Mixture of recent results and future prospects Focus on ...hep.bu.edu/~kearns/pub/kearns-CIPANP-neutrino-plenary.pdf · · Neutrino Physics Review · Ed Kearns 28 Mass Scales We know

· Neutrino Physics Review · Ed Kearns 1

Mixture of recent results and future prospectsFocus on neutrino mass and mixing

Theoretical implications: A. de Gouvea Summary Talk

Double Beta Decay: Petr Vogel Plenary Talk


Late last millennium we learned…

Atmospheric Neutrinos Solar NeutrinosNeutrino flavors mix, implying that neutrinos have mass

Super-K SNO

( ) ( ) (SSM)e e µ τν ν ν νΦ < Φ + + ≈ Φ

Confirmed by MACRO, Soudan 2 Also important: Super-K, SAGE, Gallex/GNO, Homestake


An important limit from Chooz

No evidence for reactor neutrinodisappearance over ~ 1 km


Neutrino Bases


Neutrino flavor mixing

+ for - for potential for CPV

νν

B. Kayser


Two-flavor neutrino oscillations


Matter Effects


MNS Parameterization

WHY??


SK I+II Atmospheric Neutrinos

SK-I: 1489 daysSK-II: 804 days } 23,000 ν’s

100 MeV – 10 TeV


SK I+II Finely Binned Analysis

380 bins × (SK-I+SK-II)+ 70 systematic terms

2

2 3 2

2

Super-K I+II Preliminary839.7 / 755 DOF (18%)

m 2.5 10 eVsin 2θ = 1

χ−

=

∆ = ×

Recover ∆m2 sensitivity of L/E analysis while maintaining sin22θ sensitivity of up-down zenith bins


Does it Quack Like a Duck?Use sub-sample of high-resolution events to resolve oscillation maximum

2 0.2 3 20.3

2 0.00.4

2.4 10 eV

sin 2 1.0

m

θ

+ −−

+−

∆ = ×

=

2

2

( ) 4.8( ) 5.3decoherencedecay

χ σ

χ σ

∆ =

∆ =

Statistically separate (NN & likelihood) tau-like events in high energy sample; look for up-down asymmetry (after accounting for oscillation)

disfavor no tau content by ~ 2.4σ


Super-K IIINews: Rebuilt and filling.(almost full now)

Physics program:

• proton decay

• supernova,

• high-statistics atmospheric ν (subdominant studies)

• high-statistics solar ν (spectral shape)

2008 Electronics and DAQ upgradePossible Gd-salt addition for n-capture (reactor ν, relic SN)2009 T2K beam begins


Current Solar Neutrino Results

SNO: 391 day salt data, CC energy spectrum No sign of distortion


Our little corner of MSW space

Experimental fine-tuning? Best fit parameters are in a region where we cannot (yet) see spectral distortion or day-night effect.


SNO Neutral Current Detectors

Goal: independently detect NC by n capture(after ν+2H → ν+p+n)

Also: improve measurement of CC energy spectrum (NC removed, CC/NC correlation broken)


Confirm the Results & Test the Framework


Long Baseline Experiments

KEK - Kamioka (K2K)~1 GeV neutrinosL=250 km1999-2004

Fermilab – Soudan (MINOS)~3 GeV neutrinosL=735 kmStarted 2005

CERN – Gran Sasso (Opera/ICARUS)~17 GeV neutrinos (broadband)L=732 kmStarts in 2006


K2K Final Results

9.28.6

112

158.1OBS

EXP

N

N +−

=

=3 2

3 2

Best fit: (1.19, 2.55 10 eV )Phys. region: (1.0, 2.75 10 eV )

−

−

×

×

0.92 × 1020 pot (1.05 × 1020 delivered)

~ 4σ confirmation of atmospheric neutrino mixing


MINOS

Main Injector

νs to Soudan, MN

Near Detector

Far Detector

120 GeV protons, 4x1013 ppp, 1.87 s cycle0.4 MW beam power1 kton near detector5.4 kton far detector484 steel/scintillator planes1.2 T solenoidal magnetic field750 km baseline, peak energy ~ 3 GeV92% νµ, 1.5% νe/νe-bar


MINOS First Results

( 10 GeV, only)

92177 11

OBS

EXP

E

NN

µν<

== ±

5σ deficit5.8σ spectral distortion

Expect 1.4e20 pot result soon (Nu2006)


MINOS Future Prospects


Electron ν Appearance at MINOS

Not the optimal detector for EM showers, but important physics goal is at hand with some sensitivity beyond Chooz


KamLAND Overview


KamLAND Results


KamLAND compared with Solar

KamLAND measurement is based on vacuum oscillation;solar survival probability relies on matter effect. Important comparison!


Global Fits

KamLAND

Solar

Atmospheric

ChoozAtmospheric


What we know

B. Kayser


Mass Scales

We know the neutrino is much lighterthan the quarks and leptons. The most massive must have m > 0.05 eV( ). But there are further options:

Degenerate

5 27 10 eV−×}

3 22.5 10 eV−×

Normalhierarchy

3

2

1

Invertedhierarchy

21

3

2atmm∆

A. de Gouvea


Absolute Scale of Neutrino Mass

Tritium: m < 2.2 eVKATRIN → 0.2 eV

Precision cosmology: m < 0.2 eVFuture surveys → 0.05 eV range!?


LSND

Can’t be accommodated with 3 neutrinos. Sterile? (LEP 3ν)

Significant (3.8σ), know known defectComplementary experiment (KARMEN) sees no effect (but with less sensitivity)


MiniBooNE

EnuQE (GeV)0 0.5 1 1.5 2 2.5 3

0

10

20

30

40

50

EnuQE (GeV)0 0.5 1 1.5 2 2.5 3

0

10

20

30

40

50

Osc νe

MisID νµ

νe from µ+

νe from K+

νe from K0νe from π+

540 m (10 LSND)500 MeV (10 LSND)

not

LE

µ µν ν

= ×= ×

Blind Analysis

Un-blind sample

950 kl of pure mineral oilCherenkov+scintillation1280 PMTs

STATUS:• 7.2x1020 pot• anti-ν since Jan. 2006• Expect result later this year• Important to be unambiguousand correct!• Major progress with optical model, questions about event rate


θ13 – Gateway Parameter


Off-axis Technique


Physics GoalsDiscover νe appearance (first such result barring LSND/MiniBooNE), measuring non-zero θ13

Resolve if θ23 is non-maximalMore precisely measure ∆m23


T2K

New J-PARC beam 0.7 MW beam power Construction well underwayFirst beam 2009 (but gradual turn-on)

295 km baseline, E ~ 0.7 GeV

22.5 kton FV Super-Kamiokande far detector280m and 2km near detectors


NOνA

Fermilab/NuMI beam (upgraded after collider shutdown to 6.5e20 ppy)

810 km baseline, E ~ 2.2 GeV

30 (25) kton totally active detector

Planes of liquid scintillator (mineral oil) read by WLS fiber and APD

Surface detector with small overburden (below)


Resolving the Mass Hierarchy

δm223=2.5x10-3 eV2 sin22θ23=1.0

δm212=7.1x10-5 eV2 sin22θ12=0.81

sin22θ13=0.16

νe

νe

600 MeV290 km

2.3 GeV820 km

T2K NOνA10% 10%

bigger

Matter effect enhances νe appearance for normal hierarchyEffect is reversed (enhanced anti-νe) for inverted hierarchy


Degeneracies and CPV

inverted

normalMattereffect

δT2K NOνA

νe

10% 10%

sin2 2θ 13

0.16

0.05

νe

0 +δ0+δ

5%

5%

5%


Beyond T2K


Precision Reactor Experiments

100 km10 km

Surv

ival

Pro

babi

l ity

• only depends on θ13, not δ nor mass hierarchy

• Requires careful control of systematics < 1%

• Require multiple detectors

• Require overburden to reduce background

• Can reach sin22θ ~ 0.01


Example Reactor Experiments

Daya Bay:• 200-1000 mwe overburden• 0.3/1.8-2.2 km baseline• Construct tunnels and labs (above)• 8x 20-ton modules – moveable• Goal of 0.36% systematics• Reach sin22θ ~ 0.01

Double Chooz:• 50-300 mwe overburden• 0.3/1.8-2.2 km baseline• Existing infrastructure – early start?• 2x 10-ton modules – fixed• Goal of 0.6% systematics• Reach sin22θ ~ 0.03


Conclusion

Neutrino program worldwide is currentlyvery active.

Eagerly anticipated results from MINOS and MiniBooNE are here or imminent.

Variety of projects in place or proposed tofully probe neutrino mass and mixing.The next big goal is seeing νe appearanceand measuring θ13.

Documents

Mixture of recent results and future prospects Focus on ...hep.bu.edu/~kearns/pub/kearns-CIPANP-neutrino-plenary.pdf · · Neutrino Physics Review · Ed Kearns 28 Mass Scales We know