Neutrinos that go faster than light? This seems to indicate the measurements carried out by a team of researchers led by Dario Autiero, a CNRS researcher, as part of the international OPERA experiment. This surprising result was published on Friday 23 September 2011 at 2 a.m. (Paris time) on ArXiv (1) and presented the same day at 16 p.m. during a seminar at CERN, in Geneva, which is broadcast online.
With the theory of special relativity stated in 1905, Einstein had notably proved that nothing could exceed the speed of light in a vacuum. However, more than a century later, after three years of very high precision measurements and complex analyzes, the OPERA experiment (2) reports a completely unexpected result: the neutrinos arrive at the Gran Sasso with a small but significant advance compared to the time that the light would have taken to make the same course in the vacuum.
The OPERA experiment is dedicated to the observation of a neutrino beam produced by CERN accelerators in Geneva and detected 730 km further from the underground laboratory of Gran Sasso in Italy. Light travels this distance in 2,4 milliseconds. However, the OPERA experiment was able to measure neutrinos arriving at Gran Sasso 60 nanoseconds earlier. In other words, on a "long distance run" of 730 km, the neutrinos cross the finish line 20 meters ahead of hypothetical photons which would have traveled the same distance.
“We have set up a device between CERN and Gran Sasso allowing us to synchronize at the nanosecond level and measuring the distance between the two sites to within 20 centimeters. These measurements present low uncertainties and a statistic such that we place great confidence in our results, "explains Dario Autiero, CNRS researcher at the Institute of Nuclear Physics of Lyon (IPNL). “So we're looking forward to comparing our measurements with those from other experiments, because there is nothing in our data to explain why we seem to be observing speeding neutrinos. These results are based on the observation of more than 15 neutrinos.
"This result is completely unexpected," says Antonio Ereditato, of the University of Bern and spokesperson for the OPERA experiment. “Long months of research and verification did not allow us to identify an instrumental effect explaining the result of our measurements. If the researchers participating in the OPERA experiment will continue their work, they are impatient to compare their results with other experiments so as to fully assess the nature of this observation ”.
Until now, the speed of light has always been considered an insurmountable limit. If not, it could open completely new theoretical perspectives. Given the enormous impact that such a result could therefore have on physics, independent measures are necessary so that the observed effect can be refuted or formally established. This is why the researchers of the OPERA collaboration wished to open this result to a broader examination on the part of the community of physicists.
The OPERA experiment was launched in 2006 to study the rare transformations (oscillations) of muon neutrinos into tau neutrinos. One of these oscillations was observed in 2010, testifying to the unique capacity of this experiment in the detection of almost elusive signals from tau neutrinos.
Four CNRS laboratories are involved in the OPERA experiment:
* the Lyon Institute of Nuclear Physics (CNRS / Claude Bernard-Lyon 1 University),
* the Hubert Curien Multidisciplinary Institute (CNRS / University of Strasbourg),
* the Linear Accelerator Laboratory (CNRS / Université Paris-Sud 11) which participated until 2005,
* the Annecy le Vieux Laboratory of particle physics (CNRS / University of Savoie).
Notes
1. These results were published on Friday September 23 on the open archive site ArXiv
2. The OPERA detector was designed and used by a team of researchers based in Germany, Belgium, Korea, Croatia, France, Israel, Italy, Japan, Russia, Switzerland and Turkey. This experience represents a complex scientific enterprise, carried out thanks to the expertise of a large number of scientists, engineers, technicians and students, and to the strong involvement of the various actors in this project. Special mention should be made of the LNGS / INFN and the CERN laboratories, as well as the significant financial support from Italy and Japan and the significant contributions from Germany, Belgium, France and Switzerland. . This scientific cooperation currently brings together some 160 researchers from 30 different institutions across 11 countries.
Author
Scientific Research National Center
http://www.notre-planete.info/actualites/actu_2955_.php
http://www.cnrs.fr/