INFN - Napoli Pasquale Migliozzipeople.na.infn.it/~santorel/seminari/doc/migliozzi.pdf · Pasquale...

Neutrino Oscillation Experiments

Pasquale MigliozziINFN - Napoli

Pasquale Migliozzi - INFN Napoli

Outline of the talk

The Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrixPresent experimental knowledge of the PMNS matrix

Atmospheric neutrinosSolar neutrinosAccelerator and reactor neutrinos

What is missing?Future projects

CERN-Gran Sasso (Europe) and NuMi (USA)JHF-SK (Japan) and NuMi off-axis (USA)Super Beams, Beta Beams and Neutrino Factories Conclusion


ilil U νν ∑=If neutrinos have mass:

ijijijij sandcwhere θθ sin,cos ==

τττ

µµµ

eee

li

cs

sc

iδecssccs

sc

UUUUUUUUU

U0

010

0

00

010

001

0

0

001

100

0

0

1313

1313

2323

23231212

1212

321

321

321

−⋅

−⋅

−⋅

−=

=

For three neutrinos (I assume that MiniBooNE will not confirm LSND because present datastrongly disfavor sterile neutrinos that would be compatible with LSND).

The PMNS leptonic mixing matrix

Similar to the CKM mixing matrix for quarks


τττ

µµµ

eee

li

cs

sc

iδecssccs

sc

UUUUUUUUU

U0

010

0

00

010

001

0

0

001

100

0

0

1313

1313

2323

23231212

1212

321

321

321

−⋅

−⋅

−⋅

−=

=


For three neutrinos:


Three Angles


τττ

µµµ

eee

li

cs

sc

iδecssccs

sc

UUUUUUUUU

U0

010

0

00

010

001

0

0

001

100

0

0

1313

1313

2323

23231212

1212

321

321

321

−⋅

−⋅

−⋅

−=

=


For three neutrinos:


CP violating phase!


∆mij2≡(mi

2-mj2) is in (eV/c2 )2

L is in km, and E is in GeV


NotationMixing parameters: U = U (θ12, θ13, θ23, δ) as for CKM matrix

Mass-gap parameters: M2 = ∆m212 , ± ∆m2

23

The absolute neutrino mass scale should be set by direct mass measurements:

• β-decay• 0ν2β-decay• “W-MAP”


So what do we have to measure?Three angles (θ12, θ13, θ23)Two mass differences (∆m2

12 (or δm2), ∆m223 (or ∆m2))

The sign of the mass difference ∆m2 (±∆m223)

One CP phase (δ)The source of atmospheric oscillations (detect τappearance)The absolute masse scaleAre neutrino Dirac or Majorana particles (or both)?Are there more - sterile - neutrinos?

All the underlined items can be studied with LBL experiments


The Super-Kamiokande detector50,000 ton water Cherenkov detector　(22.5 kton fiducial volume)


SK data as function of the zenithal angle

MC expectations; Oscillation fit; data pointsPossible interpretation νµ → ντ


K2K – the first LBL experiment

Results limited by systematic erroron the beam spectrum


K2K energy spectrum

The value of ∆m2 determines

the oscillation minimum,

giving the maximum event rate

suppression

(GL Fogli, E. Lisi, A. Marrone and D. Montanino, hep-ph/0303064)


Solar Neutrinos


Sudbury Neutrino Observatory

1700 tonnes InnerShielding H2O

1000 tonnes D2O

5300 tonnes Outer Shield H2O

12 m Diameter Acrylic Vessel

Support Structure for 9500 PMTs, 60% coverage

Urylon Liner andRadon Seal


ν reactions in SNO

- Good measurement of νe energy spectrum- Weak directional sensitivity ∝ 1-1/3cos(θ)

- Both SK, SNO- Mainly sensitive to νe,, less to νµ and ντ- Strong directional sensitivity

ES -- +⇒+ eνeν x x

CC-eppd ++⇒+ν e

- νe ONLY

NCxx νν ++⇒+ npd

- Measure total 8B ν flux from the sun.

- Equal cross section for all ν types


Physics Implication: Flavor Content

Strong evidence of flavor change

Φssm = 5.05+1.01-0.81 Φsno = 5.09+0.44

-0.43+0.46-0.43

Φµτ is5.3 σ from zero


Impact of solar neutrinos

By combining the four solar experiments, only the large mixing angle solutions are seen to survive:

LOW: at lower δm2, with a long tail in the quasi-vacuum region

LMA: preferred by data, below the maximal mixing line

All solar neutrino experiments(Homestake, Gallex, SK, SNO)are fitted simultaneously

LOW

LMA

maximal mixing line

QUASIVACUUM

Cl+ Ga + SK + SNO (no CHOOZ)

δm2

(eV2 )

tan2θ12


Reactor experimentsWhile atmospheric (SK) and K2K bounds on (∆m2

23, θ23) can be studied well in the 2ν approximation, a 3ν analysis is mandatory for reactor experiments:

Pee = Pee (∆m212, θ12, θ13, ∆m2

23) survival νe probabilityReactor Reactor

In practice, ∆m223 is marginalized away in the χ2 construction,

by adding the “atmospheric + K2K” likelihood

Therefore, “solar and reactor” data are linked through the parameters

(∆m212, θ12, θ13)


The KamLand experiment

180 km

300


The KamLAND dataThe KamLAND total rate singles LMA out

The KamLAND spectrum fixes the LMA sub-structure:

Above the analysis threshold (2.6 MeV) the “bulk” of the spectrum (first 4 bins above threshold) seems more suppressed than the “tail”


Ratio of Measured to Expected νe Flux from Reactor Neutrino Experiments

Continuous line is the expected value for ∆m2 = 5.5x10-5eV2 sin22θ12=0.833

G.Fogli et al., PR D66, 010001-406, (2002)


Impact of solar and reactor neutrinos

maximal mixing line

LMA - II

LMA - I

δm2

(eV2 )

sin2θ12

Taking LMA-I as the reference solution, we can extract the following ±1σ estimate for the relevant solar 3ν parameters:

LMA-I solution (~1σ) δm2 ≈ (7.3 ± 0.8)x 10-5 eV2

sin2 θ12 ≈ 0.315 ± 0.035sin2 θ13 ≤ 0.017

This is one of the conditions to fulfilled to make CP detectable in the leptonic sector


What still we have to measure?Three angles (θ12, θ13, θ23)Two mass differences (∆m2

12, ∆m223)

The sign of the mass difference ∆m2 (±∆m223)

One CP phase (δ)The source of atmospheric oscillations (detect τappearance)The absolute masse scaleAre neutrino Dirac or Majorana particles (or both)?Are there more - sterile - neutrinos?

All the underlined items can be studied with LBL experiments

DiscoveryPrecision meas.


1st

gen.

2nd

gen.

3rd

gen.


Goals of 1st generation of Long Baseline Experiments

Confront emerging picture with precision dataconfirm oscillation hypothesis:

must measure/know E & L precisely to see oscillations in L/Epin down oscillation parameters (with 10% precision)

demonstrate νµ ντ is dominant mode:Tau appearance ! (CNGS direct, MINOS NC/CC)

Look for new phenomenaevidence for non-zero θ13 → detection of νe appearancetest for possible CPT violation?etc. etc.


Close detector


The NuMi beam

Low energy beam: less flux, but better match to ∆m223

Still plenty of events: ~ 5000 νµ CC events in 2 yrs

Protons120 GeV


Expected Neutrino Energy Distributions in 2 years


1st Supermodule (1/2 detector) done, the 2nd one is being commissioned

Meanwhile first magnetizeddata on atmospheric ν


Summary of MINOS

Data-taking with NuMI beam will begin early 2005Far & Near detector on schedule, Far det. already complete (detector very stable: < 1 ns timing drifts, ~ 1% pulse height drifts) Calibration detector running & data analysis will be completemuch progress on NuMI: civil & technical components

By 2007, they will provide a precise measurementsoscillation parameters: νµ ντ case;(NC/CC ratio for mode id)search for subdominant νµ νe (discussed later)

Also ~ 24 kiloton-year exposure to atm. ν’senergy, direction resolution competitive on νµ ντ

1st direct search for CPT non-cons. (νµ νµ vs νµ νµ)


The CNGS neutrino beam

ICARUS

The beam will

start i

n may 2006


CNGS beam layout at CERN site.

Progress in the civil engineering work: excavation completed concreting started

CNGS commissioning: May 2006


Nominal ν beam (Nov. 2000)

Shared SPS operation

200 days/year

4.5x1019 pot / year

Average νµ energy 17 GeV

5 year run

Expected interactions in 1kton detector

~ 18000 νµ NC+CC

~ 80 ντ CCat ∆m2

23 = 2.5x10-3 eV2 and full mixing

The CNGS and the expected number of events

Limiting factor for θ13 search:νe + anti-νe beam contamination ~0.87%

An updated CNGS with a flux 1.5 more intense than the one approved in 2000 is now considered as the baseline option


d

d

p

p

Ionization electrons paths

Drift

ionizing track

Ionization electrons drift (msec) over large distances (meters) in a volume of highly purified liquid Argon (0.1 ppb of O2) under the action of an E field. With a set of wire grids (traversed by the electronsin ~ 2-3 µs) one can realize a massive, continuously sensitive electronic “bubble chamber”.

The ICARUS working principle


≈300‘000 kg LAr= T300

ICARUS T600 (1 half-module out of 2)

ICARUS T600 (1 half-module out of 2)


18 m

1.5 m

1.5 m

Left

Cha

mbe

rRi

ght

Cham

ber

Cathode

Long longitudinal muon track crossing the cathode plane

Track Length = 18.2 m

3D ViewTop View

dE/dx = 2.1 MeV/cm

3-D reconstruction of the long track3-D reconstruction of the long track

dE/dx distribution along the trackdE/dx distribution along the track


νµ →ντ oscillations

Analysis of the electron sampleExploit the small intrinsic νe contamination of the beam (0.8% of νµ CC)Exploit the unique e/π0 separation

Statistical excess visible before cuts ⇒ this is the main reason for performing this experiment at long baseline !

At ∆m223=3.5x10-3 eV2 165 τ → e events are expected

Main background from charged current interactions of νe in the beam 700 events are expected


τ→e search: 3D likelihood

3 variablesEvisible, PT

miss, ρl≡PTlep/(PT

lep+ PThad+PT

miss)Exploit correlation between them

LS ([Evisible, PTmiss, ρl]) (signal)

LB ([Evisible, PTmiss, ρl]) (νe CC back)

Discrimination given by

5 T600 modules, 5 years CNGS (4.5 x 1019 p.o.t./year)

0

5

10

15

20

25

30

35

40

-2 0 2 4 6 8 10lnλ

Eve

nts

/12

kto

n x

yea

r

νe CC + ντ CC

νe CC

ντ CC, τ→ e

Overflow→

lnλ ≡L([Evisible, PTmiss, ρl]) = Ls / LB

lnλ

Vertex cuts applied

A simple analysis approach: a likelihood method based on 3 variables


νµ→ ντ appearance search summary

Super-Kamiokande: 1.6 < ∆m2 < 4.0 at 90% C.L.

T3000 detector (2.35 kton active, 1.5 kton fiducial)Integrated pots = 2.25 x1020

Several decay channels are exploited (golden channel = electron)(Low) backgrounds measured in situ (control samples)High sensitivity to signal, and oscillation parameters determination

(these numbers have to be multiplied by a factor 1.5)


The Emulsion Cloud Chamber (ECC)

Emulsions for tracking, passive material astarget

Established technique charmed “X-particle” first observed

in cosmic rays (1971)DONUT/FNAL beam-dump experiment: 7 ντ

observed (2000)

< µm space res. mass

Pb

ντ

1 mm

Emulsion layers

track segments

Experience with emulsions and/or ντ searches :E531, CHORUS, NOMAD and DONUT

∆m2 = O (10-3 eV2 ) → Mtarget ~ 2 kton

modular structure (“bricks”): basic performance is preservedlarge detector → sensitivity, complexityrequired: “industrial” emulsions, fast automatic scanning


Event reconstruction with an ECCHigh precision tracking (δx < 1µm ; δθ < 1mrad)

Kink decay topologyElectron and γ/π0 identification

Energy measurement Multiple Coulomb ScatteringTrack counting (calorimetric measurement)

Ionization (dE/dx meas.)π/µ separation e/π0 separation

Topological and kinematical analysis event by event

5X0

( ~

½br

ick)

1 mm

5 cm

ECC exposure at CERN-PS

0 1-1 mm

mm

0

10

3020

40

-2

π0


Cell structure; exploited τ decay channels and topologies

“Long” decayskink angle θkink > 20 mrad

τ → e Progr. Rep. 1999

τ → µ Progr. Rep. 1999

τ → h (nπ0) Proposal 2000

+ ρ search Status Rep. 2001

“Short” decaysimpact parameter I.P. > 5 to 20 µm

τ → e Proposal 2000

τ → µ Status Rep. 2001

kink

θkink

Long decays

Pb(1 mm)

plastic base

I.P.

Short decays

emulsion layers

Pb(1 mm)

An optimized channel by channelanalysis is in progress. Ready by summer


Backgrounds for the νµ→ ντ search

Charm productionCross-section and charmed fractions based on neutrino data

Large angle µ scatteringRate of µ scattering off lead estimated by using

MC simulation including nuclear form factors(cross-checked with NOMAD data)

data from 7.3 GeV/c µ scattering off copper

µ scanned in the CHORUS emulsionsScattering off lead of µ (p= 6-10 GeV/c) experimentally studied by the Collaboration. Results in agreement with expectations

Hadron reinteractions with kink topologythe present estimate is based on a FLUKA simulationconsistent with preliminary results from dedicated experiments


Aim at the evidence of ντ appearance after a few years of data taking

0.6750.419.810.3With possible improvements

1.0643.817.29.0Final DesignCNGSx1.5 *)

Backsignal(∆m2 = 4.0 x 10-3 eV2)

signal(∆m2 = 2.5 x 10-3 eV2)

signal(∆m2 = 1.8 x 10-3 eV2)

Expected number of eventsfull mixing; 5 years run @ 4.5x1019 pot / year

*) An updated CNGS with a flux 1.5 more intense than the one approved in 1999 is now considered as the baseline option


The detector construction is in progress

νµ → νe search with OPERA(interesting by product)

A similar analysis can also be performed with the ICARUS detector


Backgrounds for the νµ → νe search

π0 identified as electrons produced in νµ NC and νµ CC with the µ not identifiedνe beam contamination (main background)τ → e from νµ→ ντ oscillations (strongly reduced thanks to the capability in detecting decay topologies)

In the following we assume a three family mixing scenario with θ23 = 45º


OPERA sensitivity to θ13

By fitting simultaneously the Ee, missing pT and Evis distributionswe got the sensitivity at 90%

2.5x10-3 eV2

0.05

5years data taking


Summary of the CNGS project

Construction of CNGS is well underway. The tunnel excavation is complete. The remaining construction work is on schedule (Beam starts by mid 2006)The ICARUS and OPERA experiments will permit

An unambiguous direct evidence of τ appearance in a νµbeamA measurement of ∆m2

23 at 10-20%Extend sensitivity for small νµ→νe mixings (competitive with other experiments)

The construction of the detectors is in progress and it is planned to be completed by mid 2006


Goals of 2nd generation of Long Baseline Experiments

Precision measurement of PMNS matrix elementssin22θ23 with 1% accuracy

∆m223 with few% accuracy

Discovery (if not done by 1st generation experiments) and measure non-zero θ13

They could give the 1st evidence of 3-flavor mixingIn case of non-zero θ13 precision measurement1st step to CP measurement

NB If θ13< 1° impossible to assess CP violation in the leptonic sector. The other condition to make CP in the leptonic sector detectable has been fulfilled by KamLAND (LMA solution)


JHF-Super-KamiokandeNeutrino Experiment

~1GeV ν beam

Kamioka JAERI(Tokai)

0.75MW 50 GeV PS( conventional ν beam)

Super-K: 22.5 kt

Plan to start in 2008-9

JHF 0.75MW + Super-Kamiokande


JHF FacilityConstruction2001～2006 (approved)

8 bunches/~5µs3.3x1014proton/pulse3.94 (3.64) sec cycle1yr ≡ 1021 POT (130 days)

ν beam-linebudget request submitted

Near detectors (280m,2km)


νµ

OA2°

Osc. Prob.=sin2(1.27∆m2L/Eν)

∆m2=3x10-3eV2

L=295km

osc

.max

.

Off Axis Beam(ref.: BNL-E889 Proposal) θTargetHorns

Decay Pipe

Super-K.

Quasi Monochromatic Beamx2~3 intense than NBB

Statistics at SK(OAB2deg, 1yr,22.5kt)~4500 νµ tot ~3000 νµ CC νe ~0.2% at νµ peak ~102 x (K2K)

Tuned at oscillation maximum

Oscillation probablity


Detectors

Muon monitors @ ~140mSpill-by-spill monitoring of beam direction

First Front detector @280mNeutrino intensity/direction

Second Front Detector @ ~2kmAlmost same Eν spectrum as for SKWater Cherenkov can work

Far detector @ 295kmSuper-Kamiokande (50kt) 0

200

400

600

800

1000

1200

1400

1600

1800

x 10 3

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Eν (GeV)

1.5km

295km

0.28km

Neutrino spectra at diff. dist

dominant syst. in K2K

p π ν

140m0m 280m 2 km 295 km


Eν reconstruction in water Cerenkov

Assume CC Quasi Elastic (QE) reaction

µµµ

µµν θcos

22

pEmmEm

EN

N

+−

−=µ

p

ccQE

inelasticνµ + n → µ + p

+nπ

νµ + n → µ + p

ν

(Eµ , pµ)

beam energy

ccQEcc-inelastic


Measurement of sin2 2θ23-∆m223

δ(sin22θ23)~0.01 δ(∆m223)~<1×10-4

δ(∆m

232

)

True ∆m232 (eV2)

OAB-2degree,5yr

δ(si

n2 2θ 2

3)


sin22θ13 from νe appearance

Off axis 2 deg, 5 years


NuMI Off-AxisTwo possible sites

Closer site, in MinnesotaAbout 711 km from FermilabClose to Soudan LaboratoryUnused former mineUtilities availableFlexible regarding exact location

Further site, in Canada, along Trans-Canada highway

About 985 km from FermilabThere are two possibilities:

About 3 km to the west, south of Stewart LodgeAbout 2 km to the east, at the gravel pit site, near compressor station


θ13 sensitivity

How the sensitivity to θ13 depends on the CP phase?In case of null results, what we can say about

future (JHF-HK, Neutrino Factory) expts?


Oscillation probability( )[ ]

( )( ) ( )[ ]

( )( ) ( )[ ]

( )( )

( ) ( ) 4321

2

122

2322

13

13

2

2

232

132

ˆ

ˆsin2sincos

ˆ1

ˆ1sinˆ

ˆsincoscossin

ˆ1

ˆ1sinˆ

ˆsinsinsinsin

ˆ1

ˆ1sinsin2sin

OOOO

P

CP

CP

e

+++≡

∆+

−∆−∆

∆+

−∆−∆

∆

−

∆−≅→

δδ

θθα

δξθα

δξθα

θθνν µ

2AA

AA

AA

AA

AAA

A

m

12

231

221

θξ

α

∝

∆∆

=mm

effects Matter ∝A

νν for for

+

−


Oi terms in osc. prob. vs θ13

JHF CNGS


Several observations

The first and the forth terms are independent of the CP violating parameter δIf θ13 is very small (≤ 1o) the second term (subdominant oscillation) competes with 1stFor small θ13, the CP terms are proportional to θ13; the first (non-CP term) to θ13

2

The CP violating terms grow with decreasing Eν (for a given L)There is a strong correlation between different parametersCP violation is observable only if all angles ≠ 0


θ13 issue

The measurement of θ13 is made complicated by the fact that oscillation probability is affected by matter effects and possible CP violationBecause of this, there is not a unique mathematical relationship between oscillation probability and θ13

Especially for low values of θ13, sensitivity of an experiment to seeing νµ→νe depends very much on δSeveral experiments with different conditions and with both ν and ν will be necessary to disentangle these effectsθ13 needs to be sufficiently large if one is to have a chance to investigate CP violation in ν sector


Accelerator expts. sensitivity vs δCP (1)

There are δCP values forwhich the sensitivity on θ13is even better than the one compute in the 2-flavor approximation (δCP=0).

Notice the different behaviour on ∆m2 of theCNGS sensitivity⇒ Possible measurementof the sign of ∆m2

31?


Conclusion in case of null resultThe measurement of θ13 is made complicated by the fact that oscillation probability is affected by matter effects and possible CP violationThe sensitivity of JHF-SK/NUMI off axis is comparable with the one of the CNGS program for high values of α and for certain values of δCP.

Of course, an additional anti-ν runwould help in increasing the sensitivity of JHF-SK for large values of α.

Another possibility is to perform a pureθ13 measurement with reactors (H.Minakata et al. hep-ph/0211111)

From G.L. Fogli et al. hep-ph/0212127

If νµ → νe is observed

In the following: assume ICARUS and OPERA taking data from 2006 on


CNGS at the start-up of JHF-SK

3 years data taking at the CNGSSensitivity: sin22θ13 < 0.035 @ 90% C.L. (a factor 4 better than CHOOZ)

Indication (90% C.L) of νe appearance if θ13 > 7°

(10.+3.7-4.4)°13.7°5.6°10°

(7.5+3.9-6.3)°11.4°1.2°7.5°

---7.0°---5.0°

---5.8°---2.5°

---5.5°---1°

θ13|maxθ13|minθ13|true90% C.L. allowed region

∆m2<0 ∆m2>0


Allowed regions for JHF (5 years) + CNGS (8years)θ13=5° θ13=10°

∆m2<0 ∆m2>0 ∆m2<0 ∆m2>0


Conclusion in case νe appearance is observed

If θ13 > 7°, CNGS could give a first indication of νeappearance after three years data taking The CNGS is an off-peak beam, therefore it has a different pattern from JHF-SK ⇒ they can be used in synergyAfter the completion of the approved CNGS program, one could continue the data taking

CNGS (8y) + JHF-SK(5y) could measure θ13 with 20% accuracy and constrain δCP


Goals of 3rd generation of Long Baseline Experiments

Precision measurement of PMNS matrix elementsDiscovery and measure non-zero δCP, and determine the mass hierarchy (if not done by 2st generation experiments)

several experiments with different running conditions will be required in order to disentangle the true solution from degenerate solutions

NB If θ13< 1° impossible to assess CP violation in theleptonic sector. However, correlation effects could mimic small θ13 I.e. :

δCP is positive and very large → giving up JHF-HK and Neutrino Factory would be a tremendous mistake because after an anti-ν run one would have a “monumental” signal


Super-JHF(4MW)+Hyper-K(1Mt)

~1,000 kt

Candidate site in Kamioka

Good for atm. νproton decay


1. Produce a radioactive ion with a short beta-decay lifetime

2. Accelerate the ion in a conventional way (PS) to “high” energy

3. Store the ion in a decay ring with straight sections.

4. By its β-decay, νe (νe) will be produced.

- SINGLE flavour (νe )- Known spectrum/intensity- Focussed (1/γ) - Low energy (Eν = 580 MeV)

The “quality factor” QF=γ/Ecms (Nint ∝ γ/ Ecms) is bigger than in a conventional neutrino factory. In addition, ion production and collection is easier. Then, 500000X more time to accelerate.

Muons:γ~500Ecms~34 MeVQF~15

6He Beta-:γ~150Ecms~1.9 MeVQF~79

18Ne Beta+:γ~250Ecms~1.86 MeVQF~135

The β beam


Neutrino Factories

The ultimate tool for probing neutrino oscillation, based on muon decays (NOT π DECAY !!!)

Enormous luminosityExceptional purityPerfect knowledge of spectrumFlavor of initial neutrino tagged by charge

Caveats:Technical challenges to muonaccelerationCost

• Proton drivers

• Targetry

• Particle production measurements

• RF manipulation

• Cooling

• Muon acceleration


µ+ → e++ νµ +νe

νµ → µ−

νµ→ µ+Oscillate

Wrong Sign muons

1016p/s

3 1020 νe/yr3 1020 νµ/yr

0.9 1021 µ/yr

77

Advantages of Muon Storage RingBoth νe and νµ species in beam:

A way to get well understood, high-intensity source of νe’s

νe→ντ or νe→νµ

High intensity allows:Probe small mixing angles

Long distancesStart to see earth matter effects for oscillations involving νe’s Reach solar neutrino region with accelerator beams


δ = 90º 99% C.L. Curves

Physics reach of β beams etc


Conclusion

Neutrino Physics appears to be an exciting field for many years to comeIn the short period (less than 10 years) LBL experiments like CNGS,NuMI and JHF

will measure some of the PMNS matrix elements (∆m213, sin2θ23) with a per

cent accuracywill determine unambiguously the source of the atmospheric neutrino deficit (τ appearance)have a good opportunity to observe for the first time the mixing angle θ13 ( ≥2º)

In the long term period, most likely several experiments with different running conditions will be required in order to disentangle the true solution from degenerate solutions and extract δCP and the mass hierarchy

INFN - Napoli Pasquale Migliozzipeople.na.infn.it/~santorel/seminari/doc/migliozzi.pdf · Pasquale...

Documents

Transcript of INFN - Napoli Pasquale Migliozzipeople.na.infn.it/~santorel/seminari/doc/migliozzi.pdf · Pasquale...