The Neutrino group at IPHC mainly dedicates its research on the oscillations of neutrinos, the study of the CP violation in the neutrino sector, and the detection of extra-terrestrial neutrinos (GeV-PeV) for physics or astrophysics with neutrino telescopes.
Past experiments & projects :
The OPERA neutrino detector in the underground Gran Sasso Laboratory (LNGS) was designed to perform the first detection of neutrino oscillations in appearance mode through the study of νμ → ντ oscillations. The apparatus consisted of an emulsion/lead target complemented by electronic detectors and it was placed in the high energy long-baseline CERN to LNGS beam (CNGS) 730 km away from the neutrino source. In 2015 the Collaboration reported the discovery of this oscillation with 5.1 σ significance. The OPERA detector is currently under dismounting.
The EUROnu Super Beam work package has studied a neutrino beam based on Supraconducting Proton Linac (SPL) at CERN and a large water Cherenkov detector, MEMPHYS, placed at the Laboratoire Souterrain de Modane (Fréjus tunnel, France), with a baseline of 130 km. The aim of this proposed experiment was to study the CP violation in the neutrino sector. The conceptual design of the neutrino beam, especially the target and the magnetic focusing device has been developed. The beam was presenting several unprecedented challenges, like the high primary proton beam power (4 MW), the high repetition rate (50 Hz) and the low energy of the protons (4.5 GeV).
Current experiments & projects :
The Double Chooz experiment goal is to search for a non-vanishing value of the θ13 neutrino mixing angle. This is the last step to accomplish prior moving towards a new era of precision measurements in the lepton sector. The most stringent constraint on the third mixing angle was coming from the CHOOZ reactor neutrino experiment with sin2(2θ13)<0.2. Double Chooz explores the range of sin2(2θ13) from 0.2 to 0.03, within three years of data taking. The improvement of the CHOOZ result requires an increase in the statistics, a reduction of the systematic errors below one percent, and a careful control of the background. Double Chooz uses two identical detectors, one at 400 m and another at 1.05 km distance from the Chooz nuclear cores. The first results announced in 2011 using only the far detector showed with low significance that θ13 was different from zero. The two detectors, near and far, are in operation since beginning of 2015.
The ESSnuSB (ESS neutrino Super Beams) project foresees the use of the ESS linac being currently under construction in Lund (Sweden) to accelerate a proton beam (2 GeV, 5 MW) to a horn system in order to produce very intense neutrino super beam. This project is led by the Neutrino group of the IPHC and the University of Uppsala. 12 institutes are already concerned worldwide. The project is now supported by a European COST Action (H2020) for four years.
It concerns the technical development and scientific exploitation of existing or planned undersea telescopes, for the detection of atmospheric (GeV) and/or cosmic (TeV) neutrinos. The data analysis activities on ANTARES (Astronomy with a Neutrino Telescope and Abyss environmental RESearch, TeV neutrinos), in operation until 2016, are focused on multi-messenger astronomy. This includes coincidences searches between high energy neutrinos from compact sources (gamma-ray bursts for instance) and gravitational wave (GW) bursts, with Virgo/LIGO. This is a novel way to disentangle signal from background both in neutrino telescopes and GW interferometers.
Next generation of undersea telescopes in Europe ; Feasibility study of ORCA. The group participates to activities linked to the next generation of undersea telescopes in Europe through the KM3NeT collaboration. In particular, since 2012, the group is involved in the feasibility study of ORCA (Oscillation Research with Cosmics in the Abyss), to be deployed on the French KM3NeT site, a denser telescope with new photon detection technology, to determine the neutrino mass hierarchy using GeV atmospheric neutrinos and their oscillations in the Earth.
JUNO (Jiangmen Underground Neutrino Observatory, China) experiment aims to determine the mass hierarchy of neutrinos from unprecedented energy spectra of neutrinos coming from several nuclear power plants. JUNO can measure few of the oscillation parameters with an accuracy less than 1% and also has a rich astroparticle physics programme. The collaboration is composed of more than 300 physicists from 55 institutes (14 countries). The data taking period is supposed to start in 2020.
Le groupe Neutrino à l’IPHC dédie principalement ses recherches aux oscillations de neutrinos, à l’étude de la violation de la symétrie CP dans le secteur du neutrino et à la détection de neutrinos extra-terrestres (GeV-PeV) pour la Physique ou l’Astrophysique avec les télescopes à neutrinos.
L’équipe a été fortement impliquée dans :
Les expériences et projets dans lesquels le groupe participe actuellement sont :