We propose a nonperturbative calculation scheme which is based on the semiclassical approximation of QCD and can be used to evaluate quantities of interest in hadronic physics. As a first application, we evaluate the mass of the pion and of the nucleon. These masses are related to a particular combination of Green functions which, in some limit, is dominated by the contribution of very small-sized instantons. The size distribution of these pseudoparticles is determined by the 't Hooft tunneling amplitude formula and therefore our calculation is free from any model parameters. We prove that instanton forces generate a light pion and a nucleon with realistic mass (Mn∼970 MeV). In connection with sum-rule approaches, we discuss the overlap of instantons with pion and nucleon resonances.

Faccioli, P. (2002). Parameter-Free Calculation of Hadronic Masses from Instantons. PHYSICAL REVIEW D, 65(9A), 1-7 [10.1103/PhysRevD.65.094014].

Parameter-Free Calculation of Hadronic Masses from Instantons

Faccioli, Pietro
2002

Abstract

We propose a nonperturbative calculation scheme which is based on the semiclassical approximation of QCD and can be used to evaluate quantities of interest in hadronic physics. As a first application, we evaluate the mass of the pion and of the nucleon. These masses are related to a particular combination of Green functions which, in some limit, is dominated by the contribution of very small-sized instantons. The size distribution of these pseudoparticles is determined by the 't Hooft tunneling amplitude formula and therefore our calculation is free from any model parameters. We prove that instanton forces generate a light pion and a nucleon with realistic mass (Mn∼970 MeV). In connection with sum-rule approaches, we discuss the overlap of instantons with pion and nucleon resonances.
Articolo in rivista - Articolo scientifico
Instanton, hadron mass
English
2002
1
7
7
Faccioli, P. (2002). Parameter-Free Calculation of Hadronic Masses from Instantons. PHYSICAL REVIEW D, 65(9A), 1-7 [10.1103/PhysRevD.65.094014].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/405628
Citazioni
  • Scopus 11
  • ???jsp.display-item.citation.isi??? 10
Social impact