Medium recoil mode of $\Delta$ production in single isobaric charge-exchange reactions

TL;DR

This paper investigates the role of medium recoil effects in $elta$ production during single isobaric charge-exchange reactions, highlighting the importance of in-medium effects for accurate modeling.

Contribution

It introduces a novel medium recoil mode associated with $elta$ production, improving the theoretical description of inelastic channels in charge-exchange reactions.

Findings

The inelastic channel contributes about 50% to the reaction.

In-medium recoil effects are crucial for reproducing experimental data.

Predictions of proton and pion emission properties are provided.

Abstract

The dynamic mechanisms underlying single charge-exchange reactions have been investigated using a theoretical framework that combines the Isospin-dependent Quantum Molecular Dynamics (IQMD) model with the statistical decay model GEMINI++. Two distinct channels contribute to the single isobaric charge-exchange reaction: quasi-elastic channel, where neutron-proton scattering drives the charge-exchange, and inelastic channel, where the $\Delta$ particle is produced during the process. In a referenced study [Phys.RevC 106.014618(2022)], experimental data have revealed that the inelastic channel accounts for approximately 50 percent of the single isobaric charge-exchange reaction. However, our current model fails in reproducing the significant contribution of inelastic channel unless the novel medium recoil mode associated with $\Delta$ production is considered in the calculations. Notably, this in-medium effect arising from inelastic nucleon-nucleon collisions is not yet incorporated into mainstream microscopic transport models. The dynamical properties of protons and pions emitting in the single isobaric charge-exchange reactions are predicted. This exploration of in-medium effects adds a valuable dimension to our understanding of the intricate dynamics involved in single charge-exchange reactions.