38 research outputs found
EURONU WP6 2009 yearly report: Update of the physics potential of Nufact, superbeams and betabeams
Many studies in the last ten years have shown that we can measure the unknown
angle theta13, discover leptonic CP violation and determine the neutrino
hierarchy in more precise neutrino oscillation experiments, searching for the
subleading channel nue -> numu in the atmospheric range. In this first report
of WP6 activities the following new results are reviewed: (1) Re-evaluation of
the physics reach of the upcoming generation of experiments to measure theta13
and delta; (2) New tools to explore a larger parameter space as needed beyond
the standard scenario; (3) Neutrino Factory: (a) evaluation of the physics
reach of a Nufact regards sterile neutrinos; (b) evaluation of the physics
reach of a Nufact as regards non-standard interactions; (c) evaluation of the
physics reach of a Nufact as regards violation of unitarity; (d) critical
assessment on long baseline tau-detection at Nufact; (e) new physics searches
at a near detector in a Nufact; (4) Beta-beams: (a) choice of ions and location
for a gamma = 100 CERN-based beta-beam; (b) re-evaluation of atmospheric
neutrino background for the gamma = 100 beta-beam scenario; (c) study of a two
baseline beta-beam; (d) measuring absolute neutrino mass with beta-beams; (e)
progress on monochromatic beta-beams; (5) Update of the physics potential of
the SPL super-beam. Eventually, we present an updated comparison of the
sensitivity to theta13, delta and the neutrino mass hierarchy of several of the
different proposed facilities.Comment: 2009 Yearly report of the Working Package 6 (Physics) of the EUROnu
FP7 EU project. 55 pages, 21 figures
Non-Standard Interactions at a Neutrino Factory: Correlations and CP violation
We explore the potential of several Neutrino Factory (NF) setups to
constrain, discover and measure new physics effects due to Non-Standard
Interactions (NSI) in propagation through Earth matter. We first study the
impact of NSI in the measurement of : we find that these could be
large due to strong correlations of with NSI parameters in the
golden channel, and the inclusion of a detector at the magic baseline is
crucial in order to reduce them as much as possible. We present, then, the
sensitivity of the considered NF setups to the NSI parameters, paying special
attention to correlations arising between them and the standard oscillation
parameters, when all NSI parameters are introduced at once. Off-diagonal NSI
parameters could be tested down to the level of , whereas the diagonal
combinations and
can be tested down to and
, respectively. The possibilities of observing CP violation in this
context are also explored, by presenting a first scan of the CP discovery
potential of the NF setups to the phases and
. We study separately the case where CP violation comes only from
non-standard sources, and the case where it is entangled with the standard
source, . In case turns out to be CP conserving, the
interesting possibility of observing CP violation for reasonably small values
of the NSI parameters emerges.Comment: Final note added. 38 pages, 11 figure
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
Reassessing the sensitivity to leptonic CP violation
We address the validity of the usual procedure to determine the sensitivity
of neutrino oscillation experiments to CP violation. An explicit calibration of
the test statistic is performed through Monte Carlo simulations for several
experimental setups. We find that significant deviations from a
distribution with one degree of freedom occur for experimental setups with low
sensitivity to . In particular, when the allowed region to which
is constrained at a given confidence level is comparable to the whole
allowed range, the cyclic nature of the variable manifests and the premises of
Wilk's theorem are violated. This leads to values of the test statistic
significantly lower than a distribution at that confidence level. On
the other hand, for facilities which can place better constraints on
the cyclic nature of the variable is hidden and, as the potential of the
facility improves, the values of the test statistics first become slightly
higher than and then approach asymptotically a distribution. The role
of sign degeneracies is also discussed.Comment: 14 pages, 5 figures, RevTeX4. The discussion of the results has been
improved and considerably extended. Version accepted for publication in JHE
On the Bayesian approach to neutrino mass ordering
We study the framework of Bayesian statistics for analyzing the capabilities
and results of future experiments looking to solve the issue of the neutrino
mass ordering. Starting from the general scenario, we then give examples of the
procedure for experiments with Gaussian and non-Gaussian distributions for the
indicator. We describe in detail what can and cannot be said about the neutrino
mass ordering and a future experiment's capabilities to determine it. Finally,
we briefly comment on the application to other binary measurements, such as the
determination of the octant of .Comment: 23 pages, 5 figures, REVTeX
Neutrino Probes of the Nature of Light Dark Matter
Dark matter particles gravitationally trapped inside the Sun may annihilate
into Standard Model particles, producing a flux of neutrinos. The prospects of
detecting these neutrinos in future multi-\kton{} neutrino detectors designed
for other physics searches are explored here. We study the capabilities of a
34/100 \kton{} liquid argon detector and a 100 \kton{} magnetized iron
calorimeter detector. These detectors are expected to determine the energy and
the direction of the incoming neutrino with unprecedented precision allowing
for tests of the dark matter nature at very low dark matter masses, in the
range of 5-50 GeV. By suppressing the atmospheric background with angular cuts,
these techniques would be sensitive to dark matter - nucleon spin dependent
cross sections at the fb level, reaching down to a few ab for the most
favorable annihilation channels and detector technology.Comment: Minor changes and clarifications, matches JCAP versio