C. Jollet

Mass hierarchy discrimination with atmospheric neutrinos in large volume ice/water Cherenkov detectors

A bstractLarge mass ice/water Cherenkov experiments, optimized to detect low energy (1–20xa0GeV) atmospheric neutrinos, have the potential to discriminate between normal and inverted neutrino mass hierarchies. The sensitivity depends on several model and detector parameters, such as the neutrino flux profile and normalization, the Earth density profile, the oscillation parameter uncertainties, and the detector effective mass and resolution. A proper evaluation of the mass hierarchy discrimination power requires a robust statistical approach. In this work, the Toy Monte Carlo, based on an extended unbinned likelihood ratio test statistic, was used. The effect of each model and detector parameter, as well as the required detector exposure, was then studied. While uncertainties on the Earth density and atmospheric neutrino flux profiles were found to have a minor impact on the mass hierarchy discrimination, the flux normalization, as well as some of the oscillation parameter (

Shashlik Calorimeters With Embedded SiPMs for Longitudinal Segmentation

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Longitudinally segmented shashlik calorimeters with SiPM readout: The SCENTT experiment

, θ13, θ23, and δCP) uncertainties and correlations resulted critical. Finally, the minimum required detector exposure, the optimization of the low energy threshold, and the detector resolutions were also investigated.

Measurement of ortho-positronium properties in liquid scintillators

Effective longitudinal segmentation of shashlik calorimeters can be achieved taking advantage of the compactness and reliability of silicon photomultipliers. These photosensors can be embedded in the bulk of the calorimeter and are employed to design very compact shashlik modules that sample electromagnetic and hadronic showers every few radiation lengths. In this paper, we discuss the performance of a calorimeter made up of 12 such modules and able to sample showers every

A non-conventional neutrino beamline for the measurement of the electron neutrino cross section

sim 4X_{0}

Yields and production rates of cosmogenic

. In summer 2016, this prototype has been exposed to electrons, muons, and hadrons at CERN PS (East Area T9 beamline). The performances in terms of energy resolution, linearity, response to minimum ionizing particles, and reconstruction of the shower profile are discussed.

^9

A compact readout based on Silicon PhotoMultipliers can provide longitudinal segmentation to shashlik calorimeters. Direct fiber-photosensor coupling prevents the fiber bundling and the ultra-compactness of new generation SiPMs allows to embed the readout in the bulk of the calorimeter. Possible applications for this detector are high granularity devices for collider physics, beam dump experiments and non-conventional neutrino facilities. In July 2016 the SCENTT collaboration tested a prototype for an electromagnetic calorimeter sampled every ∼4 X0 at the CERN PS-T9 beamline. The results for the linearity and energy resolution are provided.

Li and

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.