As one approaches the continuum limit, QCD systems, investigated via numerical simulations, remain trapped in sectors of field space with fixed topological charge. As a consequence the numerical studies of physical quantities may give biased results. The same is true in the case of two dimensional CPN −1 models. In this paper we show that metadynamics, when used to simulate CPN −1, allows to address efficiently this problem. By studying CP20 we show that we are able to reconstruct the free energy of the topological charge F (Q) and compute the topological susceptibility as a function of the coupling and of the volume. This is a very important physical quantity in studies of the dynamics of the θ vacuum and of the axion. This method can in principle be extended to QCD applications. © 2016, The Author(s).
|Titolo:||Metadynamics surfing on topology barriers: the CP N−1 case|
|Autori:||Laio, A.; Martinelli, G.; Sanfilippo, F.|
|Rivista:||JOURNAL OF HIGH ENERGY PHYSICS|
|Data di pubblicazione:||2016|
|Digital Object Identifier (DOI):||10.1007/JHEP07(2016)089|
|Fulltext via DOI:||10.1007/JHEP07(2016)089|
|Appare nelle tipologie:||1.1 Journal article|