Search for an axion-like particle in radiative $J/\ddot{I}ˆ$ decays

Abstract

We search for an axion-like particle (ALP) $a$ through the process $\ddot{I}ˆ(3686)\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}J/\ddot{I}ˆ$, $J/\ddot{I}ˆ\to {\hat{I}}^{3}a$, $a\to {\hat{I}}^3{\hat{I}}^3$ in a data sample of $(2.71\pm 0.01)\times 10^9$ $\ddot{I}ˆ(3686)$ events collected by the BESIII detector. No significant ALP signal is observed over the expected background, and the upper limits on the branching fraction of the decay $J/\ddot{I}ˆ\to {\hat{I}}^{3}a$ and the ALP-photon coupling constant $g_{a{\hat{I}}^3{\hat{I}}^3}$ are set at 95% confidence level in the mass range of $0.165\leq m_a\leq2.84\,\mbox{GeV}/c^2$. The limits on $B(J/\ddot{I}ˆ\to {\hat{I}}^{3}a)$ range from $8.3\times 10^{-8}$ to $1.8\times 10^{-6}$ over the search region, and the constraints on the ALP-photon coupling are the most stringent to date for $0.165\leq m_a\leq1.468\,\mbox{GeV}/c^2$.

10 pages, 6 figures