Speaker
Description
Fluctuation in the observed resonance decay widths is often characterized by the Porter-Thomas distribution, or the chi-square distribution. Compound nucleus reaction modelings, in which the Gaussian Orthogonal Ensemble (GOE) is involved as a propagator, have been successfully applied to study the properties of fluctuation in the S-matrix (or the cross section). In the GOE models, the fluctuation is understood as a decay amplitude in the spectral decomposition expression, $\gamma_\lambda \gamma_\lambda^\dagger / (E - E_\lambda$), where $E_\lambda$ is the eigenvalue of the GOE Hamiltonian. Such an expression can be explicitly written in terms of the S and K matrices, where the definition of the decay width is slightly different. We study the compound nucleus reaction by employing the GOE model that allows us to explore the wide model parameter space, and demonstrate how these matrix representations predict the distributions of compound nucleus decay width.