When operating at highest intensity, the NuMI beam line transports a package of 35,000 billion protons every two seconds to a graphite target. The target converts the protons into bursts of particles with exotic names such as kaons and pions. Like a beam of light emerging from a flashlight, the particles form a wide cone when leaving the target. A set of two special lenses, called horns (photo), is the key instrument to focus the beam and send it in the right direction. The beam particles decay and produce muon neutrinos, which travel in the same direction. Photo: Peter Ginter.
Right when you thought that Fermilab was a thing of the past, new work with neutrinos are exciting us all over again. The scientists associated with the MINOS experiment at the Department of Energy’s Fermi National Accelerator Laboratory just announced their findings of a rare phenomena – the transformation of muon neutrinos into electron neutrinos.
On June 14 the Japanese T2K experiment also found clues to this type of transformation. These dual reports could have a profound impact on the way we understand how neutrinos impacted the evolution of our Universe. What burning question do the results answer? Try why there is more matter than anti-matter. If muon neutrinos transform into electron neutrinos, neutrinos could be the reason.
“The Main Injector Neutrino Oscillation Search (MINOS) at Fermilab recorded a total of 62 electron neutrino-like events. If muon neutrinos do not transform into electron neutrinos, then MINOS should have seen only 49 events.” says Fermilab. “The experiment should have seen 71 events if neutrinos transform as often as suggested by recent results from the Tokai-to-Kamioka (T2K) experiment in Japan.”
Using entirely different methods, the two neutrino experiments went to work. To measure the transformation of muon neutrinos into other neutrinos, the MINOS experiment sends a muon neutrino beam 450 miles (735 kilometers) through the Earth from the Main Injector accelerator at Fermilab to a 5,000-ton neutrino detector, located half a mile underground in the Soudan Underground Laboratory in northern Minnesota. The nearly twin detectors have different purposes. At Fermilab the purity of the muon neutrino beam is calibrated while Soudan detects electron and muon activity. It’s a fast trip, too…but just one four hundreths of a second is all it takes for these incredibly tiny particles to transform.
“Science usually proceeds in small steps rather than sudden, big discoveries, and this certainly has been true for neutrino research,” said Jenny Thomas from University College London, co-spokesperson for the MINOS experiment. “If the transformation from muon neutrinos to electron neutrinos occurs at a large enough rate, future experiments should find out whether nature has given us two light neutrinos and one heavy neutrino, or vice versa. This is really the next big thing in neutrino physics.”
For more information read the Fermilab Press Release.
Provided by Universe Today
