Chiral condensate from renormalization group optimized perturbation - CNRS - Centre national de la recherche scientifique Accéder directement au contenu
Article Dans Une Revue Physical Review D Année : 2015

Chiral condensate from renormalization group optimized perturbation

Résumé

Our recently developed variant of variationnally optimized perturbation (OPT), in particular consistently incorporating renormalization group properties (RGOPT), is adapted to the calculation of the QCD spectral density of the Dirac operator and the related chiral quark condensate $\langle \bar q q \rangle$ in the chiral limit, for $n_f=2$ and $n_f=3$ massless quarks. The results of successive sequences of approximations at two-, three-, and four-loop orders of this modified perturbation, exhibit a remarkable stability. We obtain $\langle \bar q q\rangle^{1/3}_{n_f=2}(2\, {\rm GeV}) = -(0.833-0.845) \bar\Lambda_2 $, and $ \langle\bar q q\rangle^{1/3}_{n_f=3}(2\, {\rm GeV}) = -(0.814-0.838) \bar\Lambda_3 $ where the range spanned by the first and second numbers (respectively four- and three-loop order results) defines our theoretical error, and $\bar\Lambda_{n_f}$ is the basic QCD scale in the $\overline{MS}$-scheme. We obtain a moderate suppression of the chiral condensate when going from $n_f=2$ to $n_f=3$. We compare these results with some other recent determinations from other nonperturbative methods (mainly lattice and spectral sum rules).
Fichier principal
Vignette du fichier
PhysRevD.90.11204.pdf (78.17 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-01177136 , version 1 (07-06-2021)

Identifiants

Citer

Jean-Loïc Kneur, Andre Neveu. Chiral condensate from renormalization group optimized perturbation. Physical Review D, 2015, 92 (7), pp.074027. ⟨10.1103/PhysRevD.92.074027⟩. ⟨hal-01177136⟩
27 Consultations
5 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More