LHC Higgs signatures from topflavor seesaw mechanism

We study LHC Higgs signatures from topflavor seesaw realization of electroweak symmetry breaking with a minimal gauge extension SU(2)⊗SU(2)⊗U(1). This elegant renormalizable construction singles out top quark sector (instead of all other light fermions) to join the new SU(2) gauge force. It predicts extra vector-like spectator quarks (T,B), new gauge bosons (W′,Z′), and a pair of neutral Higgs bosons (h,H). We demonstrate that for the lighter Higgs boson h of mass 125 GeV, this model predicts modified Higgs signal rates in h→γγ,WW⁎,ZZ⁎ channels via gluon fusions, in h→ττ¯ mode via vector boson fusions, and in h→bb¯ mode via gauge boson associate productions. We perform a global fit for our theory by including both direct search data (LHC and Tevatron) and indirect precision constraints. We further analyze the LHC discovery potential for detecting the heavier Higgs state H.