Aug 2 – 6, 2021
Europe/Brussels timezone

A road to a beyond the SM model

Aug 2, 2021, 5:50 PM


Parallel contribution E: QCD and New Physics Parallels Track E


Prof. Giancarlo Rossi (University of Roma Tor Vergata)


We describe examples of renormalizable field theories where the breaking of chiral symmetry at the UV cutoff leaves behind at low energy dynamically generated elementary particle masses in a way alternative to the Higgs mechanism. In this scenario 1) the scale of the elementary particle masses is set by the RGI scale of the theory 2) masses are kept ``small'' owing to an enhanced chiral symmetry enjoyed by the massless theory, thus solving the 't Hooft naturalness problem, 3) in order to match the experimental value of the top mass, a super-strongly interacting sector, gauge-invariantly coupled to standard matter, needs to exist with an RGI scale, $\Lambda_T\gg\Lambda_{QCD}$, of the order of a few TeV's, 4) the peculiar dependence of the non-perturbatively generated masses upon the gauge couplings is such that it may offer a hint to solve the mass hierarchy problem, 5) $\Lambda_T$ sets the order of magnitude of the electro-weak scale, 6) the 125 GeV resonance recently identified at LHC is interpreted as a $W^+W^-/ZZ$ composite state bound by exchanges of super-strongly interacting particles to which the electro-weak bosons are coupled, 7) at (momenta)$^2 \ll \Lambda_T^2$ the couplings of the composite Higgs boson with quark, leptons and electro-weak bosons coincide with those of the Standard Model up to O($\alpha_W$) corrections, 8) with a reasonable choice of particle content, a theory extending the Standard Model with the inclusion of the new super-strong sector exhibits gauge coupling unification at a scale $\sim 10^{18}$~GeV making the proton life time comfortably larger then the present limit of $1.7 \times 10^{34}$ years.

Primary authors

Prof. Giancarlo Rossi (University of Roma Tor Vergata) Prof. Roberto Frezzotti (University of Roma Tor Vergata)

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