English
Related papers

Related papers: Neutron Resonance Data Exclude Random Matrix Theor…

200 papers

I have analyzed reduced neutron widths ({\Gamma}_{n}^0) for the subset of 1245 resonances in the nuclear data ensemble (NDE) for which they have been reported. Random matrix theory (RMT) predicts for the Gaussian orthogonal ensemble (GOE)…

Nuclear Theory · Physics 2015-05-14 P. E. Koehler

Recent analyses of the distribution of reduced neutron widths in the Nuclear Data Ensemble (NDE) and in the Pt isotopes find strong disagreement with predictions of random-matrix theory. These analyses combine the maximum-likelihood method…

Nuclear Theory · Physics 2014-05-28 J. F. Shriner , H. A. Weidenmüller , G. E. Mitchell

A recent Letter attempted to reconcile the disagreement between neutron resonance data and random matrix theory (RMT). To this end, a new formula was derived for transforming measured ({\Gamma}_{{\lambda}n}) to reduced…

Nuclear Theory · Physics 2011-01-25 P. E. Koehler , F. Bečvář , M. Krtička , J. A. Harvey , K. H. Guber

Recent measurements of resonance widths for low-energy neutron scattering off heavy nuclei show large deviations from the standard Porter-Thomas distribution. We propose a new resonance width distribution based on the random matrix theory…

Nuclear Theory · Physics 2012-10-09 Gavriil Shchedrin , Vladimir Zelevinsky

Deviations of neutron scattering width distributions from the Porter-Thomas law due to resonances overlapping are calculated in the extended framework of the random matrix approach.

Nuclear Theory · Physics 2018-12-07 Oleg V. Zhirov

The Porter-Thomas (PT) distribution of resonance widths is one of the oldest and simplest applications of statistical ideas in nuclear physics. Previous experimental data confirmed it quite well but recent and more careful investigations…

Mathematical Physics · Physics 2017-01-18 E. Bogomolny

Since it was first applied to the study of nuclear interactions by Wigner and Dyson, almost 60 years ago, Random Matrix Theory (RMT) has developed into a field of its own within applied mathematics, and is now essential to many parts of…

Exactly Solvable and Integrable Systems · Physics 2008-06-10 Mark Mineev-Weinstein , Mihai Putinar , Razvan Teodorescu

We obtained total radiation widths of s-wave resonances through R-matrix analysis of 147Sm(n,gamma) cross-sections. Distributions of these widths differ markedly for resonances below and above 300 eV, in stark contrast to long-established…

Problems in applying random-matrix theory (RMT) to nuclear reactions arise in two domains. To justify the approach, statistical properties of isolated resonances observed experimentally must agree with RMT predictions. That agreement is…

Nuclear Theory · Physics 2015-06-18 H. A. Weidenmueller

Neural networks have been used successfully in a variety of fields, which has led to a great deal of interest in developing a theoretical understanding of how they store the information needed to perform a particular task. We study the…

Disordered Systems and Neural Networks · Physics 2022-11-16 Matthias Thamm , Max Staats , Bernd Rosenow

A recent experiment on s-wave neutron scattering from $^{192,194,196}$Pt found that the reduced neutron width distributions deviate significantly from the expected Porter-Thomas distribution (PTD), and several explanations have been…

Nuclear Theory · Physics 2018-07-11 P. Fanto , G. F. Bertsch , Y. Alhassid

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…

Nuclear Theory · Physics 2015-08-05 Alexander Volya , Hans A. Weidenmüller , Vladimir Zelevinsky

We obtained an unprecedentedly large number of s-wave neutron widths through R-matrix analysis of neutron cross-section measurements on enriched Pt samples. Careful analysis of these data rejects the validity of the Porter-Thomas…

Nuclear Experiment · Physics 2014-11-21 P. E. Koehler , F. Bečvář , M. Krtička , J. A. Harvey , K. H. Guber

This work analyzes singular-value spectra of weight matrices in pretrained transformer models to understand how information is stored at both ends of the spectrum. Using Random Matrix Theory (RMT) as a zero information hypothesis, we…

Machine Learning · Computer Science 2025-11-07 Max Staats , Matthias Thamm , Bernd Rosenow

We employ the random matrix theory (RMT) framework to revisit the distribution of resonance widths in quantum chaotic systems weakly coupled to the continuum via a finite number M of open channels. In contrast to the standard first-order…

Mesoscale and Nanoscale Physics · Physics 2015-06-10 Yan V. Fyodorov , Dmitry V. Savin

The application of random-matrix theory (RMT) to compound-nucleus (CN) reactions is reviewed. An introduction into the basic concepts of nuclear scattering theory is followed by a survey of phenomenological approaches to CN scattering. The…

Nuclear Theory · Physics 2015-05-18 G. E. Mitchell , A. Richter , H. A. Weidenmueller

Statistical properties of non--symmetric real random matrices of size $M$, obtained as truncations of random orthogonal $N\times N$ matrices are investigated. We derive an exact formula for the density of eigenvalues which consists of two…

Statistical Mechanics · Physics 2010-10-21 Boris A. Khoruzhenko , Hans-Juergen Sommers , Karol Zyczkowski

Relativistic mean field (RMF) theory of nuclear matter with the isovector scalar mean field corresponding to the delta-meson [a_0(980)] is studied. While the delta-meson mean field vanishes in symmetric nuclear matter, it can influence…

Astrophysics · Physics 2009-10-30 S. Kubis , M. Kutschera

A basic prediction of the statistical model of compound nucleus reactions is that the partial widths for decay into any open channel channel fluctuate according to the Porter-Thomas distribution (PTD). A recent experiment on $s$- and…

Nuclear Theory · Physics 2018-11-06 P. Fanto , G. F. Bertsch , Y. Alhassid

We propose a novel method for analysis of experimental data obtained at relativistic nucleus-nucleus collisions. The method, based on the ideas of Random Matrix Theory, is applied to detect systematic errors that occur at measurements of…

High Energy Physics - Experiment · Physics 2009-11-11 E. I. Shahaliev , R. G. Nazmitdinov , A. A. Kuznetsov , M. K. Suleymanov , O. V. Teryaev
‹ Prev 1 2 3 10 Next ›