Cross Section Uncertainties in the NOvA Oscillation Analyses
Aaron Mislivec University of Minnesota
1
Cross Section Uncertainties in the NOvA Oscillation Analyses Aaron - - PowerPoint PPT Presentation
Cross Section Uncertainties in the NOvA Oscillation Analyses Aaron Mislivec University of Minnesota 1 The NOvA Experiment NO A Off-axis, long-baseline neutrino oscillation experiment in the NuMI MINER A neutrino beam at Fermilab 2
Aaron Mislivec University of Minnesota
1
Off-axis, long-baseline neutrino
neutrino beam at Fermilab
2
NOνA MINERνA
– ν –
νμ ν
θ δ 𝜠𝒏𝟒𝟑
𝟑
𝑁𝑏𝑡𝑡 𝐼𝑗𝑓𝑠𝑏𝑠𝑑ℎ𝑧 θ θ 𝜠𝒏𝟓𝟐
𝟑
c
ν ν ν ν ντ νμ
NC Coherent Pion Production Measurement 𝜠𝒏𝟒𝟑
𝟑
𝜠𝒏𝟑𝟐
𝟑
Long Baseline Neutrino Oscillation Measurements:
νe appearance (±30% matter effect)
Non-Oscillation Measurements:
3
Functionally identical ND and FD
event selection, and reconstruction
4
Sampling Calorimeters (Near and Far)
mineral oil + 5% pseudocumene
Far Detector
Near Detector
5
6
q (ADC)
10 102 3 10νμ
e
νe ν
p μ p p π
γ γ 1m 1m
π0
1 radiation length = 38cm (6 cell depths, 10 cell widths)
7
νe νμ ντ NC Cosmic
Learned varia+ons on the
Input Image
Events classified with Convolutional Visual Network (CVN)
νμ analysis identifies μ track using a kNN
JINST 11 P09001 (2016)
8
νe
Arbitrary units
(True - Reco)/True
1 − 0.5 − 0.5
A.U. (Area normalized) FD MC CC
µ
ν Bkgd. Total
NOvA Simulation
νμ CC: Eν = Eμ + Ehad ΔEν ~ 9% Calorimetric (not kinematic) Eν reconstruction νe CC: Eν = f(Ee, Ehad) ΔEν ~ 11%
(GeV) True q
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
Events
100 200 300 400 500
3
10 ×
GENIE QE (+RPA) Empirical MEC Valencia MEC GENIE RES
NOvA Simulation
9
(GeV)
had
Visible E
0.2 0.4 0.6 0.8 1
Events
20000 40000 60000
NOvA ND Data MEC QE RES DIS Other
P.O.T.
20
10 × 2.85
NOvA Preliminary
(GeV)
had
Visible E
0.2 0.4 0.6 0.8 1
Events
20000 40000 60000
NOvA ND Data QE RES DIS Other P.O.T.
20
10 × 2.85
NOvA Preliminary
GENIE 2.12.2 with the following modifications:
deuterium data
(Phys. Rev. D 88, 113007) Non-RES 1π ✕ 0.5 First Analysis Second Analysis ND νμ CC ND νμ CC
Utilize GENIE’s standard systematics suite:
NOνA specific uncertainties:
(R. Gran, arXiv:1705.02932)
1.7 < W < 3.0 GeV
10 Hadronic Energy Fraction
0.2 0.4 0.6 0.8 1
Events
0.02 0.04 0.06 0.08 0.1 0.12 0.14
6
10 × Simulated Selected Events Simulated Background Data
σ Shape-only 1- MC mean: 0.31 GeV Data mean: 0.31 GeV POT
20
10 × ND area norm., 8.09
A Preliminary ν NO
ND νμ CC
DIS MEC
(GeV) True q
0.2 0.4 0.6 0.8 1 1.2
Arbitrary units
Empirical MEC QE q →
RES q →
NOvA Simulation
(GeV)
ν
E
2 4 6 8
`Shape' ratio to Empirical MEC
0.5 1 1.5 2 2.5 3
Nieves et al. MEC (GENIE) Martini et al. MEC (PRC 80, 065501) Megias et al. MEC (PRD 94, 093004) Uncertainty envelope
València via GENIE vs. SuSA-MEC via PRC94, 054610
np np+nn ≤ 0.9
11
The MEC q0 shape is the largest cross section systematic in the 2017 νμ disappearance and νe appearance results:
12 (GeV) True q
0.2 0.4 0.6 0.8 1 1.2
Arbitrary units
Empirical MEC QE q →
RES q →
NOvA Simulation
|
Δm
2 L
4 E |= π 2
sin
22θ
(GeV) True q
0.2 0.4 0.6 0.8 1
P.O.T.
20
10 × Events / 9
5000 10000 15000 20000 25000
Far Detector CC MEC only
µ
ν True All MEC uncertainties
NOvA Simulation
(GeV) True q
0.2 0.4 0.6 0.8 1
Ratio
1 2 3 4 5
Near Detector
13 (GeV) True q
0.2 0.4 0.6 0.8 1 1.2
Arbitrary units
Empirical MEC QE q →
RES q →
NOvA Simulation
|
Δm
2 L
4 E |= π 2
sin
22θ
(GeV) True q
0.2 0.4 0.6 0.8 1
P.O.T.
20
10 × Events / 9
5000 10000 15000 20000 25000
Far Detector CC MEC only
µ
ν True All MEC uncertainties
NOvA Simulation
(GeV) True q
0.2 0.4 0.6 0.8 1
Ratio
1 2 3 4 5
(GeV) True q
0.2 0.4 0.6 0.8 1
P.O.T.
20
10 × Events / 9
5 10 15 20 25
Far Detector CC MEC only
µ
ν True All MEC uncertainties
NOvA Simulation
(GeV) True q
0.2 0.4 0.6 0.8 1
Ratio
1 2 3 4 5
The MEC q0 shape is the largest cross section systematic in the 2017 νμ disappearance and νe appearance results:
in True Eν Bins
Systematic shifts affect 2-6 1 2 3 4 6 5
14
Nfar(Ereco
ν
) = Posc(Etrue
ν
) × Φ(Etrue
ν
) × (Etrue
ν
, A) × R(Etrue
ν
) × ✏(...) Nnear(Ereco
ν
) = Φ(Etrue
ν
) × (Etrue
ν
, A) × R(Etrue
ν
) × ✏(...)
ND data + extrapolation leverages ND ↔ FD correlations in constraining the FD prediction
15
16
Reconstructed neutrino energy (GeV)
1 2 3 4 5
Ratio to nominal MC
0.8 0.9 1 1.1 1.2
σ ± FD shift MaCCRES σ ±
NOvA Simulation
Reconstructed neutrino energy (GeV)
1 2 3 4 5
Residual difference (%)
10 − 5 − 5 10
shift in MaCCRES FD minus ND σ + shift in MaCCRES FD minus ND σ
shift’s effect in the FD
νμ CC Selection νμ CC Selection Residual
Reconstructed neutrino energy (GeV)
1 2 3 4 5
Ratio to nominal MC
0.7 0.8 0.9 1 1.1 1.2 1.3
σ ± FD shift MEC q0 shape σ ±
NOvA Simulation
Reconstructed neutrino energy (GeV)
1 2 3 4 5
Residual difference (%)
10 − 5 − 5 10
shift in MEC q0 shape FD minus ND σ + shift in MEC q0 shape FD minus ND σ
17
shift’s effect in the FD
νμ CC Selection νμ CC Selection Residual
18
100 200 300
3
10 ×
Reconstructed Neutrino Energy (GeV)
1 2 3 4 5
ν
/ E
had.
E
0.2 0.4 0.6 0.8 1
Quantile 1 Quantile 2 Quantile 3 Quantile 4
19
Reconstructed Neutrino Energy (GeV)
1 2 3 4 5
Events / 0.1 GeV
20 40 60
310 × Simulated Selected Events Simulated Background Data
σ Full 1- POT
2010 × ND POT norm., 8.09
A Preliminary ν NO
Reconstructed Neutrino Energy (GeV)
1 2 3 4 5
Events / 0.1 GeV
10 20 30 40 50
310 × Simulated Selected Events Simulated Background Data
σ Full 1- POT
2010 × ND POT norm., 8.09
A Preliminary ν NO
Reconstructed Neutrino Energy (GeV)
1 2 3 4 5
Events / 0.1 GeV
10 20 30 40
310 × Simulated Selected Events Simulated Background Data
σ Full 1- POT
2010 × ND POT norm., 8.09
A Preliminary ν NO
Reconstructed Neutrino Energy (GeV)
1 2 3 4 5
Events / 0.1 GeV
20 40 60
310 × Simulated Selected Events Simulated Background Data
σ Full 1- POT
2010 × ND POT norm., 8.09
A Preliminary ν NO
POT Normalized
Quantile 1 ΔEν ~ 6% Quantile 2 ΔEν ~ 8% Quantile 4 ΔEν ~ 12% Quantile 3 ΔEν ~ 10%
νμ CC νμ CC νμ CC νμ CC
20
Area Normalized
Reconstructed Neutrino Energy (GeV)
1 2 3 4 5
Events / 0.1 GeV
20 40 60
310 × Simulated Selected Events Simulated Background Data
σ Shape-only 1- MC mean: 1.71 GeV Data mean: 1.71 GeV POT
2010 × ND area norm., 8.09
A Preliminary ν NO
Reconstructed Neutrino Energy (GeV)
1 2 3 4 5
Events / 0.1 GeV
10 20 30 40
310 × Simulated Selected Events Simulated Background Data
σ Shape-only 1- MC mean: 1.74 GeV Data mean: 1.73 GeV POT
2010 × ND area norm., 8.09
A Preliminary ν NO
Reconstructed Neutrino Energy (GeV)
1 2 3 4 5
Events / 0.1 GeV
10 20 30 40
310 × Simulated Selected Events Simulated Background Data
σ Shape-only 1- MC mean: 1.76 GeV Data mean: 1.75 GeV POT
2010 × ND area norm., 8.09
A Preliminary ν NO
Reconstructed Neutrino Energy (GeV)
1 2 3 4 5
Events / 0.1 GeV
20 40 60
310 × Simulated Selected Events Simulated Background Data
σ Shape-only 1- MC mean: 1.76 GeV Data mean: 1.77 GeV POT
2010 × ND area norm., 8.09
A Preliminary ν NO
Quantile 1 ΔEν ~ 6% Quantile 2 ΔEν ~ 8% Quantile 4 ΔEν ~ 12% Quantile 3 ΔEν ~ 10%
νμ CC νμ CC νμ CC νμ CC
21
extrapolation further constrains the FD prediction
Reconstructed neutrino energy (GeV)
1 2 3 4 5
Ratio to nominal MC
0.8 0.9 1 1.1 1.2
σ ± FD shift RPA shape: supp σ ±
NOvA Simulation Q1
νμ CC Selection ND MC sample extrapolated as a whole Residual
Quantile 1
Reconstructed neutrino energy (GeV)
1 2 3 4 5
Ratio to nominal MC
0.8 0.9 1 1.1 1.2
σ ± FD shift RPA shape: supp σ ±
NOvA Simulation Q1
νμ CC Selection ND MC sample extrapolated in resolution bins Residual
Quantile 1
Signal uncertainty (%)
20 − 10 − 10 20 Statistical error Total syst. error Extrapolation Detector Response Beam Calibration Normalization Cross Sections ν
Background uncertainty (%)
30 − 20 − 10 − 10 20 30 Statistical error Total syst. error Beam Extrapolation Detector Response Normalization Calibration Cross Sections ν
)
10 × (
23
θ
2
Uncertainty on sin
50 − 50 Statistical error Total syst. error
CPδ Value of Scintillation Model Scale
µNeutrino Flux
Scale
µNormalization Cross Sections
)
2
eV
10 × (
2 32
m ∆ Uncertainty on
0.05 − 0.05 Statistical error Total syst. error Scale
µNeutrino Flux Scintillation Model Scale
µNormalization
CPδ Value of Cross Sections
Largest cross section systematics for NOνA 2017 oscillation results: MEC q0 Shape, CC RES MA & MV, RES RPA
22
Cross section uncertainties becoming more important with
Continue to apply constraints from new cross section measurements, including those from NOνA In the process of binding alternate generators (NEUT, GiBUU) to NOvA software framework to study impact of models not in GENIE
23
24
NOνA joint neutrino-antineutrino results planned for Summer 2018 Improvements to cross section tune and uncertainties for NOνA Summer 2018 results:
QE, RES shifts
comparison
25
NOνA Collaboration Austin, TX Feb 2018
26
Total Observed 126 Best fit prediction 129 Cosmic Bkgd. 5.82 Beam Bkgd. 3.46 Unoscillated 763
23
θ
2
sin
0.4 0.5 0.6 0.7
)
2
eV
(10
32 2
m ∆
2 2.2 2.4 2.6 2.8 3 3.2
NOvA Preliminary
Normal Hierarchy 90% C.L. POT-equiv.
20
10 × NOvA 8.85 T2K 2016 MINOS 2014 Joint analysis
∆m2
32 = 2.444+0.079 −0.077 × 10−3 eV2
sin2 θ23 = ( UO: 0.558+0.041
−0.033
LO: 0.475+0.036
−0.044
27
POT-equiv
20
10 × Events / 8.85
5 10 15 20
NOvA Preliminary
FD data Best Fit prediction Total Background Cosmic Background Low PID
High PID
Core Peripheral
Reconstructed Neutrino Energy (GeV)
1 2 3 4 1 2 3 4 1 2 3 4 FD data Best Fit prediction Total Background Cosmic Background
28
Total Observed 66 Signal Prediction 20-48 Cosmic Bkgd. 4.9 Beam Bkgd. 15.6 Unoscillated 20.5
CP
δ
23
θ
2
sin
0.3 0.4 0.5 0.6 0.7 2 π π 2 π 3 π 2
NOvA Preliminary
σ 1 σ 2 σ 3 Best Fit NH
CP
δ
23
θ
2
sin
0.3 0.4 0.5 0.6 0.7 2 π π 2 π 3 π 2
NOvA Preliminary
σ 1 σ 2 σ 3 IH
CP
δ ) σ Significance (
1 2 3 4 5 2 π π 2 π 3 π 2
NOvA Preliminary
NH Upper octant NH Lower octant IH Upper octant IH Lower octant*
POT equiv.
20
10 × 8.85 NOvA FD
greater than 3σ.
29
Year
2016 2018 2020 2022 2024
)
2
χ ∆ = σ Significance (
1 2 3 4 5 =0.082
13
θ 2
2
, sin
2
eV
10 × =2.45
32 2
m ∆ =0.500
23
θ
2
/2, sin π =3
CP
δ Normal
and analysis improvements All projected beam intensity
NOvA Simulation
µ
ν +
e
ν NOvA joint Hierarchy CPV
Total events - neutrino mode
20 40 60 80
Total events - antineutrino mode
10 15 20 25 30
NOvA Simulation
= 0
CP
δ /2 π =
CP
δ π =
CP
δ /2 π = 3
CP
δ
2
eV
10 × 2.51 − =
2 32
m ∆ IH
2
eV
10 × 2.45 + =
2 32
m ∆ NH =0.082
13
θ 2
2
sin =0.47,0.56
23
θ
2
sin NOvA FD ) ν POT (
20
10 × 9.49 ) ν POT (
20
10 × 8.1 prediction 2017 best fit
30
31
Reconstructed Neutrino Energy (GeV)
20
10 × Events / 8.09
3
10
1 2 3 4 5
Low PID
High PID
1 2 3 4 1 2 3 4 1 2 3 4
ND Data NC CC
µ
ν
e
ν Beam Uncorrected MC
Data-driven estimates of νe backgrounds at the ND:
contained & uncontained νμ CC events
32
tify muons in reconstructed tracks using a kNN
Track length, dE/dx, scattering, fraction of track-only planes
Quality and preselection cuts (analysis specific)
νμ analysis identifies μ track using a kNN:
For both νμ and νe analyses, cosmics at FD reduced from ~106 to <10 by
33
Comparison to Previous Results
97
23
θ
2
sin
0.4 0.5 0.6 0.7
)
2
eV
(10
32 2
m ∆
2 2.2 2.4 2.6 2.8 3 3.2
NOvA Preliminary
NOvA Normal Hierarchy, 90% C.L. POT-equiv.
20
10 × Joint Analysis, 8.85 Analysis, PRL.118.151802
µ
ν
Previous result: 2.6 σ exclusion of maximal mixing New simulation & calibration: ~1.8 σ
energy resolution and scale.
New selection & analysis: ~0.5 σ
rejection – we have a totally new set of background events.
pseudo-experiments.
New data: ~0.4 σ Final result: 0.8 σ
Includes FC corrections
34
Scintillator Model
Cherenkov light is a small but important component of our scintillator response.
– Particularly for low-energy protons in hadronic showers.
uncertainties, now reduced by an
– Previously accounted for with second order terms in our scintillator model. – Those terms were unusual, so we placed large systematics.
CC events increased from 7% to 9%.
99
35
νμ → νμ: extrapolate in resolution bins νμ → νe signal: extrapolate whole spectrum νe bkgd → νe bkgd: extrapolate components separately
GENIE 2.12.2 with the following modifications:
(GeV) True q
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
Events
100 200 300 400 500
3
10 ×
GENIE QE (+RPA) Empirical MEC Valencia MEC GENIE RES
NOvA Simulation
| (GeV) q Reco |
0.5 1 1.5 2
Events
20000 40000 60000
NOvA ND Data Non MEC With untuned Empirical MEC With tuned Empirical MEC
NOvA Preliminary
36
The MEC q0 shape is the largest cross section systematic in both the newest νμ disappearance and νe appearance results:
37 (GeV) True q
0.2 0.4 0.6 0.8 1 1.2
Arbitrary units
Empirical MEC QE q →
RES q →
NOvA Simulation
1 2 3 4
P.O.T.
20
10 × Events / 9
2000 4000 6000 8000
Near Detector CC MEC only
µ
ν True All MEC uncertainties
NOvA Simulation (GeV)
ν
True E
1 2 3 4
Ratio
0.5 1 1.5 2
|
Δm
2 L
4 E |= π 2
sin
22θ
1 2 3 4
P.O.T.
20
10 × Events / 9
50 100 150
3
10 ×
CC candidates
µ
ν All True MEC only
Near Detector All MEC uncertainties
NOvA Simulation (GeV)
ν
Reco E
1 2 3 4
Ratio
0.8 0.9 1 1.1 1.2
The MEC q0 shape is the largest cross section systematic in both the newest νμ disappearance and νe appearance results:
38 (GeV) True q
0.2 0.4 0.6 0.8 1 1.2
Arbitrary units
Empirical MEC QE q →
RES q →
NOvA Simulation
|
Δm
2 L
4 E |= π 2
sin
22θ