Abstract
Universality of various fermion formulations is well established in QCD-like theories defined around the perturbative g2 = 0 fixed point. These arguments do not apply for conformal systems that exhibit an infrared fixed point at non-vanishing g2 coupling. We investigate the step scaling function for systems with 10 or 12 fundamental flavors using domain wall fermions and compare it to perturbative predictions. We test universality by contrasting our findings to results published in the literature based on staggered fermions.
Highlights
The concept of universality is a cornerstone of quantum field theory investigations on the lattice
Proving the continuum flavor symmetries are recovered as the bare gauge coupling g2 is tuned to zero is non-trivial, because one has to show that all taste-breaking operators are irrelevant at the Gaussian fixed point (GFP) [1]. (For a concise summary see e.g. Ref. [2].) If one increases the number of flavors, a new fixed point, in addition to the GFP, emerges where the gauge coupling becomes irrelevant
Universality between continuum and staggered fermions at the Gaussian g2 = 0 fixed point is subtle, but can be proven perturbatively. This proof does not apply at a g2 0 non-trivial conformal infrared fixed point (IRFP) and a simple 3-dimensional examples illustrates that universality can be broken near a conformal fixed point
Summary
The concept of universality is a cornerstone of quantum field theory investigations on the lattice. Proving the continuum flavor symmetries are recovered as the bare gauge coupling g2 is tuned to zero is non-trivial, because one has to show that all taste-breaking operators are irrelevant at the GFP [1]. [2].) If one increases the number of flavors, a new fixed point, in addition to the GFP, emerges where the gauge coupling becomes irrelevant Even though this fixed point is commonly referred to as conformal infrared fixed point (IRFP), it is an UVFP in the mass, which is the only relevant operator.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
