Speaker
Description
In light of the recent branching fraction measurement of $B^{+}\to K^{+}\nu\bar{\nu}$-decay and its deviation from the SM expectation, we analyze the prospect of an axion-like particle (ALP) as the cause of such a departure. We assume a long-lived ALP with a mass of the order of a pion that predominantly decays to two photons. We focus on the scenario where the ALP decay length is several meters and therefore a non-negligible probability to decay outside detector volume of Belle-II mimicking the $B^{+}\to K^{+}\nu\bar{\nu}$-signal. Remarkably, such an arrangement provides a simple explanation to the long-standing $B\to \pi K$-puzzle by noting that the measured $B^{0}\to \pi^{0}K^{0}$ and $B^{+} \to \pi^{0} K^{+}$ decays have a $B^{0}\to a K^{0}$ and $B^{+} \to a K^{+}$ component respectively. We also argue based on our results that the axion-photon effective coupling belongs to a region in the parameter space that is still allowed after considering all the constraints known from various experiments.
