125 GeV Higgs and enhanced diphoton signal of a light singlet-like scalar in NMSSM

Abstract

NMSSM with a light singlet-like scalar and strongly suppressed couplings to $b$ and $\tau$ is investigated. It is shown that in such a scenario the singlet-like scalar to diphoton signal can be larger than for the SM Higgs for a wide range of masses between 60 and 110 GeV, in agreement with all the LEP and LHC data. Enhancement of the singlet-like scalar to diphoton signal is correlated with positive correction to the SM-like Higgs mass from mixing between SM-like Higgs and the singlet. It is also shown that the couplings to $b$ and $\tau$ and, in consequence, branching ratios of the SM-like Higgs are anti-correlated with those of the singlet-like scalar. If the singlet-like scalar to diphoton signal is enhanced, the signal strengths of the 125 GeV Higgs in the diphoton and $W{W}^{\ast }/Z{Z}^{\ast }$ channels are predicted to be smaller than for the SM Higgs.

Comments: 7 pages, 3 figures, to appear in the Proceedings of The European Physical Society Conference on High Energy Physics (EPS-HEP2013), 18-24 July 2013, Stockholm, Sweden, mainly based on arXiv:1304.5437