Sergio Palomares-Ruiz June 22, 2005 Super-NO A Based on O. Mena, SPR and S. Pascoli hep-ph/0504015 a...

June 22, 2005June 22, 2005

Sergio Palomares-Sergio Palomares-RuizRuiz

Super-NOSuper-NOAA

Based onBased on

O. Mena, SPR and S. PascoliO. Mena, SPR and S. Pascoli

hep-ph/0504015hep-ph/0504015

a long-baseline neutrino a long-baseline neutrino experimentexperiment

with two off-axis detectorswith two off-axis detectors

June 22, 2005June 22, 2005


What we know and what we do What we know and what we do not know about neutrinosnot know about neutrinos

We We don’t knowdon’t know if there are sterile neutrinos if there are sterile neutrinos

We We don’t knowdon’t know what the absolute mass of neutrinos is what the absolute mass of neutrinos is

We We don’t knowdon’t know what is their nature: Majorana or Dirac what is their nature: Majorana or Dirac

We We don’t knowdon’t know what is the mass mechanism what is the mass mechanism

We We knowknow that neutrinos do oscillate: have mass that neutrinos do oscillate: have mass

We We knowknow that there are only 3 light active neutrinos that there are only 3 light active neutrinos

June 22, 2005June 22, 2005


Solar sector

m221 = (7.6 - 8.6) 10-5

eV2

sin2 12 = (0.28 – 0.33)

Reactor sector

sin2 13 < 0.041

Atmospheric sector

| m231 | = (1.5 – 3.4) 10-3 eV2

sin2 223 > 0.92 We We don’t knowdon’t know the octant of the octant of 2323 We We don’t knowdon’t know whether there is CP violation in the lepton sector whether there is CP violation in the lepton sector We We don’t knowdon’t know the type of mass hierarchy the type of mass hierarchy We We don’t knowdon’t know whether whether 1313 is different from 0 is different from 0

We We knowknow

O. Mena and S. J. Parke, Phys. Rev. D69:117301, 2004

June 22, 2005June 22, 2005


DegeneraciesDegeneracies

((2323 , , /2 - /2 - 2323) )

(( , , 1313))

sign(sign( m m223131))

%

%

H. Minakata and H. Nunokawa, JHEP 0110:001,2001

~ sin

~ cos

June 22, 2005June 22, 2005


Resolving degeneraciesResolving degeneracies: : ((2323 , , /2 - /2 -

2323)) Atmospheric neutrino experimentsAtmospheric neutrino experiments

Sub-GeV events (solar term)Sub-GeV events (solar term) Multi-GeV events (matter effect)Multi-GeV events (matter effect)

Very long-baseline neutrino experimentsVery long-baseline neutrino experiments Through the solar term contributionThrough the solar term contribution

Neutrino factories and Neutrino factories and beams beams ee →→ and and ee →→

June 22, 2005June 22, 2005


Resolving degeneracies: Resolving degeneracies: (( , ,

1313)) Long-baseline neutrino experimentsLong-baseline neutrino experiments

Reduce degeneracy under special configurationsReduce degeneracy under special configurations

Reactor neutrino experimentsReactor neutrino experiments Only sensitive to Only sensitive to 1313

Atmospheric neutrino experimentsAtmospheric neutrino experiments

Neutrino factories and Neutrino factories and beams beams

June 22, 2005June 22, 2005


Resolving degeneracies: Resolving degeneracies: sign(sign( mm22

3131))

Atmospheric neutrino experimentsAtmospheric neutrino experiments Multi-GeV eventsMulti-GeV events

Long-baseline neutrino experimentsLong-baseline neutrino experiments Off-axis experimentsOff-axis experiments

Neutrino Factories and Neutrino Factories and beams beams

Need of matter effects → 13 0

June 22, 2005June 22, 2005


Off-axis conceptOff-axis concept

221

43.0

EE

2

2

22 4

1

1

2

LFlux

D. Beavis et al., BNL Proposal E-889

Neutrinos produced in two body decays: → +

June 22, 2005June 22, 2005


Experimental set-upExperimental set-up

NONOAA Medium energy beamMedium energy beam 50 (30) kton calorimeter50 (30) kton calorimeter L = 810 kmL = 810 km Off-axis distance = 10 kmOff-axis distance = 10 km →→ E = 2.3 GeVE = 2.3 GeV 3.7 (6.5) x 103.7 (6.5) x 102020 pot/yr pot/yr Proton Driver = Proton Driver = 18.5 (25) x 1018.5 (25) x 102020 pot/yr pot/yr

Super-NOSuper-NOA A NONOA + another off-axis detector A + another off-axis detector

with the same L/E (L = 200 km)with the same L/E (L = 200 km) We will consider 50 kton Liquid We will consider 50 kton Liquid

Argon detectors (high efficiency)Argon detectors (high efficiency) Only neutrinosOnly neutrinos 5 years5 years

NoA

2nd detector = Super-NoA

D. S. Ayres et al. [NOA Collaboration], hep-ph/0503053

June 22, 2005June 22, 2005


ProbabilitiesProbabilities Up to second order in Up to second order in 1313, , 1212//1313, , 1212/A and /A and 1212LL

A. Cervera et al., Nucl. Phys. B579:17, 2000

P( → e) = x2 f2 + 2 x y f g cos( - ) + y2 g2

x ≡ sin 23 sin 213

y ≡ (m221 / m2

31) cos 23 sin 212

f ≡ sin(-AL/2)/( - AL/2)

g ≡ sin(AL/(2 ))/(AL/(2 ))

≡ m231 L / (4 E)

June 22, 2005June 22, 2005


AsymmetryAsymmetry

)()(

)()(

FN

FN

LPLP

LPLPD

O. Mena, SPR and S. Pascoli, hep-ph/0504015

tan

11

21FFNN LALA

D

June 22, 2005June 22, 2005



tan

11

42

12sin

2

1)cos(

sin1

2222

132

12FFNN LALA

x

yDD

June 22, 2005June 22, 2005


Bi-event plot for NOBi-event plot for NOAA


P = A cos cos + B sin sin + C

P = A cos cos + B sin sin + CIt collapses to a line if:

(AB - AB) cos sin

B = AB = -A

cos sin

NONOAA 0.9 <

<1.3

June 22, 2005June 22, 2005


Bi-event plots for Super-Bi-event plots for Super-NONOAA


PF = AF cos cos + BF sin sin + CF

PN = AN cos cos + BN sin sin + CN

BF = AF

BN = AN

It collapses to a line if:

(AFB – ABF) cos sin

It is always a line

June 22, 2005June 22, 2005


Measurable integrated Measurable integrated asymmetryasymmetry


FoNo

FoNo

NNNN

NNNNA

//

//

PD

95% C.L.

2 analysis

99%95%90%

June 22, 2005June 22, 2005


Comparison with NOComparison with NOA and A and T2KT2K pot/yr = 6.5 x 1020

pot/yr (PD) = 25 x 1020

12 km off-axis3 yrs + 3 yrs

6 yrs + 6 yrs with NOA

+3 yrs + 3 yrs

with 2nd detector at second maximum

With Super-NoAonly 5 yrs to getthere

D. S. Ayres et al. [NOA Collaboration], hep-ph/0503053

June 22, 2005June 22, 2005


ConclusionsConclusions Resolving degeneracies is a crucial taskResolving degeneracies is a crucial task

Super-NOSuper-NOAA: 2 off-axis (LAr) detectors with same : 2 off-axis (LAr) detectors with same L/E using the NuMI beam L/E using the NuMI beam →→ determination of determination of sign(sign( m m22

3131) free of degeneracies) free of degeneracies

Only need of 5 years of neutrino run to resolve the Only need of 5 years of neutrino run to resolve the type of hierarchy down to sintype of hierarchy down to sin22 2 21313 = 0.02 with = 0.02 with Proton Driver (for all values of Proton Driver (for all values of ))

Better capabilities than NOBetter capabilities than NOA + T2K at HK for A + T2K at HK for determining the type of mass hierarchydetermining the type of mass hierarchy

Sergio Palomares-Ruiz June 22, 2005 Super-NO A Based on O. Mena, SPR and S. Pascoli hep-ph/0504015 a...

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