Mi MicroBooN oBooNE cr cross-se secti tion ons s fr from om - PowerPoint PPT Presentation

Mi MicroBooN oBooNE cr cross-se secti tion ons s fr from om an osc oscillati tion ons s persp specti tive NUFACT 2017 Xiao Luo, Yale University On behalf of MicroBooNE collaboration 1

Mi Micr croBooNE and and FNA NAL L ne neutr utrino ino be beam am LArTPC ~170 tons, surface detector Fermilab Collecting BNB Neutrino Data for 17 Booster Neutrino Beam months, ~ 6.5e20 POT collected. (BNB) ~ 170 k 𝜉 𝜈 CC interactions POT BNB Neutrinos: � µ 6 -1 � /10 10 µ � 2 e /50MeV/m • Mainly 𝜉 𝜈 � Detector e -2 10 upgrade • 𝜉 𝜈 energy (~700MeV) MicroBooNE -3 10 • <1% 𝜉 # contamination. ) -4 10 � ( � Oct 2015 May 2017 -5 10 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Energy (GeV) 2

LArTPC Working princi LAr ciple – sig signals als • Charged particles lose energy through Ar excitation ( scintillation light ) and z ionization ( drift electrons ) • Electrons drift towards anode wire planes under E field. • MicroBooNE LArTPC has two induction planes and one collection plane. Y • 3D reconstruction from drift-time (X) and wire-plane matching (Y,Z). • Number of electrons collected indicates the amount of energy loss from ionization. X 3

LAr LArTPC Wo Working princi ciple Advantages: High Z target: large active volume -> lots of nu interactions. Finely segmented detector: • High spatial resolution: 3mm wire spacing -> mm vertex accuracy. • High calorimetric resolution: trace the charged particle ionization Strong particle identification power to tag • Tracks: muon, proton, charged pions, kaons, etc. • Showers: electron, gamma, pi0. • Cold electronics: Low noise -> low threshold. Challenges: • Cosmic background rejection: ionization chamber is slow (~2ms drift). Surface detector -> ~20 cosmic tracks in 4.8 ms readout window • High Z target: Nuclear effects affect nu cross-sections. • Non-uniform detector response: unresponsive channels, shorted wire region. 4

From BNB trigger stream Bird’s eye view 𝝋 MICROBOONE-NOTE-1002-PUB Time ticks (X) Collection wire number (Z) Run 3493 Event 41075, October 23 rd , 2015 5 75 cm

Mi MicroBooNE us uses es thes these bea e beauti utiful ful i images es t to s study tudy neutr neutrino no os osci cillation on • Goal I : Understand the nature of the MiniBooNE low energy excess of EM events • Goal II : SBN (together with SBND and ICARUS) search for sterile neutrinos ( ∆𝑛 ( ~ 1 𝑓𝑊 2 ) with 5 𝝉 sensitivity . • Goal III : Provide 𝝃 -Ar cross-section measurements for DUNE. 6

Go Goal al I: : go o after er Mi MiniBooNE NE Lo Low Ene Energy gy Ex Excess ss • MiniBooNE sees 2.8 𝜏 and 3.4 𝜏 event excess in 𝝃 𝝂 ⟶ 𝝃 𝒇 and 𝝃 𝝂 ⟶ 𝝃 𝒇 Significant background is from 𝜌 8 misid and 𝛿 from delta radiative • decay. • Detector can not distinguish e from 𝛿 . MiniBooNE MicroBooNE Common features Neutrino source: BNB Detector location: ~540 from the source Flux, L/E Differences Detector Cherenkov detector LAr TPC e/ 𝛿 separation NO e/ 𝛿 separation Yes Target Mineral oil (CH2) Liquid Argon (Ar) (806 tons) (180 tons) MicroBooNE primary goal: determine if the nature of the excess events are 𝜹 like or e like. 7 Phys. Rev. Lett. 110, 161801 (2013)

Go Goal al II II: : go o after er St Sterile Ne Neutri trino search - SBN SBN progr gram ICARUS SBND T600 MicroBooNE Fermilab Short Baseline Neutrino program: SBND ICARUS MicroBooNE Shared neutrino beam (BNB) reduce flux • LArTPC:110m, 112t uncertainty. LArTPC: 600m, 476t LArTPC: 470m, 87t All LArTPC detectors: reduce cross-section • uncertainty Goal: 5 𝝉 sensitivity for sterile neutrino search at ∆𝒏 𝟑 ~ 1eV 2 8

Go Goal al III III: : go go after cr cross-se section n unc uncertainty in n Dune une • Precision measurements of neutrino oscillation parameters. • Neutrino Mass Hierarchy • CP violation: 𝜀 >? Dune CDR arXiv:1512.06148 Dune Far detector is LArTPC. MicroBooNE can give direct cross-section constrain (particularly in low energy region) for Dune oscillation precision measurements. ~2X exposure 9

Osci cillation signals 𝝃 𝝂 → 𝝃 𝝂 , , 𝝃 𝝂 → 𝝃 𝒇 Signal selection 𝝃 energy reco. Syst. Uncertainty • 𝝃 𝝂 CC inclusive • 𝝃 𝝂 CC inclusive • CC0 𝝆 • CC 𝝆 𝟏 • CC 𝝆 𝟏 • Charged particle multiplicity, CC0 𝝆 10 • NC proton identification

Cr Cross-se section n impa pact on n Osc scillation n 𝝃 𝝂 CC inclusive -> 𝝃 signal selection, Systematic uncertainty 11

𝝃 𝝂 CC CC inc inclus lusiv ive cr cross ss-se sect ction First channel in MicroBooNE cross-section program: 𝜉 𝜈 CC inclusive: • Relatively simple event signature – tag long muon track as the product of the neutrino interaction. • Muon kinematics is insensitive to FSI. • A standard channel to compare with other neutrino experiments. Impact on oscillation: Signal selection of 𝜉 C disappearance channel. • 𝜉 𝜈 CC help to constrain the 𝜉 𝑓 rate. • ArgoNeuT is the only existing 𝝃 -Ar cross-section 12

𝝃 𝝂 CC CC inc inclus lusiv ive 1000 No. of Events 900 Data: Beam On- Beam Off Simulation: 800 selected ν CC+bkgd µ bkgd ν 700 µ + bkgd Cosmic ν ν e e 600 NC bkgd 26% 𝝃 𝝂 𝐃𝐃 Cosmic bkgd 500 65% CC true vertex Out of FV bkgd ν µ 400 MicroBooNE 300 preliminary Selection 200 100 • Purity: 65%, Efficiency: 30% 0 0 100 200 300 400 500 600 700 800 900 1000 Track Length (cm) • Improved analysis: • Scintillation light to improve the selection efficiency See Marco Del Tutto’s talk Tue. WG2 talk Check out MicroBooNE public note • Muon PID to reduce background MICROBOONE-NOTE-1010-PUB for details. Differential cross-section is on the way, stay tuned! 13 Note: efficiency = # of 𝝃 𝝂 𝐃𝐃 events after selection / All 𝝃 𝝂 𝐃𝐃 events inside of FV

Ne Neutri trino oscillati tion Vs Cross-se section CC 𝝆 𝟏 -> 𝝃 signal selection, Systematic uncertainty, 𝝃 Energy reconstruction 14

𝑫𝑫𝝃 𝒇 select ction Exclusive QE like “Inclusive” search (1e + 1 p) (1 e + 0 𝝆 ) 𝝃 𝒇 𝝃 𝒇 p hadrons • Higher statistics • Simpler topology • Directly compatible to • Lower backgrounds MiniBooNE • Easier 𝑭 𝝃 • Less model dependency determination 15

𝑫𝑫𝝃 𝒇 select ction Exclusive QE like “Inclusive” search 𝝆 𝟏 misID (1e + 1 p) (1 e + 0 𝝆 ) ∆→ 𝑶𝜹 𝝃 𝒇 𝝃 𝒇 p hadrons Challenges: • Higher statistics • Simpler topology • Suppress photon backgrounds: NC 𝜌 8 , CC 𝜌 8 , resonant 𝜉 • Directly compatible to • Lower backgrounds interactions in dirt-> 𝛿 MiniBooNE • Easier 𝑭 𝝃 • e/ 𝜹 separation • Less model dependency determination 16

CC 𝝆 𝟏 cr CC cross-se section measu surement Challenging channel: CC 𝛒 𝟏 𝐝𝐛𝐨𝐞𝐣𝐞𝐛𝐮𝐟 𝐟𝐰𝐟𝐨𝐮 “Shower” reconstruction is difficult especially in • the low energy range. Strategy: tagging muon and look for two • 𝜹 showers The first CC 𝝆 𝟏 cross-section result is on 𝜹 the way, stay tuned! Impact on oscillation physics: • Easiest channel to provide large pi0 sample • Utilize the pi0 for shower automated reconstruction development. • Enable us to study photon background for the 𝜉 # appearance channel. 17

PID PID – sh shower ers ( s (e/ e/ 𝜹 ) ) Electron Vs Gamma dE/dx at start of the 𝝃 𝒇 Signal 𝝃 𝒇 Background shower? Gaps e-: 1MIP • 𝛿 : 1MIP if Compton • e - scattering, 2MIP if converting to e + e - No Gap Gaps from vertex? 𝛒 𝟏 → 𝛅𝛅 𝛿: yes • e - : no • BNB DATA : RUN 5360 EVENT 45. MARCH 8, 2016. BNB DATA : RUN 5536 EVENT 1612. MARCH 22, 2016. What Impact PID? • Require good vertexing. • Use both dE/dx and gap handles -> better e - tagging. Study the energy dependence of 𝛿 contamination. • Note: ArgoNeuT electron like sample has 20% photon contamination with higher energy NuMI beam. 18 ArgoNeuT PhysRevD.95.072005

Ne Neutri trino oscillati tion Vs Cross-se section NC elastic -> 𝝃 Energy reconstruction 19

NC NC e elastic c – pr proton n iden dentification • Take advantage of LArTPC PID strength, include hadron calorimetry of the final states in energy reconstruction . • 𝜉 − 𝐵𝑠 NC elastic cross-section help identify protons and their energy reconstruction NC elastic cross-section • ultimate goal: ∆𝑡 . • Signature: single short proton track (challenging to select) • Employed BDT to identify protons 40 MeV • Continue push to lower threshold proton energy threshold. Check out our public note for Example of selected NC proton more details: link from BNB data. ~60MeV proton 20

Ne Neutri trino oscillati tion Vs Cross-se section Charged particle multiplicity -> Systematic Uncertainty from nuclear effects CC0 𝝆 -> 𝝃 Energy reconstruction, Systematic Uncertainty from nuclear effects 21