167 research outputs found
CP, T and CPT violation in future long baseline experiments
I give a short overview about the possibilities and problems related to the
measurement of CP violation in long baseline experiments. Special attention is
paid to the issue of degeneracies and a method for their resolution is
quantitatively discussed. The CP violation reach for different experiments is
compared in dependence of and \dm{21}. Furthermore a
short comment about the possible effects of matter induced T violation is made.
Finally the limits on CPT violation obtainable at a neutrino factory are shown.Comment: Talk presented at NUFACT02, London, 1-6 July, 2002. 3 pages, 2
figure
Physics Potential of the SPL Super Beam
Performances of a neutrino beam generated by the CERN SPL proton driver are
computed considering a 440 kton water Cerenkov detector at 130 km from the
target. sensitivity down to and a
sensitivity comparable to a Neutrino Factory, for ,
are within the reach of such a project.Comment: Invited talk at the Nufact02 Workshop, Imperial College of Science,
Technology and Medicine, London, July 200
Untangling CP Violation and the Mass Hierarchy in Long Baseline Experiments
In the overlap region, for the normal and inverted hierarchies, of the
neutrino-antineutrino bi-probability space for appearance,
we derive a simple identity between the solutions in the (, ) plane for the different hierarchies. The
parameter sets the scale of the
appearance probabilities at the atmospheric eV whereas controls the amount of CP
violation in the lepton sector. The identity between the solutions is that the
difference in the values of for the two hierarchies equals twice
the value of divided by the {\it critical} value
of . We apply this identity to the two proposed
long baseline experiments, T2K and NOA, and we show how it can be used to
provide a simple understanding of when and why fake solutions are excluded when
two or more experiments are combined. The identity demonstrates the true
complimentarity of T2K and NOA.Comment: 15 pages, Latex, 4 postscript figures. Submitted to New Journal of
Physics, ``Focus on Neutrino Physics'' issu
Unveiling Neutrino Mixing and Leptonic CP Violation
We review the present understanding of neutrino masses and mixings,
discussing what are the unknowns in the three family oscillation scenario.
Despite the anticipated success coming from the planned long baseline neutrino
experiments in unraveling the leptonic mixing sector, there are two important
unknowns which may remain obscure: the mixing angle and the
CP-phase . The measurement of these two parameters has led us to
consider the combination of superbeams and neutrino factories as the key to
unveil the neutrino oscillation picture.Comment: Invited brief review, 18 pages, 6 figure
Physics Potential of Very Intense Conventional Neutrino Beams
The physics potential of high intensity conventional beams is explored. We
consider a low energy super beam which could be produced by a proposed new
accelerator at CERN, the Super Proton Linac. Water Cherenkov and liquid oil
scintillator detectors are studied as possible candidates for a neutrino
oscillation experiment which could improve our current knowledge of the
atmospheric parameters and measure or severely constrain the parameter
connecting the atmospheric and solar realms. It is also shown that a very large
water detector could eventually observe leptonic CP violation. The reach of
such an experiment to the neutrino mixing parameters would lie in-between the
next generation of neutrino experiments (MINOS, OPERA, etc) and a future
neutrino factory.Comment: Talk given at the Venice Conference on Neutrino Telescopes, Venice,
March, 200
Neutrino Factories and the "Magic" Baseline
We show that for a neutrino factory baseline of a
``clean'' measurement of becomes possible, which is
almost unaffected by parameter degeneracies. We call this baseline "magic"
baseline, because its length only depends on the matter density profile. For a
complete analysis, we demonstrate that the combination of the magic baseline
with a baseline of 3000 km is the ideal solution to perform equally well for
the , sign of , and CP violation
sensitivities. Especially, this combination can very successfully resolve
parameter degeneracies even below .Comment: Minor changes, final version to appear in PRD, 4 pages, 3 figures,
RevTe
The Golden Channel at a Neutrino Factory revisited: improved sensitivities from a Magnetised Iron Neutrino Detector
This paper describes the performance and sensitivity to neutrino mixing
parameters of a Magnetised Iron Neutrino Detector (MIND) at a Neutrino Factory
with a neutrino beam created from the decay of 10 GeV muons. Specifically, it
is concerned with the ability of such a detector to detect muons of the
opposite sign to those stored (wrong-sign muons) while suppressing
contamination of the signal from the interactions of other neutrino species in
the beam. A new more realistic simulation and analysis, which improves the
efficiency of this detector at low energies, has been developed using the GENIE
neutrino event generator and the GEANT4 simulation toolkit. Low energy neutrino
events down to 1 GeV were selected, while reducing backgrounds to the
level. Signal efficiency plateaus of ~60% for and ~70% for
events were achieved starting at ~5 GeV. Contamination from the
oscillation channel was studied for the first
time and was found to be at the level between 1% and 4%. Full response matrices
are supplied for all the signal and background channels from 1 GeV to 10 GeV.
The sensitivity of an experiment involving a MIND detector of 100 ktonnes at
2000 km from the Neutrino Factory is calculated for the case of . For this value of , the accuracy in the
measurement of the CP violating phase is estimated to be , depending on the value of ,
the CP coverage at is 85% and the mass hierarchy would be determined
with better than level for all values of
Toroidal magnetized iron neutrino detector for a neutrino factory
A neutrino factory has unparalleled physics reach for the discovery and measurement of CP violation in the neutrino sector. A far detector for a neutrino factory must have good charge identification with excellent background rejection and a large mass. An elegant solution is to construct a magnetized iron neutrino detector (MIND) along the lines of MINOS, where iron plates provide a toroidal magnetic field and scintillator planes provide 3D space points. In this paper, the current status of a simulation of a toroidal MIND for a neutrino factory is discussed in light of the recent measurements of large θ13. The response and performance using the 10 GeV neutrino factory configuration are presented. It is shown that this setup has equivalent δCP reach to a MIND with a dipole field and is sensitive to the discovery of CP violation over 85% of the values of δCP
Superbeam Studies at CERN
A conventional low energy neutrino beam of great intensity could be produced by the Super Proton Linac at CERN as a first stage of a Neutrino Factory. Water Cerenkov and liquid scintillator detectors are studied as possible candidates for a neutrino oscillation experiment which could improve ourcurrent knowledge of the atmospheric parameters deltam2atm , delta23 and measure or severely constrain 13. It is also shown that a very large water detector could eventually observe leptonic CP violation
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
- âŚ