The NOvA neutrino experiment and its astrophysics program Matthew Strait, for the NOvA collaboration University of Minnesota, Twin Cities February 22, 2021 Matthew Strait (UMN) NOvA | Neutrino Telescopes 2021 February 22, 2021 1 / 27 Introduction Outline Overview of NuMI beam and NOvA detectors Neutrino oscillation results (rapidly) See more detail Wednesday 17:30: talk by Zoya Vallari Astrophysics NOvA Far Detector Matthew Strait (UMN) NOvA | Neutrino Telescopes 2021 February 22, 2021 2 / 27 Design Design Overview Fermilab's NuMI beam Near detector Observe unoscillated beam composition, energy Far detector observes: νµ ! νµ νµ ! νe ν¯µ ! ν¯µ ν¯µ ! ν¯e NOvA Simulation NOvA Far Detector νµ POT νµ Off-axis ! narrow 13 3 10 ν e 10 × ν spectrum at 2 GeV e 102 1st oscillation / GeV 5 10 maximum at 2 810 km 1 Neutrinos / m 10−1 0 5 10 15 20 Neutrino energy (GeV) Matthew Strait (UMN) NOvA | Neutrino Telescopes 2021 February 22, 2021 3 / 27 Design Detector Technology Two functionally identical detectors Segmented plastic and scintillator tracking calorimeter 63% active APD readout Near detector is 300 t, underground, 1 km from NuMI target Far detector is 14 kt, on the surface 32 pixel APD sees fiber pairs from 32 cells Matthew Strait (UMN) NOvA | Neutrino Telescopes 2021 February 22, 2021 4 / 27 Design Event Topologies 1m Proton Beam νμ + n → μ + p ! 1m Muon Michel e- Optimized for ν Charged Current μ EM showers Proton νe + n → e + p ∼6 samples per X Electron 0 Convolutional νe Charged Current neural net Proton ν + X → ν + X' classifier selects π0 (→γγ) signal events Neutral Current Matthew Strait (UMN) NOvA | Neutrino Telescopes 2021 February 22, 2021 5 / 27 Results νµ Analysis Far Detector Data: 2013{2020 | νµ disappearance Neutrino mode: 13:6 × 1020 POT Anti-neutrino mode: 12:5 × 1020 POT 211 events selected 105 events selected Background: 9.2 events Background: 2.1 events ν-beam NOvA Preliminary ν-beam NOvA Preliminary FD data FD data 20 10 2020 Best-fit 2020 Best-fit σ 1- syst. range 8 1-σ syst. range 15 Background Background 6 10 4 Events / 0.1 GeV Events / 0.1 GeV 5 2 0 1 1 0.8 0.8 0.6 0.6 0.4 0.4 0.2 0.2 Ratio to no osc. 0 Ratio to no osc. 0 0 1 2 3 4 5 0 1 2 3 4 5 Reconstructed neutrino energy (GeV) Reconstructed neutrino energy (GeV) Matthew Strait (UMN) NOvA | Neutrino Telescopes 2021 February 22, 2021 6 / 27 Results νe Analysis Far Detector Data | νe appearance 82 events in ν mode 33 events inν ¯ mode Background: 26.8 events Background: 14.0 events 1.0 wrong-sign (appearingν ¯e) 2.3 wrong-sign 22.7 other beam (intrinsic νe, νµ, ντ , 10.2 other beam neutral current) 1.6 cosmic 3.1 cosmic > 4σ electron anti-neutrino appearance ν-beam NOvA Preliminary ν-beam NOvA Preliminary 30 Core only Core only FD data 15 FD data 2020 best-fit 2020 best-fit 1-σ syst range POT 1-σ syst range 20 POT-equiv Wrong sign bkg Wrong sign bkg 10 20 Total beam bkg Total beam bkg 20 × Cosmic bkg Cosmic bkg 10 10 × 10 5 Events / 12.50 Events / 13.60 0 0 1 2 3 4 1 2 3 4 Reconstructed neutrino energy (GeV) Reconstructed neutrino energy (GeV) Matthew Strait (UMN) NOvA | Neutrino Telescopes 2021 February 22, 2021 7 / 27 Results Combined 2 Combined Appearance/Disappearance Results | θ23, ∆m32 2 −3 2 ∆m32 = (2:41±0:07)×10 eV NOvA Preliminary (normal hierarchy) NOvA FD 13.6×1020 POT equiv ν + 12.5×1020 POT ν Normal Hierarchy 90% CL 3 NOvA Preliminary NOvA MINOS+ 2020 ) 2.5 3.0 T2K 2020 IceCube 2018 σ SK 2020 ) 2 2 1.5 eV -3 1 Normal hierarchy (10 2.5 Significance ( Inverted 2 32 0.5 hierarchy m ∆ 0 0.4 0.5 0.6 0.7 2θ sin 23 2.0 NOvA Best fit Slight preference for upper 0.4 0.5 0.6 octant, normal hierarchy 2θ 2 +0:04 sin 23 sin θ23 = 0:57−0:03 Matthew Strait (UMN) NOvA | Neutrino Telescopes 2021 February 22, 2021 8 / 27 Results Combined Combined Appearance/Disappearance Results | Mass ordering, θ23, δCP NOvA Preliminary 0.7 NOvA FD 13.6×1020 POT equiv ν + 12.5×1020 POT ν 5 NOvA Preliminary 0.6 NH Lower octant 23 ) NH Upper octant θ σ 2 4 0.5 IH Lower octant sin IH Upper octant 0.4 3 Normal hierarchy ≤1σ ≤2σ ≤3σ Best Fit 0.3 NH 2 0 π π 3π 2π 2 δ 2 CP Significance ( 1 NOvA Preliminary 0 0.7 0 π π 3π 2π 2 2 δCP 0.6 23 θ 2 0.5 All values of δ allowed sin 0.4 Prefer normal hierarchy by 1.0σ ≤1σ ≤2σ ≤3σ Best Fit Prefer upper octant by 1.2σ Inverted hierarchy 0.3 IH 0 π π 3π 2π Exclude δ = π=2 inIH at > 3σ 2 δ 2 CP Matthew Strait (UMN) NOvA | Neutrino Telescopes 2021 February 22, 2021 9 / 27 Astrophysics Astrophysics NOvA Far Detector As a large fine-grained detector, the Far Detector supports a variety of astrophysical analyses Some benefit from the FD's location on the surface Some can be done in spite of it Cosmic muon rate: 150 kHz Near Detector: 100 m underground | much smaller, but much quieter 36 Hz of cosmics Matthew Strait (UMN) NOvA | Neutrino Telescopes 2021 February 22, 2021 10 / 27 Astrophysics Triggers for Astrophysics 10,752 FEBs (344,064 det. channels) FEB FEB FEB FEB FEB FEB FEB FEB FEB FEB 11,160 Front End Boards FEB FEB FEB FEB Shared Memory ARTDAQ Data Driven Triggers System DDT event stack DCM 1 ARTDAQ-1 ARTDAQ-2 ARTDAQ-N All data continuously Zero Suppressed Processor Processor Processor DCM 1 5 ms data at ½ - ⅔ MIP DCM 1 DCM 1 180 Data Concentrator Modules blocks digitized (6 - 8 MeV/cell) DCM 1 DCMs /s Data Event builder Buffered for ∼20 minutes Gb Buffer Trigger RecepOon while trigger decisions are Minimum Bias Data Slice Pointer Table 0.75 GB/S Stream made Ethernet 1 » Data Time Window Search COtS 140-200 Buffer Node Computers Data Beam triggers Buffer Nodes Buffer Nodes Buffer Nodes Buffer Nodes Data Other external triggers Buffer Nodes Buffer Nodes 200 Buffer Nodes Data-driven triggers (3,200 Compute Cores) Triggers request anywhere from 50 µs (e.g. cosmic showers) to 45 seconds (supernova) No dead time: triggers do not interfere with each other Matthew Strait (UMN) NOvA | Neutrino Telescopes 2021 February 22, 2021 11 / 27 Astrophysics Cosmic Rays Cosmic ray multi-muon seasonal effect at the Near Detector Well-known: underground cosmic rate higher in summer Less dense summer atmosphere ! more π decay before interacting But we observe more multi-µ in winter Phys.Rev.D 99 (2019) 12, 122004 Effect larger with higher multiplicity No clear explanation 10 2.5 Multiple-muon data 20 8 Effective temperature data (ECMWF) 2 6 1.5 10 4 1 > (%) > (%) > (%) > (%) µ µ 2 0.5 eff 0 eff 0 0 M = 2 / <R / <T / <R / <T µ µ − eff 10 M = 3 eff − − R 2 0.5 R T T ∆ ∆ ∆ ∆ M = 4 −4 −1 −20 M = 5 −6 −1.5 M ≥ 6 −8 −2 −30 2015-01 2015-07 2016-01 2016-07 2017-01 2017-07 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Date (year-month) Matthew Strait (UMN) NOvA | Neutrino Telescopes 2021 February 22, 2021 12 / 27 Astrophysics Cosmic Rays Seasonal multi-muon effect in the Far Detector 0 1000 2000 3000 4000 5000 6000 500 0 x (cm) −500 NOvA Preliminary 1.25 Weekly R 500 µ 1.2 <Rµ> Cosine Fit 0 y (cm) 1.15 −500 0 1000 2000 3000 4000 5000 6000 (Hz) z (cm) µ 1.1 NOvA - FNAL E929 R 3 103 Run: 23156 / 10 10 2 hits 102 hits 10 Event: 119763 / DDenergy 10 10 1 1 UTC Wed Jun 1, 2016 − − − − − 50 40 30 20 10 0 10 20 30 40 50 10 102 103 1.05 19:04:8.793091456 t (µsec) q (ADC) Study sample of muon showers with 1 multiplicity > 15 2016-01 2016-06 2016-11 2017-05 2017-09 2018-03 2018-07 Also observe winter maximum Simulation work underway to find explanation of effects in both Near and Far Matthew Strait (UMN) NOvA | Neutrino Telescopes 2021 February 22, 2021 13 / 27 Astrophysics Cosmic Rays Other Cosmic Ray Studies 1 Measurement of low-energy east-west asymmetry Caused by Earth's B field 2 Short-term weather effects Known, but understudied 3 Solar flare correlation? Claimed by L3+C L3+C: 4 Measure muon rates above 100 TeV Resolve Baksan/IceCube discrepancy? Phys.Part.Nucl. 49 (2018) 4, 639 A&A 456, 351 Matthew Strait (UMN) NOvA | Neutrino Telescopes 2021 February 22, 2021 14 / 27 Astrophysics Cosmic Rays Discovery of ICARUS µ-Flux Excess (64±4° Zenith, and 179±9° Azimuth) in NOvA-ND, due to SBN-FD 24.8. - 3.9. 2015 10 5 -Flux Excess [%] µ 12. - 23.8. 2015 0 2015-04 2015-07 2015-10 2016-01 2016-04 2016-07 2016-10 2016-12 2017-04 Matthew Strait (UMN) NOvA | Neutrino Telescopes 2021 February 22, 2021 15 / 27 Astrophysics Monopoles Magnetic Monopole Search Search for a monopole component of cosmic rays in the Far Detector Large surface area | catch rare events On surface | sensitive to lighter monopoles that don't reach far underground Signals: −2 If β & 10 : highly ionizing, like a charge of 68.5e −2 If β .