Two-particle photodisintegration of He-4: He-4(gamma,d)d, He-4(gamma,p)T, He-4(gamma,n)He-3

TL;DR

This paper presents a covariant diagram technique to calculate differential cross-sections for two-particle photodisintegration of helium-4, incorporating a nucleus as an elementary particle and ensuring gauge symmetry.

Contribution

It introduces a novel covariant diagram approach that models helium-4 as an elementary particle, simplifying the calculation of photodisintegration cross-sections while maintaining physical conservation laws.

Findings

Calculated differential cross-sections for He-4 photodisintegration reactions.

Ensured gauge symmetry and conservation laws in the model.

Provided a functional parameter for the nucleus's vertex structure.

Abstract

Using a covariant diagram technique and the concept of a nucleus as an elementary particle we calculated differential cross-sections for two-particle photodisintegration reactions of the He-4. The only functional parameter was the vertex structure function, which described the "collapse" of a He-4 nucleus and the nucleon remnants. The interaction of a real photon was determined by the value of particles charge, since the electromagnetic form factors were calculated in the photon point. The inseparability property of the electric charge from the particle mass allowed us to match the energy-momentum and charge conservation laws in the interaction. Therefore, the requirement of gauge symmetry was immediately satisfied. The covariant amplitude of the process equaled to the sum of pole diagrams and regular part.