Prospects of probing new physics in bottomonium decays and spectroscopy

Abstract

A non-standard CP-odd Higgs boson could induce a slight (but observable) lepton universality breaking in Upsilon leptonic decays. Moreover, mixing between such a pseudoscalar Higgs boson and $\eta_b$ states might shift their mass levels, thereby modifying the values of the $M_{\Upsilon(nS)}-M_{\eta_b(nS)}$ hyperfine spplitings predicted in the standard model. Besides, $\eta_b$ resonances could be broader than expected with potentially negative consequences for discovery in both $e^+e^-$ and hadron colliders. A scenario with a CP violating Higgs sector is also considered. Finally, further strategies to search for a light Higgs particle in bottomonium decays are outlined.