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Old Wine in a New Bottle: Technidilaton as the 125 GeV Higgs -- Dedicated to the late Professor Yoichiro Nambu

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 نشر من قبل Koichi Yamawaki
 تاريخ النشر 2015
  مجال البحث
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 تأليف Koichi Yamawaki




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We show that the Standard Model (SM) Higgs Lagrangian is identical to the nonlinear realization of both the scale and chiral symmetries (scale-invariant nonlinear sigma model), and is further gauge equivalent to the scale-invariant Hidden Local Symmetry (HLS) model having possible new vector bosons as the HLS gauge bosons with scale-invariant mass: SM Higgs is nothing but a (pseudo) dilaton. The effective theory of the walking technicolor has precisely the same type of the scale-invariant nonlinear sigma model, thus further having the scale-invariant HLS gauge bosons (technirhos, etc.). The technidilaton mass M_phi comes from the trace anomaly, which yields M_phi^2 F_phi^2 simeq (2.5)^2 [(8/N_F)(4/N_C)] v^4 via PCDC, in the underlying walking SU(N_C) gauge theory with N_F massless flavors, where F_phi is the decay constant and v=246 GeV. This implies F_phi simeq 5 v for M_phi simeq 125 GeV simeq v/2 in the one-family walking technicolor model (N_F=8, N_C=4), in good agreement with the current LHC Higgs data. In the anti-Veneziano limit, N_C rightarrow infty, with N_C alpha= fixed and N_F/N_C= fixed (gg 1), we have a result: M_phi^2/v^2sim M_phi^2/F_phi^2 sim 1/(N_F N_C) rightarrow 0. Then the technidilaton is a naturally light composite Higgs out of the strongly coupled conformal dynamics, with its couplings even weaker than the SM Higgs.



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