IRN Terascale @ Laboratori Nazionali di Frascati

On the Proof of Chiral Symmetry Breaking from Anomaly Matching in QCD-like Theories

16 avr. 2024, 17:34

13m

Auditorium B. Touschek (Laboratori Nazionali di Frascati)

Dark universe Dark universe

Orateur

Marcello Romano (IPhT, CEA, CNRS, Université Paris-Saclay)

Description

Confining QCD-like sectors are often present in BSM phenomenology. We critically reconsider the argument based on 't Hooft anomaly matching that aims at proving chiral symmetry breaking in 4d confining QCD-like theories with $N_c>2$ colors and $N_f$ flavors. We provide a detailed proof and clarify under which (dynamical) conditions the historical approach of $N_f$-independence holds, as a property of the solutions of the anomaly matching and persistent mass equations. The validity of $N_f$-independence was assumed in previous works based on qualitative arguments, but it was never proven rigorously. Then, we furnish a novel strategy, called `downlifting', that allows to prove chiral symmetry breaking for any $N_f\ge p_{min}$, where $p_{min}$ is the smallest prime factor of $N_c$. Contrary to earlier attempts, our results do not rely on ad-hoc assumptions on the spectrum of massless bound states. The proof can be extended to $N_f

Documents de présentation

Presentation_ChSB_Terascale_2 (2).pdf