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Neutrinos: Past, Present and Future

Neutrinos: Past, Present and Future

Robert C. WebbPhysics Department

Texas A&M University

Robert C. WebbPhysics Department

Texas A&M University

May 16, 2007 RCW PPC 2007 2

A Brief History of the Neutrino

A Brief History of the Neutrino

The Early Years…… 1930 Pauli proposes a massless neutral particle. 1932 Fermi names the “neutrino”. 1956 The first observation of electron anti-

neutrinos by Reines and Cowan. 1957-62 Possibility that neutrinos oscillate

proposed by Pontecorvo and Sakata. 1961 The muon neutrino is observed at BNL.

The Early Years…… 1930 Pauli proposes a massless neutral particle. 1932 Fermi names the “neutrino”. 1956 The first observation of electron anti-

neutrinos by Reines and Cowan. 1957-62 Possibility that neutrinos oscillate

proposed by Pontecorvo and Sakata. 1961 The muon neutrino is observed at BNL.

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Discovering the NeutrinoDiscovering the Neutrino

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Neutrino Physics 1960-1990

Neutrino Physics 1960-1990

The observation of neutrinos by Reines and Cowan ushered in a new era of the study of these elusive “beasts”Accelerator based measurements

undertaken in the US and Europe.Solar neutrino experiments begun

underground.

The observation of neutrinos by Reines and Cowan ushered in a new era of the study of these elusive “beasts”Accelerator based measurements

undertaken in the US and Europe.Solar neutrino experiments begun

underground.

May 16, 2007 RCW PPC 2007 5

The triumph of the Electro-Weak Unification

The triumph of the Electro-Weak Unification

While experimentalists set out to study the neutrino, the theorist were busy trying to find a theory for the weak interactions of the neutrino that fit…

Weinberg and Salam develop a possible candidate, but it requires a “neutral” weak current as the charged current already seen.

While experimentalists set out to study the neutrino, the theorist were busy trying to find a theory for the weak interactions of the neutrino that fit…

Weinberg and Salam develop a possible candidate, but it requires a “neutral” weak current as the charged current already seen.

May 16, 2007 RCW PPC 2007 6

Theory is working fine..butTheory is working fine..butThe Solar Neutrino problem emerges.

Ray Davis and collaborators with encouragement from John Bachall search for neutrinos from the sun using a giant tank of “cleaning fluid”. (1968)

However, they “see” too few!!What’s wrong, the theory or the experiment?? or

both!!

The Solar Neutrino problem emerges.Ray Davis and collaborators with encouragement

from John Bachall search for neutrinos from the sun using a giant tank of “cleaning fluid”. (1968)

However, they “see” too few!!What’s wrong, the theory or the experiment?? or

both!!

May 16, 2007 RCW PPC 2007 7

New experiments emerge to study this question.

New experiments emerge to study this question.

All of these measurements found too few solar neutrinos!!

This question will get the ultimate answer in 2003 from the SNO Collaboration!

All of these measurements found too few solar neutrinos!!

This question will get the ultimate answer in 2003 from the SNO Collaboration!

May 16, 2007 RCW PPC 2007 8

It’s not just the solar neutrinos that are mis-behaving..

It’s not just the solar neutrinos that are mis-behaving..

There is an anomaly in the atmospheric neutrino flux as well.

SuperK along with several other undergound experiments see too few muon neutrinos!!

There is an anomaly in the atmospheric neutrino flux as well.

SuperK along with several other undergound experiments see too few muon neutrinos!!

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Super K’s results (1998)Super K’s results (1998)

Things make sense if we allow for neutrinos to “oscillate”…

Things make sense if we allow for neutrinos to “oscillate”…

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Two neutrino mixingTwo neutrino mixing

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But neutrinos still aren’t cooperating

But neutrinos still aren’t cooperating

If there are only 3 neutrinos then there should only be two mass differences!!

If there are only 3 neutrinos then there should only be two mass differences!!

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Neutrino mass and mixingNeutrino mass and mixing

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“precision” experimentsto the rescue

“precision” experimentsto the rescue

NuMI/MINOS at FermilabK2K at KEK

and in the future…

T2K and NOVA

NuMI/MINOS at FermilabK2K at KEK

and in the future…

T2K and NOVA

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MINOS overviewMINOS overviewNUMI Beam LineNear DetectorFar DetectorBeam runningData Analysis

NUMI Beam LineNear DetectorFar DetectorBeam runningData Analysis

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The NuMI beam : MIThe NuMI beam : MI

protons

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NuMI Beam Protons Delivered

NuMI Beam Protons Delivered

May 16, 2007 RCW PPC 2007 17

NuMI Beam PerformanceNuMI Beam Performance

Total Integrated POT as of now: >3 1020, have run at up to 310kW, and up to 4.0 1013 protons per pulse

Total Integrated POT as of now: >3 1020, have run at up to 310kW, and up to 4.0 1013 protons per pulse

May 16, 2007 RCW PPC 2007 18

The 3 NuMI Beam Configurations

The 3 NuMI Beam Configurations

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MINOS Near DetectorMINOS Near Detector

Faster electronics

Partially instrumented:

282 planes of steel

153 planes of scintillator

(Rear part of detector only used to track

muons )

+…..

1 kton total mass Same basic design steel, scintillator, etc

Some differences, e.g.:

May 16, 2007 RCW PPC 2007 20

Typical Neutrino Beam Event

Typical Neutrino Beam Event

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Near Detector Events(showing multiple events in spill window)

Near Detector Events(showing multiple events in spill window)

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Near Detector CC eventsNear Detector CC events

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MINOS Far Detector Running since 2003!!

May 16, 2007 RCW PPC 2007 25

The MINOS Far Detector The MINOS Far Detector

• Currently have ~20 kt-yr of Cosmic Ray data.

• Observing single and multiple muons. LOTS• Observed upward going muons (neutrino

interaction below the detector). ~300 events in current sample.

• First physics paper on beam neutrinos submitted to Phys. Rev. Lett.

• In operation with >2 E 20 Protons on the NuMI target

• Currently have ~20 kt-yr of Cosmic Ray data.

• Observing single and multiple muons. LOTS• Observed upward going muons (neutrino

interaction below the detector). ~300 events in current sample.

• First physics paper on beam neutrinos submitted to Phys. Rev. Lett.

• In operation with >2 E 20 Protons on the NuMI target

May 16, 2007 RCW PPC 2007 26

A beam neutrino event in the MINOS Far Detector

A beam neutrino event in the MINOS Far Detector

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Atmospheric neutrinosAtmospheric neutrinos

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First results from MINOSFirst results from MINOS

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MINOS data as a function of Energy

MINOS data as a function of Energy

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MINOS SensitivityMINOS Sensitivity

May 16, 2007 RCW PPC 2007 34

The ultimate sensitivityThe ultimate sensitivity

QuickTime™ and aTIFF (LZW) decompressor

are needed to see this picture.

May 16, 2007 RCW PPC 2007 35

Electron neutrino mixing..the next target

Electron neutrino mixing..the next target

NOVA and T2K..using accelerator neutrinos.

Daya Bay and Double Chooz…using reactor neutrinos.

NOVA and T2K..using accelerator neutrinos.

Daya Bay and Double Chooz…using reactor neutrinos.

May 16, 2007 RCW PPC 2007 36

The Off-Axis conceptThe Off-Axis concept

€

E =0.43 γmπ

1+γ2θ 2

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Beam Location and Far Detector SitingBeam Location and Far Detector Siting

May 16, 2007 RCW PPC 2007 39

NOvA Far DetectorNOvA Far Detector

25 ktons1984 liquid scintillator

planes, no additional absorber (~80% active)

Scintillator cells 3.8 x 6.0 x 1570 cm

Read out from one side per plane with APDs

Expected minimum signal 20pe

25 ktons1984 liquid scintillator

planes, no additional absorber (~80% active)

Scintillator cells 3.8 x 6.0 x 1570 cm

Read out from one side per plane with APDs

Expected minimum signal 20pe

15.7m

15.7m

110m

May 16, 2007 RCW PPC 2007 40

NOvA Event SimulationsNOvA Event SimulationsOne unit is4.9 cm(horizontal)4.0 cm(vertical)

One unit is4.9 cm(horizontal)4.0 cm(vertical)

+ A -> p + 3π± + π0 +

e+A→p π+ π- e-

+ A -> p +-

Particle ID: particularly “fuzzy” e’slong track, not fuzzy gaps in tracks ( πo ?)large energy deposition (proton?)

May 16, 2007 RCW PPC 2007 41

NOvA Near DetectorNOvA Near Detector126 tons of scintillator,

83 tons of steel 23 ton fiducial mass186 liquid scintillator

planes in target, 10 in muon ranger, 1m of steel

Same cell size, same minimum signal

Read out from one side per plane with APDs plus faster electronics than in far detector

126 tons of scintillator, 83 tons of steel

23 ton fiducial mass186 liquid scintillator

planes in target, 10 in muon ranger, 1m of steel

Same cell size, same minimum signal

Read out from one side per plane with APDs plus faster electronics than in far detector

May 16, 2007 RCW PPC 2007 42

The Far Detector SiteThe Far Detector Site

May 16, 2007 RCW PPC 2007 43

Upgrading Proton Source for NOvA

Upgrading Proton Source for NOvA

Proton Plan goal (present FNAL accelerator upgrade program) is 390kW (have achieved 310kW with MINOS)

• Proton Plan 2 uses Recycler as a proton pre-injector Post-collider era: Use Recycler to accumulate protons from Booster

while MI is accelerating, saves time Recycler momentum aperture is large enough to allow slip-

stacking operation in Recycler for up to 12 Booster batches injected

Extracted to MI in a single turn and there re-captured and accelerated

Main Injector will run at its design acceleration rate of 240 GeV/s (1.333 s cycle time) 4.3×1012 p/batch, 95% slip-stacking efficiency 4.9×1013 ppp at 120 GeV every 1.333s

700 kW, or 6×1020protons per yearNow part of NOvA Project!

Proton Plan goal (present FNAL accelerator upgrade program) is 390kW (have achieved 310kW with MINOS)

• Proton Plan 2 uses Recycler as a proton pre-injector Post-collider era: Use Recycler to accumulate protons from Booster

while MI is accelerating, saves time Recycler momentum aperture is large enough to allow slip-

stacking operation in Recycler for up to 12 Booster batches injected

Extracted to MI in a single turn and there re-captured and accelerated

Main Injector will run at its design acceleration rate of 240 GeV/s (1.333 s cycle time) 4.3×1012 p/batch, 95% slip-stacking efficiency 4.9×1013 ppp at 120 GeV every 1.333s

700 kW, or 6×1020protons per yearNow part of NOvA Project!

May 16, 2007 RCW PPC 2007 44

Neutrino SummaryNeutrino Summary

• MINOS data show disappearance at low energies at 6.2 1.27x1020 Protons on Target)

• The best fit oscillation parameters are (hep-ex 0607088)

• Systematic uncertainties on m2 are ~40% of statistical

• MINOS continues to take data—still to come: cross sections, e appearance, sterile neutrino search

• MINOS data show disappearance at low energies at 6.2 1.27x1020 Protons on Target)

• The best fit oscillation parameters are (hep-ex 0607088)

• Systematic uncertainties on m2 are ~40% of statistical

• MINOS continues to take data—still to come: cross sections, e appearance, sterile neutrino search

May 16, 2007 RCW PPC 2007 45

NOvA ProspectsNOvA Prospects

NOA look for e / transitions at m2atm

First hint of θ13 being non-zero?CP violation in absence of matter effects

Matter effects in absence of msol2

NOA look for e / transitions at m2atm

First hint of θ13 being non-zero?CP violation in absence of matter effects

Matter effects in absence of msol2

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May 16, 2007 RCW PPC 2007 46

Neutrino future outlookwhat might we expect to see 50 years hence?Neutrino future outlook

what might we expect to see 50 years hence?

New group of precision experiments b eing planned to study electron neutrino-muon neutrino mixing..

Possibility that there is CP violation in the neutrino sector..

Is the neutrino a Majorana particle or not??Large underground detectors will allow us

to use neutrinos for the study of the earth, dark matter candidates, supernovae, and beyond…

New group of precision experiments b eing planned to study electron neutrino-muon neutrino mixing..

Possibility that there is CP violation in the neutrino sector..

Is the neutrino a Majorana particle or not??Large underground detectors will allow us

to use neutrinos for the study of the earth, dark matter candidates, supernovae, and beyond…