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Recent results from MINERvA
Jonathan Miller for the MINERvA Collaboration Universidad Tecnica Federico Santa Maria
1 PANIC NOW
OutlineIntroduction to MINERvA
Recent important results:
charged pion production
coherent pion production
inclusive charged current scattering
quasi-elastic scattering arXiv:1305.2243 and arXiv:1305.2234
Conclusions and Future
2
MINERvA Collaboration
David"Schmitz,"UChicago" Fermilab"Joint"Experimental=Theore?cal"Seminar"="May"10,"2013" 25"
MINERνA"More than just a detector…"
~80"collaborators"from"par?cle"and"nuclear"physics""
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 University of Chicago
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
• Located underground at Fermilab, near Chicago USA.
• Institutions from 9 countries with over 60 collaborators.
David"Schmitz,"UChicago" Fermilab"Joint"Experimental=Theore?cal"Seminar"="May"10,"2013" 25"
MINERνA"More than just a detector…"
~80"collaborators"from"par?cle"and"nuclear"physics""
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 University of Chicago
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
3
NuMI Beam
4
figure courtesy Z. Pavlović
• 120 GeV/c protons from Main Injector.
• Graphite target • ME run started
September 2013.
Backup
MINERvA Detector
6Nucl. Inst. and Meth. A743 (2014) 130
• 120 modules for tracking and colorimetry (32k readout channels) • Completion in Spring 2010,. • The MINOS near detector serves as a muon spectrometer.
Neutrino Event Generator (GENIE)
Includes a lot of physics: electron scattering, final state interaction (FSI) models, and nuclear physics models
Provides framework for realising physics analysis for neutrino (especially oscillation) experiments
NOvA, IceCube, MINERvA
7
D. Schmitz
Neutrino Energy (GeV)1 10
/ per
nuc
leus
2 c
mσ
0246810121416182022
-3910×
MINERvA <A> =12 <A> =121SciBooNE
<A> =122K2K <A> =123T2K
<A> =204BEBC II <A> =215CHARM
<A> 306SKAT <A> =407ArgoNeuT
v2.6.29GENIE
+ A+π + -µ → + A µν
43August 1st, 2014
Coherent Cross Section
[1] SciBooNE Collaboration (K. Hiraide et al.), Phys. Rev. D 78, 112004 (2008) [2] K2K Collaboration (M. Hasegawa et al.), Phys. Rev. Lett. 95, 252301 (2005) [3] T2K Collaboration NuInt 2014 preliminary result [4] BEBC WA59 Collaboration (P. Marage et al.), Z. Phys. C 31, 191 (1986) [5] CHARM II Collaboration (P. Vilain et al.), Phys. Lett. B 313, 267 (1993)
[6] SKAT Collaboration (H.J. Grabosh et al.), Z. Phys. C 31, 203 (1986) [7] ArgoNeuT Collaboration NuInt 2014 preliminary result [8] BEBC WA59 Collaboration (P. Marage et al.), Z. Phys. C 43, 523 (1989) [9] GENIE Collaboration (C. Andreopoulos et al.), Nucl. Instrum. Methods A 614, 87 (2010)
Neutrino Energy (GeV)1 10
/ per
nuc
leus
2 c
mσ
0246810121416182022
-3910× + A-π + +µ → + A µν
MINERvA <A> =12
<A> =208BEBC
II <A> =215CHARM
<A> =306SKAT
<A> =407ArgoNeuT
v2.6.29GENIE
A. Higuera, Joint Experimental-Theoretical Physics Seminar
Why understand ⌫A cross sections?
I For ⌫ oscillations, infer P⌫↵!⌫� (E⌫) from measured Nevt, kinematicsI Eg, T2K ⌫µ spectrum at SuperK:
Energy (GeV)ν Reconstructed 0 1 2 3 4 5
0
0.5
1
1.5 MC Best-fit
Rat
io t
o n
oosc
illa
tions
>
0 1 2 3 4 5
Even
ts/0
.10 G
eV
0
2
4
6
8
10
12
14
16
DATA CCQEµν+µν
CC non-QEµν+µν
CCeν+eν
NC
0
arXiv:1403.1532 and Patrick de Perio’s talk
���•� 2
Phys. Rev. Lett. 112, 181801, 2014
T2K
Results: Charged Pion Production
3.04e20 POT neutrinos
8
Publication forthcoming on arXiv:1406.6415
p(n)
⌫µ µ
�
W
⇡
p(n)
Event selection
Events contain one muon matched in MINOS.
Events contain at least one hadron track.
Only tracks which stop in the Ecal or tracker region are accepted.
Pions are identified by dE/dx, and the existence of a Michel electron at the end of the pion track.
9
Proton Score 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Eve
nts
0
5
10
15
20
25310×
Data
Coh Pion
Pion
Proton
Other
A PreliminaryνMINER
POT Normalized3.05e+20 POT
+ A+π + -µ → + A µν
Proton Score 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Eve
nts
0
1
2
3
4
5
6
310×Data
Coh Pion
Pion
Proton
Other
A PreliminaryνMINER
POT Normalized2.01e+20 POT
+ A-π + +µ → + A µν
Resultsn pions 1 pion 1 pion
10
MC
scal
ed by
0.70
Take awayMeasurements constrains interaction rate and final state interactions in pion production.
The contribution from Final State Interaction (FSI) is significant.
Needed to improve signal and background predictions for oscillation experiments.
Agreement with GENIE.
11
Results: Coherent Pion Production
12
Publication forthcoming
3.04e20 POT neutrinos 2.01e20 POT antineutrinos
A
q2
t
A
W+_
μ+_
π+_
νμ
( )_
Existence of pion and muon with no nucleon breakup (quiet vertex) and low momentum
transferred between nucleus and pion.
Event selection
2 (GeV/c)2)π
Reconstructed |t| = (q-p0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
2Ev
ents
/ 0.
025
(GeV
/c)
0
0.2
0.4
0.6
0.8
1
310×DATACOHQERES W<1.41.4<W<2.0W> 2.0Other
A PreliminaryνMINER
POT Normalized3.05e+20 POT
All Background Tuned
+ A+π + -µ → + A µν
2 (GeV/c)2)π
Reconstructed |t| = (q-p0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
2Ev
ents
/ 0.
025
(GeV
/c)
0
0.2
0.4
0.6
0.8
1
1.2310×
Data
Monte Carlo
Tuned Bkgd
A PreliminaryνMINERPOT Normalized3.05e+20 POT
+ A+π + -µ → + A µν
2 (GeV/c)2)π
Reconstructed |t| = (q-p0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
2Ev
ents
/ 0.
025
(GeV
/c)
0
100
200
300
400
500
600
700 DATACOHQERES W<1.41.4<W<2.0W> 2.0Other
A PreliminaryνMINER
POT Normalized2.01e+20 POT
All Background Tuned
+ A-π + +µ → + A µν
2 (GeV/c)2)π
Reconstructed |t| = (q-p0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
2Ev
ents
/ 0.
025
(GeV
/c)
0
100
200
300
400
500
600
700 Data
Monte Carlo
Tuned Bkgd
A PreliminaryνMINERPOT Normalized2.01e+20 POT
+ A-π + +µ → + A µν
antineutrino neutrino
13
• Events have almost no vertex energy.
• Separation of coherent scattering from incoherent background by slope of |t| due to the slope being different for diffractive and resonant processes.
• Sideband is selected as the incoherent background, is tuned to MC to minimize χ2
Results: Cross section
w/r to Beam (Degrees)πθ
0 10 20 30 40 50 60 70 80 90
)12
/Deg
ree/
C2
(cm
πθdσd
0
0.05
0.1
0.15
0.2-3910×
A PreliminaryνMINER
POT Normalized3.05e+20 POT
+ A+π + -µ → + A µν
DATAGENIE v2.6.2
Neutrino Energy (GeV) 0 2 4 6 8 10 12 14 16 18 20
)12
/C2 (c
mσ
0
5
10
15
20
25-3910× + A+π + -µ → + A µν
A PreliminaryνMINER
POT Normalized3.05e+20 POT
DATAGENIE v2.6.2
Pion Energy (GeV) 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
)12
/GeV
/C2
(cm
πdEσd
00.5
11.5
22.5
33.5
44.5
-3910×A PreliminaryνMINER
POT Normalized3.05e+20 POT
+ A+π + -µ → + A µν
DATAGENIE v2.6.2
14
Pion Energy (GeV) 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
)12
/GeV
/C2
(cm
πdEσd
00.5
11.5
22.5
33.5
44.5
-3910×A PreliminaryνMINER
POT Normalized2.01e+20 POT
+ A-π + +µ → + A µν
DATAGENIE v2.6.2
Neutrino Energy (GeV) 0 2 4 6 8 10 12 14 16 18 20
)12
/C2 (c
mσ
0
5
10
15
20
25-3910× + A-π + +µ → + A µν
A PreliminaryνMINER
POT Normalized2.01e+20 POT
DATAGENIE v2.6.2
w/r to Beam (Degrees)πθ
0 10 20 30 40 50 60 70 80 90
)12
/Deg
ree/
C2
(cm
πθdσd
0
0.05
0.1
0.15
0.2-3910×
A PreliminaryνMINER
POT Normalized2.01e+20 POT
+ A-π + +µ → + A µν
DATAGENIE v2.6.2
antin
eutr
inone
utrin
o
Take awayData shows a harder and more forward pion distribution than GENIE.
The selection of low |t| events allows a model independent measurement of coherent pion production.
Can be used to set systematic for oscillation experiments.
In the NuMI ME configuration, multiple passive targets (Pb, Fe, C) will allow a measurement of A dependence.
15
Results: Inclusive Charged Current
Scattering
Published arXiv:1403.2103
16
2.94e20 POT neutrinos
Reconstructed Bjorken x-110 1
2 (G
eV/c
)2
Rec
onst
ruct
ed Q
-110
1
10
0
100
200
300
400
500
600
700
800
W = 1.3 GeVW = 2 GeV
Data
Event SelectionEvents must have a muon in MINOS.
Target vertex must be in passive target or neighbouring scintillator.
Neutrino energy between 2 and 20 GeV.
Muon angle < 17 deg.
17
Adjusted Vertex Z (cm)450 500 550 600 650 700 750 800 850
N E
vent
s / M
odul
e
0
2
4
6
8
10
12
14
310×
DataCarbonIronLeadScintillator
Each Bunch Area-Normalized
True Event Origins - Reconstructed Vertex ZTarget 2
Target 5Target 4
Target 3
Gives MINOS acceptance (restricts kinematics). Gives estimate of contamination from scientillator.
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
Ratio Results
18
No tension between data and MC Te
nsion
betw
een d
ata a
nd M
C
Neutrino Energy (GeV)2 4 6 8 10 12 14 16 18 20
CH
σ / C
σ
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5DataSimulation/ndf = 11.31/8 = 1.412χ
CHσ : CσRatio of
Neutrino Energy (GeV)2 4 6 8 10 12 14 16 18 20
CH
σ /
Feσ
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5DataSimulation/ndf = 9.76/8 = 1.222χ
CHσ : FeσRatio of
Neutrino Energy (GeV)2 4 6 8 10 12 14 16 18 20
CH
σ /
Pbσ
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5DataSimulation/ndf = 5.03/8 = 0.632χ
CHσ : PbσRatio of
Reconstructed Bjorken x0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
dxCH
σd /
dxC
σd
0.8
1.0
1.2
1.4
1.6
1.8
2.0
DataSimulation
/ndf = 6.05/6 = 1.012χ dx
CHσd : dxCσdRatio of
Reconstructed Bjorken x0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
dxCH
σd /
dxFe
σd
0.8
1.0
1.2
1.4
1.6
1.8
2.0
DataSimulation
/ndf = 25.87/6 = 4.312χ dx
CHσd : dxFeσdRatio of
Reconstructed Bjorken x0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
dxCH
σd /
dxPb
σd
0.8
1.0
1.2
1.4
1.6
1.8
2.0
DataSimulation
/ndf = 58.46/6 = 9.742χ dx
CHσd : dxPbσdRatio of
Take awayThis is not deep inelastic scattering.
Theory input needed!
Data is not reproduced by simulation.
Can be used to improve estimate of systematic for oscillation experiments.
Unexpected excess at high x and deficit at low x points to improvements needed in models ( fermi motion + ? and shadowing).
19
Reconstructed Bjorken x-110 1
2 (G
eV/c
)2
Rec
onst
ruct
ed Q
-110
1
10
0
100
200
300
400
500
600
700
800
W = 1.3 GeVW = 2 GeV
Data
Results:Quasi-Elastic Scattering
Published in PRL and arXiv:1305.2243 and arXiv:
1305.2234
3.98e20 POT neutrinos 1.70e20 POT antineutrinos
⌫µ
p(n)
µ
W
n(p)
Event Selection, Results and Take away
Simple event selection requires single track with matching track in MINOS.
Requires no more than 1(2) additional blobs for anti-ν(ν)
Basic relativistic fermi gas model disfavored.
Increasing axial mass disfavored.
Conclusions and FutureMINERvA is important in developing neutrino generators (GENIE), required for oscillation experiments.
MINERvA ME data run has begun.
Possibilities to extend the MINERvA program.
Many analyses in progress, expect CCPi0, K production, NuE elastic in the coming months.
Some results show broad agreement with model predictions and others significant disagreement. No need to PANIC, NOW we have observation.
22
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