317 research outputs found
Physics 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.Comment: 4 pages, 1 figure. Talk given at the International Europhysics
Conference on High Energy Physics, HEP-EPS 2005, Lisbon, Portugal, July
21-27, 200
Perspectives in Neutrino Physics: 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 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 mixing as
small as 1 degree. We can thus open a window to the discovery of CP violation
in neutrino oscillations.Comment: 15 pages, 7 figures. Contribution to the proceedings of GUSTAVOFEST -
Symposium in Honour of Gustavo C. Branco: CP Violation and the Flavour
Puzzle, Lisbon, Portugal, 19-20 July 200
Physics Reach of Electron-Capture Neutrino Beams
To complete the picture of neutrino oscillations two fundamental parameters
need to be measured, theta13 and delta. 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 neutrino 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).Comment: 5 pages, 3 png figures. Talk given at the 7th International Workshop
on Neutrino Factories and Superbeams (NuFact 05), Frascati, Italy, June 200
Neutrino-nucleus interaction rates at a low-energy beta-beam facility
We compute the neutrino detection rates to be expected at a low-energy
beta-beam facility. We consider various nuclei as neutrino detectors and
compare the case of a small versus large storage ring.Comment: 6 pages, 3 figure
Reconstructing the calibrated strain signal in the Advanced LIGO detectors
Advanced LIGO's raw detector output needs to be calibrated to compute
dimensionless strain h(t). Calibrated strain data is produced in the time
domain using both a low-latency, online procedure and a high-latency, offline
procedure. The low-latency h(t) data stream is produced in two stages, the
first of which is performed on the same computers that operate the detector's
feedback control system. This stage, referred to as the front-end calibration,
uses infinite impulse response (IIR) filtering and performs all operations at a
16384 Hz digital sampling rate. Due to several limitations, this procedure
currently introduces certain systematic errors in the calibrated strain data,
motivating the second stage of the low-latency procedure, known as the
low-latency gstlal calibration pipeline. The gstlal calibration pipeline uses
finite impulse response (FIR) filtering to apply corrections to the output of
the front-end calibration. It applies time-dependent correction factors to the
sensing and actuation components of the calibrated strain to reduce systematic
errors. The gstlal calibration pipeline is also used in high latency to
recalibrate the data, which is necessary due mainly to online dropouts in the
calibrated data and identified improvements to the calibration models or
filters.Comment: 20 pages including appendices and bibliography. 11 Figures. 3 Table
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
Neutrino physics at accelerators
Present and future neutrino experiments at accelerators are mainly concerned
with understanding the neutrino oscillation phenomenon and its implications.
Here a brief account of neutrino oscillations is given together with a
description of the supporting data. Some current and planned accelerator
neutrino experiments are also explained.Comment: 23 pages, 24 figures. Talk given at the Corfu Summer Institute on
Elementary Particle Physics 200
New CP Violation in Neutrino Oscillations
Measurements of CP--violating observables in neutrino oscillation experiments
have been studied in the literature as a way to determine the CP--violating
phase in the mixing matrix for leptons. Here we show that such observables also
probe new neutrino interactions in the production or detection processes.
Genuine CP violation and fake CP violation due to matter effects are sensitive
to the imaginary and real parts of new couplings. The dependence of the CP
asymmetry on source--detector distance is different from the standard one and,
in particular, enhanced at short distances. We estimate that future neutrino
factories will be able to probe in this way new interactions that are up to
four orders of magnitude weaker than the weak interactions. We discuss the
possible implications for models of new physics.Comment: ReVTeX, 28 pages, 7 figues. v2: Modifications in section VIII to
reflect the fact that some of the couplings that were discussed in this
section are irrelevant to our analysis (as pointed out in hep-ph/0112329);
Added a discussion in section IX of the relevance of other future experiments
that will search for lepton flavor violatio
Neutrino tomography - Learning about the Earth's interior using the propagation of neutrinos
Because the propagation of neutrinos is affected by the presence of Earth
matter, it opens new possibilities to probe the Earth's interior. Different
approaches range from techniques based upon the interaction of high energy
(above TeV) neutrinos with Earth matter, to methods using the MSW effect on the
neutrino oscillations of low energy (MeV to GeV) neutrinos. In principle,
neutrinos from many different sources (sun, atmosphere, supernovae, beams etc.)
can be used. In this talk, we summarize and compare different approaches with
an emphasis on more recent developments. In addition, we point out other
geophysical aspects relevant for neutrino oscillations.Comment: 22 pages, 9 figures. Proceedings of ``Neutrino sciences 2005:
Neutrino geophysics'', December 14-16, 2005, Honolulu, USA. Minor changes,
some references added. Final version to appear in Earth, Moon, and Planet
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
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