at 90\% confidence level. The $\pi^{-} p$ charge-exchange reaction at 32.5 GeV/c was used as a source of $1.3\cdot 10^{6}$ $ \eta'$ mesons. Experiment carried out at the IHEP U-70 accelerator.