Dynamical Generation of Elementary Fermion Mass: First Lattice Evidence

Using lattice simulations we demonstrate from first principles the existence of a nonperturbative mechanism for elementary particle mass generation in models with gauge fields, fermions, and scalars, if an exact invariance forbids power divergent fermion masses and fermionic chiral symmetries broken at UV scale are maximally restored. We show that in the Nambu-Goldstone phase a fermion mass term, unrelated to the Yukawa operator, is dynamically generated. In models with electroweak interactions weak boson masses are also generated, opening new scenarios for beyond the standard model physics.

Figure 1

$r_{\mathrm{AWI}}$ as a function of $\eta$ at $\beta =5.75$, 5.85, and 5.95. Red squares denote the values of ${\eta }_{\mathrm{cr}}$, at which $r_{\mathrm{AWI}}=0$.

Figure 2

$2m_{\mathrm{AWI}}^R{r}_0\equiv 2r_0{m}_{\mathrm{AWI}}{Z}_{\tilde{V}}{Z}_P^{-1}$ vs $(b/r_0{)}^2$ in the NG phase and its linear extrapolation to the continuum limit.

Figure 3

$r_0{M}_{\mathrm{PS}}$ in the NG phase vs $(b/r_0{)}^2$ and its linear extrapolation to the continuum limit.