Superluminal Neutrino Revisit Results AnnouncedCategory: Science & Technology
Posted: June 8, 2012 10:20AM
Last year researchers at CERN surprised many people, both in the scientific community and beyond, by announcing that they had observed neutrinos moving faster than the speed of light. Such a finding would have a strong impact on either relativity, particle physics, or both. Since that experiment the researchers had asked for help with identifying any mistakes in their work and devised a new experiment to more accurately measure how fast neutrinos travel. Now the results of the new experiment have been announced, showing that the older results were in fact erroneous. However, this episode has been far from a waste of time.
The original experiment CERN was performing had the researchers creating neutrinos within the LHC in Switzerland and detecting them at the OPERA detector in Italy. The speed measurement was actually not the original intent of this experiment, but it led to the recent experiment that has made the most precise measurement of the speed of neutrinos ever. It places the speed of these curious particles to within 0.5 nanoseconds of light speed, with an error of 8 ns. While this result will not shake the physics world, something else happened during the CERN and OPERA collaboration that just might.
The neutrinos CERN has been making for OPERA have been to discover if neutrinos can change their flavor. These particles come in three types, electron, muon, and tau, and there is a debate over if they can change from one to another. If they can, then neutrinos must have some mass to them, which could be important in understanding why more matter exists in the Universe than antimatter. These particles are too small to weigh, so instead the researchers have to watch and see if one neutrino can change into another. Once before OPERA detected a tau neutrino amongst the billions of muon neutrinos from CERN, and now they have found the second. A total of six will be needed before the finding is significant though. A team in Japan though may have beaten them to it by, observing ten muon neutrinos transforming into electron neutrinos.