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 $I_c$ 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$_2$ is measured to have a specular reflectivity of $\sim$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 $\simeq 45\left(\frac{\alpha}{\pi}\right)^2\approx 200$ 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 $U_{e3}$ element (magnitude and phase) of the PMNS neutrino mixing matrix is possible via the detection of \numu\to\nue oscillations at a baseline $L$ and energy $E$ given by the atmospheric observations, corresponding to a mass squared difference $E/L \sim \Delta m^2\simeq 2.5\times 10^{-3} eV^2$. 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 $\theta_{13}$ 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