In-medium two-nucleon properties in high electric fields

TL;DR

This paper investigates how strong electric fields affect two-nucleon properties in hot dense nuclear matter, revealing modifications in bound states, phase shifts, and potential phase instabilities.

Contribution

It derives and solves a generalized Galitskii-Bethe-Salpeter equation including field effects, showing novel influences on nuclear matter properties under strong electric fields.

Findings

Bound states become resonances under strong fields.

Pairing occurs at higher temperatures due to the field.

Deuteron lifetimes are explicitly calculated in strong Coulomb fields.

Abstract

The quantum mechanical two - particle problem is considered in hot dense nuclear matter under the influence of a strong electric field such as the field of the residual nucleus in heavy - ion reactions. A generalized Galitskii-Bethe-Salpeter equation is derived and solved which includes retardation and field effects. Compared with the in-medium properties in the zero-field case, bound states are turned into resonances and the scattering phase shifts are modified. Four effects are observed due to the applied field: (i) A suppression of the Pauli-blocking below nuclear matter densities, (ii) the onset of pairing occurs already at higher temperatures due to the field, (iii) a field dependent finite lifetime of deuterons and (iv) the imaginary part of the quasiparticle self-energy changes its sign for special values of density and temperatures indicating a phase instability. The latter effect may influence the fragmentation processes. The lifetime of deuterons in a strong Coulomb field is given explicitly.