Applied Asymptotic Expansions In Momenta And Masses

The book presents asymptotic expansions of Feynman integrals in various limitsof momenta and masses and their applications to problems of physical interest.The ... » 

The book presents asymptotic expansions of Feynman integrals in various limitsof momenta and masses and their applications to problems of physical interest.The problem of expansion is systematically solved by formulating universalprescriptions that express terms of the expansion using the original Feynmanintegral with its integrand expanded into a Taylor series in appropriatemomenta and masses. Knowledge of the structure of the asymptotic expansion atthe diagrammatic level is key in understanding how to perform expansions at theoperator level. Most typical examples of these expansions are presented theoperator product expansion the largemass expansion Heavy Quark EffectiveTheory and NonRelativistic QCD. TOCIntroduction. Offshell expansions. Onshell expansions. Expansions near threshold. Conclusion. «