A realization of the composite Higgs scenario in the context of the effective
model with the SU(2)L​×U(1)R​ symmetric four-Fermi interactions
proposed by Miransky, Tanabashi and Yamawaki is studied. The model implements
Nambu's mechanism of dynamical electroweak symmetry breaking leading to the
formation of tˉt and bˉb quark condensates. We explore the vacuum
structure and spectrum of the model by using the Schwinger proper-time method.
As a direct consequence of this mechanism, the Higgs acquires a mass in accord
with its experimental value. The present prediction essentially differs from
the known overestimated value, mχ​=2mt​, making more favourable the top
condensation scenario presented here. The mass formulas for the members of the
second Higgs doublet are also obtained. The Nambu sum rule is discussed. It is
shown that the anomalous U(1)A​ symmetry breaking modifies this rule at next
to leading order in 1/Nc​.Comment: 14 pages, version to appear in EPJ