The two Higgs doublet type-II seesaw model: Naturalness and B¯→Xsγ versus heavy Higgs masses

We extend the work [1] to a more general and detailed analysis through studying the naturalness problem and B physics constraints within the context of two higgs doublets model augmented with a complex scalar triplet field (2HDMcT). We first derive the modified Vetman conditions and show that naturalness problem might be evaded at the electroweak scale. Then, we evaluate the branching ratio of B¯→Xsγ radiative decay at the Next to leading order. Besides unitarity, boundedness from below constraints and the present collider data from Higgs signal rate measurements, the parameter space of 2HDMcT is then revisited to see how the modified Veltman conditions and B¯→Xsγ experimental bounds induce significant delimitations. Our analysis shows that the naturalness affects drastically the masses of heavy Higgs h3, A2, H2± and H±±. More specifically, we considered three benchmark scenarios corresponding to μ2>20,40,70 GeV. For μ2>40, we find stringent upper limits on mh2, mA1 and mH1± at 880, 920 and 918 GeV respectively. If, in addition, the measurements of B¯→Xsγ decay rate are also considered, the lower masses limits of nonstandard Higgs bosons (h2, h3, A1, A2, H1±, H2±, H±±) are pushed up to higher values located between 490 and 750 GeV. Besides, we also demonstrate that the B¯→Xsγ experimental limits can only be accommodated within 2HDMcT if two conditions are fullfilled: α1 parameter positive and the Higgs mass hierarchy mh3>mH2±>mH±±.