A light supersymmetric Higgs sector hidden by a standard model-like Higgs

Extending the Higgs sector of the MSSM by triplets alleviates the little hierarchy problem and naturally allows for enhancements in the diphoton decay rate of the lightest CP-even Higgs h. In the present paper we analyze in detail the Higgs phenomenology of this theory with m h ≃ 126 GeV. We mostly focus on a light Higgs sector where lightest CP-even scalar A, the next-to-lightest CP-even scalar H and the charged H ± Higgses are naturally at the electroweak scale. It turns out that for any value m A ≃3; m h there is a parameter region at small tan β where the CP-even Higgs sector appears at colliders as the SM one, except for loop-induced corrections. Notably the existence of this SM-like point, which is absent in the MSSM, is shared with supersymmetric theories where there are extra singlets. We also highlight a second parameter region at small m A and small tan β where the h signal strengths, diphoton channel included, are SM-like except those of bottoms and taus which can have at most a 10-15% splitting. Improvements in the A and H ± searches are worth while in order to discriminate this scenario from the SM. © 2013 SISSA, Trieste, Italy.