Belle II observation prospects for axion-like particle production from $B$ meson annihilation decay

We investigate a new production mechanism of axion-like particle (ALP) from $B$ meson annihilation decays and its observation potential at the Belle and Belle II experiments. This mechanism allows for the production of ALP from $B$ meson decays in association with a large variety of mesons. In this article, we first estimate the branching ratios of such processes with a perturbative QCD method. Focussing on the most promising $B\to h{a}^{\mathrm{\prime }}$ ($h=K^{\pm },{\pi }^{\pm },D^0$ and $D_s$) channels, we perform sensitivity studies for $a^{\mathrm{\prime }}$ decaying invisibly or into diphoton with Belle and Belle II experiments.