Studying Neutrinos at the High Energy Frontier

Although the properties of neutrinos have been intensively studied, we are still missing data about their behaviour in the TeV energy scale, as well as conclusive tests of lepton universality in neutrino scattering.

Embracing the discussions on recently identified flavour anomalies, which hint at lepton universality violation, the study of high-energy neutrino interactions involving both heavy leptons and heavy quarks may be a powerful and complementary tool to search for new physics effects. Such interaction channels require high neutrino energy.

Here I propose to measure high energy neutrinos with a detector sensitive to heavy flavour particles.

This project (FASERnu) employs a novel approach to exploit the CERN Large Hadron Collider (LHC) as an intense neutrino source, which allows for the study of the high energy frontier of man-made neutrinos. An emulsion hybrid neutrino detector with a target mass of 1.2 tonnes will be employed. Such a detector structure has been well proven to be sensitive to heavy flavour particles: tau, charm and beauty.

Data taking will be carried out during the forthcoming Run 3 of LHC operation (2021-2024), which would yield >20,000 neutrino interactions in the detector.

During the timeline of this grant, neutrino cross sections will be measured for all three flavours in the uncharted energy range between 360 GeV and 6 TeV. Furthermore, the channels associated with heavy quark (charm and beauty) production will be studied. I established this project within the framework of the FASER experiment.

The letter of intent and technical proposal of this project were approved by the CERN committees and I presently act as one of the project leaders of the neutrino program in FASER.

FASERnu will not only investigate an unexplored energy regime, but will also provide relevant inputs to future neutrino experiments at the High-Luminosity-LHC (HL-LHC) and then at the Future Circular Collider (FCC).