Neutron Resonance Widths and the Porter-Thomas Distribution

Abstract

Experimental evidence has recently put the validity of the Porter-Thomas distribution (PTD) for partial neutron widths into question. We identify two terms in the effective Hamiltonian that violate orthogonal invariance (the basis for the PTD). Both are due to the coupling to the decay channels. We show that realistic estimates for the coupling to the neutron channel and for non-statistical gamma decays yield significant modifications of the PTD.

5 pages, 2 figures

References in corpus (6)

• Distribution of Partial Neutron Widths for Nuclei close to a Maximum of the Neutron Strength Function
• Resonance width distribution in RMT: Weak coupling regime beyond Porter-Thomas
• Porter-Thomas distribution in unstable many-body systems
• Resonance width distribution for open quantum systems
• Neutron Resonance Data Exclude Random Matrix Theory
• Interaction of Regular and Chaotic States

Cited by in corpus (6)

• Power-law random banded matrices and ultrametric matrices: eigenvector distribution in the intermediate regime
• Modification of the Porter-Thomas distribution by rank-one interaction
• Neutron width statistics in a realistic resonance-reaction model
• Porter-Thomas fluctuations in complex quantum systems
• Statistical-model description of $\gamma$ decay from compound-nucleus resonances
• Deviations from the Porter-Thomas Distribution due to Nonstatistical $\gamma$ Decay below the ${}^{150}$Nd Neutron Separation Threshold