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arXiv · hep-ph/0111322

Parameter free calculation of hadronic masses from instantons

Pietro Faccioli
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Abstract

We propose a non-perturbative calculation scheme which is based on the semi-classical 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. Such masses are related to a particular combination of Green functions which, in some limit, is dominated by the contribution of \emph{very small-sized} instantons. The size distribution of these pseudo-particles 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 ($M_n \sim 970 MeV$). In connection with sum-rules approaches, we discuss the overlap of instantons with pion and nucleon resonances.

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Pietro Faccioli. 2001-11-25. Parameter free calculation of hadronic masses from instantons. https://doi.org/10.1103/physrevd.65.094014

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