The rare decay $h\to \mathrm{\Upsilon }\gamma$ has a very small rate in the Standard Model, due to a strong cancellation between the direct and indirect diagrams. Models with a changed $hbb$ coupling can thus lead to a great increase in this decay. Current limits on two Higgs doublet models still allow for the possibility that the $hbb$ coupling might have a sign opposite to the Standard Model, the so-called “wrong-sign.” We show how $h\to \mathrm{\Upsilon }\gamma$ can be used to put limits on the wrong-sign solutions.

• Received 15 August 2016

DOI:https://doi.org/10.1103/PhysRevD.94.075017