CP violation and mass hierarchy at medium baselines in the large theta(13) era

The large value of theta(13) recently measured by rector and accelerator experiments opens unprecedented opportunities for precision oscillation physics. In this paper, we reconsider the physics reach of medium baseline superbeams. For theta(13) ~ 9 degree we show that facilities at medium baselines -- i.e. L ~ O(1000 km) -- remain optimal for the study of CP violation in the leptonic sector, although their ultimate precision strongly depends on experimental systematics. This is demonstrated in particular for facilities of practical interest in Europe: a CERN to Gran Sasso and CERN to Phyasalmi nu_mu beam based on the present SPS and on new high power 50 GeV proton driver. Due to the large value of theta(13), spectral information can be employed at medium baselines to resolve the sign ambiguity and determine the neutrino mass hierarchy. However, longer baselines, where matter effects dominate the nu_mu->nu_e transition, can achieve much stronger sensitivity to sign(Delta m^2) even at moderate exposures.Comment: 14 pages, 14 figures, version to appear in EPJ

A new design for the CERN-Fr\'ejus neutrino Super Beam

We present an optimization of the hadron focusing system for a low-energy high-intensity conventional neutrino beam (Super-Beam) proposed on the basis of the HP-SPL at CERN with a beam power of 4 MW and an energy of 4.5 GeV. The far detector would be a 440 kton Water Cherenkov detector (MEMPHYS) located at a baseline of 130 km in the Fr\'ejus site. The neutrino fluxes simulation relies on a new GEANT4 based simulation coupled with an optimization algorithm based on the maximization of the sensitivity limit on the $\theta_{13}$ mixing angle. A new configuration adopting a multiple horn system with solid targets is proposed which improves the sensitivity to $\theta_{13}$ and the CP violating phase $\delta_{CP}$.Comment: 11 pages, 18 figures, 2 table

A compact light readout system for longitudinally segmented shashlik calorimeters

The longitudinal segmentation of shashlik calorimeters is challenged by dead zones and non-uniformities introduced by the light collection and readout system. This limitation can be overcome by direct fiber-photosensor coupling, avoiding routing and bundling of the wavelength shifter fibers and embedding ultra-compact photosensors (SiPMs) in the bulk of the calorimeter. We present the first experimental test of this readout scheme performed at the CERN PS-T9 beamline in 2015 with negative particles in the 1-5~GeV energy range. In this paper, we demonstrate that the scheme does not compromise the energy resolution and linearity compared with standard light collection and readout systems. In addition, we study the performance of the calorimeter for partially contained charged hadrons to assess the $e/\pi$ separation capability and the response of the photosensors to direct ionization.Comment: To appear in Nuclear Instruments and Methods in Physics Research,

Multicentre Withinperson Randomised Controlled Trial of 0.5 Mm Versus 1.5 Mm Subcrestal Placement of Dental Implants With Internal Conical Connection: Five-year Post-loading Results

PURPOSE. To assess whether there are any clinical benefits to placing single dental implants either 0.5 or 1.5 mm subcrestally in healed bone crests. MATERIALS AND METHODS. Sixty partially edentulous patients at six centres requiring two single implant-supported crowns had both sites randomly allocated according to a split-mouth design to either 0.5 mm or 1.5 mm subcrestal implant placement; implants in aesthetic areas were submerged for 3 months while those in non-aesthetic areas were not. Provisional acrylic crowns were fitted and replaced with definitive metal-ceramic crowns after 2 months. Patients were followed up to 5 years after loading. Outcome measures were: crown and implant failures, complications, aesthetics assessed using the pink esthetic score (PES), peri-implant marginal bone level changes, and patient prefe-rence, recorded by blinded assessors. RESULTS. Two patients dropped out. There were no statistically significant differences in failure rate (out of 58 patients, four implants failed in the 0.5 mm group versus one in the 1.5 mm group; difference =-5.17%; 95% CI-10.87% to 0.53%; P = 0.250) or complications (out of 58 patients eight complications occurred in eight patients from the 0.5 mm group versus five complications in five patients from the 1.5 mm group (difference =-5.17%; 95% CI-14.01% to 3.67%; P = 0.453) between groups. At 5 years after loading, the mean pink aesthetic scores were 10.89 ± 2.30 and 10.79 ± 2.41 in the 0.5 and 1.5 mm groups, respecti-vely, a difference that was not statistically significant (P = 0.943). Patients from the 0.5 mm group lost on average 0.53 ± 1.43 mm peri-implant marginal bone, and those in the 1.5 mm group lost 0.31 ± 0.98 mm, a statistically significant difference (0.26 mm; 95% CI 0.05 to 0.47; P = 0.016). Patients did not prefer any depth of implant placement over the other. There were no differences in outcomes between centres. CONCLUSIONS. No clinically appreciable differences were noted when placing implants surrounded by at least 1 mm of bone 0.5 mm or 1.5 mm subcrestally. Clinicians are therefore free to choose which strategy they prefer

EUROnu-WP6 2010 Report

This is a summary of the work done by the Working Package 6 (Physics) of the EU project "EUROnu" during the second year of activity of the project.Comment: 82 pages, 51 eps figure

Precision on leptonic mixing parameters at future neutrino oscillation experiments

We perform a comparison of the different future neutrino oscillation experiments based on the achievable precision in the determination of the fundamental parameters theta_{13} and the CP phase, delta, assuming that theta_{13} is in the range indicated by the recent Daya Bay measurement. We study the non-trivial dependence of the error on delta on its true value. When matter effects are small, the largest error is found at the points where CP violation is maximal, and the smallest at the CP conserving points. The situation is different when matter effects are sizable. As a result of this effect, the comparison of the physics reach of different experiments on the basis of the CP discovery potential, as usually done, can be misleading. We have compared various proposed super-beam, beta-beam and neutrino factory setups on the basis of the relative precision of theta_{13} and the error on delta. Neutrino factories, both high-energy or low-energy, outperform alternative beam technologies. An ultimate precision on theta_{13} below 3% and an error on delta of < 7^{\circ} at 1 sigma (1 d.o.f.) can be obtained at a neutrino factory.Comment: Minor changes, matches version accepted in JHEP. 30 pages, 9 figure

Prospect for Charge Current Neutrino Interactions Measurements at the CERN-PS

Tensions in several phenomenological models grew with experimental results on neutrino/antineutrino oscillations at Short-Baseline (SBL) and with the recent, carefully recomputed, antineutrino fluxes from nuclear reactors. At a refurbished SBL CERN-PS facility an experiment aimed to address the open issues has been proposed [1], based on the technology of imaging in ultra-pure cryogenic Liquid Argon (LAr). Motivated by this scenario a detailed study of the physics case was performed. We tackled specific physics models and we optimized the neutrino beam through a full simulation. Experimental aspects not fully covered by the LAr detection, i.e. the measurements of the lepton charge on event-by-event basis and their energy over a wide range, were also investigated. Indeed the muon leptons from Charged Current (CC) (anti-)neutrino interactions play an important role in disentangling different phenomenological scenarios provided their charge state is determined. Also, the study of muon appearance/disappearance can benefit of the large statistics of CC muon events from the primary neutrino beam. Results of our study are reported in detail in this proposal. We aim to design, construct and install two Spectrometers at "NEAR" and "FAR" sites of the SBL CERN-PS, compatible with the already proposed LAr detectors. Profiting of the large mass of the two Spectrometers their stand-alone performances have also been exploited.Comment: 70 pages, 38 figures. Proposal submitted to SPS-C, CER

Glass resistive plate chambers in the OPERA experiment

Abstract OPERA is an underground neutrino oscillation experiment to search for ν τ appearance from a pure ν μ beam produced at CERN. To flag the events due to the neutrino interactions with the rock surrounding the OPERA detector, a large VETO system, based on the use of Glass Resistive Plate Chambers (GRPC) has been realized. We describe the detectors, the tests performed before the installation in the underground laboratories and the monitor system for the water pollution in the GRPC gas mixture