10 research outputs found
Physics potential of the CERN-MEMPHYS neutrino oscillation project
We consider the physics potential of CERN based neutrino oscillation
experiments consisting of a Beta Beam (BB) and a Super Beam (SPL) sending
neutrinos to MEMPHYS, a 440 kt water \v{C}erenkov detector at Frejus, at a
distance of 130 km from CERN. The discovery reach and the
sensitivity to CP violation are investigated, including a detailed discussion
of parameter degeneracies and systematical errors. For SPL sensitivities
similar to the ones of the phase II of the T2K experiment (T2HK) are obtained,
whereas the BB may reach significantly better sensitivities, depending on the
achieved number of total ion decays. The results for the CERN-MEMPHYS
experiments are less affected by systematical uncertainties than T2HK. We point
out that by a combination of data from BB and SPL a measurement with
antineutrinos is not necessary and hence the same physics results can be
obtained within about half of the measurement time compared to one single
experiment. Furthermore, it is shown how including data from atmospheric
neutrinos in the MEMPHYS detector allows to resolve parameter degeneracies and,
in particular, provides sensitivity to the neutrino mass hierarchy and the
octant of .Comment: 32 pages, 17 figures, minor improvements on the text wrt to v2,
version to appear in JHE
Optimized Two-Baseline Beta-Beam Experiment
We propose a realistic Beta-Beam experiment with four source ions and two
baselines for the best possible sensitivity to theta_{13}, CP violation and
mass hierarchy. Neutrinos from 18Ne and 6He with Lorentz boost gamma=350 are
detected in a 500 kton water Cerenkov detector at a distance L=650 km (first
oscillation peak) from the source. Neutrinos from 8B and 8Li are detected in a
50 kton magnetized iron detector at a distance L=7000 km (magic baseline) from
the source. Since the decay ring requires a tilt angle of 34.5 degrees to send
the beam to the magic baseline, the far end of the ring has a maximum depth of
d=2132 m for magnetic field strength of 8.3 T, if one demands that the fraction
of ions that decay along the straight sections of the racetrack geometry decay
ring (called livetime) is 0.3. We alleviate this problem by proposing to trade
reduction of the livetime of the decay ring with the increase in the boost
factor of the ions, such that the number of events at the detector remains
almost the same. This allows to substantially reduce the maximum depth of the
decay ring at the far end, without significantly compromising the sensitivity
of the experiment to the oscillation parameters. We take 8B and 8Li with
gamma=390 and 656 respectively, as these are the largest possible boost factors
possible with the envisaged upgrades of the SPS at CERN. This allows us to
reduce d of the decay ring by a factor of 1.7 for 8.3 T magnetic field.
Increase of magnetic field to 15 T would further reduce d to 738 m only. We
study the sensitivity reach of this two baseline two storage ring Beta-Beam
experiment, and compare it with the corresponding reach of the other proposed
facilities.Comment: 17 pages, 3 eps figures. Minor changes, matches version accepted in
JHE
Theta_13: phenomenology, present status and prospect
The leptonic mixing angle theta_13 is currently a high-priority topic in the
field of neutrino physics, with five experiments under way, searching for
neutrino oscillations induced by this angle. We review the phenomenology of
theta_13 and discuss the information from present global oscillation data. A
description of the upcoming reactor and accelerator experiments searching for a
non-zero value of theta_13 is given, and we evaluate the sensitivity reach
within the next few years.Comment: Topical review, 55 pages, 23 figures, v2: various minor improvements,
references added, new section 6, matches version to appear in J. Phys.
Topical Review on "Beta-beams"
Neutrino physics is traversing an exciting period, after the important
discovery that neutrinos are massive particles, that has implications from
high-energy physics to cosmology. A new method for the production of intense
and pure neutrino beams has been proposed recently: the ``beta-beam''. It
exploits boosted radioactive ions decaying through beta-decay. This novel
concept has been the starting point for a new possible future facility. Its
main goal is to address the crucial issue of the existence of CP violation in
the lepton sector. Here we review the status and the recent developments with
beta-beams. We discuss the original, the medium and high-energy scenarios as
well as mono-chromatic neutrino beams produced through ion electron-capture.
The issue of the degeneracies is mentioned. An overview of low energy
beta-beams is also presented. These beams can be used to perform experiments of
interest for nuclear structure, for the study of fundamental interactions and
for nuclear astrophysics.Comment: Topical Review for Journal of Physics G: Nuclear and Particle
Physics, published version, minor corrections, references adde
Damping of supernova neutrino transitions in stochastic shock-wave density profiles
Supernova neutrino flavor transitions during the shock wave propagation are
known to encode relevant information not only about the matter density profile
but also about unknown neutrino properties, such as the mass hierarchy (normal
or inverted) and the mixing angle theta_13. While previous studies have
focussed on "deterministic" density profiles, we investigate the effect of
possible stochastic matter density fluctuations in the wake of supernova shock
waves. In particular, we study the impact of small-scale fluctuations on the
electron (anti)neutrino survival probability, and on the observable spectra of
inverse-beta-decay events in future water-Cherenkov detectors. We find that
such fluctuations, even with relatively small amplitudes, can have significant
damping effects on the flavor transition pattern, and can partly erase the
shock-wave imprint on the observable time spectra, especially for
sin^2(theta_13) > O(10^-3).Comment: v2 (23 pages, including 6 eps figures). Typos removed, references
updated, matches the published versio
Experimental results on neutrino oscillations
The phenomenon of neutrino oscillation has been firmly established: neutrinos
change their flavor in their path from their source to observers. This paper is
dedicated to the description of experimental results in the oscillation field,
of their present understanding and of possible future developments in
experimental neutrino oscillation physics.Comment: Long review (98 pages, 50 figures
Large underground, liquid based detectors for astro-particle physics in Europe: scientific case and prospects
This document reports on a series of experimental and theoretical studies
conducted to assess the astro-particle physics potential of three future
large-scale particle detectors proposed in Europe as next generation
underground observatories. The proposed apparatus employ three different and,
to some extent, complementary detection techniques: GLACIER (liquid Argon TPC),
LENA (liquid scintillator) and MEMPHYS (\WC), based on the use of large mass of
liquids as active detection media. The results of these studies are presented
along with a critical discussion of the performance attainable by the three
proposed approaches coupled to existing or planned underground laboratories, in
relation to open and outstanding physics issues such as the search for matter
instability, the detection of astrophysical- and geo-neutrinos and to the
possible use of these detectors in future high-intensity neutrino beams.Comment: 50 pages, 26 figure
Physics at a future Neutrino Factory and super-beam facility
The conclusions of the Physics Working Group of the international scoping study of a future Neutrino Factory and super-beam facility (the ISS) are presented. The ISS was carried by the international community between NuFact05, (the 7th International Workshop on Neutrino Factories and Superbeams, Laboratori Nazionali di Frascati, Rome, June 21-26, 2005) and NuFact06 (Ivine, California, 24{30 August 2006). The physics case for an extensive experimental programme to understand the properties of the neutrino is presented and the role of high-precision measurements of neutrino oscillations within this programme is discussed in detail. The performance of second generation super-beam experiments, beta-beam facilities, and the Neutrino Factory are evaluated and a quantitative comparison of the discovery potential of the three classes of facility is presented. High-precision studies of the properties of the muon are complementary to the study of neutrino oscillations. The Neutrino Factory has the potential to provide extremely intense muon beams and the physics potential of such beams is discussed in the final section of the report.The conclusions of the Physics Working Group of the international scoping study of a future Neutrino Factory and super-beam facility (the ISS) are presented. The ISS was carried by the international community between NuFact05, (the 7th International Workshop on Neutrino Factories and Superbeams, Laboratori Nazionali di Frascati, Rome, June 21-26, 2005) and NuFact06 (Ivine, California, 24{30 August 2006). The physics case for an extensive experimental programme to understand the properties of the neutrino is presented and the role of high-precision measurements of neutrino oscillations within this programme is discussed in detail. The performance of second generation super-beam experiments, beta-beam facilities, and the Neutrino Factory are evaluated and a quantitative comparison of the discovery potential of the three classes of facility is presented. High-precision studies of the properties of the muon are complementary to the study of neutrino oscillations. The Neutrino Factory has the potential to provide extremely intense muon beams and the physics potential of such beams is discussed in the final section of the report
Physics at a future neutrino factory and super-beam facility
The conclusions of the Physics Working Group of the International Scoping Study of a future Neutrino Factory and super-beam facility (the ISS) are presented. The ISS was carried out by the international community between NuFact05, (the 7th International Workshop on Neutrino Factories and Super-beams, Laboratori Nazionali di Frascati, Rome, 21-26 June 2005) and NuFact06 (Ivine, CA, 24-30 August 2006). The physics case for an extensive experimental programme to understand the properties of the neutrino is presented and the role of high-precision measurements of neutrino oscillations within this programme is discussed in detail. The performance of second-generation super-beam experiments, beta-beam facilities and the Neutrino Factory are evaluated and a quantitative comparison of the discovery potential of the three classes of facility is presented. High-precision studies of the properties of the muon are complementary to the study of neutrino oscillations. The Neutrino Factory has the potential to provide extremely intense muon beams and the physics potential of such beams is discussed in the final section of the report