Working Group 1 Summary:

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Working Group 1 Summary
D. Casper
M. Lindner
K. Nakamura
Oscillation Physics (mostly) - Part 3 -
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• Outline
• Current knowledge of masses and mixings
• Giunti, Maltoni
• Degeneracies future LBL experiments
• Minakata, Sugiyama, Whisnant, Donini,
  Migliozzi, Winter
• New reactor plans impact on LBL
• Yasuda, Huber, Choubey
• Theory beyond 3n LBL oscillation physics
• deGouvea, Sato, Abazajian, Shrock, Ohlsson,
  Chen
• ... and plenary speakers
• ... apologies for what is not mentioned

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Knowledge of masses and mixings
3n parameters m1, Dm231, Dm221, q23, q12, q13,
d, F2, F3

• Giunti The absolute neutrino mass scale
• Kinematical measurement
• Mainz-Troitsk m lt 2.2 eV
• ? future KATRIN m S mi U2ei lt 0.3 eV
• ? atmospheric splitting 0.05 eV
• ? if m lt 3 10-2 ? normal hierarchy
• Cosmology (Raffelt)
• WMAP 2dF Ly a ? S mi lt 0.7 - 1.2eV
  
• ? further improvement expected X5

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3) Neutrino less double beta decay (for
Majorana masses)
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Giunti
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We know it is LMA! ?? CP violation
Maltoni Global fits
(3 neutrinos, ignoring LSND)
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Inlcluding LSND in 4 neutrino fits 22 scheme
ruled out by solar atm. data 31 scheme
strongly disfavoured ? tension in the data
Maltoni ?
32 scheme fits better ?? cosmology CPT
violation ? tension in the analyses...? ?
MiniBooNE
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• Impact of solar density variations
• 8 density change affects LMA region
  considerably
• requires huge magnetic fields ... ?? solar
  modelling?

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De Holanda, Smirnov hep-ph/0212270
Near future ?Formaggio (Awaited) results from
SNO
Day Night Contours ()
Probability Contours
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Future LBL experiments degeneracies
? do not compare apples with pies

• - degeneracies
• correlations

• Compare only studies which
• include all relevant experimental theoretical
  aspects
• - have equally ambitious scenarios as a function
  of
• time, technology, cost, ... ? unbiased attitude

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?? bi-probability plots
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Minakata, Yasuda Overview of degeneracies
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• Sensitivity studies, especially for sin2(2q13)
  and d-CP
• Probabilities show only qualitative behaviour
• Asymmetries are dangerous
• Perform event rate based analysis
• Include trigonometric correlations and
  degeneracies
• Include errors for external parameters
  (solar)
• Do not fix unknown parameters (e.g. d0)
• Include matter effects and matter profile
  uncertainties
• Do not omit relevant terms in oscillation
  formulae
• Proper statistical methods
• ...

Compare only complete studies (or at least
equivalent studies)
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Example MINOS sin2q13 sensitivity

• sensitivity to some parameter combination
• sensitivity to sin2q13

Huber, ML, Rolinec, to appear
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Tazanakos Updated MINOS discovery potential
Better unit pot Old limits 7.4 1020 pot Asked
for 25 1020 pot / 5y
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Strategies to break degeneracies ? combine

• Various baselines
• Different energies
• Neutrinos and anti-neutrinos
• Different oscillation channels
• Spectral information
• Oscillation with without matter
• ...
• all directions / combinations have advantages
  and disadvantages
• optimization relatively clear for next
  generation
• JHF-SK NuMI reactor
• final answer difficult for long term future
  (technology, ...)
• ...but what we know is encoutaging and it
  can only become better

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Degeneracies session Results of main groups
agree
? Impact / resoltion of degeneracies at different
LBL levels
Next generation
Sugiyama Resolving JHF degeneracies
Whisnant Combining superbeams
Migliozzi Silver channel and the neutrino factory
Neutrino factory
Donini Combining superbeams and the neutrino
factory
Winter Resolving degeneracies for different
values of Q13
) This does not mean that any study includes all
relevant aspects
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Combining JHF-SK NuMI_at_ 890 ? Synergies
Barger, Marfatia, Whisnant Huber, ML,
Winter Minakata, Nunokawa, Parke ...
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Winter
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Donini, Migliozzi
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Donini
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New reactor ideas impact on LBL
Yasuda New short baseline reactor ideas
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Yasuda, Suekane Combine reactor with JHK-SK
Very active case studies in different places ?
Link
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Huber Combining beams and reactors

• Similar sensitivity at LMA-I und atmospheric
  best fit
• Reactor sensitivity is less Dm231 and less Dm221
  dependent

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Combine Improved sin2(2q13) , sgn(Dm2) and CP
limits

• JHF-SK NuMI-890 Reactor-II perform best
• Sensitivity to sgn(Dm2) for any Dm221
• Sensitivity to CP violation in LMA-II region

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Choubey Implications of Kamland/Precision
measurement of parameters before nufact
SPMAX poor q12 sensitivity
SPMIN good q12 sensitivity

• KamLAND is not
• in the ideal place!

LMA-I ? 70 km LMA-II ? 20-30 km

• Propose a new reactor experiment at ideal
  distance
• HLMA ? even some q13 sensitivity

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Improving the solar parameters is important for
LBL!
Current studies assume typically a 10 relative
error on solar param. ... which enters via
correlations ... and contributes to the error /
limitations of LBL measurements!
? think of ideas to improve solar parameters to
few level
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Theory
There exist many models for neutrino masses
Chen Neutrino masses and mixings in SO(10) models
? attractive framework for neutrino masses
Shrock Neutrino masses without a new energy scale

• interesting alternative to explain neutrino
  masses without
• conventional see-saw in DSB framework TeV
  scales

Dirac or Majorana? Majorana see-saw ??
smallnes of neutrino masses
simplest leptogenesis scenario Dirac
other tiny Yukawa couplings exist
may be enforced by extra U(1) (strings,
...) ? experiments must decide ?? 0n2b decay, L
violation
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deGouvea Natural expectations for Ue3

• random mass matrices (anarchy) predicts large
  mixings
• large neutrino mixings may be rather natural
• why is Ue3 , i.e. sin2(2q13) so small?
• expect sin2(2q13) close to experimental
  limit
• or some protective symmetry must operate

How small could sin2(2q13) be? In general
arbitrarily small, inlcuding zero Models anarchy
? close to limit textures ? mass
ratio suppression typically down to 10-2

sin2(2q13) 0 possible, requires model
tuning Quantum corrections (RGE) ? dsin2(2q13)
10-4 .... 10-1 ? good reasons to expect
sin2(2q13) 10-2 ? reachable
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Ohlsson Extrinsic CPT violation in neutrino
oscillations

• matter violates C, CP and CPT
• interesting theoretical consequences for
  oscillation formulae
• for LBL a tiny effect ?? theoretical error of
  LBL studies

Sato Lepton flavour violation in long baseline
experiments

• 3n oscillation may be affected by LFV effects
• must be included in analysis
• less sensitivity to oscillation parameters

Abazajian Cosmological energy density of
neutrinos from oscillation measurements

• connection between cosmological energy density
  oscillation
• Future measurements of q12 and q13 will further
  constrain
• the cosmological neutrino density

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Conclusions

• Knowledge of oscillation parameters
• KamLAND has established LMA region ? ideal for
  leptonic CP violation
• Further improvements of solar data expected
  (SNO)
• MiniBooNE will clarify LSND evidence
• LBL studies have become better
• Degeneracies correlations under control
• Strategies to break degeneracies by combining
• e.g. Silver channels at NuFact
• Synergies in next generation superbeams
• New reactor experiments superbeams are
  synergetic
• ? sin2(2q13) sensitivity down to 10-2
• Theory
• Reasons to expect sin2(2q13) not below this
  magnitude

? Lets measure it with next generation
experiments ? NuFact