First observation of low energy electron neutrinos in a liquid argon time projection chamber

Citation: Acciarri, R., Adams, C., Asaadi, J., Baller, B., Bolton, T., Bromberg, C., . . . ArgoNeu, T. C. (2017). First observation of low energy electron neutrinos in a liquid argon time projection chamber. Physical Review D, 95(7), 15. doi:10.1103/PhysRevD.95.072005The capabilities of liquid argon time projection chambers (LArTPCs) to reconstruct the spatial and calorimetric information of neutrino events have made them the detectors of choice in a number of experiments, specifically those looking to observe electron neutrino (nu(e)) appearance. The LArTPC promises excellent background rejection capabilities, especially in this "golden" channel for both short and long baseline neutrino oscillation experiments. We present the first experimental observation of electron neutrinos and antineutrinos in the ArgoNeut LArTPC, in the energy range relevant to DUNE and the Fermilab Short Baseline Neutrino Program. We have selected 37 electron candidate events and 274 gamma candidate events, and measured an 80% purity of electrons based on a topological selection. Additionally, we present a separation of electrons from gammas using calorimetric energy deposition, demonstrating further separation of electrons from background gammas

Improved Limits on Millicharged Particles Using the ArgoNeuT Experiment at Fermilab

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.Comment: Version accepted by PR

First Measurement of Electron Neutrino Scattering Cross Section on Argon

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.Comment: added acknowledgement

Indkomne bøger fra oktober 1999 til september 2000

Head and neck cancer (HNC) has a high incidence in Brazil, with cancer of the oral cavity being one of the five most common cancers among Brazilians. Alcohol and tobacco consumption may contribute to synchronous or metachronous HNC and esophageal cancer. The early detection of superficial esophageal cancer and dysplasia in asymptomatic patients with HNC, after successfully treating the primary cancer, may provide an effective cure. A prospective study involving 60 patients with HNC was carried out at the State University of Campinas (UNICAMP) to screen for superficial esophageal cancer and dysplasia using endoscopy and a 2% lugol dye solution followed by biopsy of the suspicious areas. Five patients (8.3%) had superficial esophageal cancer, which was diagnosed as intraepithelial carcinoma in three of them (5.0%). In four patients, the superficial esophageal cancer was synchronous, and in one it was metachronous to HNC. Five patients (8.3%) had dysplasias in the esophageal epithelium (three were classified as mild and two as moderate). These results demonstrate the value of endoscopic screening of the esophagus using lugol dye in patients with HNC, particularly because superficial esophageal cancer is extremely difficult to detect by conventional methods in asymptomatic patients.22170-

First observation of low energy electron neutrinos in a liquid argon time projection chamber

The capabilities of liquid argon time projection chambers (LArTPCs) to reconstruct the spatial and calorimetric information of neutrino events have made them the detectors of choice in a number of experiments, specifically those looking to observe electron neutrino (νe) appearance. The LArTPC promises excellent background rejection capabilities, especially in this "golden" channel for both short and long baseline neutrino oscillation experiments. We present the first experimental observation of electron neutrinos and antineutrinos in the ArgoNeut LArTPC, in the energy range relevant to DUNE and the Fermilab Short Baseline Neutrino Program. We have selected 37 electron candidate events and 274 gamma candidate events, and measured an 80% purity of electrons based on a topological selection. Additionally, we present a separation of electrons from gammas using calorimetric energy deposition, demonstrating further separation of electrons from background gammas

First measurement of the cross section for νμ and ν μ induced single charged pion production on argon using

We report on the first cross section measurement of charged-current single charged pion production by neutrinos and antineutrinos on argon. This analysis was performed using the ArgoNeuT detector exposed to the NuMI beam at Fermilab. The measurements are presented as functions of muon momentum, muon angle, pion angle, and angle between muon and pion. The flux-averaged cross sections are measured to be 2.7±0.5(stat)±0.5(syst)×10-37 cm2/Ar for neutrinos at a mean energy of 9.6 GeV and 8.4±0.9(stat)-0.8+1.0(syst)×10-38 cm2/Ar for antineutrinos at a mean energy of 3.6 GeV with the charged pion momentum above 100 MeV/c. The results are compared with several model predictions

First measurement of the cross section for νμ\nu_\mu and νˉμ\bar{\nu}_\mu induced single charged pion production on argon using ArgoNeuT

We report on the first cross section measurement of charged-current single charged pion production by neutrinos and antineutrinos on argon. This analysis was performed using the ArgoNeuT detector exposed to the NuMI beam at Fermilab. The measurements are presented as functions of muon momentum, muon angle, pion angle, and angle between muon and pion. The flux-averaged cross sections are measured to be $2.7\pm0.5(stat)\pm0.5(syst) \times 10^{-37} \textrm{cm}^{2}/\textrm{Ar}$ for neutrinos at a mean energy of 9.6 GeV and $8.4\pm0.9(stat)^{+1.0}_{-0.8}(syst) \times 10^{-38} \textrm{cm}^{2}/\textrm{Ar}$ for antineutrinos at a mean energy of 3.6 GeV with the charged pion momentum above 100 MeV/$c$. The results are compared with several model predictions

Demonstration of MeV-scale physics in liquid argon time projection chambers using ArgoNeuT

MeV-scale energy depositions by low-energy photons produced in neutrino-argon interactions have been identified and reconstructed in ArgoNeuT liquid argon time projection chamber (LArTPC) data. ArgoNeuT data collected on the NuMI beam at Fermilab were analyzed to select isolated low-energy depositions in the TPC volume. The total number, reconstructed energies, and positions of these depositions have been compared to those from simulations of neutrino-argon interactions using the fluka Monte Carlo generator. Measured features are consistent with energy depositions from photons produced by deexcitation of the neutrino's target nucleus and by inelastic scattering of primary neutrons produced by neutrino-argon interactions. This study represents a successful reconstruction of physics at the MeV scale in a LArTPC, a capability of crucial importance for detection and reconstruction of supernova and solar neutrino interactions in future large LArTPCs