Enrico Rinaldi (RIKEN BNL Research Center)- Strongly-coupled theories with many flavors: new dynamics near the conformal window

Aula B ()

Aula B

Lattice gauge theory is a robust framework to study non-perturbative physics and it is amenable to numerical simulations. It has been successfully used to study the low-energy regime of QCD. Modern-day lattice simulation codes are actually flexible enough that users can change the theory being simulated: we can study different number of colors $N_c$, number of quarks $N_f$ and quarks in different representations $N_r$, in addition to the usual parameters, gauge coupling $\beta$ and quark masses $m_f$. These new theories, although interesting in their own rights as well-defined gauge theories, can be used as templates to study physics beyond the Standard Model (BSM). In particular, as tentative candidates for a dynamical mechanism to break the electroweak symmetry and replace the Higgs sector, they need to be close to the conformal window in order to satisfy stringent experimental constraints. I will report on a particular SU(3) gauge theory with 8 fermions in the fundamental representation. In particular I will highlight and how lattice simulations of the flavor-singlet scalar and pseudoscalar spectrum compare to QCD and how the observed features in the spectrum indicate the possibility that the theory is very close to the conformal window.