Catalina Espinoza

Monochromatic neutrino beams

In the last few years spectacular results have been achieved with the demonstration of non vanishing neutrino masses and flavour mixing. The ultimate goal is the understanding of the origin of these properties from new physics. In this road, the last unknown mixing [Ue3] must be determined. If it is proved to be non-zero, the possibility is open for Charge Conjugation-Parity (CP) violation in the lepton sector. This will require precision experiments with a very intense neutrino source. Here a novel method to create a monochromatic neutrino beam, an old dream for neutrino physics, is proposed based on the recent discovery of nuclei that decay fast through electron capture. Such nuclei will generate a monochromatic directional neutrino beam when decaying at high energy in a storage ring with long straight sections. We also show that the capacity of such a facility to discover new physics is impressive, so that fine tuning of the boosted neutrino energy allows precision measurements of the oscillation parameters even for a [Ue3] mixing as small as 1 degree. We can thus open a window to the discovery of CP violation in neutrino oscillations.In the last few years spectacular results have been achieved with the demonstration of non vanishing neutrino masses and flavour mixing. The ultimate goal is the understanding of the origin of these properties from new physics. In this road, the last unknown mixing [Ue3] must be determined. If it is proved to be non-zero, the possibility is open for Charge Conjugation-Parity (CP) violation in the lepton sector. This will require precision experiments with a very intense neutrino source. Here a novel method to create a monochromatic neutrino beam, an old dream for neutrino physics, is proposed based on the recent discovery of nuclei that decay fast through electron capture. Such nuclei will generate a monochromatic directional neutrino beam when decaying at high energy in a storage ring with long straight sections. We also show that the capacity of such a facility to discover new physics is impressive, so that fine tuning of the boosted neutrino energy allows precision measurements of the oscillation parameters even for a [Ue3] mixing as small as 1 degree. We can thus open a window to the discovery of CP violation in neutrino oscillations.

Energy dependence of CP-violation reach for monochromatic neutrino beam

Abstract The ultimate goal of future neutrino facilities is the determination of CP violation in neutrino oscillations. Besides | U ( e 3 ) | ≠ 0 , this will require precision experiments with a very intense neutrino source and energy control. With this objective in mind, the creation of monochromatic neutrino beams from the electron capture decay of boosted ions by the SPS of CERN has been proposed. We discuss the capabilities of such a facility as a function of the energy of the boost and the baseline for the detector. We compare the physics potential for two different configurations: (I) γ = 90 and γ = 195 (maximum achievable at present SPS) to Frejus; (II) γ = 195 and γ = 440 (maximum achievable at upgraded SPS) to Canfranc. We conclude that the SPS upgrade to 1000 GeV is important to reach a better sensitivity to CP violation iff it is accompanied by a longer baseline.

Physics Reach of Electron-Capture Neutrino Beams

To complete the picture of neutrino oscillations two fundamental parameters need to be measured, θ 13 and δ. The next generation of long baseline neutrino oscillation experiments –superbeams, betabeams and neutrino factories– indeed take aim at measuring them. Here we explore the physics reach of a new candidate: an electron-capture beam. Emphasis is made on its feasibility thanks to the recent discovery of nuclei that decay fast through electron capture, and on the interplay with a betabeam (its closest relative).

A Combined beta-beam and electron capture neutrino experiment

The next generation of long baseline neutrino experiments will aim at determining the value of the unknown mixing angle, θ13, the type of neutrino mass hierarchy and the presence of CP-violation in the lepton sector. Beta-beams and electron capture experiments have been studied as viable candidates for long baseline experiments. They use a very clean electron neutrino beam from the β-decays or electron capture decays of boosted ions. In the present article we consider an hybrid setup which combines a beta-beam with an electron capture beam by using boosted Ytterbium ions. We study the sensitivity to the CP-violating phase δ and the θ13 angle, the CP-discovery potential and the reach to determine the type of neutrino mass hierarchy for this type of long baseline experiment. The analysis is performed for different neutrino beam energies and baselines. Finally, we also discuss how the results would change if a better knowledge of some of the assumed parameters was achieved by the time this experiment could take place.

Phisics Reach with a Monochromatic Neutrino Beam from Electron Capture

Neutrino oscillation experiments from different sources have demonstrated non-vanishing neutrino masses and flavour mixings. The next experiments have to address the determination of the connecting mixing U(e3) and the existence of the CP violating phase. Whereas U(e3) measures the strength of the oscillation probability in appearance experiments, the CP phase acts as a phase-shift in the interference pattern. Here we propose to separate these two parameters by energy dependence, using the novel idea of a monochromatic neutrino beam facility based on the acceleration of ions that decay fast through electron capture. Fine tuning of the boosted neutrino energy allows precision measurements able to open a window for the discovery of CP violation, even for a mixing as small as 1 degree.

Search for new physics with neutrinos at Radioactive Ion Beam facilities

AstroParticule et Cosmologie (APC), Universit´e Paris Diderot - Paris 7,10, rue Alice Domon et L´eonie Duquet, 75205 Paris cedex 13, France.(Dated: September 27, 2012)We propose applications of Radioactive Ion Beam facilities to investigate physics beyond theStandard Model. In particular, we focus on the possible measurement of coherent neutrino-nucleusscattering and on a search for sterile neutrinos, by means of a low energy beta-beam with a Lorentzboost factor γ ≈ 1. In the considered setup the collected radioactive ions are sent inside a 4πdetector. For the first application we provide the number of events associated with neutrino-nucleuscoherent scattering, when the detector is filled in with a noble liquid. For the sterile search weconsider that the spherical detector is filled in with a liquid scintillator, and that the neutrinodetection channel is inverse-beta decay. We provide the exclusion curves for the sterile neutrinomixing parameters, based upon the 3+1 formalism, depending upon the achievable ion intensity.Our results are obtained both from total rates, and including spectral information with binning inenergy and in distance. The proposed experiment represents a possible alternative to clarify thecurrent anomalies observed in neutrino experiments.

The capabilities of monochromatic EC neutrino beams with the SPS upgrade

The goal for future neutrino facilities is the determination of the U(e3) mixing and CP violation in neutrino oscillations. This will require precision experiments with a very intense neutrino source and energy control. With this objective in mind, the creation of monochromatic neutrino beams from the electron capture decay of boosted ions by the SPS of CERN has been proposed. We discuss the capabilities of such a facility as a function of the energy of the boost and the baseline for the detector. We conclude that the SPS upgrade to 1000 GeV is crucial to reach a better sensitivity to CP violation iff it is accompanied by a longer baseline. We compare the physics potential for two different configurations: I) γ = 90 and γ = 195 (maximum achievable at present SPS) to Frejus; II) γ = 195 and γ = 440 (maximum achievable at upgraded SPS) to Canfranc. The main conclusion is that, whereas the gain in the determination of U(e3) is rather modest, setup II provides much better sensitivity to CP violation.

Physics Potential of SPS Upgrade in regard to Beta/EC Beams

The goal for future neutrino facilities is the determination of the [Ue3] mixing and CP violation in neutrino oscillations. This will require precision experiments with a very intense neutrino source. With this objective the creation of neutrino beams from the radioactive decay of boosted ions by the SPS of CERN from either beta or electron capture transitions has been propossed. We discuss the capabilities of such facilities as a function of the energy of the boost and the baseline for the detector. We conclude that the SPS upgrade to 1000 GeV is crucial to have a better sensitivity to CP violation if it is accompanied by a longer baseline. We compare the physics potential for two different configurations. In the case of beta beams, with the same boost for both β (neutrinos) and β (antineutrinos), the two setups are: I) γ = 120, L = 130 Km (Frejus); II) γ = 330, L = 650 Km (Canfranc). In the case of monochromatic EC beams we exploit the energy dependence of neutrino oscillations to separate out the two parameters U(e3) and the CP phase δ. Setup I runs at γ = 90 and γ = 195 (maximum achievable at present SPS) to Frejus, whereas Setup II runs at γ = 195 and γ = 440 (maximum achievable at upgraded SPS) to Canfranc. The main conclusion is that, whereas the gain in the determination of U(e3) is rather modest, setup II provides much better sensitivity to CP violation.

CP violation from a combined Beta Beam and Electron Capture neutrino experiment

We consider the proposal of a facility comprising a hybrid setup for a neutrino beam which combines an electron capture decay with a β+ decay from the same radioactive ion with the same boost. We study the sensitivity to the mixing angle θ13 and the CP‐phase, the CP discovery potential and the reach to determine the type of neutrino mass hierarchy. The analysis is performed for different boosts and baselines demonstrating that the combination of the two decay channels, with different neutrino energies, achieves remarkable results.

Physics Potential of Beta/EC Beams in regard to CP Violation in Neutrino Oscillations

The goal for future neutrino facilities is the determination of the [Ue3] mixing and CP violation in neutrino oscillations. This will require precision experiments with a very intense neutrino source. With this objective the creation of neutrino beams from the radioactive decay of boosted ions by the SPS of CERN from either beta or electron capture transitions has been propossed. We discuss the capabilities of such facilities as a function of the energy of the boost and the baseline for the detector. We conclude that the SPS upgrade to 1000 GeV is crucial to have a better sensitivity to CP violation if it is accompanied by a longer baseline. We compare the physics potential for two different configurations. In the case of beta beams, with the same boost for both β+ (neutrinos) and β− (antineutrinos), the two setups are: I) γ = 120, L = 130 Km (Frejus); II) γ = 330, L = 650 Km (Canfranc). In the case of monochromatic EC beams we exploit the energy dependence of neutrino oscillations to separate out the two...