Underground neutrino experiment sets the stage for deep discovery about matter

[Judi Lynn]

Date:
March 26, 2018
Source:
DOE/Oak Ridge National Laboratory
Summary:
Scientists have shown they can shield a sensitive, scalable 44-kilogram germanium detector array from background radioactivity. This accomplishment is critical to developing and proposing a much larger future experiment -- with approximately a ton of detectors -- to study the nature of neutrinos.


If equal amounts of matter and antimatter had formed in the Big Bang more than 13 billion years ago, one would have annihilated the other upon meeting, and today's universe would be full of energy but no matter to form stars, planets and life. Yet matter exists now. That fact suggests something is wrong with Standard Model equations describing symmetry between subatomic particles and their antiparticles. In a study published in Physical Review Letters, collaborators of the MAJORANA DEMONSTRATOR, an experiment led by the Department of Energy's Oak Ridge National Laboratory, have shown they can shield a sensitive, scalable 44-kilogram germanium detector array from background radioactivity.

This accomplishment is critical to developing and proposing a much larger future experiment -- with approximately a ton of detectors -- to study the nature of neutrinos. These electrically neutral particles interact only weakly with matter, making their detection exceedingly difficult.

"The excess of matter over antimatter is one of the most compelling mysteries in science," said John Wilkerson of ORNL and the University of North Carolina, Chapel Hill. Wilkerson leads the MAJORANA DEMONSTRATOR, which involves 129 researchers from 27 institutions and 6 nations. "Our experiment seeks to observe a phenomenon called 'neutrinoless double-beta decay' in atomic nuclei. The observation would demonstrate that neutrinos are their own antiparticles and have profound implications for our understanding of the universe. In addition, these measurements could provide a better understanding of neutrino mass."

In a 2015 report of the U.S. Nuclear Science Advisory Committee to the Department of Energy and the National Science Foundation, a U.S.-led ton-scale experiment to detect neutrinoless double-beta decay was deemed a top priority of the nuclear physics community. Nearly a dozen experiments have sought neutrinoless double-beta decay, and as many future experiments have been proposed. One of their keys to success depends on avoiding background that could mimic the signal of neutrinoless double-beta decay.

More:
https://www.sciencedaily.com/releases/2018/03/180326140232.htm

[Jack-o-Lantern]

1. Very interesting and informative, thanks for the post.

[eppur_se_muova]

2. Good thing we can count on cheap germanium from China, the world's principal supplier ...

... unless something goes wrong.