neutrinos: past, present and future
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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.
May 16, 2007 RCW PPC 2007 3
Discovering the NeutrinoDiscovering the Neutrino
May 16, 2007 RCW PPC 2007 4
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!!
May 16, 2007 RCW PPC 2007 9
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”…
May 16, 2007 RCW PPC 2007 10
Two neutrino mixingTwo neutrino mixing
May 16, 2007 RCW PPC 2007 11
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!!
May 16, 2007 RCW PPC 2007 12
Neutrino mass and mixingNeutrino mass and mixing
May 16, 2007 RCW PPC 2007 13
“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
May 16, 2007 RCW PPC 2007 14
MINOS overviewMINOS overviewNUMI Beam LineNear DetectorFar DetectorBeam runningData Analysis
NUMI Beam LineNear DetectorFar DetectorBeam runningData Analysis
May 16, 2007 RCW PPC 2007 15
The NuMI beam : MIThe NuMI beam : MI
protons
May 16, 2007 RCW PPC 2007 16
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
May 16, 2007 RCW PPC 2007 19
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
May 16, 2007 RCW PPC 2007 21
Near Detector Events(showing multiple events in spill window)
Near Detector Events(showing multiple events in spill window)
May 16, 2007 RCW PPC 2007 22
May 16, 2007 RCW PPC 2007 23
Near Detector CC eventsNear Detector CC events
May 16, 2007 RCW PPC 2007 24
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
May 16, 2007 RCW PPC 2007 27
May 16, 2007 RCW PPC 2007 28
May 16, 2007 RCW PPC 2007 29
May 16, 2007 RCW PPC 2007 30
Atmospheric neutrinosAtmospheric neutrinos
May 16, 2007 RCW PPC 2007 31
First results from MINOSFirst results from MINOS
May 16, 2007 RCW PPC 2007 32
MINOS data as a function of Energy
MINOS data as a function of Energy
May 16, 2007 RCW PPC 2007 33
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
May 16, 2007 RCW PPC 2007 37
May 16, 2007 RCW PPC 2007 38
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…
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