Statistical Nuclear Reactions & Quantum Pre-Equilibrium Models

par M. Benjamin Menant (CEA DAM)

jeudi 16 avr. 2026, 14:00 → 15:00 Europe/Paris

100/2-A201 - Salle A201 (IJCLab)

Statistical Nuclear Reactions & Quantum Pre-Equilibrium Models

Nuclear reaction cross sections display resonances that are (mainly) attributed to the formation of bound single-particle states, referred to as quasibound, that form and decay through the residual interaction. Resonances quickly become extremely dense withincreasing incident energy and strongly overlap so one is interested in averaged cross sections only. The latter splits into "averaged & fluctuation" S-matrix contributions whose calculation are respectively the subject of direct & statistical nuclear reaction theory.

I will detail the statistical part that is based on a random matrix model for the NuclearHamiltonian. Below ~10 MeV incident energy, the residual interaction has enough time to mix all accessible quasibound states, i.e. to reachstatistical equilibrium, before it decays. Such an equilibrated system is referred to as compound nucleus. At higher incident energy, the system can decay before reaching equilibrium, leading to pre-equilibrium (or precompound) emissions. Their modeling splits into Multi-Step Direct & Multi-Step Compound mechanisms that will be the main focus of my talk, especially the second one.