Manmade Neutrinos

Morgan Wascko Imperial College London

Super-K muon event

Motivation

→ν ν µ e ) P(

• Why are we here?

• Where is all the antimatter?

• Neutrino oscillation offers a new test of CP symmetry P(νµ→νe)

M.O. Wascko NEPPSR 2009 2 Outline

• Experimental methods to determine neutrino properties

• Early days • Standard Model

• Neutrino Mass • Discovery • Open Questions

M.O. Wascko NEPPSR 2009 3 Hints

e- n ⇒ p “desperate remedy”

“I have done something very bad today by proposing a particle that cannot be detected; it is something no theorist F.A. Scott, Phys Rev. 48, 391 (1935) should ever do.” — Wolfgang Pauli (1930)

M.O. Wascko NEPPSR 2009 4 Hints

ν e- n ⇒ p “desperate remedy”

“I have done something very bad today by proposing a particle that cannot be detected; it is something no theorist F.A. Scott, Phys Rev. 48, 391 (1935) should ever do.” — Wolfgang Pauli (1930)

M.O. Wascko NEPPSR 2009 4 νs in Standard Model

• No charge • No color • Fixed helicity • No mass • Flavors don’t mix

Fermilab Visual Media Services

M.O. Wascko NEPPSR 2009 5 Discovery

νN(n,p) →N’(n-1,p+1)+e+ • Reines & Cowan - reactors

• First try at Hanford • Cosmic backgrounds too high

• Second try at Savannah River • Success!

• Science 124, 103 (1956) H2O w/ • Phys. Rev. 117, 159 (1960) CdCl

M.O. Wascko NEPPSR 2009 6 Helicity

• Goldhaber 1958 • 152Eu decays via atomic electron capture 152 152 • Eu→ Sm*νe • Results in neutrino and • Place 152Eu in a magnetic recoil nucleus field, and oscillate field • 152Sm* decays rapidly to • Look for asymmetry ground state via ~900 keV photon • Result: neutrinos are left • Measuring the polarisation handed! of the photons yields helicity of neutrinos! Phys.Rev. 109, 1015 - 1017 (1958)

M.O. Wascko NEPPSR 2009 7 Expanding the Toolbox

Pion Decay π→µν

M.O. Wascko NEPPSR 2009 8 Pion Decay Chain

π+

νµ

+ µ νµ e+

νe

M.O. Wascko NEPPSR 2009 9 νµ

νµ

νe Neutrino Beam

M.O. Wascko NEPPSR 2009 9 First Neutrino Beam

Phys. Rev. Lett. 9, 36 - 44 (1962)

M.O. Wascko NEPPSR 2009 10 Muon neutrinos!

νA→µ-X

M.O. Wascko NEPPSR 2009 11 Increasing the flux

- Iouter + Iinner +

+

-

M.O. Wascko NEPPSR 2009 12 Neutrino horns K2K T2K

CERN

MiniBooNE FNAL

M.O. Wascko NEPPSR 2009 13 Reminder

νµ µ- νµ νµ W+ Z0 n p p p

Charged Current Neutral Current

M.O. Wascko NEPPSR 2009 14 Gargamelle

M.O. Wascko NEPPSR 2009 15 NC Signals & BGs νp→νp

F J Hasert et al. 1973 Phys. Lett. 46B 12 1

(Also get νe→νe, of course)

M.O. Wascko NEPPSR 2009 16 3 generations

• Look at invisible width around Z0 resonance • Favors 3 light neutrinos • Not sensitive to neutrinos heavier than Z0

• See: J. Dress at the XX International C. Caso et al., Euro.Phys.J C3, 1 (1998) Symposium on Lepton and Photon and (URL: http://pdg.lbl.gov/) Interactions at High Energy, Rome, Italy (July 2001).

2.984±0.008 → 2 σ away from 3!

M.O. Wascko NEPPSR 2009 17 νs in Standard Model

✓No charge ✓No color ✓Fixed helicity ✓No mass ✓Flavors don’t mix

Fermilab Visual Media Services

M.O. Wascko NEPPSR 2009 18 An example

M.O. Wascko NEPPSR 2009 19 MiniBooNE Detector •800 tons of pure mineral oil •6m radius steel sphere •~2m earth overburden •1520 8" PMTs • 1280 in main tank (sphere) • 240 in veto region (shell) •DAQ records t,Q •“Hits”

M.O. Wascko NEPPSR 2009 20 M.O. Wascko NEPPSR 2009 21 Neutrinos in oil A neutrino can do many things in mineral oil... About 75% CC, 25 % NC NC events lose energy when neutrino escapes detector

other 13% CC events deposit all energy in detector νµ νµ

CCQE 39% NCE 16% Z0 νµ,e - - p µ ,e p

W+ n p

NCpi0 7% νµ νµ

νµ µ- Z0 0 p,n π + W + CC pi+ 25% p,n n π n

M.O. Wascko NEPPSR 2009 22 Particle Images

•Muons

• Sharp, clear rings

• Long, straight tracks

•Electrons

• Scattered rings

• Multiple scattering

• Radiative processes

•Neutral Pions

• Double rings

• Decays to two photons

• Photons pair produce

M.O. Wascko NEPPSR 2009 23 Looking at Tank Data

Radioactive Decays, Noise Hits

Stopping

Through-going Stopping Muons Through-going Muons

M.O. Wascko NEPPSR 2009 24 Looking at Tank Data

Radioactive Decays, Noise Hits

Stopping

Muon Cut: Veto Hits<6 Through-going Stopping Muons Through-going Muons

M.O. Wascko NEPPSR 2009 24 Looking at Tank Data Putting it all together...

Radioactive Decays, Noise Hits

Stopping Muon Decay Electrons

Through-going

Cosmic Muons

M.O. Wascko NEPPSR 2009 25 Looking at Tank Data Putting it all together...

Radioactive Decays, Noise Hits

Stopping Muon Decay Electrons

Decay Electron Cut: Tank Hits>200 Through-going

Cosmic Muons

M.O. Wascko NEPPSR 2009 25 Triggering on Neutrinos •MiniBooNE's neutrino trigger is unbiased •The Booster dumps protons onto our target in 1.6μs intervals, several times per second • “Beam spill” •We know exactly when neutrinos from the beam are passing through the detector •When this happens, we record all detector activity in a 20μs interval around the beam spill Protons on target

Time(~µs) 20 µs

M.O. Wascko NEPPSR 2009 26 Triggering on Neutrinos •MiniBooNE's neutrino trigger is unbiased •The Booster dumps protons onto our target in 1.6μs intervals, several times per second • “Beam spill” •We know exactly when neutrinos from the beam are passing through the detector •When this happens, we record all detector activity in a 20μs interval around the beam spill Protons on target Neutrinos in detector

Time(~µs) 20 µs

M.O. Wascko NEPPSR 2009 26 Triggering on Neutrinos •MiniBooNE's neutrino trigger is unbiased •The Booster dumps protons onto our target in 1.6μs intervals, several times per second • “Beam spill” •We know exactly when neutrinos from the beam are passing through the detector •When this happens, we record all detector activity in a 20μs interval around the beam spill Protons on target Neutrinos in detector Recorded event

Time(~µs) 20 µs

M.O. Wascko NEPPSR 2009 26 Picking out Neutrinos

BeamBeam and CosmicDecayOnly BGe-

• Times of hit-clusters • Beam spill clearly evident • simple cuts eliminate cosmic backgrounds

• Neutrino Candidate Cuts • <6 veto PMT hits • >200 tank PMT hits • Only neutrinos are left!

M.O. Wascko NEPPSR 2009 27 Picking out Neutrinos

BeamBeam and DecayOnly e-

• Times of hit-clusters • Beam spill clearly evident • simple cuts eliminate cosmic backgrounds

• Neutrino Candidate Cuts • <6 veto PMT hits • >200 tank PMT hits • Only neutrinos are left!

M.O. Wascko NEPPSR 2009 27 Picking out Neutrinos

Beam Only

• Times of hit-clusters • Beam spill clearly evident • simple cuts eliminate cosmic backgrounds

• Neutrino Candidate Cuts • <6 veto PMT hits • >200 tank PMT hits • Only neutrinos are left!

M.O. Wascko NEPPSR 2009 27 Discovery of Neutrino Mass

Super Kamiokande M.O. Wascko NEPPSR 2009 28 Why ν mass is difficult

• Usual techniques • Mass reconstruction • Spectrometry

• Cannot directly measure ν mass eigenstates!

• Must use less direct techniques

Phys Rev. Lett. 33, 1406 (1974) M.O. Wascko NEPPSR 2009 29 Why ν mass is difficult e- e+

• Usual techniques • Mass reconstruction • Spectrometry

• Cannot directly measure ν mass eigenstates!

• Must use less direct techniques

Phys Rev. Lett. 33, 1406 (1974) M.O. Wascko NEPPSR 2009 29 Why ν mass is difficult µ+ µ-

• Usual techniques • Mass reconstruction • Spectrometry

• Cannot directly measure ν mass eigenstates!

• Must use less direct techniques

Phys Rev. Lett. 33, 1406 (1974) M.O. Wascko NEPPSR 2009 29 Hints

• Solar Neutrino Problem PRL 20 1205 (1968)

• Atmospheric Muon Neutrino Deficit PRD 18 2239 (1978)

M.O. Wascko NEPPSR 2009 30 Neutrino Oscillation

Pontecorvo, Maki, Nakagawa, Sakata

if neutrinos have mass...

a neutrino that is produced as a νµ + + • (e.g. π → µ νµ)

might some time later be observed as a νe - • (e.g. νe n → e p)

+ νµ - π νe e X µ+ ν detector ν source

M.O. Wascko NEPPSR 2009 31 Neutrino Oscillation

ν cosθ. sinθ ν µ = 1 ν sinθ.cosθ ν ! e" !− "! 2" • Consider only two types of neutrinos ν1 νµ ν2 • If weak states differ from mass states ϴ i.e. (νµ νe)≠(ν1 ν2) νe • • Then weak states are mixtures of mass states

iE t iE t ν (t) >= sinθ ν > e− 1 + cosθ ν > e− 2 | µ − | 1 | 2

Probability to find νe when 2 • P (ν ν )= < ν ν (t) > you started with νµ osc µ → e | e| µ |

M.O. Wascko NEPPSR 2009 32 L P(ν ν )=sin2 2θ sin2(1.27∆m2 ) µ → e 12 12E • 2 fundamental parameters 2 2 2 • Δm 12 (=m1 -m2 ) ↔ period • θ12 ↔ magnitude

• 2 experimental parameters • L = distance travelled • E = neutrino energy

• Tune L&E for Δm2 range, uncertainties determine θ sensitivity • Neutrino disappearance and appearance

M.O. Wascko NEPPSR 2009 33 L P(ν ν )=sin2 2θ sin2(1.27∆m2 ) µ → e 12 12E • 2 fundamental parameters 2 2 2 • Δm 12 (=m1 -m2 ) ↔ period • θ12 ↔ magnitude

• 2 experimental parameters • L = distance travelled • E = neutrino energy

• Tune L&E for Δm2 range, uncertainties determine θ sensitivity • Neutrino disappearance and appearance

M.O. Wascko NEPPSR 2009 33 L P(ν ν )=sin2 2θ sin2(1.27∆m2 ) µ → e 12 12E • 2 fundamental parameters 2 2 2 • Δm 12 (=m1 -m2 ) ↔ period • θ12 ↔ magnitude

• 2 experimental parameters • L = distance travelled • E = neutrino energy

• Tune L&E for Δm2 range, uncertainties determine θ sensitivity • Neutrino disappearance and appearance

M.O. Wascko NEPPSR 2009 33 L P(ν ν )=sin2 2θ sin2(1.27∆m2 ) µ → e 12 12E • 2 fundamental parameters 2 2 2 • Δm 12 (=m1 -m2 ) ↔ period • θ12 ↔ magnitude

• 2 experimental parameters • L = distance travelled • E = neutrino energy

• Tune L&E for Δm2 range, uncertainties determine θ sensitivity • Neutrino disappearance and appearance

M.O. Wascko NEPPSR 2009 33 L P(ν ν )=sin2 2θ sin2(1.27∆m2 ) µ → e 12 12E • 2 fundamental parameters 2 2 2 • Δm 12 (=m1 -m2 ) ↔ period • θ12 ↔ magnitude

• 2 experimental parameters • L = distance travelled • E = neutrino energy

• Tune L&E for Δm2 range, uncertainties determine θ sensitivity • Neutrino disappearance and appearance

M.O. Wascko NEPPSR 2009 33 L P(ν ν )=sin2 2θ sin2(1.27∆m2 ) µ → e 12 12E • 2 fundamental parameters 2 2 2 • Δm 12 (=m1 -m2 ) ↔ period • θ12 ↔ magnitude

• 2 experimental parameters • L = distance travelled • E = neutrino energy

• Tune L&E for Δm2 range, uncertainties determine θ sensitivity • Neutrino disappearance and appearance

M.O. Wascko NEPPSR 2009 33 Presenting Oscillations L P(ν ν )=sin2 2θ sin2(1.27∆m2 ) µ → e 12 12E

• Recall: • L and E determine the Δm2 sensitivity region • sin22θ gives amplitude of oscillations • No signal: exclusion regions • Inside the region: excluded • Outside the region: cannot be ruled out • Signal: allowed regions • Shown by shaded areas specifying Δm2 and sin22θ • Size of allowed region determined by experimental uncertainties

M.O. Wascko NEPPSR 2009 34 http://hitoshi.berkeley.edu/neutrino Solar

2 -5 2 Δm 12 =(7.59±0.21)×10 eV +1.6 θ12=34.4° -1.5

http://hitoshi.berkeley.edu/neutrino Atmospheric

2 -3 2 Δm 23=(2.43±0.11)×10 eV θ23=45±6°

http://hitoshi.berkeley.edu/neutrino Confirming Atmospherics

νµ+N→µ+X

• Need same L/E to probe same Δm2 region as atmospheric • Confirmed with accelerator neutrinos • K2K and MINOS

K2K: PRL 98, 081802 (2005) MINOS: PRL 101, 131802 (2008)

M.O. Wascko NEPPSR 2009 36 Confirming Atmospherics

νµ+N→µ+X

• Need same L/E to probe same Δm2 region as atmospheric • Confirmed with accelerator neutrinos • K2K and MINOS

K2K: PRL 98, 081802 (2005) MINOS: PRL 101, 131802 (2008)

M.O. Wascko NEPPSR 2009 36 3 Flavors

flavor mass

M.O. Wascko NEPPSR 2009 37 3 Flavors

Atmospheric Cross-Mixing Solar

where cij = cosθij, etc.

M.O. Wascko NEPPSR 2009 37 3 Flavors

Atmospheric Cross-Mixing Solar

where cij = cosθij, etc.

Mass (eV) 0.05 ν3 flavour key:

atmospheric νe νµ ντ

0.009 solar ν2 1 ? ν

M.O. Wascko NEPPSR 2009 37 Open Questions

flavour key: νe νµ ντ • What is the last mixing angle? Mass (eV) • Do νs violate CP symmetry? 0.05 ν3 • What is the mass hierarchy? atmospheric • What is the absolute mass scale? 0.009 solar ν2 1 Are νs the same as νs? ? ν •

M.O. Wascko NEPPSR 2009 38 Searching for θ13

M.O. Wascko NEPPSR 2009 39 T2K “Tokai-To-Kamioka”

• Physics Goals: • precise atmospheric oscillation measurements • search for θ13 • Start with world’s largest detector: Super-Kamiokande • Build new neutrino beam • Near detectors at 280m to constrain beam flux

http://xxx.lanl.gov/abs/hep-ex/0106019

M.O. Wascko NEPPSR 2009 40 T2K experimental strategy Intense beam Gigantic detector π, π, π, π, Κ oscillation protons ν, ν, ν, ν

M.O. Wascko NEPPSR 2009 41 T2K experimental strategy Intense beam Gigantic detector π, π, π, π, Κ oscillation protons ν, ν, ν, ν

NA-61 Φν(E)

M.O. Wascko NEPPSR 2009 41 T2K experimental strategy Intense beam Gigantic detector π, π, π, π, Κ oscillation protons ν, ν, ν, ν

NA-61 Φν(E) σ σ

νµ µ νµ µ p p

near far σ(E)⋅Φν (E) ⇔ σ(E)⋅Φν (E) ν µ

proton

M.O. Wascko NEPPSR 2009 π 41 T2K experimental strategy Intense beam Gigantic detector π, π, π, π, Κ oscillation protons ν, ν, ν, ν

NA-61 Φν(E) σ σ

νµ µ νµ µ p p

near far σ(E)⋅Φν (E) ⇔ σ(E)⋅Φν (E) ν µ

proton

M.O. Wascko NEPPSR 2009 π 41 Background Uncertainties

• Need precise cross section measurements • νµ and νµ

- νµ µ- νµ µ

+ + W+ W π n p p CCQE CC1π+ p T2K Energy

M.O. Wascko NEPPSR 2009 42 Background Uncertainties

• Need precise cross section measurements • νµ and νµ

- νµ µ- νµ µ

+ + W+ W π n p p CCQE CC1π+ p

M.O. Wascko NEPPSR 2009 42 Let’s measure σν

K. Hiraide

• SciBooNE well matched to T2K

- νµ µ- νµ µ

+ + 0 1 2 3 W+ W π n p p CCQE CC1π+ p

M.O. Wascko NEPPSR 2009 43 SciBooNE collaboration

SciBooNE, 2008 • Universitat Autonoma de Barcelona • University of Colorado • Columbia University • Fermi National Accelerator Laboratory • High Energy Accelerator Research Organization (KEK) • Imperial College London* • Indiana University • Institute for Cosmic Ray Research • Kamioka Observatory • Kyoto University* • Los Alamos National Laboratory Spokespersons: • Louisiana State University T.Nakaya, Kyoto University M.O.Wascko, Imperial College • Massachusetts Institute of Technology • Purdue University Calumet • Università degli Studi di Roma and INFN-Roma • Saint Mary’s University of Minnesota • Tokyo Institute of Technology • Universidad de Valencia

M.O. Wascko NEPPSR 2009 44 SciBooNE Detector Scintillator Bar Muon Range (SciBar) Detector (MRD) Parts recycled from past Used in K2K experiment experiments

ν beam

Electron Catcher (EC) Used in CHORUS, HARP and K2K

M.O. Wascko NEPPSR 2009 45 SciBooNE Detector Scintillator Bar Muon Range (SciBar) Detector (MRD) Parts recycled from past Used in K2K experiment experiments

DOE-wide Pollution Prevention Star (P2 Star) Award ν beam

Electron Catcher (EC) Used in CHORUS, HARP and K2K

M.O. Wascko NEPPSR 2009 45 SciBooNE Performance

SciBooNE installed and commissioned in spring 2007

0

ν ν ν

Phys.Rev.D 78 112004 (2008), arXiv:0811.0369 http://nuint09.ifae.es M.O. Wascko Columbia HEP Seminar 46 SciBooNE Performance

SciBooNE installed and commissioned in spring 2007

0

ν ν ν

Phys.Rev.D 78 112004 (2008), arXiv:0811.0369 http://nuint09.ifae.es M.O. Wascko Columbia HEP Seminar 46 SciBooNE Performance

SciBooNE installed and commissioned in spring 2007

0

ν ν ν

Phys.Rev.D 78 112004 (2008), arXiv:0811.0369 http://nuint09.ifae.es M.O. Wascko Columbia HEP Seminar 46 Off-Axis Beam

• Use kinematics of pion decay to tune the neutrino energy • Flux peak at target energy for desired value of L/E

• Eν well matched to Super-K

M.O. Wascko NEPPSR 2009 47 Off-Axis Beam

• Use kinematics of pion decay to tune the neutrino energy • Flux peak at target energy for desired value of L/E

• Eν well matched to Super-K

M.O. Wascko NEPPSR 2009 47 Absolute Scale of Neutrino Mass

M.O. Wascko NEPPSR 2009 48 Beta decay endpoint

2 2 • Sensitive to = √(∑ |Uei| mi ) M.O. Wascko NEPPSR 2009 49 Tritium Decay Spectrometers

3 Source Electron Spectrometer Electron Counter Nuclear Physics A 719 Source = H (2003) C153

T2

high activity .high energy resolution . high efficiency .integral spectrum: select Ee > Eth . low background

Detector

Source Pre-Spectrometer Spectrometer 70 m

M.O. Wascko NEPPSR 2009 50 Physics Reach

Assuming normal hierarchy

Yad Fiz 67, No. 11 (2004), pp. 1977–1982

M.O. Wascko NEPPSR 2009 51 KATRIN Spectrometer NEMO3

The Nature of Neutrino Mass

CUORE

SNO+ M.O. Wascko NEPPSR 2009 53 Double Beta Decay

• Can happen if single β decay is energetically forbidden • (A,Z)→(A,Z+2) + 2e- + 2ν

• If ν = ν, then can have 0νββ decay • (A,Z)→(A,Z+2) + 2e- • Best way to search for Majorana particles

2 2 • 1/τ = G(Q,Z) |M| 2 2 • mββ = ∑ |Uei| mi εi

M.O. Wascko NEPPSR 2009 54 Experimental techniques

Technique Nuclei Experiments

CUORICINO Bolometers 130Te →CUORE Heidelberg-Moscow, GERDA, Semiconductors 76Ge MAJORANA, COBRA 48Ca,116Cd, MOON, CANDLES, Scintillators 150Nd ELEGANT, KIEV, SNO+

Xenon 136Xe EXO, XMASS, NEXT

Ca, Cd, 100Mo, NEMO3 Tracker/Calo Nd, Se, Te, 96Zr →SuperNEMO

M.O. Wascko NEPPSR 2009 55 Observation?

• In 2001, a subgroup of the Heidelberg-Moscow experiment released a discovery claim • Somewhat controversial

• mββ = 440 meV (4.2σ)

Next generation can confirm or rule out

M.O. Wascko NEPPSR 2009 56 Observation?

214Bi ? 0νββ 214Bi

• In 2001, a subgroup of the Heidelberg-Moscow experiment released a discovery claim • Somewhat controversial

• mββ = 440 meV (4.2σ)

Next generation can confirm or rule out

M.O. Wascko NEPPSR 2009 56 Open Questions

1950s 1990s 2010s

Mass (eV) ν3 • Is CP violated by neutrinos? What is the mass hierarchy? 0.05 atmospheric • • What is the absolute scale? 0.009 solar ν2 • Are they Majorana or Dirac? ? ν1 • Why are they so small?

M.O. Wascko NEPPSR 2009 57 Open Questions

1950s 1990s 2010s

Mass (eV) ν3 • Is CP violated by neutrinos? What is the mass hierarchy? 0.05 atmospheric • • What is the absolute scale? 0.009 solar ν2 • Are they Majorana or Dirac? ? ν1 • Why are they so small?

Worldwide program to answer these - join us!

M.O. Wascko NEPPSR 2009 57 Thanks!

M.O. Wascko NEPPSR 2009 58