Session H20: Neutrino Oscillations and Scattering

Live

NOvA is a two detector, long baseline neutrino oscillation experiment measuring the disappearance of muon neutrinos and anti-neutrinos and the appearance of electron neutrinos and antineutrinos in the NuMI beam from Fermi National Lab. The two detectors are liquid scintillator sampling calorimeters positioned 14.6 mrad off-axis. The near detector is located 100 m underground at Fermilab. The far detector is 14 kton and located 810 km away near Ash River, Minnesota. NOvA’s main physics goals are to make measurements of the neutrino mass hierarchy, the octant of the atmospheric mixing angle, and CP violation in neutrino oscillations. Besides neutrino oscillations, NOvA has also made measurements of neutrino cross sections, cosmic rays, and other exotic phenomena. This talk will give an overview of the design of the NOvA experiment and its detectors and how they contribute to the experiment’s physics goals.   

Live

NOvA is a long-baseline neutrino oscillation experiment, designed to make precision neutrino oscillation measurements using $\nu_{\mathrm{\mu }}$ disappearance and $\nu_{\mathrm{e}}$ appearance. It consists of two functionally equivalent detectors and utilizes the Fermilab NuMI neutrino beam. NOvA uses a convolutional neural network for particle identification of $\nu_{\mathrm{e}}$ events in each detector. As part of the validation process of this classifier's performance, we apply a data-driven technique called Muon Removal. In a Muon-Removed Electron-Added study we select $\nu _{\mathrm{\mu }}$ charged-current candidates from both data and simulation in our Near Detector and then replace the muon candidate with a simulated electron of the same energy. In a Muon-Removed Decay-In-Flight study we identify muons that have decayed in flight in either detector and remove the muon, resulting in a sample of just electromagnetic showers. Each sample is then evaluated by our classifier to obtain selection efficiencies. Our last analysis found agreement between the selection efficiencies of data and simulation, showing that our classifier selection is generally robust in $\nu_{\mathrm{e}}$ charged-current signal selection.   

Live

The Deep Underground Neutrino Experiment (DUNE) is a next-generation neutrino oscillation experiment. DUNE plans to utilize a near detector (ND) which is capable of moving transverse to the direction of the neutrino beam. By moving to different off-axis angles, the neutrino rate at different true neutrino energies can be measured. In the current generation of experiments, data collected at an ND is unfolded to make a prediction of the oscillated neutrino flux, measured as an event rate at a far detector (FD). This unfolding relies on a good understanding of the relationship between the measured and true neutrino energy, which strongly depends on our models of neutrino interactions. These models contribute a significant amount of uncertainty to the overall measurement of oscillation parameters. By instead using a linear combination of off-axis ND fluxes which approximates the oscillated FD flux, we can more directly compare ND and FD data, reducing the contribution of these model uncertainties to the overall systematic error of the measurement. In this talk, I will discuss the mathematical methods for determining linear combinations and the improved sensitivity of an oscillation analysis which incorporates this new technique.   

Live

ANNIE is a 26-ton gadolinium loaded water Cherenkov detector located on the Booster Neutrino Beam (BNB) at Fermilab. The primary physics goals of ANNIE are to study the multiplicity of final state neutrons from neutrino-nucleus interactions and charged current quasi-elastic (CCQE) cross-section measurements in water. ANNIE provides a unique opportunity to study this physics in a controlled beam experiment in an energy range of 700MeV, which is relevant to both atmospheric neutrinos and long-baseline experiments. ANNIE is aiming to serve as a detector R{\&}D testbed for future neutrino experiments by leveraging Large Area Picosecond Photo-Detectors (LAPPDs) and neutron tagging in Gadolinium-loaded water to make detailed neutrino measurements. The full implementation of the ANNIE physics phase detector was completed in 2019 and is now taking beam data. In this talk, I will present the updates from the physics phase and discuss about the new technologies.   

On Demand

NOvA is a long baseline neutrino oscillation experiment which consists of two functionally identical detectors utilizing liquid scintillator tracking calorimeters. NOvA strives to measure $\nu_{\mathrm{e\thinspace }}$appearance and $\nu_{\mathrm{\mu }}$disappearance at the far detector using neutrinos originating from the NuMI Beam at Fermilab. The near detector is positioned at Fermilab, and measures the $\nu_{\mathrm{\mu }}$component of the NuMI beam as well as background components which could be misinterpreted as the $\nu_{\mathrm{\mu \thinspace }}$to $\nu _{\mathrm{e}}$oscillated signal at the far detector. The background contains: Charged Current $\nu_{\mathrm{\mu }}$, Neutral Current, and $\nu_{\mathrm{e}}$events. In order to predict the far detector signal, NOvA needs to determine what fraction of the near detector sample can be attributed to each of these components. To accomplish this, NOvA decomposes the near detector measurement in three different ways and extrapolates these components separately to obtain a data-driven correction to the intrinsic $\nu_{\mathrm{e}}$background. In the past, NOvA has done extensive studies decomposing the neutrino mode of the NuMI beam. More recently, we have studied the anti-neutrino mode. In my talk, I will present details of the decomposition and extrapolation techniques for predicting the far detector spectrum using both the neutrino and anti-neutrino modes.   

On Demand

NOvA is a long-baseline neutrino oscillation experiment that is designed to probe the neutrino mass hierarchy and mixing structure. It uses two functionally identical liquid scintillator detectors $14.6$mrad off-axis from the NuMI beamline at Fermilab, allowing a tightly focused neutrino flux peaked at around 2 GeV. The Near Detector is located 100m underground and is used to characterize the neutrino and anti-neutrino beams before oscillations. The Far Detector is placed at a distance of $810$ km from the beam source and is used to look for neutrino oscillations, primarily in the $\nu_{\mu}$ $\rightarrow$ $\nu_{\mu}$ and the $\nu_{\mu}$ $\rightarrow$ $\nu_{e}$ channels and their anti-neutrino counterparts. In this talk, I will present an overview of the latest results from the joint fit to the $\nu_{\mu}$ ($\bar{\nu}_{\mu}$)-disappearance and $\nu_{e}$ ($\bar{\nu}_{e}$)-appearance analyses, utilizing an accumulated exposure of $8.85\times10^{20}$ protons-on-target in the neutrino mode and $12.33\times10^{20}$ protons-on-target in the anti-neutrino mode. A particular highlight of these results is the observation of $\bar{\nu}_{e}$-appearance at a level of $4.4\sigma$   

Status of New IceCube DeepCore Neutrino Oscillation Analyses

The DeepCore sub-array within the IceCube Neutrino Observatory is a densely instrumented region of Antarctic ice designed to observe atmospheric neutrino interactions above 5 GeV, via Cherenkov radiation. At these energies, Earth-crossing muon neutrinos have a high chance of oscillating to tau neutrinos. These oscillations have been previously observed in DeepCore through both muon neutrino disappearance and tau neutrino appearance channels. This talk will present the status of the IceCube Collaboration’s newest analyses of neutrino oscillation parameters. In addition to several more years of data, these analyses benefit from recent significant efforts in improving background rejection, reconstruction techniques, modeling of systematic uncertainties, particle identification, and much more.   

Abstract Withdrawn

New electron-nucleus scattering data is necessary to develop accurate models of neutrino-nucleus interactions, which are essential for the DUNE physics program. Designed for multi-GeV electron beam fixed-target kinematics, the LDMX (Light Dark Matter eXperiment) detector concept consists of a small precision tracker, and electromagnetic and hadronic calorimeters, all with near 2$\pi$ azimuthal acceptance from the forward beam axis out to $\sim$40$^\circ$ angle. This detector would be capable of measuring correlations among electrons, pions, protons, and neutrons in electron-nucleus scattering at exactly the energies relevant for DUNE physics. In particular, LDMX is ideally suited for probing inelastic electron-nucleus scattering in DUNE kinematics, which is poorly constrained by existing experimental data. LDMX would provide exclusive final-state cross-section measurements with unmatched acceptance in the $40^\circ$ forward cone. We compare the predictions of the three widely-used generators (GENIE, GiBUU, GEANT) in the LDMX region of acceptance to illustrate the large modeling discrepancies in electron-nucleus interactions at DUNE-like kinematics that could be addressed with future LDMX data.