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

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 3 LBL oscillation physics deGouvea, Sato, Abazajian, Shrock, Ohlsson, Chen... and plenary speakers... apologies for what is not mentioned

Knowledge of masses and mixings Giunti: The absolute neutrino mass scale 1)Kinematical measurement: Mainz-Troitsk: m < 2.2 eV  future KATRIN: m = |  m i U 2 ei | < 0.3 eV  atmospheric splitting ~0.05 eV  if m <  normal hierarchy 2)Cosmology: (Raffelt) WMAP + 2dF + Ly    m i < eV   further improvement expected ~X5 3 parameters: m 1,  m 2 ,  m 2 21,  23,  12,  13, ,  2,  

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

Giunti:

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

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

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

Near future  Formaggio: (Awaited) results from SNO De Holanda, Smirnov hep-ph/ Day – Night Contours (%) Probability Contours Projected SNO Assuming D 2 O NC Result

Future LBL experiments & degeneracies  do not compare apples with pies Compare only studies which - include all relevant experimental & theoretical aspects - have equally ambitious scenarios as a function of time, technology, cost,...  unbiased attitude - degeneracies - correlations

 bi-probability plots

Minakata, Yasuda: Overview of degeneracies

Sensitivity studies, especially for sin 2 (2  13 ) and  -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.  =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)

Huber, ML, Rolinec, to appear Example: MINOS sin 2  13 sensitivity sensitivity to some parameter combination sensitivity to sin 2  13

Tazanakos: Updated MINOS discovery potential Better unit: pot Old limits: pot Asked for pot / 5y

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 Strategies to break degeneracies  combine:

Sugiyama: Resolving JHF degeneracies Whisnant: Combining superbeams Donini: Combining superbeams and the neutrino factory Migliozzi: Silver channel and the neutrino factory Winter: Resolving degeneracies for different values of  13 Degeneracies session: Results of main groups agree *  Impact / resoltion of degeneracies at different LBL levels: *) This does not mean that any study includes all relevant aspects Next generation Neutrino factory

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

Winter

Donini, Migliozzi +

Donini:

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

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

Huber: Combining beams and reactors Similar sensitivity at LMA-I und atmospheric best fit Reactor sensitivity is less  m 2 31 and less  m 2 21 dependent

JHF-SK + NuMI Reactor-II perform best Sensitivity to sgn(  m 2 ) for any  m 2 21 Sensitivity to CP violation in LMA-II region Combine: Improved sin 2 (2  13 ), sgn(  m 2 ) and CP limits

Choubey: Implications of Kamland/Precision measurement of parameters before nufact SPMIN: good   sensitivity SPMAX: poor   sensitivity  KamLAND is not in the ideal place! LMA-I  70 km LMA-II  km Propose a new reactor experiment at ideal distance HLMA  even some  13 sensitivity

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

Theory Shrock: Neutrino masses without a new energy scale Chen: Neutrino masses and mixings in SO(10) models There exist many models for neutrino masses  attractive framework for neutrino masses  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  0 2  decay, L violation

deGouvea: Natural expectations for U e3  random mass matrices (anarchy) predicts large mixings large neutrino mixings may be rather natural  why is U e3, i.e. sin 2 (2  13 ) so small? expect sin 2 (2  13 ) close to experimental limit or some protective symmetry must operate How small could sin 2 (2  13 ) be? In general arbitrarily small, inlcuding zero Models: anarchy  close to limit textures  mass ratio suppression ~ typically down to sin 2 (2  13 ) = 0 possible, requires model tuning Quantum corrections (RGE)   [sin 2 (2  13 ) ] =  good reasons to expect sin 2 (2  13 ) =  reachable

Abazajian: Cosmological energy density of neutrinos from oscillation measurements Sato: Lepton flavour violation in long baseline experiments 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  3 oscillation may be affected by LFV effects  must be included in analysis  less sensitivity to oscillation parameters  connection between cosmological energy density & oscillation  Future measurements of q 12 and q 13 will further constrain the cosmological neutrino density

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  sin 2 (2  13 ) sensitivity down to 10  Theory: Reasons to expect sin 2 (2  13 ) not below this magnitude  Lets measure it with next generation experiments  NuFact