Hints of new physics in bottomonium decays and spectroscopy

A non-standard light CP-odd Higgs boson could induce a slight (but observable) lepton universality breakdown in Upsilon leptonic decays. Moreover, the mixing between such a pseudoscalar Higgs boson and ηb states might shift the mass levels of the latter, thereby changing the values of the mϒ(nS)−mηb(nS) splittings predicted in the standard model. Besides, also the ηb width could be broader than expected, with potentially negative consequences for its discovery in both e+e− and hadron colliders.