Cross section measurements and capabilities at NOvA Leo Aliaga - PowerPoint PPT Presentation

Cross section measurements and capabilities at NOvA Leo Aliaga March 12, 2018 Cross Section Measurement Strategy Workshop, Fermilab

Outline Overview. • Overview of the NOvA beam, detector and simulation. • Strategy and challeges. Recent results. Inclusive Analyses. Conclusions. 2 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Overview 3 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Introduction NOvA is a long baseline oscillation experiment to measure: • Mixing angle Θ 23 . • CP-violating phase. • Mass hierarchy determination. The ND provides an excellent opportunity to measure neutrino interaction cross sections with high statistics. With these measurements we can • Constrain our cross section systematics. • Contribute to the current efforts of the neutrino community on understanding neutrino interactions. • Collaborate with future experiments such as DUNE. 4 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

NuMI Beam at NOvA NOvA detectors are off-axis, 14 mrad w.r.t NuMI beam axis. • It is a narrow-band beam centered around 2GeV. NUMI FHC In FHC: 96.2% ν μ , 3.3% ν μ , and 0.5% ν e. 5 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Muon Neutrino NuMI Beam at NOvA NOvA Even with a narrow band beam, NOvA is still sensitive to many different nu+A interaction channels. High data rate at the ND. Protons on target: J.A. Formaggio, G.P. Zeller Rev. Mod. Phys. 84, 1307 (2012) • 8.09 x 10 20 in the FHC mode. • Currently 6.26 x 10 20 in the RHC mode. 6 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Muon Neutrino NuMI Beam at NOvA T2K + MicroBooNE + NOvA + MINERvA Even with a narrow band beam, NOvA is still sensitive to many different nu+A interaction channels. High data rate at the ND. Protons on target: J.A. Formaggio, G.P. Zeller Rev. Mod. Phys. 84, 1307 (2012) • 8.09 x 10 20 in the FHC mode. • Currently 6.26 x 10 20 in the RHC mode. 7 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Muon Antineutrino NuMI Beam at NOvA T2K + MicroBooNE + NOvA + MINERvA Even with a narrow band beam, NOvA is still sensitive to many different nu+A interaction channels. High data rate at the ND. Protons on target: J.A. Formaggio, G.P. Zeller Rev. Mod. Phys. 84, 1307 (2012) • 8.09 x 10 20 in the FHC mode. • Currently 6.26 x 10 20 in the RHC mode. 8 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

NOvA Near Detector Wavelength- shifting fibers routed to a single cell on an Avalanche Photodiode (APD). Made of PVC with liquid scintillator, 3.9m x 3.9 m x 12.67 m. 193 ton, 192 planes and ~20k channels. • Fully active region: 77% hydrocarbon, 16% chlorine and 6% TiO 2 . • Muon Catcher: steel + NOvA cell at downstream end to range-out muons. O(10) ns single hit timing resolution 9 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

NOvA Near Detector Events Display Colors show time: Muon Catcher Top View Side View Muon Catcher Hits associated in time and space are used to form a candidate interaction. Tracks and showers are reconstructed from these hits. 10 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Strategy Simulation • We use G4NuMI for the beam simulation, GENIE (2.12.2) for the neutrino interactions and Geant4 (4.10.1) for propagating the particles. • A correction to the central value is made coming from: - The beam: PPFX for the hadrons production in the beamline. - The cross section: a tuning is applied to account for FSI current knowledge (see Aaron’s talk yesterday). • The beam and cross section systematics are determined by PPFX and the GENIE knobs scheme. • The simulation of the intensity dependent of high rate of muons originating in the surrounding rocks ( rock muons ) is integrated overlaying with the neutrino events . • The detector response is also simulated and the uncertainties on the calibration parameters are dealt with systematic shifted MC. 11 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Strategy Data and MC analysis • Vertices should be inside a fully active (fiducial) region to cut rock muons. Muon Catcher Top View Side View Muon Catcher • Tracks should be contained in the fiducial + Muon Catcher to avoid shower leaking. 12 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Strategy: main challenges 1. Most of the tools have been optimized for the oscillation analysis. • Cross section analysis requires refine existing or develop new tools. 2. We are more sensitive to some systematics than the oscillation analysis: beam normalization or cross section mis-modeling goes directly in our uncertainty. • We use PPFX ( P ackage to P redict the F lu X ) and the GENIE reweighing scheme for systematics. • We implemented the multi-universe approach to handle beam and cross section uncertainties. • We are working to a fully generated event by event MC with different generators, such as GiBUU and NEUT. 13 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Strategy: main challenges 3. Develop a PID algorithm for non-lepton final state particles. • We are moving to a final state particle identification for recognizing the neutrino event. • NOvA uses a Convolutional Neural Network (CNN) where a series of image filters are applied to hit map images to extract features associated with an interaction. • Some analyses are using a convolutional visual network (CVN) trained on topological features of individual prongs itself at the NOvA detectors. 14 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Current Analyses 15 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Current Analyses 16 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Our Strategy First results presented on Dec 1, 2017 17 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Our Strategy Top Priority 18 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Our Strategy And then, we will make the ratios for the semi [ex,in]clusive channels. 19 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Our Strategy Will constraint the flux 20 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Our Delivery Measurements respect to different particle kinematics (momentum and angle) and neutrino energy. • Unfolded cross-sections. • Event rates at the detector and a folding matrix. • Correlation and covariance matrices. 21 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Beam Hadron Production Uncertainties • ~ <1.5 hadronic interactions> contributes to the peak. Muon neutrino flux: • ~ 8% uncertainty at the peak. Incident mesons, quasi-elastic and proton interacting in materials beyond carbon would reduce the beam uncertainty significantly. New data on HP experiments such as NA61 and EMPHATIC will help. 22 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

Recent Results from NOvA - ν μ CC Neutral Pion. - NC Coherent Neutral Pion. Preliminary results were presented in JETP, Dec 1st, 2017. 23 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

ν μ CC Neutral Pion Flux-average cross section of muon and neutral pion kinematics (angle respect to the beam and momentum), Q 2 and W. It uses a data-driven technique for the signal and background fit: makes a template fit of the PID distribution of the signal and background per kinematic bin to match the MC to Data. 0.5 < p μ < 0.6 GeV/c Photon score and a After fit Before fit CC π 0 ID are developed based on dE/dx and “gappiness" of the tracks. The CC π 0 ID separates signal from background. The CC Nue Inclusive uses this procedure (see some slides ahead). 24 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab

ν μ CC Neutral Pion: Some Results Shown in JETP, Dec 1st, 2017 Result consistent with GENIE FSI model. GENIE shape prediction lightly over-predicts around p μ ~ 0.3 GeV/c and Q 2 ~ 0.6 GeV 2 . 25 3-12-2018 Leo Aliaga | Cross Section Measurement Strategy Workshop, Fermilab