[en] The Nemo collaboration is looking to measure neutrinoless double beta decay and to have a sensitivity for the effective neutrino mass on the order of 0.1 eV. The NEMO3 detector is now operating in the Frejus Underground Laboratory. The fundamental design of the detector, the expected performance and the first results are presented. (Author) 4 refs

[en] The discovery of neutrinoless double beta decay (ββ0ν), forbidden in the Standard Theory, would permit to determine if neutrinos are massive Majorana particles (ν = ν-bar). With this aim, the NEMO collaboration has built the NEMO3 detector with a sensitivity of 0,2 eV on the neutrino effective mass. This detector is composed of a ββ emitter source, a wire chamber and a calorimeter made of 1940 scintillation counters in order to measure the energy and time of flight of the electrons. The ββ0ν signal expected is a few events per year. To measure it, it is essential to have a precise knowledge of the calorimeter energy and time calibration, and to master all the background sources. The first part of this work was dedicated to the study of the daily calibration survey with the help of a relative calibration system based on laser light. An automated program for laser spectra study and calculation of calibration corrections has been achieved. The behaviour of the whole calorimeter has been characterized for a 23 days period. The second part of this work was the study of the neutrons and γ ray contribution to the background of the experiment. The data taking with and without iron shielding,with and without neutron source were systematically compared with simulations. The very good agreement between experiment and simulations allows us to conclude that with γ and neutron shieldings together with a magnetic field, the objective of 0 external background event will be reached. (author)

[en] The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector aiming at the measurement of anti-neutrinos issued from nuclear reactors at a 53km distance, having as primary goal the determination of the neutrino mass hierarchy. The detector will be located 1800m.w.e. underground and consists of a 20 kiloton liquid scintillator contained in a 35.4m diameter acrylic sphere, instrumented by more than 17000 20 inch PMTs ensuring a 77% photocathode coverage. The required energy resolution to discriminate between the hierarchies at the 3–4 σ C.L. in about 6 years of data taking is 3% at 1 MeV. To achieve such a precision, severe constraints on the detector components quality are set: the PMTs need a quantum efficiency of more than 27% and the attenuation length of the liquid has to be better than 20m (at 430 nm). The precise measurement of the antineutrino spectrum will allow to reduce the uncertainty below 1% on solar oscillation parameters. The international collaboration of JUNO was established in 2014, the civil construction started in 2015 and the RandD of the detectors is ongoing. The expected start of data taking is set for 2020.

[en] The aim of the OPERA experiment is to provide an unambiguous evidence for the ν_μ ↔ ν_τ oscillation by looking at the appearance of ν_τ in a pure ν_μ. The ν_μ beam produced at CERN will be sent towards the Gran Sasso underground laboratory, where OPERA detector is under construction. The detector, the physics potential and performances for neutrino oscillation studies are presented

[en] The aim of the OPERA experiment is to provide unambiguous evidence for the ν_μ↔ν_τ oscillation by looking at the appearance of ν_τ in a pure ν_μ beam. The detector is located on the high-energy, long-baseline CERN to LNGS beam (CNGS) 730 km away from the neutrino source. The apparatus consists of a target made of lead/emulsion-films bricks complemented by electronic detectors. The neutrino interaction inside the bricks is tagged using the electronic trackers. In August 2006, a short CNGS run was successfully performed and a first sample of neutrino events was collected. Experiment description and results from the first CNGS run are reported in details

[en] The aim of the OPERA experiment is to provide unambiguous evidence for the ν_μ ↔ ν_τ oscillation by looking at the appearance of ν_τ in a pure ν_μ beam. This oscillation will be sought in the region of the oscillation parameters indicated by the atmospheric neutrino results. The experiment is part of the CNGS (CERN Neutrino beam to Gran Sasso) project. The νμ beam produced at CERN will be sent towards the Gran Sasso underground laboratory, where the OPERA detector is under construction. The detector, the physics potential, and performance for neutrino oscillation studies including the subleading ν_μ ↔ ν_ε search are presented

[en] Pulse shape discrimination in liquid scintillator detectors is a well-established technique for the discrimination of heavy particles from light particles. Nonetheless, it is not efficient in the separation of electrons and positrons, as they give rise to indistinguishable scintillator responses. This inefficiency can be overtaken through the exploitation of the formation of ortho-Positronium (o-Ps), which alters the time profile of light pulses induced by positrons. We characterized the o-Ps properties in the most commonly used liquid scintillators, i.e. PC, PXE, LAB, OIL and PC + PPO. In addition, we studied the effects of scintillator doping on the o-Ps properties for dopants currently used in neutrino experiments, Gd and Nd. Further measurements for Li-loaded and Tl-loaded liquid scintillators are foreseen. We found that the o-Ps properties are suitable for enhancing the electron-positron discrimination

No abstract available

[en] The goal of the INFN SCENTT R&D project is to develop the calorimeter technologies for the instrumentation of decay tunnels in conventional neutrino beams. This instrumentation is required to achieve a substantial improvement in the uncertainty on neutrino fluxes for the next generation cross section experiments. In particular, we are designing a positron tagger based on purely calorimetric techniques that is able to measure the rate and the spectrum of the positrons produced in the $K^{+}\to {\mathrm{e}}^{+}{\pi }^0{\nu }_e$ decay. The ν_e flux is inferred from the positron rate in the decay tunnel. Considering the large dimensions of the tagger, the most cost effective technology is based on small modules of Fe/Scintillator shashlik calorimeters, with adequate segmentation and energy resolution to efficiently tag the positrons over the charged pion background. This contribution presents preliminary results obtained with two shashlik calorimeter prototypes readout with an array of Silicon PhotoMultipliers and tested at the CERN PS-T9 beamline.

[en] The NEMO 3 detector, which has been operating in the Frejus underground laboratory since February 2003, is devoted to the search for neutrinoless double-beta decay (ββ0ν). The half-lives of the two neutrino double-beta decay (ββ2ν) have been measured for ¹⁰⁰Mo and ⁸²Se. After 389 effective days of data collection from February 2003 until September 2004 (phase I), no evidence for neutrinoless double-beta decay was found from ∼7 kg of ¹⁰⁰Mo and ∼1 kg of ⁸²Se. The corresponding limits are T_1/2(ββ0ν)>4.6x10²³ yr for ¹⁰⁰Mo and T_1/2(ββ0ν)>1.0x10²³ yr for ⁸²Se (90% C.L.). Depending on the nuclear matrix element calculation, the limits for the effective Majorana neutrino mass are ν><0.7-2.8 eV for ¹⁰⁰Mo and ν><1.7-4.9 eV for ⁸²Se