ICARUS: Neutrinos Travel At Light Speed. Period. Faster-than-light neutrino findings really, thoroughly dead. This week, the XXV International Conference on Neutrino Physics and Astrophysics (better known as Neutrino 2012) is taking place in Japan, and a number of announcements have been made in association with the meeting.
Neutrinos have some fascinating properties (which we'll discuss at length this weekend), but it's now clear there is one exceptional feature they lack: the ability to go faster than light. CERN Press Release. UPDATE 8 June 2012.
Einstein Avenged: Neutrinos Bow to Light Speed Laws. CERN has disclosed results of experiments undertaken after previous tests seemed to indicate subatomic particles called "neutrinos" were capable of traveling faster than the speed of light.
The original results caused a stir several months ago and threatened to upend several well-established theories, but the subsequent experiments indicate neutrinos do indeed obey the universal speed limit. Eight months after the multinational Opera research team caused an uproar among physicists with its findings that some neutrinos appeared to travel faster than light, its findings have been officially refuted. 'Faster than light' physicist steps down. An Italian physicist at the head of a team behind a controversial experiment that appeared to contradict Albert Einstein's theory of relativity has resigned.
Antonio Ereditato stepped down as co-ordinator of the so-called OPERA experiment, Italy's National Institute of Nuclear Physics (INFN) said on Friday. Ereditato's resignation came before a vote on a motion by some members of his OPERA team that he be removed after tests this month contradicted an earlier claim that the universe's speed limit had been broken. ICARUS experiment at Gran Sasso laboratory reports new measurement of neutrino time of flight consistent with the speed of light. Icarus experiment measures neutrino speed: Even neutrinos are not faster than light. The ICARUS experiment at the Italian Gran Sasso laboratory has reported a new measurement of the time of flight of neutrinos from CERN to Gran Sasso.
The ICARUS measurement, using last year's short pulsed beam from CERN, indicates that the neutrinos do not exceed the speed of light on their journey between the two laboratories. This is at odds with the initial measurement reported by OPERA last September. "The evidence is beginning to point towards the OPERA result being an artefact of the measurement," said CERN Research Director Sergio Bertolucci, "but it's important to be rigorous, and the Gran Sasso experiments, BOREXINO, ICARUS, LVD and OPERA will be making new measurements with pulsed beams from CERN in May to give us the final verdict. In addition, cross-checks are underway at Gran Sasso to compare the timings of cosmic ray particles between the two experiments, OPERA and LVD. Faster-than-light neutrino measurement has two possible errors. The OPERA collaboration, which made headlines in September with the revolutionary claim to have clocked neutrinos travelling faster than the speed of light, has identified two possible sources of error in its experiment.
If true, its result would have violated Einstein’s Special Theory of Relativity, a cornerstone of modern physics. OPERA had collected data suggesting that neutrinos generated at CERN near Geneva, Switzerland, and sent 730 kilometres to its detector at Gran Sasso National Laboratory in Italy were arriving 60 nanoseconds faster than a light beam would take to travel the same distance. Many physicists were skeptical but the measurement seemed to have been done carefully and reached a statistically significant level. But according to a statement OPERA began circulating today, two possible problems have now been found with its set-up. An anonymously sourced account on Science Insider today broke the news that OPERA may have made a mistake. Was Einstein wrong - or was the cable loose? Neutrino Parents Call Into Question Faster-than-light Results. If them neutrinos are faster than light, physicists have a lot of work to do. The story of the faster-than-light neutrinos is a rather unusual one.
The good folks at Gran Sasso seem embarrassed by their own results. They had checked, rechecked, and re-rechecked their data, and investigated all the sources of systematic error they could think of, eliminating them all. Yet those pesky neutrinos were still arriving 60ns too soon. You might think this would be a cause for celebration—after all, finding exciting new physics on the horizon is supposed to be every physicist's dream, right?
The truth is that they knew they were not just getting close to a fire, but standing in the flames while taking a gasoline shower. It's important to understand why this result is going to be aggressively attacked but the data probably won't. But physics rarely works like that. Researchers are now asking "What tweaks to the standard model can accommodate this result? " Two papers examining these consequences have now come out. Faster-than-light neutrinos dealt another blow. Read more: "Neutrinos: Complete guide to the ghostly particle" Faster-than-light neutrinos can't catch a break.
If they exist they would not only flout special relativity but also the fundamental tenet that energy is conserved in the universe. This suggests that either the speedy neutrino claim is wrong or that new physics is needed to account for it. In September, physicists with the OPERA experiment in Gran Sasso, Italy, reported that neutrinos had apparently travelled there from CERN near Geneva, Switzerland, faster than light.