Working Group 1 Summary: D. Casper

1. Working Group 1 Summary: D. Casper * M. Lindner K. Nakamura Oscillation Physics (mostly) - Part 3 -

2. 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

3. 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 < 2.2 eV •  future KATRIN: m = |S mi U2ei| < 0.3 eV •  atmospheric splitting ~0.05 eV •  if m < 3 10-2 normal hierarchy • Cosmology: (Raffelt) • WMAP + 2dF + Ly a  S mi < 0.7 - 1.2eV •  further improvement expected ~X5

4. 3) Neutrino less double beta decay (for Majorana masses)

5. Giunti:

6. We know it is LMA!  CP violation Maltoni: Global fits (3 neutrinos, ignoring LSND)

7. Inlcluding LSND in 4 neutrino fits 2+2 scheme: ruled out by solar + atm. data 3+1 scheme: strongly disfavoured  tension in the data Maltoni  3+2 scheme: fits better  cosmology CPT violation:  tension in the analyses...?  MiniBooNE

8. Impact of solar density variations: • 8% density change affects LMA region considerably • requires huge magnetic fields ... solar modelling?

9. Projected SNO Assuming D2O NC Result De Holanda, Smirnov hep-ph/0212270 Near future Formaggio: (Awaited) results from SNO Day – Night Contours (%) Probability Contours

10. 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

11.  bi-probability plots

12. Minakata, Yasuda: Overview of degeneracies

13. 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. d=0) * 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)

14. Example: MINOS sin2q13 sensitivity • sensitivity to some parameter combination • sensitivity to sin2q13 Huber, ML, Rolinec, to appear

15. Tazanakos: Updated MINOS discovery potential Better unit: pot Old limits: 7.4 1020 pot Asked for 25 1020 pot / 5y

16. 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

17. 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

18. Combining JHF-SK & NuMI@ 890  Synergies Barger, Marfatia, Whisnant Huber, ML, Winter Minakata, Nunokawa, Parke ...

19. Winter

20. + Donini, Migliozzi

21. Donini:

22. New reactor ideas & impact on LBL Yasuda: New short baseline reactor ideas

23. Yasuda, Suekane: Combine reactor with JHK-SK Very active case studies in different places  Link

24. Huber: Combining beams and reactors • Similar sensitivity at LMA-I und atmospheric best fit • Reactor sensitivity is less Dm231 and less Dm221 dependent

25. 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

26. 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

27. 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

28. 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

29. 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)  d[sin2(2q13) ] = 10-4 .... 10-1  good reasons to expect sin2(2q13) = 10-2  reachable

30. 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 • Futuremeasurements of q12 and q13 will further constrain the cosmological neutrino density

31. 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