progress in neutrino-nuclear scattering · •current and future long and short baseline...
TRANSCRIPT
Progress in Neutrino-Nuclear Scattering!much ado about ν-A things
Kendall Mahn!Michigan State University
Image from recent workshop on neutrino scattering (NuInt2014)
OutlineTheoretical status Results from MINERvA
What is neutrino scattering?!Why is neutrino nuclear (ν-A) scattering important to oscillation expt’s?!
What is the current state of knowledge about ν-A?
Future experiments
Results from MicroBooNE
2
Talks in this session:
• Charged Current Quasi Elastic (CCQE) and multinucleon processes (2p2h)
Energy transfer!figure from Ref 1
3
Processes in Neutrino Scattering!merely players
W"
2p2h
νµ"
N’,N’"N,"N"
µ�"
"
W"
CCQE
νµ"
N’"N"
µ�"
"
Observable
neutrino (anti)
• muon or electron (+)
• proton (neutron)
Energy transfer!figure from Ref 1
4
Processes in Neutrino Scattering!merely players
• Production of pions, CC1π+/0/- and NC1π+/0/-
W"
νµ""
N"N’"
Δ"π"
CCπ"" µ�""
resonant coherent W"
νµ""
A"
π+"
CCπ"" µ�""
A"
(GeV)νE0 1 2 3 4 5 6
flux
(arb
.)µν
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8T2K off-axis flux
T2K on-axis flux
MiniBooNE flux
A near detector fluxνNO
A fluxνMINER
• Neutrinos probe the V-A nature of the weak interaction
• But, neutrino decay-in-flight beams are not mono-energetic
• Spread of beam is larger than nuclear effects 5
Neutrino Sources and Nuclear Effects!
[Ref 2]
DUNE ~1-10 GeV
• Multiple processes contribute to each observable topology
• CCQE-like observable topology: muon, proton, no pions
• Includes true CCQE, 2p2h, CC1π (pion absorbed in nucleus)
6
Nuclear Effects Example!
W"
CCQE
νµ"
N’"N"
µ�"
"
W"
2p2h
νµ"
N’,N’"N,"N"
µ�"
"
W"
νµ""
N"N’"
Δ"π"
CCπ"" µ�""
• Oscillation depends on energy
• Estimate from hadronic and/or leptonic information
EQE� =
m2p �m�2
n �m2µ + 2m�
nEµ
2(m�n � Eµ + pµ cos �µ)
Why is ν-A important for oscillation expts?!
E⌫
= Eµ
+X
Ehadronic
(GeV)true - EQErecoE
-1 -0.5 0 0.5
Arb
itra
ry U
nit
sCCQE
5)×Nieves multinucleon (
5)×-decay (∆pionless
• Nuclear effects bias true and estimated neutrino energy
muon
hadronic
Neutrino
[Ref 3]
8
• Even with a near detector, critical reliance on model !
• 2p2h feed-down to oscillation peak from [Ref 4]
(GeV)νE0 0.5 1 1.5 2
νFl
ux*E
0
20
40
60
80
100
120
140310×
Multinucleon Feed-down on Oscillated Flux
(GeV)νE0 0.5 1 1.5 2
νFl
ux*E
0
200
400
600
800
1000910×
Multinucleon Feed-down, ND280 Flux
Why is ν-A important for oscillation expts?!
Far detector!Eν - EνQE smearing for Eν=0.8 GeV
Near detector !Eν - EνQE smearing for Eν=0.8 GeV
ND(⌫µ) = �(E⌫)⇥ �(E⌫ , A)⇥ ✏ND
FD(⌫µ) = �(E⌫)⇥ �(E⌫ , A)⇥ ✏FD ⇥ P (⌫µ ! ⌫e)
• Current and future long and short baseline oscillation rely on modeling of neutrino interaction physics even with near detectors. Need:
• Predicted signal, background efficiency, energy estimate for
• Muon and electron neutrinos, and antineutrinos
• But, outstanding QE, 1π puzzles indicate our understanding is incomplete
Path forward: test modern models for processes of interest with a variety of experimental probes
9
Summary of ν-A issues!there is nothing either good or bad, but
thinking makes it so
• Unprecedented experimental information! ArgoNEUT, MicroBooNE, MINERvA, NOvA, T2K
• Range of beam energies, target materials, with neutrinos and antineutrino sources
• Coming soon: new information from neutrons (ANNIE, CAPTAIN)
• Impressive model development in neutrino interaction software programs (GENIE [Ref 5], GiBUU, NEUT, NuWro)
• New alliance between theorists and experimentalists (NuSTEC)
• Next School will be in October 2017
• Subscribe [email protected] (see backup)
10
Recent Progress, Effort in ν-A !The undiscovered country
See posters on interaction
models
• CCQE-like process important for T2K, NOvA, DUNE, Hyper-K, SBL programs
• “QE puzzle”: MiniBooNE results at odds with higher energy measurements, single nucleon models
• New T2K analysis consistent between MiniBooNE: higher QE-like cross section suggestive of presence of nuclear effects, including 2p2h processes
(GeV)νE0 1 2 3 4 5 6
/ nu
cleo
n)2
cm-3
8 (1
0σ
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
NEUT v5.1.4.2
T2K flux (arb units)
MiniBooNE flux (arb units)
MiniBooNE T2K Full T2K Restricted0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
11
New T2K CCQE-like results!
W"
CCQE
νµ"
N’"N"
µ�"
"
W"
2p2h
νµ"
N’,N’"N,"N"
µ�"
"
(GeV)µ
True p0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
nucl
eon
GeV2
cm
-38
10 θ
dpdc
osσ2 d
0
0.2
0.4
0.6
0.8
1
1.2
< 0.80µθ0.70 < true cos < 0.80µθ0.70 < true cos• Detailed information (cross section in muon kinematics) [Ref 6] compared to latest QE and 2p2h models!
• Different energy beams is important, as no complete model yet: !
• MINERvA (higher energy) differential measurement of muon, proton
• ArgoNeuT proton multiplicity
• Antineutrino beams provide complementary information
12
New T2K CCQE-like results!
(GeV)µ
True p0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
nucl
eon
GeV2
cm
-38
10 θ
dpdc
osσ2 d
0
0.2
0.4
0.6
0.8
1
1.2
< 0.80µθ0.70 < true cos < 0.80µθ0.70 < true cos
(GeV)µ
True p0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
nucl
eon
GeV2
cm
-38
10 θ
dpdc
osσ2 d
00.10.20.30.40.50.60.70.80.9
1 < 0.00µθ-1.00 < true cos
Data: shape uncertaintyFlux normalization uncertaintyMartini et alNieves et al
Analysis I
< 0.00µθ-1.00 < true cos
(GeV)µ
True p0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
nucl
eon
GeV2
cm
-38
10 θ
dpdc
osσ2 d
00.10.20.30.40.50.60.70.80.9
1 < 0.00µθ-1.00 < true cos
Data: shape uncertaintyFlux normalization uncertaintyMartini et alNieves et al
Analysis I
< 0.00µθ-1.00 < true cos (GeV)µ
True p0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
nucl
eon
GeV2
cm
-38
10 θ
dpdc
osσ2 d
00.10.20.30.40.50.60.70.80.9
1 < 0.00µθ-1.00 < true cos
Data: shape uncertaintyFlux normalization uncertaintyMartini et al (w/o 2p2h)Martini et al
Analysis I
< 0.00µθ-1.00 < true cos
• CC inclusive selection, use estimate of available energy from all charged particle tracks (proton, pion, muon) [Ref 7]
• 2p2h model not “enough”: new experimental way to test model13
Novel MINERvA Test of Nuclear Effects!
Similar analysis soon
from NOvA
• Important background (and signal) process for oscillation (non-standard) physics
• Challenge to reconcile low energy and MiniBooNE and higher energy MINERvA data
• NOMAD also sees disagreements in production of backward going pions
• Challenge to reconcile pion and muon kinematics within same model for MiniBooNE
14
Single Pion Production Puzzles!a madness most discreet
Brand new MINERvA update
[Ref 8]
W"
νµ""
N"N’"
Δ"π"
CCπ"" µ�""
!
• T2K pion production predominantly from delta
• Pion production on T2K mostly from Δ resonance
• First differential measurement on water [Ref 9]
• T2K carbon, water measurements consistent: 2σ lower than GENIE prediction
15
New T2K CCπ+ results on water!
• Observation of coherent ν-C scattering from MINERvA [Ref 10]
• New T2K measurements
off-axis: 2.2σ excess over background, consistent with and lower than current models [Ref 11]
on-axis: 1.7σ excess over background, suppression at high pion angle like MINERvA [Ref 12] 16
Coherent Pion Production!Success!
Detection and modeling of rare
process
T2K preliminary
• New measurement from NOvA for νe interactions on scintillator (carbon) [Ref 13]
• Measurement also from MINERvA [Ref 14]: Sets scale of different νe/νμ nuclear effects of <15-30% 17
Electron Neutrino Interactions!
• NCπ0 is a background to νe appearance searches
• Challenge to reconcile MiniBooNE NC and CC π0/+ production within same model
• Evidence for NC diffractive π0 seen by MINERvA [Ref 15]
• Proof-of-concept LAr NCπ0 measurement from ArgoNeuT [Ref 16]
18
Neutral Current Measurements!
MicroBooNE, NOvA soon!
• Flux changes across on-axis T2K detector due to off-axis effect
• Compare nearby detectors to infer cross section using known flux properties
• Results [Ref 17] on iron target consistent with NEUT, GENIE
(GeV)E0 1 2 3 4
p.o.
t.)21
/50M
eV/1
02
Flux
(/cm
0
0.5
1
1.5
1210!
Module 3Module 2Module 1Module 0
!
" #
$%&'()*+%,
-*./
!
!"
# $%
& '!"
!!
(
!'
!"
)
!&
(GeV)νE0 1 2 3 4 5 6 7
/nucl
eon)
2 (
cmσ
0
10
20
30
40
50-3910×
p.o
.t.)
21
/50
MeV
/10
2 f
lux
(/c
mµ
ν
0
500
1000
1500
910×
MINOSNEUTGENIENEUT flux averageGENIE flux average
T2K INGRID
T2K INGRID flux ave.
19
Novel T2K CC Inclusive Results!
• Nuclear effects in neutrino interactions are important for the current and future oscillation physics program: all depend on model
• New measurements from current experiments (ArgoNeuT, MINERvA NOvA and T2K) facing current puzzles in QE, 1π physics
• Complementary datasets at different beam energies being compared to the modern models; novel experimental techniques
• Coherent picture emerging in CC coherent pion scattering
• New measurements of νe interactions, new information for NC
• MicroBooNE coming online, and new information soon on neutron yields from neutrino interactions (ANNIE, CAPTAIN)
20
Summary !O brave ν world, that has such people in't!
Thank you to the organizers for the invitation!
Please check out the wealth of posters on neutrino cross sections!
Special thanks:
L. Fields (MINERvA) J. Paley, M. Muther (NOvA) S. Bolognesi, C. Wilkinson (T2K)
References can be found in backup slides
21
Backup slides
22
References1. B Foris, and C N Papanicolas, Electron Scattering and Nuclear Structure
http://www.annualreviews.org/doi/pdf/10.1146/annurev.ns.37.120187.001025
2. Fluxes from:
1. T2K off-axis: official, http://t2k-experiment.org/publications/the-t2k-neutrino-flux-prediction/
2. T2K on-axis: not official, digitized from http://arxiv.org/abs/1509.06940
3. MINERvA: not official, from this analysis http://arxiv.org/pdf/1406.6415v3.pdf
4. NOvA: not official, digitized from https://arxiv.org/abs/1511.00287 Fig 3
3. Plot from T2K: Phys. Rev. Lett. 112, 181801 (2014) http://arxiv.org/abs/1403.1532
23
References4. NuPRISM LOI; http://arxiv.org/abs/1412.3086
5. New GENIE v.2.10 manual: http://arxiv.org/pdf/1510.05494v1.pdf
6. T2K CC0π, accepted by PRD, http://arxiv.org/abs/1602.03652
7. MINERvA nuclear effects, Phys. Rev. Lett. 116, 071802 (2016), https://arxiv.org/abs/1511.05944. Plot from NuINT talk.
8. MINERvA CC1π+, Phys.Rev. D92, 092008 (2015). https://arxiv.org/pdf/1406.6415v3.pdf
24
References9. T2K CC1π+ on water, submitted to PRD, http://arxiv.org/abs/1605.07964
10. MINERvA CC coherent pion prod, Phys. Rev.Lett. 113, 261802 (2014). http://arxiv.org/abs/1409.3835
11.T2K ND280 CC coherent pion: http://arxiv.org/pdf/1604.04406v1.pdf, submitted to PRD
12.T2K INGRID CC coherent pion: plot from NuInt2015 talk: http://indico.ipmu.jp/indico/getFile.py/access?contribId=34&sessionId=7&resId=0&materialId=slides&confId=46
13.NOvA νe: Wine and Cheese FNAL seminar: http://theory.fnal.gov/jetp/talks/nova_20160226.pdf
14.MINERvA νe: Phys. Rev. Lett 116, 081802 (2016) http://arxiv.org/abs/1509.05729
25
References!
15. MINERvA diffractive π0, submitted to PRL; https://arxiv.org/abs/1604.01728
16.ArgoNEUT NCπ0 http://arxiv.org/abs/1511.00941
17.T2K CC inclusive result: Phys. Rev. D 93, 072002 (2016), http://arxiv.org/abs/1509.06940
26
To subscribe to NuSTEC news list
1. Send an e-mail to [email protected]
2. Leave the subject line blank
3. Type "subscribe nustec-news firstname last name" (without the qutation marks) in the body
27
Status of neutron measurements from neutrinos
• ANNIE: first measurements of abundance of final state neutrons from neutrino-oxygen interactions **ref
• Uses Gd doped water and Large Area Picosecond Photosensor Detectors
• Currently making background measurements
• CAPTAIN: measure response of LAr detectors to neutrons, rate of n from nu-Ar
• Mini-CAPTAIN: operating in neutron beam
28