Probability distribution of observables from a Bogoliubov vacuum projected onto good particle number: application to scission configurations of an actinide

TL;DR

This paper introduces a method to compute the probability distribution functions of various observables in nuclear fission, using a projected Bogoliubov vacuum, and applies it to actinide scission configurations.

Contribution

It presents a novel approach to determine the full probability distribution of observables from a projected Bogoliubov vacuum, extending current projection techniques.

Findings

Significant fluctuations in fission observables are captured within the mean-field approximation.

The method shows good convergence and feasibility for analyzing actinide scission states.

Fluctuations in fragment shapes and interactions are quantitatively assessed.

Abstract

Nuclear fission dynamics described within nuclear energy density functional frameworks (EDF) have seen substantial advances in the last decade. Part of this success stems from projection techniques, which allow the computation f probability distribution functions (pdf) for selected observables such as particle number and angular momentum of the fragments. Predicting the pdf of other observables, such as the total kinetic energy of the fragments, remains undone. This work proposes a method to determine the complete pdf of a new category of observables from a Bogoliubov vacuum projected onto good particle number. It relies on sampling nucleonic configurations in coordinate and intrinsic-spin representation. We assess the feasibility and convergence properties of the method and apply it to states representative of the scission of an actinide. Fluctuations in fragment shapes, inter-fragment Coulomb and nuclear interaction as well as the corresponding torques are analyzed. We find that a significant fraction of the fluctuation of several measured fission observables is already present within the mean-field picture.