Session Z18: Neutrino Cross-Sections

Live

NOvA is a long-baseline neutrino oscillation experiment built to measure the rate of electron-neutrino appearance to constrain oscillation parameters: an analysis that relies on accurate estimates of the electron-antineutrino cross section. The status of a measurement of the electron-antineutrino charged-current inclusive cross section in the NOvA near detector is presented. We expect to select over 10,000 signal events in the fiducial volume of the detector over the data-taking period. The analysis employs a data-driven template-fit approach to signal estimation. Future work includes the measurement of electron neutrino to antineutrino cross-section ratios and development of an analysis framework designed for high-performance computing platforms.   

Live

Neutrino cross section measurements serve two major purposes; they can provide a deeper understanding of particle interactions, and they help to lower one of the leading systematic uncertainties on neutrino oscillation measurements. In this talk, I will present current and future work towards a muon antineutrino inclusive cross section measurement using data taken from the NOvA's near detector. There are various stages in performing this analysis which include - among other work - the training of a muon track classifier, cut optimization, energy estimation, and purity and efficiency studies using Monte Carlo simulation. I will discuss the work which has already gone into this analysis, and future work that remains to be done. In addition, I will discuss various challenges unique to the antineutrino measurement which have been foreseen and how we plan to address them.   

Live

NOvA is a long-baseline neutrino oscillation experiment primarily designed to measure the muon (anti)neutrino disappearance and electron (anti)neutrino appearance in the off-axis Fermilab NuMI beam. It uses two functionally identical liquid scintillator detectors separated by 810 km and a narrow band beam centered around 2 GeV. Energetic neutral pions produced in $\Delta$ resonant and deep-inelastic interactions are a significant background to the electron (anti)neutrino appearance measurement as the photons coming from neutral pion decay may be misidentified as an (anti)neutrino appearance signal. The high statistics antineutrino mode data in the Near Detector (ND) can be used to perform a measurement of the cross-section of the muon antineutrino charged-current (CC) neutral-pion production. The analysis uses a convolutional neural network (CNN) trained on individually simulated particles to identify neutral pions in the final state. The development and the performance of the CNN approach to neutral pion identification and the status of the analysis are presented.   

Live

MicroBooNE is a liquid argon time projection chamber with a focus on measuring neutrino-argon cross sections and investigating the anomalous excess of electron-like low-energy neutrino events reported by MiniBooNE. It uses GENIE version three for its neutrino interaction simulation, more specifically the GENIE out-of-the-box G18\_10a\_02\_11a tune. To ensure the simulation agrees well with real-world data, MicroBooNE tunes parameters associated with the charged current (CC) quasi-elastic and meson exchange current cross sections to external data from T2K. The presentation will discuss how MicroBooNE tunes these parameters using T2K CC data with zero pions in the final state to form the MicroBooNE GENIE tune currently used by the electron-like low-energy excess searches. It will then discuss how systematic uncertainties associated with the simulation are quantified by considering the spread of possible parameter values acquired from the fit to external data.   

Live

The MicroBooNE detector has an active mass of 85 tons of liquid argon and is located along the Booster Neutrino Beam (BNB) at Fermilab. It has a rich physics program including the search for a low-energy excess observed at MiniBooNE and measurements of neutrino-Argon interaction cross sections. In this talk, we present a procedure, based on the Wiener-SVD unfolding method, to extract the nominal neutrino flux-averaged total and differential cross sections of the inclusive muon neutrino charged-current interaction on argon. This procedure relies on a minimal set of assumptions while maximizing the power in comparing data results with predictions from theory and event generators. Taking advantage of the power of a Liquid Argon Time Projection Chamber (LArTPC) and the Wire-Cell tomographic event reconstruction paradigm, this procedure enables a new round of cross section measurements at MicroBooNE.   

Live

MicroBooNE is an 85-ton active-mass liquid argon time projection chamber located on the Booster Neutrino Beam at Fermi National Accelerator Laboratory. The primary goal of MicroBooNE is to investigate an apparent excess of low-energy electromagnetic events observed by the MiniBooNE experiment in muon neutrino-to-electron neutrino oscillations. A significant background for this study are photon showers from neutral pion decay, which can mimic the electromagnetic shower signature of electrons from electron neutrinos. In this talk, I will present the latest differential cross-section measurements of neutral pions produced in charged current muon neutrino interactions in MicroBooNE, with a particular focus on the kinematics of the outgoing lepton and pion final states.   

Live

MicroBooNE, a Liquid Argon Time Projection Chamber (LArTPC) situated in the muon-neutrino-dominated Booster Neutrino Beam at Fermilab, is studying $\nu_{e}$ charged-current (CC) interaction rates to shed light on the measured MiniBooNE low energy excess. A sample of CC electron neutrino events can be produced by replacing the primary muon track candidates from CC muon neutrino events with simulated electrons. This sample uses hadron showers from data to replace those from neutrino generators which typically have large uncertainties. This can be used to cross check selection efficiencies which otherwise must also rely on models. We discuss the development of this technique in MicroBooNE, its first application in a LArTPC, and present preliminary comparisons with simulated $\nu_{e}$-CC event samples.   

Live

The DUNE near detector complex design consists of multiple detector systems to produce complementary constraints on the neutrino flux and interaction systematic uncertainties for the oscillation analysis. One of these detectors is the gaseous argon near detector (ND-GAr), which is a magnetized high-pressure gaseous argon TPC with surrounded ECAL and muon ID systems. In addition to measurements for the oscillation analysis, ND-GAr is a highly capable detector for dedicated neutrino cross-section measurements. The one ton of argon fiducial mass and high intensity neutrino beam will produce numerous neutrino interactions for high statistics measurements. The gaseous argon provides a very low energy threshold for tracking protons which will enable detailed study of the nuclear system in neutrino interactions, and the magnetic field and ECAL will provide precise reconstruction of event kinematics. This talk will present an overview of the measurement capabilities of ND-GAr and the prospects for valuable neutrino cross-section measurements.   

Live

Neutrino induced charged-current coherent (CC-Coh) pion production is a rare neutrino-nucleus interaction channel with a controversial history. The interaction channel has been studied extensively at ~7GeV and higher neutrino energies, and is well modeled at these neutrino energies by the Rein-Sehgal model. Recent experiments (SciBooNE and K2K) both attempted to measure this interaction channel’s cross section at lower neutrino energies (~2.5GeV and below), but did not observe the channel and set upper limits. Recently, the T2K collaboration successfully measured the CC-Coh pion production cross section at comparable low neutrino energies, but found that the Rein-Sehgal model is not satisfactory at these lower neutrino energies. The Micro Booster Neutrino Experiment (MicroBooNE) is a Liquid Argon Time Projection Chamber (LArTPC) that is located in the Booster Neutrino Beamline (BNB) at Fermilab. MicroBooNE is in the unique position to measure the CC-Coh pion production cross section at comparable neutrino energies to the SciBooNE experiment with the largest data sample of neutrino-nucleus interactions on argon in the world. This talk will show progress towards the highest-statistics cross section measurement of CC-Coh pion production on argon at ~1GeV neutrino energies.