Asymptotically Safe Standard Model Extensions?

Understand

We consider theories with a large number $N_F$ of charged fermions and compute the renormalisation group equations for the gauge, Yukawa and quartic couplings resummed at leading order in $1/N_F$.

• We construct extensions of the Standard Model where SU(2) and/or SU(3) are asymptotically safe.
• When the same procedure is applied to the Abelian U(1) factor, we find that the Higgs quartic can not be made asymptotically safe and stay perturbative at the same time.