In September 2011, the OPERA experiment announced to have measured the travel time of the neutrinos between their production at the output of the CERN SPS and their arrival in the OPERA detector in Gran Sasso tunnel 730 km away [Ada11]. The precision of the measurement, based on the use of a GPS signal, was sufficient to claim that neutrinos could have traveled faster than the speed of light in vacuum c. This result was in contradiction with a fundamental law from the Theory of Relativity which excludes any propagation of energy or matter faster than c (Einstein is wrong!). It trigerred a lot of articles in the press and shows in TV, as well as theoretical papers on one side and experimental verifications on the other side (Borexino, ICARUS and LVD, observing the CNGS beam at the same place as OPERA at the Gran Sasso) .
After months of investigations, the OPERA team finally found that its result was biased by an optical fiber attached improperly and a clock oscillator ticking too fast at the level of the GPS receiver [Ada12]. At the same time, Borexino [Alv12], ICARUS [Ant12] and LVD [Aga12] did not confirm that neutrinos would travel faster than light. The anomaly was definitively killed at the Neutrino-2012 Conference in Kyoto [Ber12].
An interesting point of view (studies of the OPERA anomaly that could be relevant for analyses from the perspective of phenomenology of philosophy of science) is given in [Ame12].
More details can be found in https://en.wikipedia.org/wiki/Faster-than-light_neutrino_anomaly
References
| Author(s) | Title | Reference | |||
|---|---|---|---|---|---|
| Ada11 | T. Adam et al., OPERA Collaboration | Measurement of the neutrino velocity with the OPERA detector in the CNGS beam | arXiv:1109.4897v1 | ||
| Ada12 | T. Adam et al., OPERA Collaboration | Measurement of the neutrino velocity with the OPERA detector in the CNGS beam | JHEP 10 (2012) 093; arXiv:1109.4897v4 | ||
| Aga12 | N. Yu. Agafonova et al., LVD collaboration | Determination of a time shift in the OPERA set-up using high energy horizontal muons in the LVD and OPERA detector | Phys. Rev. Lett. 109 (2012) 070801; arXiv:1206.2488 | ||
| Alv12 | P. Alvarez Sanchez et al., Borexino collaboration | Measurement of CNGS muon-neutrino speed with Borexino | Phys. Lett. B716 (2012) 401; arXiv:1206.3554 | ||
| Ame12 | G. Amelino-Camelia | Phenomenology of philosophy of science: OPERA data | arXiv:1206.3554 | ||
| Ant12 | M. Antonello et al., ICARUS collaboration | Precision measurement of the neutrino velocity with the ICARUS detector in the CNGS beam | JHEP 11 (2012) 49; arXiv:1208.2629 | ||
| Ber12 | S. Bertolucci | Neutrino speed: a report on the muon-neutrino speed measurements of the Borexino, ICARUS and LVD experiments with the CNGS beam | Nucl. Phys. B (Proc. Suppl.) 235-236 (2013) 289 |