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ArgoNeuT, a Liquid Argon Time Projection Chamber (LAr-TPC), has collected thousands of neutrino and anti-neutrino events between 0.1 and 10 GeV in the NuMI beamline at Fermilab (FNAL). Among other issues, the experiment will measure the cross section of the neutrino and anti-neutrino Charged Current Quasi-Elastic (CC QE) interaction on Ar target and analyze the vertex activity associated with such events. ArgoNeuT data analysis and FSI studies in progress are described and first measurements of inclusive muon neutrino Charged Current differential cross sections on Argon are reported.

Cryogenic noble liquid detectors are presently considered one of the best options for WIMP Dark Matter searches, especially when extensions to multi ton scale sensitive masses are foreseen. The WArP experiment is the first one that exploits the unique characteristics of liquid Argon to make a highly sensitive search for WIMP Dark Matter candidates. In 2008, a double phase detector has been assembled in the Gran Sasso National Laboratory with 140 kg sensitive mass and a discovery potential in the range of 5 × 10-45 cm2 in the spin-independent WIMP-nucleon cross-section. In addition to standard neutrons and gamma-rays passive shields, WArP implements an 8 ton liquid Argon active shield with 4p coverage. The detector was commissioned and put into operation during the first half of 2009 for a first technical run. Detector design, construction and assembly are described, together with the very first results of this technical run.

Cryogenic noble liquid detectors are presently considered one of the best options for WIMP Dark Matter searches, especially when extensions to multi ton scale sensitive masses are foreseen. The WArP experiment is the first one that exploits the unique characteristics of liquid Argon to make a highly sensitive search for WIMP Dark Matter candidates. In 2008, a double phase detector has been assembled in the Gran Sasso National Laboratory with 140 kg sensitive mass and a discovery potential in the range of 5 × 10−45 cm2 in the spin-independent WIMP-nucleon cross-section. In addition to standard neutrons and gamma-rays passive shields, WArP implements an 8 ton liquid Argon active shield with 4π coverage. The detector was commissioned and put into operation during the first half of 2009 for a first technical run. This first run lasted about three months and then it was stopped for some detector repairs and modifications in the summer of 2009. A second run was started at the beginning of 2010. Detector design, construction and assembly are described, together with the results of the technical run and the very first results of the 2010 run.

ArgoNeuT, a Liquid Argon Time Projection Chamber (LAr-TPC), has collected thousands of neutrino and anti-neutrino events between 0.1 and 10 GeV in the NuMI beamline at Fermilab (FNAL). Among other issues, the experiment will measure the cross section of the neutrino and anti-neutrino Charged Current Quasi-Elastic (CC QE) interaction on Ar target and analyze the vertex activity associated with such events. ArgoNeuT data analysis and FSI studies in progress are described and first measurements of inclusive muon neutrino Charged Current differential cross sections on Argon are reported.

The liquid argon time projection chamber (LArTPC) detector technology has an excellent capability to measure properties of low-energy neutrinos produced by the sun and supernovae and to look for exotic physics at very low energies. In order to achieve those physics goals, it is crucial to identify and reconstruct signals in the waveforms recorded on each TPC wire. In this paper, we report on a novel algorithm based on a one-dimensional convolutional neural network (CNN) to look for the region-of-interest (ROI) in raw waveforms. We test this algorithm using data from the ArgoNeuT experiment in conjunction with an improved noise mitigation procedure and a more realistic data-driven noise model for simulated events. This deep-learning ROI finder shows promising performance in extracting small signals and gives an efficiency approximately twice that of the traditional algorithm in the low energy region of \\(\\sim\\)0.03-0.1 MeV. This method offers great potential to explore low-energy physics using LArTPCs.

A search for millicharged particles, a simple extension of the standard model, has been performed with the ArgoNeuT detector exposed to the Neutrinos at the Main Injector beam at Fermilab. The ArgoNeuT Liquid Argon Time Projection Chamber detector enables a search for millicharged particles through the detection of visible electron recoils. We search for an event signature with two soft hits (MeV-scale energy depositions) aligned with the upstream target. For an exposure of the detector of \\(1.0\\) \\(\\times\\) \\(10^{20}\\) protons on target, one candidate event has been observed, compatible with the expected background. This search is sensitive to millicharged particles with charges between \\(10^{-3}e\\) and \\(10^{-1}e\\) and with masses in the range from \\(0.1\\) GeV to \\(3\\) GeV. This measurement provides leading constraints on millicharged particles in this large unexplored parameter space region.

We report the first electron neutrino cross section measurements on argon, based on data collected by the ArgoNeuT experiment running in the GeV-scale NuMI beamline at Fermilab. A flux-averaged \\(\\nu_e + \\overline{\\nu}_e\\) total and a lepton angle differential cross section are extracted using 13 \\(\\nu_e\\) and \\(\\overline{\\nu}_e\\) events identified with fully-automated selection and reconstruction. We employ electromagnetic-induced shower characterization and analysis tools developed to identify \\(\\nu_e/\\overline{\\nu}_e\\)-like events among complex interaction topologies present in ArgoNeuT data (\\(\\langle E_{\\bar{\\nu}_e} \\rangle = 4.3\\) GeV and \\(\\langle E_{\\nu_e} \\rangle = 10.5\\) GeV). The techniques are widely applicable to searches for electron-flavor appearance at short- and long-baseline using liquid argon time projection chamber technology. Notably, the data-driven studies of GeV-scale \\(\\nu_e/\\overline{\\nu}_e\\) interactions presented in this Letter probe an energy regime relevant for future DUNE oscillation physics.

We report on the first measurement of 39Ar in argon from underground natural gas reservoirs. The gas stored in the US National Helium Reserve was found to contain a low level of 39Ar. The ratio of 39Ar to stable argon was found to be ≤4×10-17 (84% C.L.), less than 5% the value in atmospheric argon (39Ar/Ar=8×10-16). The total quantity of argon currently stored in the National Helium Reserve is estimated at 1000 tons. 39Ar represents one of the most important backgrounds in argon detectors for WIMP dark matter searches. The findings reported demonstrate the possibility of constructing large multi-ton argon detectors with low radioactivity suitable for WIMP dark matter searches.

We present the results of a search for heavy QCD axions performed by the ArgoNeuT experiment at Fermilab. We search for heavy axions produced in the NuMI neutrino beam target and absorber decaying into dimuon pairs, which can be identified using the unique capabilities of ArgoNeuT and the MINOS near detector. This decay channel is motivated by a broad class of heavy QCD axion models that address the strong CP and axion quality problems with axion masses above the dimuon threshold. We obtain new constraints at a 95\\% confidence level for heavy axions in the previously unexplored mass range between 0.2-0.9 GeV, for axion decay constants around tens of TeV.

Precise calorimetric reconstruction of 5-50 MeV electrons in liquid argon time projection chambers (LArTPCs) will enable the study of astrophysical neutrinos in DUNE and could enhance the physics reach of oscillation analyses. Liquid argon scintillation light has the potential to improve energy reconstruction for low-energy electrons over charge-based measurements alone. Here we demonstrate light-augmented calorimetry for low-energy electrons in a single-phase LArTPC using a sample of Michel electrons from decays of stopping cosmic muons in the LArIAT experiment at Fermilab. Michel electron energy spectra are reconstructed using both a traditional charge-based approach as well as a more holistic approach that incorporates both charge and light. A maximum-likelihood fitter, using LArIAT's well-tuned simulation, is developed for combining these quantities to achieve optimal energy resolution. A sample of isolated electrons is simulated to better determine the energy resolution expected for astrophysical electron-neutrino charged-current interaction final states. In LArIAT, which has very low wire noise and an average light yield of 18 pe/MeV, an energy resolution of \\(\\sigma/E \\simeq 9.3\\%/\\sqrt{E} \\oplus 1.3\\%\\) is achieved. Samples are then generated with varying wire noise levels and light yields to gauge the impact of light-augmented calorimetry in larger LArTPCs. At a charge-readout signal-to-noise of S/N \\(\\simeq\\) 30, for example, the energy resolution for electrons below 40 MeV is improved by \\(\\approx\\) 10%, \\(\\approx\\) 20%, and \\(\\approx\\) 40% over charge-only calorimetry for average light yields of 10 pe/MeV, 20 pe/MeV, and 100 pe/MeV, respectively.