We study the renormalization group evolution up to the fixed point of the lattice topological susceptibility in the 2D O(3) nonlinear sigma model. We start with a discretization of the continuum topological charge by a local charge density polynomial in the lattice fields. Among the different choices we propose also a Symanzikimproved lattice topological charge. We check step by step in the renormalization group iteration the progressive dumping of quantum fluctuations, which are responsible for the additive and multiplicative renormalizations of the lattice topological susceptibility with respect to the continuum definition. We find that already after three iterations these renormalizations are negligible and an excellent approximation of the fixed point is achieved. We also check by an explicit calculation that the assumption of slowly varying fields in iterating the renormalization group does not lead to a good approximation of the fixed point charge operator.
Scheda prodotto non validato
Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo
|Titolo:||Renormalization group flow and fixed point of the lattice topological charge in the 2D O(3) sigma model|
|Data di pubblicazione:||1997|
|Appare nelle tipologie:||1.1 Articolo in rivista|