Search for the rare decay $\eta \prime \to {\pi }^{0}{\pi }^{0}{\pi }^{0}{\pi }^{0}$ at BESIII

Using a sample of $1.31×{10}^{9}\text{}\text{}J/\psi $ events collected with the BESIII detector, we perform a search for the rare decay ${\eta }^{\prime }\to 4{\pi }^{0}$ via $J/\psi \to \gamma {\eta }^{\prime }$. No significant ${\eta }^{\prime }$ signal is observed in the $4{\pi }^{0}$ invariant mass spectrum. With a Bayesian approach, the upper limit on the branching fraction is determined to be $B\left({\eta }^{\prime }\to 4{\pi }^{0}\right)<4.94×{10}^{-5}$ at the 90% confidence level, which is a factor of 6 smaller than the previous experimental limit.