It turns out there’s mass. For years, the international OPERA experiment (Oscillation Project with Emulsion-tRacking Apparatus) has been studying the oscillations of muon neutrinos into tauonic neutrinos. This high-energy physics experiment has been achieved through the collaboration between CERN in Geneva and the Gran Sasso National Laboratories (the largest in the world). The experiment has been realised through the use of the CNGS neutrino beam (CERN Neutrinos to Gran Sasso). Well, the experiment has led to surprising results for particle physics.
There are 3 types of neutrinos: muon, electronic and tauonic. These neutrinos lack any electrical charge and therefore manage to cross the Earth without being disturbed. The three types of neutrinos can be identified because, when they interact with matter, they produce electrically charged leptons, respectively bearing the names: electron, muon and tau particles. The OPERA experiment is the only study that has been able to reveal all three of these charged leptons and, therefore, identify all three types of neutrinos. Essentially, OPERA has demonstrated that these neutrinos have mass, whereas, in the past, it was thought to be inexistent and impossible to prove. A few years ago, neutrinos were believed to be potentially responsible for dark matter. Yet these results and this new knowledge of their mass demonstrate that neutrinos can only contribute to dark matter in an insignificant fraction. How has it been possible to prove what was once believed to be indemonstrable? By shooting a beam of neutrinos from CERN in Geneva towards the Gran Sasso and measuring the relative transformation from one type to another that takes place during the 730-kilometre journey in the subsoil, namely measuring its “oscillation”. Years of preparation, the last 4 of which have been spent on veritable experimentation, have served to distinguish the tau neutrino from its counterpart, the antineutrino, and to explain how it interacts with matter.
The Fantini Group has been actively collaborating on this project from the very beginning! Various fixtures and components have been created for the OPERA experiment, on behalf of the National Institute of Nuclear Physics, and installed directly at the Gran Sasso underground laboratories. Specifically, the following was provided:
- processed blades installed on the two spectrometers
- structures to assemble the spectrometers
- copper bars for the lower and upper windings of the spectrometers
- lower and upper heat exchangers to cool the copper windings
- beams to align and brace the spectrometers
- 124 semi-walls to house the detector elements
- upper and lower support systems to suspend the semi-walls
The conclusions reached by the OPERA experiment (published by the INFN – National Institute for Nuclear Physics and published by the Physical Review Letters) are astonishing because they upset the very concept of the standard model on which particle physics has been based.
We are extremely proud that Fantini has contributed to this discovery. Fantini, Italian excellence. Throughout the world.