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 = | mi U2

ei| < 0.3 eV atmospheric splitting ~0.05 eV if m < 3 10-2 normal hierarchy

2) Cosmology: (Raffelt) WMAP + 2dF + Ly mi < 0.7 - 1.2eV further improvement expected ~X5

3 parameters: m1, m2, m2

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. data3+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,Smirnovhep-ph/0212270

Day – Night

Contours (%)

Probability

Contours

Projected SNO Assuming D2O

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 sin2(213) 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 sin213 sensitivity

• sensitivity to some parameter combination• sensitivity to sin213

Tazanakos: Updated MINOS discovery potential

Better unit: potOld limits: 7.4 1020 potAsked for 25 1020 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 & NuMI@ 890 Synergies Barger, Marfatia, WhisnantHuber, ML, WinterMinakata, 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 casestudies in different places Link

Huber: Combining beams and reactors

• Similar sensitivity at LMA-I und atmospheric best fit• Reactor sensitivity is less m2

31 and less m221 dependent

• JHF-SK + NuMI-890 + Reactor-II perform best • Sensitivity to sgn(m2) for any m2

21

• Sensitivity to CP violation in LMA-II region

Combine: Improved sin2(213) , sgn(m2) 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 kmLMA-II 20-30 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 02 decay, L violation

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(213) so small? expect sin2(213) close to experimental limit or some protective symmetry must operate

How small could sin2(213) be?In general arbitrarily small, inlcuding zeroModels: anarchy close to limit textures mass ratio suppression ~ typically down to 10-2

sin2(213) = 0 possible, requires model tuningQuantum corrections (RGE) [sin2(213) ] = 10-4 .... 10-1

good reasons to expect sin2(213) = 10-2 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 q12 and q13 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 sin2(213) sensitivity down to 10

Theory:• Reasons to expect sin2(213) not below this magnitude

Lets measure it with next generation experiments NuFact