2010/06/01 by Francesco Sannino
Mathematics · Physics and Astronomy · #Black Holes and Theoretical Physics #Conformal map #Fermion #Lattice (music) #Mathematical analysis #Mathematical physics #Mathematics #Momentum (technical analysis) #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Theoretical physics #Upper and lower bounds #hep-lat #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevd.82.081701
published as Phys.Rev.D82:081701,2010 · 4 pages, 2 figures. 2columns
arxiv created 2010/06/01 · openalex publication_date 2010/10/05 · arxiv updated 2014/11/21 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We use the expression for the S parameter in the perturbative region of the conformal window to establish its dependence on the explicit introduction of fermion masses. We demonstrate that the relative ordering with which one sends to zero either the fermion mass or the external momentum leads to drastically different limiting values of S. Our results apply to any fermion matter representation and can be used as benchmark for the determination of certain relevant properties of the conformal window of any generic vectorlike gauge theory with fermionic matter. We finally suggest the existence of a universal lower bound on the opportunely normalized S parameter and explore its theoretical and phenomenological implications. Our precise results constitute an ideal framework to correctly interpret the lattice studies of the conformal window of strongly interacting theories.