The MINERνA Experiment -Brian G Tice- Rutgers, The State University of New Jersey On behalf of the MINERνA collaboration MINERνA Workshop on Electron-Nucleus Scattering XII Marciana Marina, Isola d Elba June 25-29, 2012
Outline Meet MINERνA The NuMI beam The MINERvA Detector First results ν μ inclusive charged current ν μ inclusive charged current ratios of nuclear targets ν μ charged current quasi elastic ν μ charged current quasi elastic June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 2
MINERvA Main INjector ExpeRiment ν-a MINERvA is a neutrino scattering experiment at Fermilab in Batavia, IL, USA. Collaboration of 80 nuclear and particle physicists. University of Athens University of Texas at Austin Centro Brasileiro de Pesquisas Físicas Fermilab University of Florida Université de Genève Universidad de Guanajuato Hampton University Inst. Nucl. Reas. Moscow Mass. Col. Lib. Arts Northwestern University Otterbein University Pontificia Universidad Catolica del Peru University of Pittsburgh University of Rochester Rutgers University Tufts University University of California at Irvine University of Minnesota at Duluth Universidad Nacional de Ingeniería Universidad Técnica Federico Santa María William and Mary June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 3
NuMI Beamline Delivers ~35x10 12 protons on target (POT) per spill at ~0.5 Hz, a beam power of 300-350 kw. 120 GeV proton Carbon target pc π ± and K ± Magnetic horns focus + or - π + / K + μ + ν μ or π - / K - μ - ν μ MINERvA June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 4
Tuning to Hadron Production Data Hadron production simulated with Geant4 to predict flux. Flux is reweighted based on hadron production data compared to Geant4. NA49 Data v. Geant4 June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 5
Neutrinos Seen ν μ ν μ Data collected: LE 3.98x10 20 POT LE 1.7x10 20 POT June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 6
Neutrinos Seen ν μ ν μ Data collected: LE 3.98x10 20 POT LE 1.7x10 20 POT June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 7
MINERvA Detector 120 scintillator modules for tracking and calorimetry (~32k readout channels). Construction completed Spring 2010. He and Water added in 2011. MINOS Near Detector serves as muon spectrometer. June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 8
Another Module One Module 16.7 mm 17 mm X V X U Charge sharing for improved position resolution (~3 mm) and alignment σ = 3mm Scintillator - tracking Lead - EM calorimetry Steel - hadronic calorimetry June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 9
Inclusive Charged Current Scattering June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 10
Strip Number Event Reconstruction recoil blobs MINOS matched track vertex recoil blobs MINOS Module Number Reconstructed objects MINOS tracks, other tracks, vertices, endpoints, blobs vertex June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 11
Vertex Distributions - Acceptance MINOS-matched muons (for CC inclusives sample) Energy threshold ~2 GeV. Good angular acceptance up to scattering angles of about 10 degrees, with limit of about 20 degrees. Bias is complex but well understood. June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 12
Muon Energy (GeV) Recoil Energy (GeV) Neutrino Energy (GeV) Neutrino Energy (GeV) June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 13
Stability March 22, 2010 July 12, 2010 June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 14
Nuclear Target Ratios Analysis June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 15
250 kg Liquid He 500kg Water Active Scintillator Modules He Water Tracking Region 1 Fe / 1 Pb 323kg / 264kg 1 Pb / 1 Fe 266kg / 323kg 3 C / 1 Fe / 1 Pb 166kg / 169kg / 121kg 0.3 Pb 228kg.5 Fe /.5 Pb 161kg/ 135kg June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 16
250 kg Liquid He 500kg Water Active Scintillator Modules He Water Tracking Region 1 Fe / 1 Pb 323kg / 264kg 1 Pb / 1 Fe 266kg / 323kg 3 C / 1 Fe / 1 Pb 166kg / 169kg / 121kg 0.3 Pb 228kg.5 Fe /.5 Pb 161kg/ 135kg Target 3 Target 5 June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 17
Strip Number C An event from target 3 Fe Pb view looking upstream Pb Fe DATA Module Number Elba XII - The MINERνA Experiment Brian G. Tice June 27, 2012 18
Strip Number C Another event from target 3 Fe Pb view looking upstream Pb Fe DATA Module Number Elba XII - The MINERνA Experiment Brian G. Tice June 27, 2012 19
Vertices reconstructed wrongly into scintillator are background. Use upstream tracker modules as faux targets to subtract the plastic background. June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 20
Background Subtraction Use faux targets to predict rate if passive target were CH. Prediction done in bins of muon momentum. June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 21
Background Subtraction Use faux targets to predict rate if passive target were CH. Background subtracted in both MC and data ~without using MC cross section model. June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 22
Target 5 Results Uses ~25% neutrino data recorded and~20% of target mass. Iron Lead June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 23
Use a Ratio to Mitigate Errors Pb 2 Pb(Fe) and 2(1) have ~same efficiency related to XY position. Pb(2) and Fe(1) have ~same efficiency related to Z position. ε xy ε z ε xy ε z ~1 ε xy ε z ε xy ε z Fe 1 All targets in same beam flux largely cancels All targets in same detector similar reconstruction Pb CH #2 Fe CH #1 June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 24
Target 5 Results - Ratio Uses ~25% neutrino data recorded and~20% of target mass. Pb CH #2 Fe CH #1 Red band = systematic errors Black bars = MC+data stat. error Higher statistics Plot X, Q 2 in bins of neutrino energy June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 25
Systematic Error - Iron of Target 5 ~25% June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 26
Systematic Error - Ratio Pb CH #2 Fe CH #1 ~2.5% June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 27
Antineutrino Quasi Elastic Scattering June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 28
If elastic kinematics, E ν =2.8 GeV, Q 2 =0.1GeV 2 If elastic kinematics, E ν =2.5 GeV, Q 2 =0.3GeV 2 30 MeV deposited in single channel. Neutron interaction candidate. Beam direction View of detector from above Require a μ + matched into MINOS. Require no other tracks. Require 0 or 1 clumps of energy deposition (neutron candidate). Sum recoil energy (excluding 10cm around vertex). June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 29
Why don t we cut on vertex activity? We want to measure it! Scattering off a nucleus can be messy. We must interrogate the final state products to allow testing of MEC and FSI models. Illustration: Fermilab/Diana Canzone June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 30
Recoil Energy Cut Expect higher Q 2 QE events to have more recoil energy. Recoil cut scales with Q 2 QE. Total selection purity is ~80%. June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 31
Kinematic Distribution June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 32
Getting to dσ/dq 2 QE Background subtraction Unfolding detector smearing Efficiency correction Unfolded Q 2 QE (GeV 2 ) Unfolded Q 2 QE (GeV 2 ) June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 33
dσ/dq 2 QE Monte Carlo Genie 2.6.4 M A = 0.99 GeV RFG Pauli-blocking No MEC Unfolded True Q 2 Q 2 QE (GeV) 2 ) June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 34
dσ/dq 2 QE Unfolded Q 2 QE (GeV 2 ) NuWro: Golan, Juszczak, Sobczyk. arxiv: 1202.4197 [nucl-th] June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 35
Neutrino Charged Current Quasi Elastic Scattering June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 36
Recoil Region Require a μ - matched into MINOS. Require 0 or 1 other tracks (proton candidate). Require 0 or 1 clumps of energy deposition (proton candidate). Sum recoil energy (excluding 10cm around vertex). June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 37
Sideband regions will be used to understand background in data. Proton reconstruction not yet used in Q 2, E ν calculations. June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 38
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Neutrino and Antineutrino CCQE 2-4 GeV June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 40
Neutrino and Antineutrino CCQE 4-10 GeV June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 41
Conclusions MINERvA is performing well and is producing results. Systematic errors have been explored. Improvements possible. Nuclear target ratios analysis method works well. Needs to use full statistics in hand. Wait for more data. Our first antineutrino dσ/dq 2 QE is public. Neutrino dσ/dq 2 QE is coming soon. and more exclusive analyses are in progress! June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 42
Backup June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 43
Understanding Our Flux Vary the target position and the horn current to change the flux spectrum. Monitor spread of μ ± from π ± decay MINERvA June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 44
Current Flux Uncertainties Preliminary! Tertiary = non-na49 Z. Pavlovic, PhD Thesis, Texas (2008) Can be improved with work! Elba XII - The MINERνA Experiment Brian G. Tice June 27, 2012 45
Alignment and Strip Response Elba XII - The MINERνA Experiment Brian G. Tice June 27, 2012 46
Where do the muons go? Today's results Elba XII - The MINERνA Experiment Brian G. Tice June 27, 2012 47
Tracking Resolutions 4.0mm σ = 2 σ= 15 mrad 2 Split-track study of rock m in tracker region Elba XII - The MINERνA Experiment Brian G. Tice June 27, 2012 48 48
Muon Energy Uncertainty MINOS de/dx + mass model = 2% [MINOS, NIM A 596, 190 (2008)] range vs. curvature data-mc ~25 MeV range vs curvature in MINOS Total: ±3% p> 1.5 GeV ±5% P<1.5 GeV MINERvA mass model = 11 MeV tracker = 17 MeV Nucl.Tgts. m energy loss = 30 MeV Elba XII - The MINERνA Experiment Brian G. Tice June 27, 2012 49
Energy Scale and Stability Elba XII - The MINERνA Experiment Brian G. Tice June 27, 2012 50
Michels, π 0 and e/ Separation Reconstructed π 0 Michel e Photons From Reconstructed π 0 Elba XII - The MINERνA Experiment Brian G. Tice June 27, 2012 51
shower energy resolution Elba XII - The MINERνA Experiment Brian G. Tice June 27, 2012 52
Tracking x Matching Efficiency Method ID clean μ in MINOS, point back to MINERvA Why not 100%? * big shower * pileup * deadtime MC overlaid with data Single event MC correction -4.6±2.5% Elba XII - The MINERνA Experiment Brian G. Tice June 27, 2012 53
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Double ratio of cross sections What cancels? Plastic cross sections are the same Assume that flux is the same for all targets Bin sizes are the same June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 56
Double ratio of cross sections reduced Double ratio gives us the ratio of lead to iron cross section, and with more cancellations to come... We know how many nucleons were used to build MINERνA (to ~2%) June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 57
Separable Efficiency/Acceptance Measured to true number of events Separate event selection efficiency into: Acceptance dependent on XY position Acceptance dependent of Z position Other effects specific to the nuclear target June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 58
Separable Efficiency/Acceptance Comparing samples with different acceptances Plastic reference target in the same region in Z Iron and Lead target are in the same region in Z Iron and its plastic reference occupy the same XY region Lead and its plastic reference occupy the same XY region June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 59
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Systematic Errors on dσ/dq 2 QE Unfolded Q 2 QE (GeV 2 ) June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 63
Neutrino Energy & Q 2 Area Normalization June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 64
Neutrino Energy & Q 2 Absolute Normalization June 27, 2012 Elba XII - The MINERνA Experiment Brian G. Tice 65