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Neutrino Shadow Play– Neutrino interactions for oscillation measurements

Xianguo LU / 卢显国 University of Oxford

INT-18-1a: Nuclear ab initio Theories and Neutrino PhysicsSeattle, 9 March 2018

皮影 Shadow playSource: http://www.cnhubei.com/ztmjys-pyts

http://www.cnhubei.com/ztmjys-pyts

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THE Universe– Matter & very little antimatter (matter-antimatter asymmetry)

CP-Symmetry violation (CP violation)

Xianguo Lu, Oxford

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v

v

v

Neutrino– Oscillation

https://www.nobelprize.org/nobel_prizes/physics/laureates/2015/

Neutrino mass:shift between interaction and propagation states

Flavor states(interaction states)

Xianguo Lu, Oxford

https://www.nobelprize.org/nobel_prizes/physics/laureates/2015/

4

v


oscillation between flavor states as a function of time

Xianguo Lu, Oxford

https://www.wizardacademy.org/product/pendulum/

v

v

https://www.wizardacademy.org/product/pendulum/

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v

v

v



Xianguo Lu, Oxford

P(v) + P(v

) = 1

6

v

v

v

v

v


P(v) + P(v

) = 1

If only 2 flavors, same oscillation behavior→ CP violation not observed


P(v) + P(v

) = 1

Xianguo Lu, Oxford

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v

v

v

ve

v

v

v

ve

Oscillation property difference → CP violation

Neutrino– CP violation

P(ve) + P(v

) + P(v

) = 1 P(v

e) + P(v

) + P(v

) = 1

oscillation between flavor states as a function of time ~distance/energy

Xianguo Lu, Oxford

*3-flavor paradigm *3-flavor paradigm

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What we measureEvent counts

Final-state kinematics

What we want to know aboutNumber of neutrinos as a function of neutrino energy

The big picture of neutrino detection in oscillation measurements

Nuclear Filter

Xianguo Lu, Oxford

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static nucleon target

Neutrino energy in GeV regiem

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Quasi-elastic scattering (QE)

charged current (CC) → l'

quasi-elastic (QE) N → N'

static nucleon target

N N'

-//e/e+/

/

e/

e

W

Charged-Current Quasi-Elastic(CCQE)

Xianguo Lu, Oxford

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nuclear target(bound nucleon)

Fermi motion biases E reconstruction

Xianguo Lu, Oxford

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Multinucleon correlations: cross section unknown, strong bias to all final-state kinematics

Science 320 (2008) 1476-1478

initial correlation large relative motion

Xianguo Lu, Oxford

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Science 320 (2008) 1476-1478

initial correlation large relative motion

nuclear target(bound nucleons)


Multinucleon correlations: cross section unknown, strong bias to all final-state kinematics

In particle-hole excitation:➔ Impulse approximation: independent particles (1p1h)➔ RPA (random phase approximation): sum of 1p1h

excitation (over all pairs) → “screening effect”➔ npnh (n2): sub-leading terms in ph expansion →

short range correlations, meson exchange currents etc.

Xianguo Lu, Oxford

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Resonance production (RES)

nuclear target


QE-like N → N'including resonance production (RES) → N'followed by absorption


Multinucleon correlations: cross section unknown, strong bias to all final-state kinematicsQE-like: absorbed in nucleus ← final-state interaction (FSI)

N

ee

W

CC1+ via production

Xianguo Lu, Oxford

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nuclear emission

nuclear target



Multinucleon correlations: cross section unknown, strong bias to all final-state kinematicsQE-like: absorbed in nucleus ← final-state interaction (FSI)FSI → energy-momentum transferred in nucleus, possible nuclear emission

QE-like N → N'including resonance production (RES) → N'followed by absorption

Xianguo Lu, Oxford

16Source: http://vmsstreamer1.fnal.gov/VMS_Site_03/VMSFlash/090924Minerva/index.htm

MINERvA

http://vmsstreamer1.fnal.gov/VMS_Site_03/VMSFlash/090924Minerva/index.htm

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Scintillator trackerCharged lepton: seenProton: track

Nucl.Instrum.Meth. 676 (2012) 44-49, Nucl.Instrum.Meth. A743 (2014) 130-159

MINERvA

Xianguo Lu, Oxford

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Nucl.Instrum.Meth. 676 (2012) 44-49, Nucl.Instrum.Meth. A743 (2014) 130-159

Scintillator tracker:Hydrocarbon (CH) targetHomogeneous non-magnetized active tracker

MINERvA

Xianguo Lu, Oxford

19Diagram by M. Betancourt

Energy

20

Rev.Mod.Phys. 84 (2012) 1307-1341

NuMI low energy beam <E

> ~ 3 GeV

L. Fields

21

11C*

n

recoil

Fermi motion

Today's topic:

-p mesonless production MINOSND

Xianguo Lu, Oxford

Observables: ➢ Transverse kinematics imbalances

[XL, L. Pickering, S. Dolan et al., Phys.Rev. C94 (2016) no.1, 015503]➢ Initial neutron momentum

[A. Furmanski, J. Sobczyk, Phys.Rev. C95 (2017) no.6, 065501]

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A brief history of Shadow Art

Cave of Pettakere, Bantimurung district (kecamatan), South Sulawesi, Indonesia. Hand stencils estimated between 35,000-40,000 BP

https://en.wikipedia.org/wiki/Cave_painting

Xianguo Lu, Oxford

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https://en.wikipedia.org/wiki/Cave_painting

Cueva de las Manos located Perito Moreno, Argentina. The art in the cave dates between 13,000-9,000 BP


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https://zh.wikipedia.org/wiki/%E7%9A%AE%E5%BD%B1%E6%88%B2

Traditional Chinese “movie”


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http://www.spoon-tamago.com/2015/08/03/illusionistic-shadow-art-by-shigeo-fukuda/

Japanese modern art


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http://www.spoon-tamago.com/2015/08/03/illusionistic-shadow-art-by-shigeo-fukuda/

Japanese modern art


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Transverse kinematic imbalances– a neutrino shadow play

Xianguo Lu, Oxford

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Source: http://zhejiangpiying.sokutu.com/tupian.html

To make Neutrino Shadow Play, we need ✔ beam of light✔ screen


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To make Neutrino Shadow Play, we need ✔ beam of light → accelerator✔ screen



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To make Neutrino Shadow Play, we need ✔ beam of light → accelerator✔ screen → transverse plane



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Static nucleon target



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Nuclear target


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Nuclear target



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Nuclear targetStatic nucleon target


XL, L. Pickering, S. Dolan et al., Phys.Rev. C94 (2016) no.1, 015503

Convolution of Fermi motion and intra-nuclear momentum transfer due to FSI, resonance production, 2p2h etc.

Xianguo Lu, Oxford

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Nuclear target


XL, L. Pickering, S. Dolan et al., Phys.Rev. C94 (2016) no.1, 015503

Convolution of Fermi motion and intra-nuclear momentum transfer due to FSI, resonance production, 2p2h etc.

Xianguo Lu, Oxford

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EXTENSION: RADICAL SOLUTION TO NUCLEAR EFFECT PROBLEM

Xianguo Lu, Oxford

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Lepton-proton interaction → 3 charged particles: l p → l' X Y– Leading order realization in standard model:

Xianguo Lu, Oxford

XL et al., Phys.Rev. D92 (2015) no.5, 051302

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Xianguo Lu, Oxford


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Xianguo Lu, Oxford


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Xianguo Lu, Oxford


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Double-transverse momentum imbalance pTT

● H: 0 ● Heavier nuclei: irreducible symmetric broadening

● by Fermi motion O(200 MeV)● further by FSI

● CHn: Hydrogen shape is only detector smearing.

● With good detector resolution, hydrogen yield can be extracted. ● With very good res., event-by-event selection of -H interaction is possible.

Phys.Rev. D92 (2015) no.5, 051302

XL et al., Phys.Rev. D92 (2015) no.5, 051302Xianguo Lu, Oxford

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Chin. Phys. C 38, 090001 (2014)

H2

● Pure hydrogen

– Technical requirement: bubble chamber (historical: 73, 79, 78, 82, 86)

– Safety issue: explosive

● “Since the use of a liquid H2 bubble chamber is excluded in the ND hall due to safety concerns, ...” [FERMILAB-PUB-14-022]

● Neutrino interactions on hydrogen:

– In the last ~30 years there has been no new measurement

– Nuclear-effect independent measurement of neutrino energy

Xianguo Lu, Oxford

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arXiv:1512.09042

2better tracking res.

Toy simulation of T2K performance➢ T2K neutrino flux on CH target➢ Realistic detector resolution

Extracting neutrino-hydrogen events from CH targets

Xianguo Lu, Oxford

44https://indico.fnal.gov/event/16205/contribution/3/material/slides/0.pdf

Application in DUNE

Slide from Hongyue Duyang

U. of South Carolina

https://indico.fnal.gov/event/16205/contribution/3/material/slides/0.pdf

45https://indico.fnal.gov/event/16205/contribution/3/material/slides/0.pdf

Application in DUNE

Slide from Hongyue Duyang

U. of South Carolina

Background shape: constrained by multiple nuclear targets, especially carbon (graphite)

https://indico.fnal.gov/event/16205/contribution/3/material/slides/0.pdf

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END OF EXTENSIONBACK TO

NUCLEAR EFFECT MEASUREMENT

Xianguo Lu, Oxford

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A more general analysis of kinematic imbalance

Transverse:

Longitudinal:

New variable:

Neutrino energy is unknown (in the first place), equations are not closed.

A. Furmanski, J. Sobczyk, Phys.Rev. C95 (2017) no.6, 065501

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Transverse:

Longitudinal:

New variable:


Assuming exclusive -p-A' final statesUse energy conservation to close the equations

pn: recoil momentum of the nuclear remnant


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49




11C*

n

For CCQE, A' = 11C*No more unknownsp

n: neutron Fermi motion

recoil

Fermi motion


Transverse:

Longitudinal:

New variable:


Xianguo Lu, Oxford

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Signal definition: ● Charged current● One muon and at least one proton in

the restricted final-state phase space● No mesons

Measurement:Data sample: NuMI low energy neutrino data, 3.281020 POTInteraction target: tracker (mostly CH)

● Event selection● Background estimation and subtraction● Unfolding● Efficiency correction

➢ Flux integrated cross section as results Focus today

Xianguo Lu, Oxford

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Simulation: GENIE [Nucl.Instrum.Meth. A614 (2010) 87-104]

● Nominal: version 2.8.4 ✔ global Fermi Gas (RFG) model with Bodek-Ritchie (BR) tail [Phys. Rev. D 23, 1070 (1981)]✔ hA FSI [AIP Conf.Proc. 1405 (2011) 213-218]

● No-FSI: Nominal without FSI

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● No-FSI: Nominal without FSI● MnvGENIE-v1: GENIE MINERvA Tune (v1) [only 2p2h relevant for this analysis]

➢ Added Random Phase Approximation (RPA) [Phys.Rev. C70 (2004) 055503] ➢ Non-resonance pion production scaled down by 75% [Phys.Rev. D90 (2014) no.11, 112017]➢ Valencia 2p2h [Nieves et al., Phys.Lett. B707 (2012) 72-75, Phys. Rev. C 86, 015504 (2012), Phys.Rev. D88 (2013) no.11,

113007, arXiv:1601.02038] ✔ tuned to MINERvA inclusive data → significant enhancement in small 4-momentum

transfer region [Phys.Rev.Lett. 116 (2016) 071802]

Science 320 (2008) 1476-1478

→ representing energy transfer from the neutrino to the targetXianguo Lu, Oxford

Phys.Rev.Lett. 116 (2016) 071802

53







Detector simulation: GEANT4 (4.9.2)

GENIE used in other experiments (e.g. NOvA, T2K, BooNE, DUNE)

This analysis: GENIE MINERvA Tune (v1) used in cross section extraction

Xianguo Lu, Oxford

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RESULTS: Flux integrated cross section

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Single-Particle Kinematics● Muon momentum, angle

● Good description by GENIE MINERvA Tune (v1)● All predictions have same shape

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● Muon momentum, angle● Proton momentum, angle

Single-Particle Kinematics

● GENIE Nominal and No-FSI have different shape● GENIE MINERvA Tune (v1) excess at high angle

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nuclear emission

nuclear target


nuclear target


FSI decomposition in mesonless proton production:

Proton FSI:● Non-interacting (no change of energy and direction of the proton)● Acceleration: energy of proton increased after FSI● Deceleration: energy of proton decreased after FSI

Pion FSI: pion absorption

Xianguo Lu, Oxford

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● Muon momentum, angle● Proton momentum, angle

Pionless resonant production dominates low angle

Single-Particle Kinematics

Proton FSI acceleration localized at high angle

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NUCLEAR EFFECT DIAGNOSTICS

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11C*

n

recoil

Fermi motion


Transverse:

Longitudinal:

New variable:


Xianguo Lu, Oxford



61

pn is Fermi motion magnitude → “QE peak”

– GENIE No-FSI

● CCQE with Fermi motion

Nuclear Effect Diagnostics

Fermi Gas model prediction

Bodek-Ritchie tail

11C*

n

recoil

Fermi motion

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– GENIE No-FSI– p-FSI Non-interacting



11C*

n

recoil

Fermi motion

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QE peak dominated by CCQE without FSIDirect constraint of Fermi motion





Fermi Gas model prediction

Bodek-Ritchie tail

11C*

n

recoil

Fermi motion

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64

T is Fermi motion direction → isotropic

Fermi motion only

Xianguo Lu, Oxford



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Nuclear Effect Diagnostics● CCQE with Fermi motion


– GENIE No-FSI

Fermi motion only

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Nuclear Effect Diagnostics● CCQE with Fermi motion



Fermi motion only

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Baseline for all non-Fermi motion effectsFactor out Fermi motion uncertaintyComplementary to p

n

Fermi motion only



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With full nuclear effects

pT (nuclear effects)

boosting outgoing proton


dragging outgoing proton

Baseline for all non-Fermi motion effectsFactor out Fermi motion uncertaintyComplementary to p

n

Xianguo Lu, OxfordIntranuclear momentum transfer

69



● CCQE with Fermi motion● FSI deceleration vs. acceleration


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Deceleration at large T

70





Acceleration at both small and (due to transverse projection) large

T


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Only acceleration can enter small T


Xianguo Lu, Oxford


Acceleration at both small and (due to transverse projection) large

T

72



11C*

n

recoil

Fermi motion

Xianguo Lu, Oxford

Acceleration to the left of QE peakStrongly distort QE peak

73




11C*

n

For RES, DIS, 2p2h, no longer exclusive -p-A' final states

recoil

Fermi motion


Transverse:

Longitudinal:

New variable:


Xianguo Lu, Oxford

Fermi motion Intranuclear momentum transfer

74

● CCQE with Fermi motion● FSI deceleration vs. acceleration● Pionless resonant production, pion absorption FSI, and 2p2h


pn: smeared p

T beyond QE peak → tail

– -FSI Absorption

Pion production and 2p2h process: strong intra-nuclear momentum transfer due to momentum sharing with proton

11C*

n

recoil

Fermi motion

Xianguo Lu, Oxford

p small → p large

75



pn: smeared p


– -FSI Absorption– 2p2h

(= MnvGENIE-v1 – GENIE Nominal)

11C*

n

recoil

Fermi motion

Xianguo Lu, Oxford

Pion production and 2p2h process: strong intra-nuclear momentum transfer due to momentum sharing with proton p small → p large

76



GENIE describes the tail reasonably well due to large contribution from 2p2h tuned to MINERvA inclusive measurements

11C*

n

recoil

Fermi motion

Xianguo Lu, Oxford

pn: smeared p


– -FSI Absorption– 2p2h

(= MnvGENIE-v1 – GENIE Nominal)

Pion production and 2p2h process: strong intra-nuclear momentum transfer due to momentum sharing with proton p small → p large

77





Xianguo Lu, Oxford

Proton momentum shared by others, decelerated → large

T region

– -FSI Absorption

78





Proton momentum shared by others, decelerated → large

T region

– -FSI Absorption– 2p2h (= MnvGENIE-v1 – GENIE Nominal)

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ADVANCED TOPICS: GENIE FSIs

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Advanced Topics: GENIE FSIs● (pre2015) hA: effective model, include “elastic component” in intranuclear scattering, used in

GENIE MINERvA Tune (v1)● hA2015: removed “elastic component”, replacing hA in MnvGENIE-v1-hA2015

No p-FSI acceleration

Xianguo Lu, Oxford

81

Advanced Topics: GENIE FSIs

No p-FSI acceleration

● (pre2015) hA: effective model, include “elastic component” in intranuclear scattering, used in GENIE MINERvA Tune (v1)

● hA2015: removed “elastic component”, replacing hA in MnvGENIE-v1-hA2015

Xianguo Lu, Oxford

QE peak not distorted, but much narrower

82

Advanced Topics: GENIE FSIs● (pre2015) hA: effective model, include “elastic component” in intranuclear scattering, used in

GENIE MINERvA Tune (v1)● hA2015: removed “elastic component”, replacing hA in MnvGENIE-v1-hA2015● hN2015: full cascades + Oset, replacing hA in MnvGENIE-v1-hN2015

hA2015 and hN2015 difference in● Large

T (concentrated)

● pn tail (diluted)Xianguo Lu, Oxford

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ADVANCED TOPICS: NUWRO

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84


Simulation: NuWro [Phys.Rev. C86 (2012) 015505]

● Version: 11q ✔ Local Fermi Gas (LFG) or Spectral Function (SF) [Benhar et al., Nucl.Phys. A579 (1994) 493-517]✔ FSI: intranuclear cascades of hadronic interactions + Oset model [Nucl.Phys. A484 (1988) 557-592]

● Valencia 2p2h [Nieves et al., Phys.Lett. B707 (2012) 72-75, Phys. Rev. C 86, 015504 (2012)]






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85

Advanced Topics: NuWro● Fermi motion

Xianguo Lu, Oxford

p small → p large SF describes Fermi motion very well(intranuclear momentum transfer)

Fermi motion

86

Advanced Topics: NuWro● Fermi motion● Resonance / 2p2h strength

SF describes Fermi motion very wellResonance / 2p2h lacks of local strength

Xianguo Lu, Oxford

p small → p large(intranuclear momentum transfer)

87

ADVANCED TOPICS: COMPARISON TO T2K

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Advanced Topics: Comparison to T2K [arXiv:1802.05078] *same target, slight difference in signal phase space definition

MINERvA-T2K difference mainly due to RES:Very small resonance contribution at T2K

arXiv:1802.05078(regularized)

● T

Rev.Mod.Phys. 84 (2012) 1307-1341

NuMI LE <E

> ~ 3 GeV

L. Fields

89

MINERvA-T2K difference mainly due to RESFermi motion (isotropic) baseline consistent


● T

Rev.Mod.Phys. 84 (2012) 1307-1341

NuMI LE <E

> ~ 3 GeV

L. Fields

90

Only differ by longitudinal momentum imbalancep

n has better resolution

● T

● pT


91

MINERvA-T2K difference mainly due to RESThe QE peaks are consistent

● T

● pT

Rev.Mod.Phys. 84 (2012) 1307-1341

NuMI LE <E

> ~ 3 GeV

L. Fields


92Xianguo Lu, Oxford

Summary and Outlook

93Xianguo Lu, Oxford

Summary and Outlook

94

Summary and Outlook● Muon-proton mesonless production at MINERvA

➢ 2014: LE neutrino beam, CH target➢ 2016: LE neutrino beam, CH + nuclear targets➢ This analysis: LE neutrino beam, CH (3.281020 POT)➢ Future: medium energy neutrino beam CH + nuclear targets (E

~ 6 GeV, 121020 POT)

● In this analysis, we have shown ✔ Single-particle kinematics (muon and proton momentum and angle)✔ Transverse kinematic imbalances (

T, p

T)

✔ Initial neutron momentum (pn)

11C*

n

recoil

Fermi motion

Xianguo Lu, Oxford

95



~ 6 GeV, 121020 POT)


T, p

T)


By rearranging final-stat kinematics, nuclear effects can be diagnosed:✔ p

n strong constraint to Fermi motion

✔ T factors out Fermi motion uncertainty and have direct sensitivity to FSI

Xianguo Lu, Oxford

96



~ 6 GeV, 121020 POT)


T, p

T)


By rearranging final-stat kinematics, nuclear effects can be diagnosed:✔ p

n strong constraint to Fermi motion

✔ T factors out Fermi motion uncertainty and have direct sensitivity to FSI

Interesting observation:➢ GENIE MINERvA Tune (v1)

✔ Describes data well to first order✔ Critical component is Valencia 2p2h tuned to MINERvA inclusive data

➢ NuWro ✔ SF provides very good description of data

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97



~ 6 GeV, 121020 POT)

● In this analysis, we have shown✔ Single-particle kinematics (muon and proton momentum and angle)✔ Transverse kinematic imbalances (

T, p

T)


● New developments➢ Transverse kinematic imbalances

✔ New system to solve the nuclear effect problem in neutrino interaction most relevant for oscillation measurements

✔ Radical approach → double transverse kinematic imbalance [Phys. Rev. D 92, 051302(R)] ➢ First measurement of Furmanski-Sobczyk initial neutron momentum

✔ diagnostic power➢ Practically efficient way to select pure CCQE events (beyond the scope of this talk)

Xianguo Lu, Oxford

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Source: http://www.cnhubei.com/ztmjys-pyts

谢谢 !

http://www.cnhubei.com/ztmjys-pyts

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BACKUP

100

● Data-MC comparison at reconstructed level after sideband fit

GENIE MINERvA Tune (v1) describes data well (to first order)Large concentration of pure QE at high angleGENIE excess above data beyond 60 deg (see discussion later slides)

Selected Sample

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101


Selected Sample

GENIE MINERvA Tune (v1) describes data well (to first order)Depletion at small

T

GENIE excess at T → 180 deg.

102


● Strong separation of pure QE● Double-peak structure, very strong in

GENIE

11C*

n

recoil

Fermi motion

Selected Sample

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arXiv:1802.05078

66.4 deg

http://arXiv.org/abs/arXiv:1802.05078

106

END

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