Deep Elastic Processes of Composite Particles in Field Theory and Asymptotic Freedom

TL;DR

This paper introduces a field-theoretical approach to analyze deep elastic processes of composite particles, specifically defining the pion distribution amplitude and deriving the pion form factor asymptotics within perturbative QCD.

Contribution

It provides the first explicit definition of the pion distribution amplitude and formulates a pQCD parton picture for hard exclusive processes.

Findings

Explicit calculation of the pion electromagnetic form factor at large Q^2.

Expression for the asymptotic behavior of the pion form factor.

Formulation of a new type of parton model for exclusive processes.

Abstract

This is an English translation of my 1977 Russian preprint. It contains the first explicit definition of the pion distribution amplitude (DA), the expression for the pion form factor asymptotics in terms of the pion DA, and formulates the pQCD parton picture for hard exclusive processes. Abstract of the original paper: The large Q^2 behavior of the pion electromagnetic form factor is explicitly calculated in the non-Abelian gauge theory to demonstrate a field-theoretical approach to the deep elastic processes of composite particles. The approach is equivalent to a new type of parton model.