I plan to discuss the extended electroweak symmetry breaking (EWSB) scenarios by applying “unitarity sum rules”, which are required conditions on low-energy coefficients to ensure unitarity. The sum rules tell us nontrivial relationship between the properties of new particles/phenomena and the low-energy observables such as the 125GeV Higgs signal strengths (coupling strengths). In this talk, we discuss the implications of the sum rules in two kinds of extended EWSB scenarios : (i) EWSB with extra Higgs bosons (based on Ref. [1]) and (ii) EWSB with extra spin-1 particles (based on Ref. [2]).
References:
[1] R. Nagai, M. Tanabashi and K. Tsumura, ``Does unitarity imply finiteness of electroweak oblique corrections at one loop? Constraining extra neutral Higgs bosons,'' Phys. Rev. D91 (2015) no.3, 034030 [arXiv:1409.1709 [hep-ph]].
[2] T. Abe and R. Nagai, ``Classification of simple heavy vector triplet models,'' Phys. Rev. D95 (2017) no.7, 075022 [arXiv:1607.03706 [hep-ph]].