Friday, February 16, 2018

Neutron lifetime puzzle deepens, but no dark matter seen

Two ways to measure neutron lifetimes, Quanta illustration.

The discrepancy between the “bottle” and “beam” measurements has persisted since both methods of gauging the neutron’s longevity began yielding results in the 1990s. At first, all the measurements were so imprecise that nobody worried. Gradually, though, both methods have improved, and still they disagree.

Now, researchers at Los Alamos National Laboratory in New Mexico have made the most precise bottle measurement of the neutron lifetime yet, using a new type of bottle that eliminates possible sources of error in earlier designs. The result, which will soon appear in the journal Science, reinforces the discrepancy with beam experiments and increases the chance that it reflects new physics rather than mere experimental error. (Full story)

Novel exciton interactions in carbon nanotubes


Stephen Doorn performs spectroscopic
characterization of carbon nanotubes. LANL photo.

Nanotechnology researchers studying small bundles of carbon nanotubes have discovered an optical signature showing excitons bound to a single nanotube are accompanied by excitons tunneling across closely interacting nanotubes. That quantum tunneling action could impact energy distribution in carbon nanotube networks, with implications for light-emitting films and light harvesting applications.

"Observing this behavior in carbon nanotubes suggests there is potential to detect and control a similar response in more complex, multi-layered semiconductor and semiconductor-metal heterostructures,” said Stephen Doorn, of the Center for Integrated Nanotechnologies at Los Alamos and a coauthor of the study, recently published in Nature Communications. (Full story)

Augmented reality combines worlds to make the real world safer

Augmented reality goggles project holograms
onto the existing environment to help solve
infrastructure challenges, LANL image.

Los Alamos National Laboratory is investigating the technology’s applications and writing software in support of the Laboratory’s national security mission, such as tracking inventories or giving workers instructions for using equipment on the job and in real time. Other new uses of augmented reality technology being developed at Los Alamos may save time, money, and even lives by improving procedures for structural-health monitoring. (Full story)