Effects of two inert scalar doublets on Higgs boson interactions and the electroweak phase transition
We study some implications of the presence of two new scalar weak doublets beyond the standard model which have zero vacuum expectation values and are charged under an extra Abelian gauge symmetry. The additional gauge sector does not couple directly to standard-model particles. We investigate specifically the effects of the scalars on oblique electroweak parameters and on the interactions of the 125 GeV Higgs boson, especially its decay modes h→γγ,γZ and trilinear self-coupling, all of which will be probed with improved precision in future Higgs measurements. Moreover, we explore how the new scalars may give rise to strongly first-order electroweak phase transition and also show its correlation with sizable modifications to the Higgs trilinear self-coupling.
© 2015 American Physical Society. Received 24 June 2015; published 31 August 2015. We would like to thank Masaya Kohda for helpful discussions. A. A. is supported by the Algerian Ministry of Higher Education and Scientific Research under the CNEPRU Project No. D01720130042. The work of G. F. and J. T. was supported in part by the research Grant No. NTU-ERP-102R7701, the MOE Academic Excellence Program (Grant No. 102R891505), and the National Center for Theoretical Sciences of Taiwan.
Submitted - 1501.06605v1.pdf
Published - PhysRevD.92.035020.pdf