CFT Zoo

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision 		Previous revision
banks_zaks_fixed_point [2021/05/08 23:52]
Scott Lawrence [Banks-Zaks fixed point] 		banks_zaks_fixed_point [2021/05/10 05:34] (current)
Scott Lawrence [Banks-Zaks fixed point]
Line 3: Line 3:
 {{tag>4d}} {{tag>4d}}
  
-The Banks-Zaks fixed point is an IR-stable CFT describing long-distance behavior of QCD for certain parameters. The Lagrangian of QCD is+A Banks-Zaks fixed point is an IR-stable CFT describing long-distance behavior of QCD for certain parameters. The Lagrangian of QCD is
 \[ \[
 \mathcal L= \mathcal L=
Line 10: Line 10:
 where color and spacetime indices have been suppressed. The flavor index $a$ runs over $N_f$ flavors of fermions.  where color and spacetime indices have been suppressed. The flavor index $a$ runs over $N_f$ flavors of fermions. 
  
-This theory is asymptotically free (i.e., has a UV-stable fixed point) for $N_f < \frac {33} 2$. For $N_f$ just below that threshold, an IR-stable fixed point is visible in perturbation theory. This fixed point has been found to extend down at least to $N_f \sim 12$ in lattice studies.+This theory is asymptotically free (i.e., has a UV-stable fixed point) for $N_f < \frac {33} 2$. For $N_f$ just below that threshold, an IR-stable fixed point is visible in perturbation theory if the fermions are taken to be massless. This fixed point has been found to extend down at least to $N_f \sim 12$ in lattice studies.
  
  
Last modified: 2021/05/08 23:52
CC Attribution-Noncommercial-Share Alike 4.0 International Except where otherwise noted, content on this wiki is licensed under the following license: CC Attribution-Noncommercial-Share Alike 4.0 International