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Neutrino Neutrino Experiments Experiments Kevin McFarland Kevin McFarland University of Rochester University of Rochester Weak Interactions and Weak Interactions and Neutrinos Neutrinos , 6 June 2005 , 6 June 2005

Neutrino Experiments

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Neutrino Experiments. Kevin McFarland University of Rochester Weak Interactions and Neutrinos Delfoi , 6 June 2005. Neutrinos: View from the Center of the Earth. Today we’ll choose a broad overview rather than a focused study in depth - PowerPoint PPT Presentation

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Page 1: Neutrino Experiments

Neutrino ExperimentsNeutrino Experiments

Kevin McFarlandKevin McFarlandUniversity of RochesterUniversity of Rochester

Weak Interactions and NeutrinosWeak Interactions and Neutrinos, 6 June 2005, 6 June 2005

Page 2: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 2

Neutrinos: View from theCenter of the Earth

• Today we’ll choose a broad overview– rather than a focused study in depth– neutrino people: this is for the energy frontier folks.

please be patient! you’ll get your turn later in the week

clever photos courtesy Symmetry magazine

Page 3: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 3

The Broadest Goals

• Understand mixing of neutrinos– a non-mixing? CP violation?

• Understand neutrino mass– absolute scale and hierarchy

• Understand interactions– new physics? new properties?

• Use neutrinos as probes– nucleon, earth, sun*, supernovae*

* fascinating topics, but outside thescope of this talk. See Dave Wark…

Page 4: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 4

Neutrino Mass Eigenstates

• The building blocks of what we know– #s with weak couplings:

• W+: 3 observed (DONUT)• Z0: exactly 3 (LEP, SLD)

– Solar neutrino oscillation: …, SNO, KAMLAND– Atmospheric neutrinos: …, Super-K, K2K– Puzzles and null results: LSND, CHOOZ

• LSND “puzzle” is requirement of more neutrinos• CHOOZ/Palo Verde suggest one small mixing

Page 5: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 5

Qualitative Questions

• The questions facing us now are fundamental, and not simply a matter of “measuring oscillations better”

• Examples:– Are there more than three neutrinos?– What is the hierarchy of masses?– Can neutrinos contribute significantly to the

mass of the universe?– Is there CP violation in neutrino mixings?

Page 6: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 6

The Broadest Goals

• Understand mixing of neutrinos– a non-mixing? CP violation?

• Understand neutrino mass– absolute scale and hierarchy

• Understand interactions– new physics? new properties?

• Use neutrinos as probes– nucleon, earth, etc.

Page 7: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 7

What We Hope to Learn From Neutrino Oscillations

• Near future– validation of three generation picture

• confirm or disprove LSND oscillations• precision tests of “atmospheric” mixing at

accelerators

• Farther Future – neutrino mass hierarchy, CP violation?

• Precision at reactors• sub multi MegaWatt sources• 10 100 1000 kTon detectors

Page 8: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 8

Minimal Oscillation Formalism• If neutrino mass eigenstates: 1, 2, 3, etc.

• … are not flavor eigenstates: e, , • … then one has, e.g.,

cos sin

sin cosi

j

take only two generations

for now!

cos sin4 4i j

sin cos4 4i j

time

different masses

alter time evolution

Page 9: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 9

Oscillation Formalism (cont’d)• So, still for two generations…

• Oscillations require mass differences• Oscillation parameters are mass-squared differences, m2, and mixing angles, .

• One correction to this is matter… changes , L dep.

E

LmmP

4

)(sin2sin)(

21

2222

Wolfenstein, PRD (1978)

22

22

22

)2cos(2sin

)2cos(2sin

2sin2sin

xLL

x

M

M

nm

EnGx eF

2

22

e- density

appropriate units give the usual

numerical factor 1.27 GeV/km-eV2

Page 10: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 10

Solar Neutrinos• There is a glorious history

of solar neutrino physics– original goals: demonstrate

fusion in the sun– first evidence of oscillations

SAGE - The Russian-AmericanGallium Experiment

Page 11: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 11

Culmination: SNO• D2O target uniquely observes:

– charged-current– neutral-current

• The former is onlyobserved for e

(lepton mass)

• The latter for all types• Solar flux is consistent

with models– but not all e at earth

X Xd pn ed ppe

Page 12: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 12

KAMLAND• Sources are

Japanesereactors– 150-200 km

for most offlux. Rate uncertainty ~6%

• 1 kTon scint. detector inold Kamiokande cavern– overwhelming confirmation

that neutrinos change flavorin the sun via mattereffects

Page 13: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 13

Solar Observations vs. KAMLAND

+ KAMLAND =

• Solar neutrino observations are best measurement of the mixing angle

• KAMLAND does better on m212

Page 14: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 14

Atmospheric Neutrinos

• Neutrino energy: few 100 MeV – few GeV• Flavor ratio robustly predicted• Distance in flight: ~20km (down) to 12700 km (up)

Page 15: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 15

Super-Kamiokande

• Super-Kdetector hasexcellent e/separation

• Up / down difference!

old, but good data!

2004 Super-K analysis

Page 16: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 16

K2K

• Experiment has completeddata-taking– confirms atmospheric

neutrino oscillation parameters with controlled beam

– constraint on m223 (limited statistics)

figures courtesy T. NakayaNeutrino Beam from KEK to Super-K

Page 17: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 17

Enough For Three Generations

• Oscillations have told us the splittings in m2, but nothing about the hierarchy

• The electron neutrino potential (matter effects) can resolve this in oscillations, however.

figures courtesy B. Kayser

msol2 m12

2≈8x10-5eV2 matm2 m23

2≈2.5x10-3eV2

Page 18: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 18

Three Generation Mixing

• Note the new mixing in middle, and the phase,

slide courtesy D. Harris

Page 19: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 19

But CHOOZ…• Like KAMLAND, CHOOZ and

Palo Verde expt’s looked at anti-e from areactor– compare expected to observed

rate, ~4%

m223

• If electron neutrinos don’t disappear, they don’t transform to muon neutrinos

– limits ->e flavor transitions at and therefore |Ue3| is “small”

Page 20: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 20

Optimism has been Rewarded

• By which he meant…had not

Eatm /Rearth < matm2 <Eatm /hatm

and had not solar density profileand msol

2 beenwell-matched…

• We might not be discussing oscillations!

“We live in the best of all possible worlds”– Alvaro deRujula, Neutrino 2000

Page 21: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 21

Are Two Paths Open to Us?• If “CHOOZ” mixing, 13, is small, but not too

small, there is an interesting possibility

• At atmospheric L/E,

m232, 13

m122, 12

e

2 22 2 2 1( )

( ) sin 2 sin4e

m m LP

E

SMALLLARGE

SMALLLARGE

Page 22: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 22

Implication of two paths• Two amplitudes

• If both small,but not too small,both can contribute ~ equally

• Relative phase, , between them can lead toCP violation (neutrinos and anti-neutrinos differ) in oscillations!

m232, 13

m122, 12

e

Page 23: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 23

Leptons Have Rediscovered the Wonders of Three Generations!

• CP violation and matter effects lead to a complicated mix…

• CP violation gives ellipsebut matter effects shiftthe ellipse in along-baseline acceleratorexperiment…

Minakata & Nunokawa JHEP 2001

Page 24: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 24

But LSND…• LSND anti-e excess

– 87.9±22.4±6.0 events– statistically overwhelming;

however…

figures courtesy S. Brice

LSND m2 ~ 0.1-1.0 eV2

Atmos. m2 ≈ 2.5x10-3 eV2

Solar m2 ≈ 8.0x10-5 eV2

cannot be accommodated with only three neutrinos

Page 25: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 25

SignalMis-IDBeam

MiniBooNE

• A very challenging experiment!

• Have ~0.5E21protons on tape

• First e

appearanceresults inlate 2005

figures courtesy S. Brice

Page 26: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 26

Next Steps(Brazenly Assuming Three Neutrinos)

• MINOS and CNGS

• Reactors

• T2K and NOvA

• Mating Megatons and Superbeams

• Beta (e) beams andneutrino factories (e and )

graphical witcourtesy A. deRujula

Page 27: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 27

Isn’t all of this overkill?

• Disentangling the physics from the measurements is complicated (S. Parke)

• The short version of the story is that different measurements have different sensitivity to matter effects, CP violation– Matter effects amplified for long L, large E

– CP violation cannot be seen in disappearance (reactor) measurement ee

Page 28: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 28

NuMI-Based Long Baseline Experiments

• 0.25 MWatt 0.4 MWatt proton source

• Two generations: – MINOS (running)– NOvA (future)

15mrad Off Axis

Page 29: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 29

MINOS735km baseline5.4kton Far Det.1 kton Near Det.Running since early

2005

Goal: precise disappearancemeasurementGives m2

23

Page 30: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 30

CNGSGoal: appearance• 0.15 MWatt source• high energy beam• 732 km baseline• handfuls of events/yr

e-, 9.5 GeV, pT=0.47 GeV/c

interaction, E=19 GeV

fiugres courtesy A. Bueno

3kton

Pb

Emulsion layers

1 mm

1.8kTon

figures courtesy D. Autiero

Page 31: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 31

Back to Reactors• Recall that

KAMLANDsaw anti-e

disappearanceat solar L/E

• Have not seendisappearance atatmospheric L/E

Page 32: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 32

Why Reactors?• CHOOZ (reactor) has left us without evidence of

anti-e disappearance indicating |Ue3|>0

– reactors are still the most sensitive probe!• CHOOZ used a single detector

– therefore, dead-reckoning used to estimate neutrino flux from the reactor

– could improve with a near/far technique

• KAMLAND has improved knowledge of how to reject backgrounds significantly

(remember, their reactors are ~200 km away!)

Page 33: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 33

not an engineering

drawing

How Reactors?• To get from ~4% uncertainties to ~1% uncertainties,

need a near detector to monitor neutrino flux• For example, Double-CHOOZ proposes to add a second

near detector and compare rates– new detectors with 10 ton mass– total error budget on rate ~2%– low statistics 10t limit spectral

distortion, 1 km baseline likelyshorter than optimum

• Optimization beyond Double-CHOOZ…– ~100 ton detector mass

– optimize baseline for m223

– background reduction with active or passive shielding

Page 34: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 34

Where Reactors?

• A series of proposals with different technical choices

• All challenging experiments to limit systematics

Page 35: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 35

Megawatt Class Beams

• J-PARC– initially 0.7 MWatts 4 MWatts

• FNAL Main Injector– current goal 0.25 MWatts 0.4 MWatts– future proton driver upgrades?

• Others?

Page 36: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 36

J-PARC Facility

Page 37: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 37

• First Suggested by Brookhaven (BNL 889)• Take advantage of Lorentz Boost and 2-

body kinematics• Concentrate flux

at one energy• Backgrounds lower:

– NC or other feed-downfrom highlow energy

– e (3-body decays)

A Digression: Off-axis

figure courtesy D. Harris

Page 38: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 38

T2K• Tunable off-axis beam from J-

PARC to Super-K detector– beam and backgrounds are kept

below 1% for e signal

– ~2200 events/yr (w/o osc.)

=0, no matter effects

figures courtesy T. Kobayashi

Page 39: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 39

NuMI-Based Long Baseline Experiments

• 0.25 MWatt 0.4 MWatt proton source

• Two generations: – MINOS (running)– NOvA (future)

15mrad Off Axis

Page 40: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 40

NOA• Use Existing NuMI

beamline• Build new 30kTon

Scintillator Detector • 820km baseline--

compromise between reach in 13 and matter effects

Assuming m2=2.5x10-3eV2

e+A→p + - e-

figure courtesy M. Messier

figures courtesy J. Cooper

Goal:eappearanceIn beam

Page 41: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 41

Future Steps after T2K, NOvA

• Beam upgrades (2x – 5x)

• Megaton detectors (10x – 20x)

• BUT, it’s hard to make such steps without encountering significant

TECHNICAL DIFFICULTIES– hereafter “T.D.”

Page 42: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 42

TD: More Beam Power, Cap’nExample: Fermilab Proton Driver

~ 700m Active Length8 GeV Linac

8 GeVneutrino

MainInjector@2 MW

SY-120Fixed-Target

Neutrino“Super- Beams”

NUMI

Off- Axis

Parallel Physics and Machine Studies …main justificationIs to serve as source for new Long baseline neutrino experimentsfigure courtesy G.W. Foster

Page 43: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 43

TDs: Beamlines• Handling Many MWatts of proton power and

turning it into neutrinos is not trivial!

NuMI downstream absorber. Note elaborate cooling. “Cost more than NuTeV beamline…” – R. Bernstein

NuMI Horn 2. Note conductors and alignment fixtures

NuMI tunnel boring machine. 3.5yr civil construction

NuMI Target

shielding. More mass

than far detector!

pictures courtesy D. Harris

Page 44: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 44

TDs: Detector Volume• Scaling detector volume is not

so trivial

• At 30kt NOvA is about the same mass as BaBar, CDF, Dzero, CMS and ATLAS combined…– want monolithic, manufacturabile structures– seek scaling as surface rather than volume if possible

figure courtesy G. Rameika

Page 45: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 45

For Perspective…• Consider the Temple of the

Olympian Zeus…• 17m tall, just like NOvA!

– a bit over ½ the length

• It took 700 years to complete– delayed for lack of funding

for a few hundred years

• Fortunately construction technology has improved– has the funding situation?

17m

your speaker

Page 46: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 46

Perspective (cont’d)…• 120m long, 10% less than

NOvA– roughly the same height and

width

• It was rebuilt over a mere four years– Funded by

John D. Rockfeller

• Morals:– grand endeavors!

– know who holds your checkbook…

your speaker

120m

• Consider the…

Page 47: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 47

TDs: Detector Volume (cont’d)• For megatons, housing a detector is difficult!

• Sensor R&D: focus on reducing cost

– in case of UNO,large photocathode PMTs

– goal: automated production,1.5k$/unit

figures courtesy C.-K. Jung

10% photocathode

60m60m

40% photocathode

UNO. ~1Mton. (20x Super-K)

Dep

th (

bel

ow

su

rfac

e)

Span

UNO: 60m span1500m depth

Field Map, Burle 20” PMT

Page 48: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 48

TDs: Neutrino Interactions• At 1-few GeV neutrino energy (of interest for osc. expt’s)

– Experimental errors on total cross-sections are large• almost no data on A-dependence

– Understanding of backgrounds needsdifferential cross-sections on target

– Theoretically, this region is a mess…transition from elastic to DIS

n–p0

nn+

figures courtesy D. Casper, G. Zeller

Page 49: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 49

Futuristic Accelerator Beams

• Great experimental benefits to new beam technology, but beams are very challenging! And costly…

Detector Needsfigures courtesy D. Harris• Conventional Beam

• Beta Beam

• Neutrino Factory

Page 50: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 50

More to learn from the sky?• Sign-separated atmospheric neutrinos

– MINOS detector is first with this capability– determine charge

from bend

• Why study neutrino vs. anti-neutrino oscillations? – possibility to test CPT violation scenarios if suggested by MiniBooNE and

LSND results

Time vs Y

Time vs Z

Y vs X

Y vs Z

yx

z

Strip vs Plane

~1 yr MINOSfigures courtesy M. Bishai, H. Gallagher

Page 51: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 51

Observing Matter Effected Oscillations

• We apparently have seen matter effects in the sun… can we verify it in the earth?

• Best resultsfrom Super-K

• Expect ~2%effect– Not there yet

• Interestingfor futuresolar experiments…

Page 52: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 52

The Broadest Goals

• Understand mixing of neutrinos– a non-mixing? CP violation?

• Understand neutrino mass– absolute scale and hierarchy

• Understand interactions– new physics? new properties?

• Use neutrinos as probes– nucleon, earth, etc.

Page 53: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 53

Neutrinoless Double-Beta Decay

• Double beta decay

is a rare, butobserved process

• “Neutrinoless” implies that the neutrino is its own anti-particle (Majorana particle)

• The prize:

Z Z+2 2 2AA

e

graphics courtesy Symmetry magazine

0 2 phase space nucl. matrix elems.m

calculable evaluable w/ largish uncertainties

2ii

ei ii

m U m e (i is a “Majorana phase”. Please look it up because

I’m not going there…)

Page 54: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 54

Experimental Challenges• Observables: electron energy, and the final state

nucleus (EXO)– Electron energy

requires excellentresolution and lownon backgrounds

– Tagging the finalstate nucleus is “findinga needle in a haystack”

• Must also have significant quantities of decaying isotopes– not necessarily easy to purify. good detector material?

sum electron energy / Q

2

0

Page 55: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 55

Current Results to Date• Results• To notice:

– 76Ge, 130Te havelarge quantities,best limits so far

– There is a claimedobservation

• controversial• significant non-

backgrounds(hard-to-predict Bi lines)

figure and table from APS report: direct mass group

Page 56: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 56

Future

• If the Heidelberg-Moscow 76Ge result is correct, should be confirmed “easily”

• If not, want to push sensitivities to m2 to

at least level of m223 (maybe m2

12)

– approximately two (maybe four) orders of magnitude lower than present situation

• Experiments are very difficult want confirming signals in multiple isotopes– many exciting ideas for future experiments

Page 57: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 57

Approaches: CUORE• Calorimetric (thermal) detector which

is the source (TeO2)– ~keV resolution at endpoint (2528 keV)– Currently running “Cuoricino”, 40 kg– Full CUORE expects to have 750 kg,

reduced background levelsTeO2 crystal

heat bath

Thermal sensor

e-

e-

figures courtesy E.Fiorini

Cuoricino (Hall A)

CUORE R&D (Hall C)

CUORE (Hall A)

Page 58: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 58

100Mo6914 g

265 days

DataMonte-CarloRadonMonte-Carlo

E1+E2 (MeV)

arbitrary unit

Approaches: NEMO-3• Tracking/calorimetric detector external

to source foils (10kg of isotopes)– Geiger mode wire chambers, B=25G– Scint/Low Rad. PMT calorimeter– Gamma and neutrino shielding– First results w/

100Mo and 82Se– Developing

proposal toscale to 100kg

figures courtesy X.Sarazin

det

ecto

r in

Fre

jus

min

e

Page 59: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 59

decay kinematics: microcalorimeters magnetically adiabatic collimating electrostatic spectrometers

3H

187Re

Other Mass Determinations?

powerful, but very indirect

cosmology &structure formation

D.N. Spergel et al: m < 0.69 eV (95%CL)

figures courtesy K. Eitel

potential for ~few eV sensitivity

astrophysics:SN ToF measurements

direct, but precision requires detailed knowledge of SN

direct, but very challenging experiments

Page 60: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 60

10 eV

KATRINphase space determines energy spectrumE0 = Ee + E (+ recoil corrections)

theoretical spectrum near endpoint

dN/dE (E0-Ee) × [ (E0-Ee)2 – m2 ]1/2

retarding (variable) E-field allows only E>Eret. to pass

energy resolution:: E/E=Bmin/Bmax

Bmax = 6 TBmin = 3×10-4 Tso E~1 eV

MAC-E spectrometers(Mainz, Troitsk) m<2.2eV(95%CL)

(sensitivity limit)

KATRIN sensitivity m<0.2eV(90%CL)commissioning in 2008

3 3H He

figures courtesy K. Eitel

Page 61: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 61

The Broadest Goals

• Understand mixing of neutrinos– a non-mixing? CP violation?

• Understand neutrino mass– absolute scale and hierarchy

• Understand interactions– new physics? new properties?

• Use neutrinos as probes– nucleon, earth, etc.

Page 62: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 62

Neutrino Interactions

• So broad a subject… so little time

• Precision EWK

• Neutrino magnetic moments

• Parity-violating probe

• (More on non-standard interactions from S. Parke’s talk)

Page 63: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 63

Neutral Currents in Neutrinos• Neutrino neutral current?

– LEP invisible width, only 2– NuTeV may be

very largeisospin violation

• Future reactors? Conrad, Link, Shaevitz

– if reactor experiments have precision for 13, may also be able to measure neutral currents

– opportunity for a purely leptonic probe

e ee e

Page 64: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 64

MINERvA, for Oscillations• Noted that neutrino interactions are poorly known…• Backgrounds or signal rate uncertainties for next

accelerator oscillation experiments could limit precision• Enter MINERvA at NuMI beamline

– newly approved cross-sectionexperiment in NuMI near hall

– construction start in late 2006;taking data by 2008

νµp→νµpπ0

Photon tracks!

For example,MINERvA helpsMINOS knowrelationshipbetween visibleand true energyfigures courtesy B. Ziemer, D. Harris, R. Flight

Page 65: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 65

The Broadest Goals

• Understand mixing of neutrinos– a non-mixing? CP violation?

• Understand neutrino mass– absolute scale and hierarchy

• Understand interactions– new physics? new properties?

• Use neutrinos as probes– nucleon, earth, etc.

Page 66: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 66

MINERvA, Axial Form Factors• An experiment like MINERvA

can add to knowledge ofnucleon structure!– Jefferson Lab for

neutrinos

• Example: axialstructure of protonat high Q2.– of interest because

of puzzling behaviorof vector form factors

figures courtesy H. Budd, R. Flight

Page 67: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 67

Journey to the Center of the (Spherical) Earth: Geoneutrinos

• Another use of neutrinos as a probe• The journey in brief:

– earth radiates 30-45 TWatts in heat– the hypothesis: this is due to

radioactivity of the earth– this radioactivity emits low energy

anti-neutrinos from U and Thdecays detectable via

– one complication: much ofU/Th is in crust

1.8p e n MeV

figures courtesy G. Fiorentini

Page 68: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 68

Geoneutrinos (cont’d)• Crust distribution is location

dependent, but can be determinedby geochemical surveys

• Subtraction of the variable (local)part leaves the “global” U/Th

• At right, expected local andmaximum “global” signal for U– “TNU” unit is 10-32 ev/prot-yr

Kamioka

KamLAND S(U+Th)=(82±52stat.) TNUclearly needs more data!

figures courtesy G. Fiorentini

Page 69: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 69

Other Interesting Ideas• Why is this so important to neutrino physics?• Field has been driven by unexpected results

from nearly every window we’ve looked in!• To me, it seems like every neutrino conference I

go to I hear at least one novel and audacious idea for an experiment…– Gallium source calibration– EXO Barium tagging– etc.

• So here’s one I recently learned about. It may work, it may not. It is illustrative…

Page 70: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 70

keV Neutrino Source• If one could make:

– 200 MCurie 3H2 source

– 3000 m3 sphericalXe TPC volume at 1bar

• One could lookat atmospheric L/Ein the lab

• NOSTOS experiment. Obviously not trivial technically…

figures courtesy I. Giomataris

Page 71: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 71

Breathless Conclusions• There is a lot going on in neutrino physics!• Nature has been kind to us

so far, and answers tofundamental questionsmay be ripe for the picking

• But, new experiments aregetting more difficult…– Still, we’ve been historically patient in neutrino

physics (e.g., 30 years from Pauli to Reines and Cowan)

– And it’s been worth the wait!

Page 72: Neutrino Experiments

6 June 2005 Kevin McFarland, Neutrinos (Expt'l) 72

Acknowledgementsinput or source material supplied by (with or without their knowledge):A. deRujula, B. Kayser, D. Harris (also editorial help! thank you!), T. Nakaya,S. Parke, S. Brice, D. Autiero, T.. Kobayashi, M. Messier, J. Cooper, G.W. Foster, G. Rameika, C.-K. Jung, M. Bishai, H. Gallagher, B. Ziemer, H. Budd, E. Fiorini, G. Gratta, X. Sarazin, K. Eitel, R. Flight, D. Casper,H. Minakata, G. Zeller, G. Fiorentini, I. Giomataris and Symmetry magazine

also, thank you to my children and wife for their patience with my absence.

and to my group for puttingup with only email contact for the week!