The fantastic results still stay! The sensational OPERA experiment, which gave us the faster-than-light neutrino results, have repeated the experiment and have found similar results. Neutrinos continue to travel faster than light and the amount by which they break the speed barrier is also the same. The experiment was carried out during 30th October to 2nd November.
The latest results give a 60.7 ns advance for the neutrinos with a 7.4 ns error for the systematic and 6.9 ns statistical error. This means that the previous results are not discredited. The difference between the previous experiment and this present one is the proton bunch size.
Î”t = 60.7 ns +/- 7.4 (systematic) +/- 6.9 (statistical)
Still Skeptical, as they should be!
Scientists are still skeptical and not willing to accept this result yet. Even OPERA and CERN scientists say that the experiment has to be repeated by MINOS or T2K and only then can the experimental results verified.
Detecting one neutrino at a time
This time, the beam of neutrinos has been bunched in 3 ns bins separated by 520 ns. This means that each bunch in the beam consists of basically one neutrino. The experiment has, thus, been repeated with essentially single neutrinos. The number of events is much less than the last time. While OPERA used 16111 events last time, this time they have stuck to merely 20 events. This has led to many people questioning the statistics of the experiment. OPERA, however, claims that the accuracy is just as good, if not better.
The paper of the repeated experiment is already on ArXiv. Here’s the link to the short paper.
Repeat Experiment Needed!
This experiment re-run proves that the beam bunching has nothing to do with the observed results. The effects have not gone away, but that might depend on the CNGS (Cern Neutrino to Gran Sasso) beam structure as well as the systematics of the OPERA detector. A repeat of the experiment in some other part of the world is the need of the day.