# Synopsis: Order out of chaos

Experiments point to order in parts of the nuclear spectrum believed to be chaotic in nature.

The quest for order in nuclear spectra is an exciting problem in nuclear and particle physics. An extreme example of spectroscopic complexity is provided by the highly excited states of intermediate- to heavy-mass nuclides. For several decades, the dominant belief has been that this part of the nuclear spectrum is completely random in nature, leading to the development of several stochastic approaches to its study.

In a paper in Physical Review Letters, P. E. Koehler, J. A. Harvey, and K. H. Guber (Oak Ridge National Laboratory, US) in collaboration with F. Bečvář and M. Krtička (Charles University, Czech Republic), show that new data from the Oak Ridge Electron Linear Accelerator (ORELA) strongly disagree with this dominant lore. The data, which resulted from precision measurements of widths of neutron resonances, suggest collective, as opposed to chaotic, behavior of the constituent nucleons. This result challenges several nuclear models currently employed throughout nuclear physics, and even parts of astrophysics, while providing valuable clues into the mechanisms that produce the baffling complexity of nuclear energy levels. – Abhishek Agarwal

More Features »

### Announcements

More Announcements »

Nuclear Physics

## Previous Synopsis

Atomic and Molecular Physics

## Next Synopsis

Semiconductor Physics

## Related Articles

Nuclear Physics

### Synopsis: Strong Force Calculations for Weak Force Reactions

Theorists have used lattice-QCD calculations to predict two weak-force-driven reactions—proton fusion and tritium decay. Read More »

Particles and Fields

### Synopsis: Proton Loses Weight

The most precise measurement to date of the proton mass finds a value that is 3 standard deviations lower than previous estimates. Read More »

Particles and Fields

### Viewpoint: Scattering Experiments Tease Out the Strong Force

The scattering of protons from a carbon isotope can be used to test models of the strong force. Read More »