2,186 research outputs found
Searching for short baseline anomalies with the LAr-TPC detector at shallow depths
The ICARUS Collaboration has operated successfully the Liquid Argon time
projection chamber (LAr-TPC), a novel and continuously sensitive bubble chamber
like neutrino detector in the GranSasso Laboratory and an underground neutrino
beam coming from the CERN-SPS. ICARUS may now be moved at the 8 GeV
FNAL-Booster for a search of LSND-like neutrino-electron anomalies at a shallow
depth and shorter distance from the target, where three experiments will
simultaneously study neutrinos at three different locations. New and
substantial modifications are described in order to make ICARUS operable in the
presence of such a large cosmic ray muon background
First operation of a liquid Argon TPC embedded in a magnetic field
We have operated for the first time a liquid Argon TPC immersed in a magnetic
field up to 0.55 T. We show that the imaging properties of the detector are not
affected by the presence of the magnetic field. The magnetic bending of the
ionizing particle allows to discriminate their charge and estimate their
momentum. These figures were up to now not accessible in the non-magnetized
liquid Argon TPC.Comment: 9 pages, 3 figure
ArgoNeuT and the Neutrino-Argon Charged Current Quasi-Elastic Cross Section
ArgoNeuT, a Liquid Argon Time Projection Chamber in the NuMI beamline at
Fermilab, has recently collected thousands of neutrino and anti-neutrino events
between 0.1 and 10 GeV. The experiment will, among other things, measure the
cross section of the neutrino and anti-neutrino Charged Current Quasi-Elastic
interaction and analyze the vertex activity associated with such events. These
topics are discussed along with ArgoNeuT's automated reconstruction software,
currently capable of fully reconstructing the muon and finding the event vertex
in neutrino interactions.Comment: 6 pages, 4 figures, presented at the International Nuclear Physics
Conference, Vancouver, Canada, July 4-9, 2010, to be published in Journal of
Physics: Conference Series (JPCS
Test of a Liquid Argon TPC in a magnetic field and investigation of high temperature superconductors in liquid argon and nitrogen
Tests with cosmic ray muons of a small liquid argon time projection chamber
(LAr TPC) in a magnetic field of 0.55 T are described. No effect of the
magnetic field on the imaging properties were observed. In view of a future
large, magnetized LAr TPC, we investigated the possibility to operate a high
temperature superconducting (HTS) solenoid directly in the LAr of the detector.
The critical current of HTS cables in an external magnetic field was
measured at liquid nitrogen and liquid argon temperatures and a small prototype
HTS solenoid was built and tested.Comment: 5 pages, 5 figures, to appear in Proc. of 1st International Workshop
towards the Giant Liquid Argon Charge Imaging Experiment (GLA2010), Tsukuba
(Japan), March 201
ArgoNeuT, a liquid argon time projection chamber in a low energy neutrino beam
ArgoNeuT (Argon Neutrino Test), a NSF/DOE project at Fermilab, is the first
LArTPC to go in a low energy neutrino beam and just the second LArTPC to go in
a neutrino beam ever. ArgoNeuT sits just upstream of the on-axis MINOS near
detector in the NuMI beamline, about 1 km from the target station and 100 m
underground. The detector features a 47X40X90 cm (169 L) active volume TPC with
a fully contained recirculation and purification system. Among other physics,
ArgoNeuT will measure the charged-current quasi-elastic (anti-) neutrino cross
section on argon at an energy of ~3 GeV.Comment: 3 pages, 2 figures, to appear in the proceedings of the 11th
International Conference on Topics in Astroparticle and Underground Physics
(TAUP 2009), Rome, Italy, 1-5 July 200
Possible, alternative explanations of the T2K observation of the nu_e appearance from an initial nu_mu
An alternative explanation to the emergence of sin^2(2 theta_13) > 0 is
discussed. It is pointed out that the recorded T2K events might have been due
to some other new physics in the neutrino sector, related to the LSND/MiniBooNE
sterile neutrino anomalies, for which there is nowadays a growing evidence. The
presently running ICARUS detector with the CNGS beam will be able to
distinguish between these two possible sources of the effectComment: 5 pages, 1 figur
High Efficiency Detection of Argon Scintillation Light of 128nm Using LAAPDs
The possibility of efficient collection and detection of vacuum ultraviolet
light as emitted by argon, krypton, and xenon gas is studied. Absolute quantum
efficiencies of large area avalanche photodiodes (LAAPDs) are derived at these
wavelengths. VUV light of wavelengths down to the 128nm of Ar emission is shown
to be detectable with silicon avalanche photodiodes at quantum efficiencies
above 42%. Flexible Mylar foil overcoated with Al+MgF is measured to have a
specular reflectivity of 91% at argon emission wavelength. Low-pressure
argon gas is shown to emit significant amounts of non-UV radiation. The average
energy expenditure for the creation of non-UV photons in argon gas at this
pressure is measured to be below 378 eV.Comment: 5 pages, 4 figures, Talk given at IEEE 2005 Nuclear Science Symposium
and Medical Imaging Conference, Puerto Ric
Atmospheric neutrinos in a Large Liquid Argon detector
In view of the evaluation of the physics goals of a large Liquid Argon TPC,
evolving from the ICARUS technology, we have studied the possibility of
performing precision measurements on atmospheric neutrinos. For this purpose we
have improved existing Monte Carlo neutrino event generators based on FLUKA and
NUX by including the 3-flavor oscillation formalism and the numerical treatment
of Earth matter effects. By means of these tools we have studied the
sensitivity in the measurement of Theta(23) through the accurate measurement of
electron neutrinos. The updated values for Delta m^2(23) from Super-Kamiokande
and the mixing parameters as obtained by solar and KamLand experiments have
been used as reference input, while different values of Theta(13) have been
considered. An exposure larger than 500 kton yr seems necessary in order to
achieve a significant result, provided that the present knowledge of systematic
uncertainties is largely improved.Comment: Talk given at the worksgop "Cryogenic Liquid Detectors for Future
Particle Physics", LNGS (Italy) March 13th-14th, 200
A new approach for the ortho-positronium lifetime determination in a vacuum cavity
Currently, the experimental uncertainty for the determination of the
ortho-positronium (o-Ps) decay rate is at 150 ppm precision; this is two orders
of magnitude lower than the theoretical one, at 1 ppm level. Here we propose a
new proof of concept experiment aiming for an accuracy of 100 ppm to be able to
test the second-order correction in the calculations, which is ppm. The improvement relies on
a new technique to confine the o-Ps in a vacuum cavity. Moreover, a new method
was developed to subtract the time dependent pick-off annihilation rate of the
fast backscattered positronium from the o-Ps decay rate prior to fitting the
distribution. Therefore, this measurement will be free from the systematic
errors present in the previous experiments. The same experimental setup
developed for our recent search for invisible decay of ortho-positronium is
being used. The precision will be limited by the statistical uncertainty, thus,
if the expectations are fulfilled, this experiment could pave the way to reach
the ultimate accuracy of a few ppm level to confirm or confront directly the
higher order QED corrections. This will provide a sensitive test for new
physics, e.g. a discrepancy between theoretical prediction and measurements
could hint the existence of an hidden sector which is a possible dark matter
candidate.Comment: 12 pages, 8 Figures, prepared for the proceedings of the PSAS2018
conference, Vienna (Austria
Neutrino oscillation physics at an upgraded CNGS with large next generation liquid Argon TPC detectors
The determination of the missing element (magnitude and phase) of
the PMNS neutrino mixing matrix is possible via the detection of \numu\to\nue
oscillations at a baseline and energy given by the atmospheric
observations, corresponding to a mass squared difference . While the current optimization of the CNGS
beam provides limited sensitivity to this reaction, we discuss in this document
the physics potential of an intensity upgraded and energy re-optimized CNGS
neutrino beam coupled to an off-axis detector. We show that improvements in
sensitivity to compared to that of T2K and NoVA are possible with
a next generation large liquid Argon TPC detector located at an off-axis
position (position rather distant from LNGS, possibly at shallow depth). We
also address the possibility to discover CP-violation and disentangle the mass
hierarchy via matter effects. The considered intensity enhancement of the CERN
SPS has strong synergies with the upgrade/replacement of the elements of its
injector chain (Linac, PSB, PS) and the refurbishing of its own elements,
envisioned for an optimal and/or upgraded LHC luminosity programme.Comment: 37 pages, 20 figure
- âŠ