Study of Charged-Current neutrino interactions on water with nuclear - PowerPoint PPT Presentation

� � � � ・ NINJA Study of Charged-Current neutrino interactions on water with nuclear emulsion in the NINJA experiment � Ayami Hiramoto (Kyoto Univ.) Y . Suzuki, T.Fukuda, T,Nakaya for the NINJA collaboration 2019.09.09

2 Introduction • Neutrino-nucleus interaction is one of the major sources of the uncertainty for neutrino oscillation experiments. • 2p2h (multi-nucleon) interactions mimic the CCQE signals. • Direct measurement of low momentum protons (and pions) is very important. Reconstructed Neutrino Energy (MC) CCQE 2p2h (multi-nucleon)

3 NINJA • N eutrino I nteraction research with N uclear emulsion and J -PARC A ccelerator. • Water target (same as SK) detector @ T2K near detector hall • Emulsion: 3D tracking device, sub-micron position resolution. H 2 O measurement with ~200MeV/c proton threshold Phys. Rev. D 98, 032003 (2018) 900 a.u. @T2K ND280 800 CCQE 2p2h high 700 2p2h low 600 500 Proton momentum @NINJA position 400 300 200 100 0 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 GeV/c Proton Momentum [GeV/c]

4 Detectors Time stamper Emulsion shifter or scintillator-based tracker MRD ECC INGRID or Baby MIND ν water + (T2K near detectors) film iron + scintillator Emulsion doesn’t have time resolution

5 ECC (Emulsion cloud chamber) • Water target layers , emulsion film + iron plate tracking layers • Position , Angle and Energy deposit (blackness) of the tracks at each plate are provided. Water (2mm) 2cm ν

6 What we measure? • Charged particles: mu, charged-pi, proton (, electron) => Track multiplicity of charged particles • P β (momentum) estimation by Multiple Coulomb Scattering • Particle identification using energy deposit => Momentum & angle distribution of mu, pi, proton Multiple Coulomb scattering in ECC Iron plate (500µm) water �

7 NINJA Beam exposure ① Pilot run (2014) Detector test run with emulsion shifter -> published PTEP ， 063C02 (2017) PTEP ， 063H02 (2017) ② Test runs 65kg iron target run, 2016 nu + anti-nu -> next talk Water target test run , 2017-2018 anti-nu -> my talk Data MC 3kg water, 0.7 * 10 21 POT anti-nu NEUT5.4.0 + GEANT4 Today we only have 70% of all data. ③ Physics Run (2019) 75kg water -> Data taking from this Nov. Under preparation

8 Neutrino Event Candidates All muon ID tracks 1cm � ν 10,741 ECC starting Sand muon 250 H 2 O layer starting Fe starting 97 Interactions on Interactions on H 2 O emulsion, base 69 Muon momentum Miss connection consistency check 62

9 Total: 62 events (MC: 66.2) Track Multiplicity MC is normalized by POT with the estimated detector efficiency • Since it was anti-neutrino run, most events are single track events. Track Criteria: • |tan θ x | ≦ 1.3, |tan θ y | ≦ 1.3, Number of emulsion layers ≧ 2 ( ↑ will be increased to |tan θ |<4.0 at physics run) Neutrino Flux (MC) Track multiplicity POT events 17 numu 10 50 CCQE 21 2p2h numubar events/10 16 10 CC1pi nue 40 CC Multi-pi 15 10 nuebar CC Other NC 14 10 30 events ν µ 13 10 Work in Progress 20 12 10 11 10 Anti-neutrino mode @ on-axis 10 10 10 0 0 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 # of Charged Particle Tracks E [GeV/c] ν

10 Muon Tracks • Muons are limited by acceptance of the MRD. • MRD: 6.5cm*9 iron plates => most muons are penetrating tracks • Require to penetrate at least two iron plates at MRD. Muon angle P µ estimated from MRD range 30 Number of events events Work in Progress 60 muon 25 pion 50 proton muon (numubar) ν 20 µ 40 muon (numu) 15 pion (numubar) 30 pion (numu) 10 20 Work in Progress proton (numubar) proton (numu) 5 10 0 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0 0.2 0.4 0.6 0.8 1 Muon Momentum [GeV/c] Muon cos θ

11 Particle Identification • Blackness of a track = Energy deposit • Proton-like / Pion – like separation is performed by Likelihood ratio using blackness parameter. Blackness (MC) PID Likelihood ratio (MC) Proton: Purity 90.2% Eff. 85.3% Pion: Purity 84.7% Eff. 89.8% P β : 0.2-0.3GeV/c angle: 0.5-0.7 rad Blackness

12 # of Proton/Pion Tracks • Our understanding of vertexing efficiency is not sufficient yet. • We are trying to confirm all backgrounds, detector efficiency and systematic uncertainties. # of Proton tracks # of Pion tracks events events 60 CCQE CCQE 60 2p2h 2p2h 50 CC1pi CC1pi 50 CC Multi-pi CC Multi-pi CC Other CC Other 40 NC NC 40 events events ν ν µ µ 30 30 20 Work in Progress Work in Progress 20 10 10 0 0 0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10 # of Protons # of Pions

13 Proton Angle and Momentum • Protons down to 200MeV/c are detected on water! Proton angle Proton momentum events events 12 CCQE CCQE 16 2p2h 2p2h 10 CC1pi 14 CC1pi CC Multi-pi CC Multi-pi 12 CC Other CC Other 8 NC NC 10 events events ν ν µ µ 6 8 Work in Progress Work in Progress 6 4 4 2 2 0 0 0 20 40 60 80 100 120 140 160 180 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 200MeV/c Proton Angle [deg] Proton Momentum [GeV/c]

14 Proton Angle and Momentum • Protons down to 200MeV/c are detected on water! 180 Proton Angle [deg] 1 160 Work in Progress 140 0.8 120 0.6 100 80 0.4 60 40 0.2 20 0 0 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Proton Momentum [GeV/c]

15 Pion Angle and Momentum • Pion-like tracks are also detected. Pion angle Pion momentum events events 6 7 CCQE CCQE 2p2h 2p2h Work in Progress 6 5 CC1pi CC1pi CC Multi-pi CC Multi-pi 5 CC Other CC Other 4 NC NC 4 events events ν ν µ µ 3 3 Work in Progress 2 2 1 1 0 0 0 20 40 60 80 100 120 140 160 180 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 Proton Angle [deg] Pion Momentum [GeV/c] We will update our results with full data quickly

16 Physics run 2019 • Data taking from Nov. 2019 Wall • Placed among T2K-WAGASCI • 75kg water target • ~0.5*10 21 POT Wall => 3000 CC interactions H 2 O: 75kg Fe: 130kg CH: 15kg emulsion : 30kg First goals: • # of proton, pion and their momentum/angle distribution • Cross section measurement divided by number of protons and pions

17 Summary and Prospects • NINJA measures neutrino interactions on water with 200MeV/c proton threshold. • First measurement of muon, proton and pion kinematics using water target ECC was shown. => Protons >200MeV/c were detected on water target • We will increase statistics ( × 1.4) and update our results including all systematic uncertainties. Next talk => Fe ECC test run results

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19 Nuclear Emulsion • Photographic films which have sensitivity to charged particles. => No time resolution • A charged particle passing through emulsion makes AgBr crystals. After developing, we can see silver grains in films. • Automatic scanning by microscope provide us position, angle and dE/dx information of tracks. Developing Charged particle Nuclear Emulsion Silver grains

20 Fe interactions Muon Angle Track Multiplicity Number of events events 90 50 CCQE 80 2p2h CC1pi 70 40 CC Multi-pi muon (numubar) CC Other 60 NC muon (numu) 30 50 events ν µ pion (numubar) 40 pion (numu) 20 30 proton (numubar) 20 10 proton (numu) 10 0 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1 2 3 4 5 6 7 8 9 10 # of Charged Particle Tracks Muon cos θ # of Proton tracks # of Pion tracks events events 100 CCQE 100 CCQE 2p2h 2p2h CC1pi CC1pi 80 80 CC Multi-pi CC Multi-pi CC Other CC Other NC NC 60 60 ν events ν events µ µ 40 40 20 20 0 0 0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10 # of Protons # of Pions

21 Fe interactions Proton Angle Proton Momentum 35 events events 18 CCQE CCQE 30 16 2p2h 2p2h CC1pi CC1pi 14 CC Multi-pi CC Multi-pi 25 CC Other CC Other 12 NC NC 20 ν events 10 events ν µ µ 15 8 6 10 4 5 2 0 0 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 0 20 40 60 80 100 120 140 160 180 Proton Momentum [GeV/c] Proton Angle [deg] Pion Angle Pion Momentum events events 14 CCQE CCQE 7 2p2h 2p2h 12 CC1pi CC1pi 6 CC Multi-pi CC Multi-pi 10 CC Other CC Other 5 NC NC 8 ν events ν events µ µ 4 6 3 4 2 2 1 0 0 0 20 40 60 80 100 120 140 160 180 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 Proton Angle [deg] Pion Momentum [GeV/c]

22 Momentum Reconstruction / PID All tracks from vertices µ candidates others P β by ECC MCS Momentum reconstruction PID by VPH using ECC M CS If proton, Momentum estimation by ECC range

23 Momentum Reconstruction • Measure scattering angle at each iron plate ( δθ i ) • θ 0 is the RMS of δθ i • Scattering at water and emulsion should be considered as well δθ 2 � �� δθ 1 � δθ 3 � � � � � � � � � Water � Film � Film � Iron �