Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

No evidence of the double nature of neutrinos

05.06.2014

The Majorana nature of neutrinos and the neutrinoless double-beta decay

Neutrinos are tiny, neutral elementary particles that, contrary to the standard model of physics, have been proven to have mass. One possible explanation for this mass could be that neutrinos are their own antiparticles, so-called Majorana particles.


This image shows the insertion of the EXO-200 detector into the cryostat 650 meters below ground at the Waste Isolation Pilot Plant (WIPP) near Carlsbad (New Mexico).

Credit: SLAC

Though experimental evidence for this is still lacking, many theoretical extensions of the standard model of physics predict the Majorana nature of neutrinos. If this hypothesis proves to be true, many previously unanswered questions about the origin of our universe and the origin of matter could be answered.

650 meters of shielding

In the EXO-200 experiment (Enriched Xenon Observatory), which is operated in the U.S. state of New Mexico, 650 meters below the earth's surface, scientists are looking for the evidence. Physicists from the research group of Professor Peter Fierlinger of the Excellence Cluster Universe at the Technische Universitaet Muenchen are major contributors to this experiment.

The most sensitive method to experimentally verify the Majorana question is the search for a process called "neutrinoless double-beta decay". This process is a special radioactive decay that may only occur if neutrinos are their own antiparticles.

Unprecedented accuracy

The EXO-200 experiment has searched for these decays over several years. From the fact that not one of these decays has been detected, the scientists can now deduce a lower limit for the half-life of the decay of at least 1025 years – around one million-billion years more than the age of the universe.

"Although this measurement attains unprecedented accuracy, the question about the nature of neutrinos can still not be answered," says Dr. Michael Marino, member of the research group of Professor Peter Fierlinger and responsible for the analysis of the now published data. "That's why this open issue remains one of the most exciting questions in physics."

This result demonstrates the high sensitivity of the detector and also the future potential of this method. Hence the EXO-200 measurements are also the basis for a much larger future experiment that finally could confirm or refute the Majorana nature of neutrinos."

International cooperation

The EXO-200 experiment uses liquid xenon that was enriched to 80.6 percent of xenon-136 in Russian centrifuges. Xenon-136 is an isotope that is allowed by theory to undergo neutrinoless double-beta decay. The experiment's location in the Waste Isolation Pilot Plant (WIPP) 650 meters below ground provides shielding against radioactive decays and cosmic radiation.

EXO-200 is a collaboration of research groups from Canada, Switzerland, South Korea, Russia and the USA; the Technische Universitaet Muenchen is the only German partner.

###

Original publication

J. B. Albert, et.al., The EXO-200 Collaboration: Search for Majorana neutrinos with the first two years of EXO-200 data, Nature, Adv. online publication, June 5, 2014

Dr. Andreas Battenberg | Eurek Alert!
Further information:
http://www.tum.de

Further reports about: Majorana Marino Xenon accuracy explanation extensions matter particles physics tiny

More articles from Physics and Astronomy:

nachricht Cassiopeia's hidden gem: The closest rocky, transiting planet
04.08.2015 | Harvard-Smithsonian Center for Astrophysics

nachricht Quantum States in a Nano-object Manipulated using a Mechanical System
04.08.2015 | Universität Basel

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Greenhouse gases' millennia-long ocean legacy

Continuing current carbon dioxide (CO2) emission trends throughout this century and beyond would leave a legacy of heat and acidity in the deep ocean. These...

Im Focus: Glaciers melt faster than ever

Glacier decline in the first decade of the 21st century has reached a historical record, since the onset of direct observations. Glacier melt is a global phenomenon and will continue even without further climate change. This is shown in the latest study by the World Glacier Monitoring Service under the lead of the University of Zurich, Switzerland.

The World Glacier Monitoring Service, domiciled at the University of Zurich, has compiled worldwide data on glacier changes for more than 120 years. Together...

Im Focus: Quantum Matter Stuck in Unrest

Using ultracold atoms trapped in light crystals, scientists from the MPQ, LMU, and the Weizmann Institute observe a novel state of matter that never thermalizes.

What happens if one mixes cold and hot water? After some initial dynamics, one is left with lukewarm water—the system has thermalized to a new thermal...

Im Focus: On the crest of the wave: Electronics on a time scale shorter than a cycle of light

Physicists from Regensburg and Marburg, Germany have succeeded in taking a slow-motion movie of speeding electrons in a solid driven by a strong light wave. In the process, they have unraveled a novel quantum phenomenon, which will be reported in the forthcoming edition of Nature.

The advent of ever faster electronics featuring clock rates up to the multiple-gigahertz range has revolutionized our day-to-day life. Researchers and...

Im Focus: Superfast fluorescence sets new speed record

Plasmonic device has speed and efficiency to serve optical computers

Researchers have developed an ultrafast light-emitting device that can flip on and off 90 billion times a second and could form the basis of optical computing.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Success 4.0 – Is Your Company Fit for the Future? New Series of Events for Executives

04.08.2015 | Event News

3rd Euro Bio-inspired - International Conference and Exhibition on Bio-inspired Materials

23.07.2015 | Event News

Clash of Realities – International Conference on the Art, Technology and Theory of Digital Games

10.07.2015 | Event News

 
Latest News

Small tilt in magnets makes them viable memory chips

04.08.2015 | Information Technology

New Design Brings World’s First Solar Battery to Performance Milestone

04.08.2015 | Power and Electrical Engineering

Magnetism at Nanoscale

04.08.2015 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>