Daya Bay researchers find anti-neutrino discrepancy in models vs. measurements

An artist's representation of a neutrino.
An artist's representation of a neutrino. | Courtesy of Shutterstock

Researchers working on the International Daya Bay Collaboration said this week that progress has been made in measuring anti-neutrinos, highlighting weaknesses in current theories in this area of physics.

The collaboration is currently developing methods to measure neutrino activity. These particles are formed from nuclear fusion in stars, collisions between cosmic rays and the atmosphere of Earth, and nuclear energy generation.

A research team from the Chinese University of Hong Kong's (CUHK) Department of Physics has developed subsystems to monitor these particles and their counterparts, anti-neutrinos.

In developing this measurement process, it was discovered that an abundance of anti-neutrinos was produced when energy levels of approximately 5 million electron volts (MeV) were produced in reactors. Researchers said this amount is approximately 10 percent higher than predictions made utilizing theoretical models. Researchers said this descrepancy is approximately four standard deviations.

“This unexpected disagreement between our observation and predictions strongly suggested that the current calculations would need some refinement,” Kam-Biu Luk, a researcher from the University of California at Berkeley and Lawrence Berkeley National Laboratory, said.

The announcement also said anti-neutrino flux is approximately 6 percent below predictions within nuclear reactors. The flux refers to the total amount of particles produced over the entire energy range.