Thanks to the experiments at the LHC of CERN, scientists were able to confirm all the predictions of the Standard Model of particles, in particular the existence of a Higgs boson. However, several gaps are present in the Standard Model, especially the lack of explanation for dark matter and dark energy (which constitute 25% and 70% of the Universe, respectively), the mass of the neutrinos, the absence of antimatter in the Universe.The New Physics, that is to say the particles and the phenomena which would explain these gaps, is actively sought for in unexplored regions.In this context, the SHiP experiment looks for particles difficult to detect because they interact very little with matter and have a long time of life. These particles are good candidates for dark matter. Moreover, if their presence is confirmed, one would be able to explain the mass of the neutrinos and the asymmetry matter-antimatter in the Universe.

Lay summary

The SHiP detector would be housed in an underground hall at CERN, 120 m long by 20 m wide, and powered by an SPS proton accelerator extraction line. The known particles (of the Standard Model), produced when the SPS protons hit the SHiP target, will be largely absorbed in a filter portion of the detector. The new particles, instead, would continue on their way to disintegrate in a particular area of the detector, thus becoming detectable.

This subsidy from the SNSF allows to finance the salary of a postdoc who will participate in the design and research & development phase of the SHiP experiment.

The ability to remove the background from ordinary (Standard Model) particles is vital to successfully detect the particles associated to New Physics. One of the elements of the filter is intended for the suppression of the muons, very penetrating charged particles and difficult to stop. The idea is to use an electromagnet to produce a magnetic field having a particular topology, in order to deflect the trajectory of the muons towards the outside of the detector. The postdoc will therefore participate in the design and simulation of the electromagnet, which could be of superconducting type.

After the muon filter, SHiP provides a detector that will study light particles, such as the tau neutrino. This neutrino is the least known and the tau anti-neutrino is the only particle predicted by the Standard Model that has not yet been observed. For the construction of this subsystem, SHiP foresees a detector based on scintillating fiber technology (SciFi). The light produced by the passage of a charged particle is conveyed by the fibers to semiconductor photodetectors (SiPM). The EPFL group has already developed this technology as part of the LHCb experiment. The second part of this SNSF project is devoted to adapting the SciFi and SiPM technology to SHiP.