U.Egede, A. Golutvin, M. Patel, F. Redi, O. Lantwin

The Search for Hidden Particles (SHiP) experiment is part of a proposed new fixed-target facility at CERN's Super Proton Synchroton (SPS) accelerator. The experiment will search for very weakly-interacting long-lived and relatively low mass particles, including Heavy Neutral Leptons, right-handed partners of the active neutrinos; supersymmetric particles, such as sgoldstinos; or new scalar-, axion- or vector- particles. The lack of evidence for heavy new particles in searches at the Large Hadron Collider has renewed interest in models involving such particles. If they are sufficiently weakly-interacting, then the new particles could have evaded all previous searches and could form a so-called "hidden-sector". Hidden sector models can address a number of the major problems in particle physics. For example, different models can provide a dark matter candidate, explain inflation of the early Universe, explain the pattern of neutrino oscillations and masses, and generate the observed baryon asymmetry of the Universe.

The discovery of any hidden- sector particle would therefore have implications for particle physics, astrophysics and cosmology and the impact of such a discovery would be enormous. The physics case for SHiP is detailed in the document that can be found here.

The experiment and the associated facility were proposed by Imperial group members (see the "Expression of Interest" here) and the collaboration is led by Imperial physicist A. Golutvin. The technical proposal for the experiment has been reviewed by CERN's SPS committee and is presently being reviewed further by CERN. The Imperial group are working on developing the large magnetic shield that is used to sweep out the huge flux of muons produced in the SHiP target. Removing these muons is critical to the viability of the entire facility and the collaboration developing the shield is led by M. Patel. On the physics side, the group are particular interested in the Heavy Neutral Lepton search.