Prospects for detecting axion-like particles via the decay $Z\to af\bar{f}$ at future $Z$ factories

Abstract

We investigate the prospects for detecting axion-like particles (ALPs, dubbed as "a") via the decay $Z\to af\bar{f}$ at future $Z$ factories. Considering the decay channels $a\to {\mu }^{+}{\mu }^{-}$ and $a\to b\bar{b}$ , four types of signals ${\mu }^{+}{\mu }^{-}/E$, $bb/E$, $e^{+}{e}^{-}{\mu }^{+}{\mu }^{-}$ and $e^{+}{e}^{-}bb$ are explored. We demonstrate that these channels are promising for detecting ALPs at $Z$ factories and obtain the sensitivity bounds on the couplings $g_{aZZ}$ and $g_{a\gamma Z}$.

Comments: 16 pages, 5 figures, submitted to Physical Review D