15 research outputs found
Combined potential of future long-baseline and reactor experiments
We investigate the determination of neutrino oscillation parameters by
experiments within the next ten years. The potential of conventional beam
experiments (MINOS, ICARUS, OPERA), superbeam experiments (T2K, NOvA), and
reactor experiments (D-CHOOZ) to improve the precision on the ``atmospheric''
parameters , , as well as the sensitivity to
are discussed. Further, we comment on the possibility to
determine the leptonic CP-phase and the neutrino mass hierarchy if
turns out to be large.Comment: 4 pages, 4 figures, Talk given by T.S. at the NOW2004 workshop, Conca
Specchiulla (Otranto, Italy), 11--17 Sept. 200
Prospects of accelerator and reactor neutrino oscillation experiments for the coming ten years
We analyze the physics potential of long baseline neutrino oscillation
experiments planned for the coming ten years, where the main focus is the
sensitivity limit to the small mixing angle . The discussed
experiments include the conventional beam experiments MINOS, ICARUS, and OPERA,
which are under construction, the planned superbeam experiments J-PARC to
Super-Kamiokande and NuMI off-axis, as well as new reactor experiments with
near and far detectors, represented by the Double-Chooz project. We perform a
complete numerical simulation including systematics, correlations, and
degeneracies on an equal footing for all experiments using the GLoBES software.
After discussing the improvement of our knowledge on the atmospheric parameters
and by these experiments, we investigate the
potential to determine within the next ten years in detail.
Furthermore, we show that under optimistic assumptions and for
close to the current bound, even the next generation of experiments might
provide some information on the Dirac CP phase and the type of the neutrino
mass hierarchy.Comment: 38 pages, 13 figures, Eqs. (1) and (5) corrected, small corrections
in Figs. 8, 9, and Tab. 4, discussion improved, ref. added, version to appear
in PRD, high resolution figures are available at
http://www.sns.ias.edu/~winter/figs0403068.htm
On a model with two zeros in the neutrino mass matrix
We consider a Majorana neutrino mass matrix with
, in the basis
where the charged-lepton mass matrix is diagonal. We show that this pattern for
the lepton mass matrices can be enforced by extending the Standard Model with
three scalar SU(2) triplets and by using a horizontal symmetry group
\mathbbm{Z}_4. The Ma--Sarkar (type-II seesaw) mechanism leads to very small
vacuum expectation values for the triplets, thus explaining the smallness of
the neutrino masses; at the same time, that mechanism renders the physical
scalars originating in the triplets very heavy. We show that the conditions
allow both for
a normal neutrino mass spectrum and for an inverted one. In the first case, the
neutrino masses must be larger than and the atmospheric mixing angle
must be practically equal to . In the second case, the
product must be of order one or
larger, thus correlating the large or maximal atmospheric neutrino mixing with
the smallness of the mixing angle .Comment: 13 pages, no figures, plain LaTeX; one equation added, published
references updated, final version for J. Phys.
Status of global fits to neutrino oscillations
We review the present status of global analyses of neutrino oscillations,
taking into account the most recent neutrino data including the latest KamLAND
and K2K updates presented at Neutrino2004, as well as state-of-the-art solar
and atmospheric neutrino flux calculations. We give the two-neutrino solar +
KamLAND results, as well as two-neutrino atmospheric + K2K oscillation regions,
discussing in each case the robustness of the oscillation interpretation
against departures from the Standard Solar Model and the possible existence of
non-standard neutrino physics. Furthermore, we give the best fit values and
allowed ranges of the three-flavour oscillation parameters from the current
worlds' global neutrino data sample and discuss in detail the status of the
small parameters \alpha \equiv \Dms/\Dma as well as ,
which characterize the strength of CP violating effects in neutrino
oscillations. We also update the degree of rejection of four-neutrino
interpretations of the LSND anomaly in view of the most recent developments.Comment: v6: In the last Appendix we provide updated neutrino oscillation
results which take into account the relevant oscillation data released by the
MINOS and KamLAND collaboration
Neutral currents and tests of three-neutrino unitarity in long-baseline experiments
We examine a strategy for using neutral current measurements in long-baseline
neutrino oscillation experiments to put limits on the existence of more than
three light, active neutrinos. We determine the relative contributions of
statistics, cross section uncertainties, event misidentification and other
systematic errors to the overall uncertainty of these measurements. As specific
case studies, we make simulations of beams and detectors that are like the K2K,
T2K, and MINOS experiments. We find that the neutral current cross section
uncertainty and contamination of the neutral current signal by charge current
events allow a sensitivity for determining the presence of sterile neutinos at
the 0.10--0.15 level in probablility.Comment: 24 pages, Latex2e, uses graphicx.sty, 2 postscript figures. Submitted
to the Neutrino Focus Issue of New Journal Physics at http://www.njp.or
Physics potential of future reactor neutrino experiments
The flux is a necessary ingredient to measure the cross section in the near detector. This document briefly describes how to extract the neutrino flux in NuMI (Neutrinos at Main Injector) beams
Physics at a Fermilab Proton Driver
This report documents the physics case for building a 2 MW, 8 GeV superconducting linac proton driver at Fermilab
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