physics working group summary 2 nd iss meeting kek, tsukuba, japan january 23-25, 2006 walter winter...

Physics working group summaryPhysics working group summary

22ndnd ISS Meeting ISS MeetingKEK, Tsukuba, JapanKEK, Tsukuba, Japan

January 23-25, 2006January 23-25, 2006

Walter WinterWalter WinterInstitute for Advanced Study, PrincetonInstitute for Advanced Study, Princeton

For the ISS physics working groupFor the ISS physics working group

Jan. 24+25, 2006 ISS KEK Summary - Walter Winter

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ContentsContents Introduction Introduction Meeting summary:Meeting summary:

– Theory (… and muon physics)Theory (… and muon physics)– Phenomenology: Phenomenology:

Non-accelerator measurements and “new physics”Non-accelerator measurements and “new physics”– Physics with a superbeam, beta beam, Physics with a superbeam, beta beam,

neutrino factoryneutrino factory Towards the final product:Towards the final product:

Performance indicators and presentation of results?Performance indicators and presentation of results?

Open questions, next stepsOpen questions, next steps SummarySummary


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Three-flavor oscillations: RequirementsThree-flavor oscillations: Requirements

Coupling strength: 13

Atmosphericoscillation:Amplitude: 23

Frequency: m312

Solaroscillation:Amplitude: 12

Frequency: m212

Sub-leading

effect: CP

Neutrino oscillation parameters (1Neutrino oscillation parameters (1):):mm2121

22 ~ 8.2 10 ~ 8.2 10-5-5 eV eV22 +- 5%+- 5%

sinsin22221212 ~ 0.83 ~ 0.83 +- 5%+- 5%

||mm313122| ~ (2 – 2.5) 10| ~ (2 – 2.5) 10-3-3 eV eV22

sinsin22222323 ~ 1 ~ 1 +- 7%+- 7%

sinsin2222CPCPMass hierarchy? Mass hierarchy?

(see e.g. Bahcall et al, hep-ph/0406294; Super-K, hep-ex/0501064; CHOOZ+solar papers)

Key to subleadingeffects (CP violation,

mass hierarchy)

Superbeam/-factory/Beta Beam

TheoryTheory(plus some muon physics)(plus some muon physics)

Why are the parameters, which we Why are the parameters, which we want to study, interesting at all?want to study, interesting at all?

(more specific versions of “big questions”)

(Murayama)


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Flavor symmetry?Flavor symmetry?Same gauge quantum numbers, but mass hierarchy Same gauge quantum numbers, but mass hierarchy andand

small mixings “unnatural” (for quarks, charged leptons)small mixings “unnatural” (for quarks, charged leptons) Hidden quantum number?Hidden quantum number?

Same for neutrino generations, different for charged Same for neutrino generations, different for charged leptons, quarks?leptons, quarks?

Break flavor symmetry by small VEVBreak flavor symmetry by small VEV Hierachies, e.g., mHierachies, e.g., muu:m:mcc:m:mtt ratio ratio

Atmospheric mixing maximal+two large mixing anglesAtmospheric mixing maximal+two large mixing angles How big quantitatively? From anarchy: How big quantitatively? From anarchy: 1313 not too small? not too small?

(Murayama)

Symmetry“Flavor symmetry”

Emmy NoetherConserved quantity

Hidden quantum number


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Quark-Lepton complementarity?Quark-Lepton complementarity? Understand phenomenological relationships Understand phenomenological relationships

between quarks and leptons at deeper levelbetween quarks and leptons at deeper level Example:Example: Deeper underlying reason or accidental?Deeper underlying reason or accidental? Note: CKM/MNSNote: CKM/MNS

matrix is compositedmatrix is compositedof two partsof two parts

Implement QLC?Implement QLC?Important in future:Important in future:parameter precision measurements!parameter precision measurements!

(Minakata)


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Massive neutrinos in cosmologyMassive neutrinos in cosmology Two applications: Leptogenesis and mass boundsTwo applications: Leptogenesis and mass bounds Evolution of large scale structure Evolution of large scale structure

well understood; massive well understood; massive neutrinos damp fluctuations neutrinos damp fluctuations on horizon scale; power spectrum! on horizon scale; power spectrum!

Bounds from different Bounds from different combinations of CMB, galaxy combinations of CMB, galaxy clustering, cluster abundance, clustering, cluster abundance, grav. Lensing, Lyman grav. Lensing, Lyman

Limits: 2 eV (CMB alone, robust)Limits: 2 eV (CMB alone, robust)0.42 eV (use of Lyman 0.42 eV (use of Lyman ) – but: systematics issue?) – but: systematics issue?

Future: e.g. large cluster surveys (> 100,000) 0.03 eV!Future: e.g. large cluster surveys (> 100,000) 0.03 eV!

(Fukugita)


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Flavor physics to establish SUSY?Flavor physics to establish SUSY? Probe origin of SUSY breaking terms and models Probe origin of SUSY breaking terms and models

beyond MSSM beyond MSSM from studies of flavor and CP violationfrom studies of flavor and CP violation

Charged LFV (e.g. Charged LFV (e.g. -> e -> e) + neutrino ) + neutrino oscillations provide independent information on oscillations provide independent information on see-saw;see-saw;large mixing angles might enhance charged LFVlarge mixing angles might enhance charged LFV;;especially especially 1313 measurement would allow measurement would allow predictions of charged LFVpredictions of charged LFV

Good example for accumulating complementary Good example for accumulating complementary hints from different experiments to obtain clearer hints from different experiments to obtain clearer picture of physicspicture of physics

(Hisano)


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(Towards) search for charged lepton (Towards) search for charged lepton mixing at NuFactmixing at NuFact

Charged lepton mixing from manyCharged lepton mixing from manydifferent modelsdifferent models

Many diff. Processes, e.g. Many diff. Processes, e.g. -> e -> e Some processes detector limited, others Some processes detector limited, others beam limitedbeam limited

Polarized muons useful to reduce Polarized muons useful to reduce backgrounds and discriminate modelsbackgrounds and discriminate modelsproduce e.g. by pion decay at rest + produce e.g. by pion decay at rest + change spin by crossing fieldchange spin by crossing field

Many beam requirements: intensity, Many beam requirements: intensity, pulsed or continuous beam (dep. on pulsed or continuous beam (dep. on process),process), low pion contamination, narrow low pion contamination, narrow energy spreadenergy spread

(Kuno)

NF Frontend: 1014 muons/s

Current proton drivers: 108 muons/s

(MEG)

few MW PD: 1011-12 muons/s

(PRISM)


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LFV in DIS processesLFV in DIS processes Motivation: E. g. SleptonMotivation: E. g. Slepton

mixing (SUSY) introduces mixing (SUSY) introduces LFV at one loopLFV at one loop

-associated LFV-associated LFVinteresting for Higgs-boson interesting for Higgs-boson mediated processesmediated processes

Use DIS process: Use DIS process: e.g. e.g. N -> N -> X X at neutrino factoryat neutrino factoryO(10O(1022) events for 50 GeV) events for 50 GeVAlso possible: neutrino beam?Also possible: neutrino beam?

Cross section increases with energy!Cross section increases with energy!Therefore: argument for as large ETherefore: argument for as large E as possible as possible

Problem: Misidentification of events/Backgrounds; Problem: Misidentification of events/Backgrounds; MC in progressMC in progress

(Kanemura)

Phenomenology (+ some Theory)Phenomenology (+ some Theory)… of neutrino oscillations… of neutrino oscillations

Non-accelerator neutrino property measurementsNon-accelerator neutrino property measurements Non-standard physicsNon-standard physicsIs there anything else beyond three-flavor Is there anything else beyond three-flavor oscillations?oscillations?What possible mechanisms?What possible mechanisms?How does one test those?How does one test those?


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Prospects on Prospects on properties properties… from non-accelerator sources… from non-accelerator sources

mm21212 2 from KamLAND;from KamLAND;

but wrong baseline for but wrong baseline for 1212

New reactor experiment?New reactor experiment? Gadolinium-loaded SK for Gadolinium-loaded SK for

solar parameters?solar parameters? Atmospheric parameters:Atmospheric parameters:

Large magn. iron detector?Large magn. iron detector?Precision comparable to LBL; Precision comparable to LBL; Also: Deviations from Also: Deviations from maximal mixing, octant maximal mixing, octant degeneracy degeneracy

(Choubey)


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Unitarity triangles for lepton sectorUnitarity triangles for lepton sector Similar to quark sector: Use unitarity trianglesSimilar to quark sector: Use unitarity triangles In see-saw mechanism: 6x6-Matrix unitary;In see-saw mechanism: 6x6-Matrix unitary;

in all realistic scenarios: active mixing unitaryin all realistic scenarios: active mixing unitary Matter effects change unitarity trianglesMatter effects change unitarity triangles Example: Higher EExample: Higher E

makes sides comparable;makes sides comparable; Easier to calculate areaEasier to calculate area Easier to establish CP viol.Easier to establish CP viol.

(Xing)


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Status of 3+2 schemeStatus of 3+2 scheme Can accommodate all dataCan accommodate all data Implies: Too low BG forImplies: Too low BG for

superbeams, wrong near superbeams, wrong near detector non-osc. assumptiondetector non-osc. assumption

Eventually checked by MiniBOONE !?Eventually checked by MiniBOONE !? If confirmedIf confirmed: Some new interesting physics: Two : Some new interesting physics: Two

new very similar osc. Frequencies introduced; new very similar osc. Frequencies introduced; CP violation by different phases?CP violation by different phases?Then probably new SBL experiment needed …Then probably new SBL experiment needed …

(Sorel)


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Lepton flavor violation?Lepton flavor violation? May appear in production, propagation, or detectionMay appear in production, propagation, or detection

Neutrinos propagate “off-shell”Neutrinos propagate “off-shell” Interference effects if same Interference effects if same

in/out statesin/out states Strong correlations between osc. Strong correlations between osc.

and new physics parametersand new physics parameters Different for different types of expDifferent for different types of exp Models shown: MSSM penguins …Models shown: MSSM penguins …

Describe produced state by flavor

mixture

Shift of matter effect

Describe detected state by flavor

mixture (simplified)

(Sato)

Physics with a superbeam, beta beam,Physics with a superbeam, beta beam,neutrino factoryneutrino factory


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T2KKT2KK Idea: “Double Chooz” Idea: “Double Chooz”

of superbeams? of superbeams?

In addition: StrongerIn addition: StrongerCP phase dependence +CP phase dependence +matter effectsmatter effectsat longer baselineat longer baseline

10% systematics hardly10% systematics hardlyproblem anymore …problem anymore …

Substantially improved mass hierarchy reachSubstantially improved mass hierarchy reach

(Kajita)


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Facilities using a Water Cherenkov detectorFacilities using a Water Cherenkov detector Principle advantage of betaPrinciple advantage of beta

beam: No intrinsic beam BGbeam: No intrinsic beam BG New efficiency andNew efficiency and

BG matrices for migrationBG matrices for migration High gamma beta beamHigh gamma beta beam

best alternative (even “low flux”)best alternative (even “low flux”)

(Couce)

Two differen

toptions!


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Better neutrino factory detector?Better neutrino factory detector?

1313 sensitivity sensitivity

Better detector threshold Better detector threshold makes L=2000-3000 km makes L=2000-3000 km very efficient very efficient 1313-baseline -baseline

for exclusion limitfor exclusion limit

Mass hier., CP violationMass hier., CP violationAll of the following help:All of the following help:– Better threshold (especially)Better threshold (especially)

– Better energy resolutionBetter energy resolution

– Smaller matter density Smaller matter density uncertainty (for large uncertainty (for large 1313))

“Magicbaseline”

(Winter)

Towards the final product:Towards the final product:Performance indicators Performance indicators

and presentation of results?and presentation of results?


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Performance indicatorsPerformance indicators

Many, many in circulationMany, many in circulation Need to be identical to compare resultsNeed to be identical to compare results Matter ofMatter of

– DefinitionDefinition– Tested hypothesis Tested hypothesis – Purpose Purpose – TasteTaste– Computation powerComputation power


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xample: xample: 1313 performance indicators performance indicators

1313 exclusion limit (sensitivity limit): exclusion limit (sensitivity limit): Describes the new Describes the new 1313 limit for the limit for the

hyopthesis of no signalhyopthesis of no signal ( (1313=0)=0) Correspond to new limit after the Correspond to new limit after the

experiment has been (unsuccessfully) experiment has been (unsuccessfully) performedperformed

1313 discovery reach: discovery reach: Describes if Describes if 1313=0 can be excluded =0 can be excluded

for the for the hypothesis of a certain set hypothesis of a certain set of parametersof parameters ( (1313>0)>0) CP fraction plots often used for

discovery potentials!


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Example: Example: CPCP-performance indicators-performance indicators ExamplesExamples

– Allowed region in Allowed region in --1313-plane-planeIdentify how much parameter space remains for specific Identify how much parameter space remains for specific hypotheses of true valueshypotheses of true values

– Sensitivity to max. CP violation Sensitivity to max. CP violation /2 or 3/2 or 3/2/2Can CP violation be detected for the hypothesis of max. Can CP violation be detected for the hypothesis of max. CP violation?CP violation?

– Sensitivity to “any” CP violationSensitivity to “any” CP violationFor what fraction of CP violating values can CP For what fraction of CP violating values can CP violation be detected? (CP fraction plots)!violation be detected? (CP fraction plots)!

– Precision of Precision of How precisely can one measure How precisely can one measure (only defined in the (only defined in the high precision limit, since high precision limit, since cyclic; also: not Gaussian!) cyclic; also: not Gaussian!)

– CP coverageCP coverageHow precisely can one measure How precisely can one measure or what fraction of the or what fraction of the parameter space can be excluded?parameter space can be excluded?

Which one(s) useful for ISS study?Which one(s) useful for ISS study?

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Towards the presentation of results:Towards the presentation of results:Build strong physics case!Build strong physics case!

Main objectives?Main objectives?– Find Find 1313

– Establish mass hierarchyEstablish mass hierarchy– Search for leptonic CP violationSearch for leptonic CP violation

Important physics limits:Important physics limits:– 1313 large? large?

Neutrino factory physics case?Neutrino factory physics case?Or vice verse: Only if Or vice verse: Only if 1313 small? small?Better detector key component?Better detector key component?

– Physics for Physics for 1313 zero? zero?Such as by some symmetry …Such as by some symmetry …May be important for fundingMay be important for fundingagencies!agencies!E. g. mass hierarchy, MSW effect…E. g. mass hierarchy, MSW effect…

(Fig. from

Huber, L

indner, Winter,

hep-ph/0412199)

Theory needed:Why are these parameters

interesting at all?


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More physics can be done!More physics can be done! Include other possible physics;Include other possible physics;

qualitatively or quantitatively? How?qualitatively or quantitatively? How? Examples:Examples:

– Measure Measure 1313 precisely as soon as found precisely as soon as found– Measure Measure CPCP precisely as soon as found precisely as soon as found– Measure leading atmospheric parametersMeasure leading atmospheric parameters– Deviations from maximal atmospheric mixingDeviations from maximal atmospheric mixing– Resolution of octant degeneracyResolution of octant degeneracy– Test unitarityTest unitarity– New physics ad-mixtures?New physics ad-mixtures?– MSW effect sensitivityMSW effect sensitivity– Matter density measurements?Matter density measurements?– ……

Certainly goodtheoretical motivation,

e.g., quark-lepton-complementarity, mass

models etc.


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Example: Optimization for large Example: Optimization for large 1313

Mass hierarchy no Mass hierarchy no problem for L >> problem for L >> 1000 km1000 km

CP fraction for CP fraction for CP violation CP violation (3(3“Standard”“Standard”

“Optimal “Optimal appearance”appearance”L=1000 km/EL=1000 km/E=20 GeV=20 GeV

possible alternative?possible alternative?(Huber, Lindner, Rolinec, Winter, to appear)


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Example: New physics testsExample: New physics testsHow can this be done by “simple” experimental strategies?How can this be done by “simple” experimental strategies?Theory/Phenomenology: Theory/Phenomenology:

Link specific models (e.g. LFV) with general tests?Link specific models (e.g. LFV) with general tests?Or: Just wait until some inconsistency discovered?Or: Just wait until some inconsistency discovered?

Examples:Examples: detection Pdetection Peeee+P+Pee++PPee = 1? = 1?

Requires action! (“Wait and see” does not work here …)Requires action! (“Wait and see” does not work here …)2.2. Neutral currents (hard, but maybe competitive to 1. ?)Neutral currents (hard, but maybe competitive to 1. ?)

3.3. Spectral signature from effects on probability level Spectral signature from effects on probability level (decay, …)(decay, …)Advantage: Characteristic depletion/enhancement in certain regions ofAdvantage: Characteristic depletion/enhancement in certain regions ofspectrum, oscillation nodes not shiftedspectrum, oscillation nodes not shifted

4.4. More complicated: Hamiltonian-level effects (LFV etc.)More complicated: Hamiltonian-level effects (LFV etc.)Problem: Shifts oscillation nodes, confusion with “standard” parametersProblem: Shifts oscillation nodes, confusion with “standard” parameters

Note: At least 1. and 2. sufficient but not necessary for new physics!Note: At least 1. and 2. sufficient but not necessary for new physics!

See many talks inthis workshop for

specific possible effects!E.g. Hisano, Kanemura,

Sato, Sorel, Xing


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Some biased conceptualities …Some biased conceptualities … How to present multiple options, such as for detector How to present multiple options, such as for detector

etc?etc?– Avoid too many options mixed up (confusing)Avoid too many options mixed up (confusing)– Discuss different options in one section andDiscuss different options in one section and

choose one “representative” for main linechoose one “representative” for main lineof argumentation?of argumentation?

– Need that representative asap if September goal!!!Need that representative asap if September goal!!! Problem: Computation time for more complex Problem: Computation time for more complex

calculations: GLoBES on parallel cluster!calculations: GLoBES on parallel cluster!So far: used mainly opportunistic systemsSo far: used mainly opportunistic systems

At the end: Very small number of meaningful key At the end: Very small number of meaningful key figures requiredfigures required

Open questionsOpen questions

Physics – DetectorPhysics – Detector

Physics – AcceleratorPhysics – Accelerator

Detector – (Physics) – AcceleratorDetector – (Physics) – Accelerator


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Open questions: Physics-Open questions: Physics-DetectorDetector

Ken Long: “close loop”Ken Long: “close loop”Need now best possible detector Need now best possible detector concept (such as in glb-files) with concept (such as in glb-files) with 1. Better low energy efficiences1. Better low energy efficiences2. Better energy resolution?2. Better energy resolution?

Can be either one detector or hybrid technology Can be either one detector or hybrid technology (same site)(same site)

Better detector = key component in large Better detector = key component in large 1313 discussion!?discussion!?

In addition: In addition: ee detection, silver channel concepts + detection, silver channel concepts +Relevance for physics, optimization, baselinesRelevance for physics, optimization, baselines


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Open questions: Physics-AcceleratorOpen questions: Physics-Accelerator Physics: What muon energy really required?Physics: What muon energy really required? Acc.: How much would that reduce the effort?Acc.: How much would that reduce the effort? Example: 40 GeV for Example: 40 GeV for 1313, , CPCP, mass hier.:, mass hier.:

Physics: How large can flux uncertainty be? Physics: How large can flux uncertainty be? (Scott Berg)(Scott Berg)


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Storage ring+possible NF program?Storage ring+possible NF program? t=0 yr: Start with one baseline, t=0 yr: Start with one baseline,

two polarities, “golden channel”, L=3,000 km two polarities, “golden channel”, L=3,000 km EE = 20 GeV, m = 20 GeV, mDD=50kt, 2 MW proton driver?=50kt, 2 MW proton driver?

t=3 yr: First data analysist=3 yr: First data analysisProblem: not in fortunate region in param. spaceProblem: not in fortunate region in param. spaceDecision: Go to “magic” baseline + silver channel Decision: Go to “magic” baseline + silver channel after five more years of data takingafter five more years of data taking

t=5 yr: Upgrade, still at L=3,000 km t=5 yr: Upgrade, still at L=3,000 km EE = 40 GeV, m = 40 GeV, mDD=100kt, 4 MW proton driver=100kt, 4 MW proton driver

t=8 yr: Stop data taking; connect new storage ringt=8 yr: Stop data taking; connect new storage ring t=10 yr: Start at “magic” baseline+silver channel (new t=10 yr: Start at “magic” baseline+silver channel (new

baseline) with one polarity (neutrino appearance only)baseline) with one polarity (neutrino appearance only) t=13 yr: Data analysis: Signal! Start precision measurementt=13 yr: Data analysis: Signal! Start precision measurement t=15 yr: Decide to change polarityt=15 yr: Decide to change polarity t=20 yr: End of programt=20 yr: End of program

+ -

+

-

silver

MB Flexible storage ring concept? Physics: How many baselines?


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Open questions: Detector-AcceleratorOpen questions: Detector-Accelerator(maybe not our business …)(maybe not our business …)

33 sensitivity to sin sensitivity to sin22221313

Optimization: Better detector versus higher muon energy? Optimization: Better detector versus higher muon energy?

Better Eres Better threshold Better Eres+thresh.

(Huber, Lindner, Rolinec, Winter, to appear)


34

Next steps: Goals for BostonNext steps: Goals for Boston Conceptual cases? Link to theory?Conceptual cases? Link to theory?

Examples:Examples:– Large Large 1313: sin: sin22221313 > 0.01 > 0.01

(Physics case for NuFact at all? vs. Superbeams?)(Physics case for NuFact at all? vs. Superbeams?)

– Small Small 1313: 10: 10-4-4 < sin < sin22221313 < 10 < 10-1-1

(NuFact’s “golden age”?)(NuFact’s “golden age”?)

– ““Zero” Zero” 1313: sin: sin22221313 << 10 << 10-4-4

(What physics can be done? What does that mean?)(What physics can be done? What does that mean?) How to deal with a positive MiniBOONE signal? How to deal with a positive MiniBOONE signal?

Disaster or “golden age” of neutrino physics?Disaster or “golden age” of neutrino physics?Last-minute changes or matter of argumentation?Last-minute changes or matter of argumentation?How to conceptualize “new physics” tests and post-MiniBOONE physics?How to conceptualize “new physics” tests and post-MiniBOONE physics?

How many baselines needed?How many baselines needed? Channel requirements, optimization, …Channel requirements, optimization, …


35

SummarySummary Theory/phenomenology: very rich information Theory/phenomenology: very rich information

collected from many different sourcescollected from many different sources Next steps: How to conceptualize/order that?Next steps: How to conceptualize/order that?

General approaches to new physics tests?General approaches to new physics tests? Experiment simulations and muons:Experiment simulations and muons:

– Partly work in progress (superbeams, beta beams, etc.)Partly work in progress (superbeams, beta beams, etc.)– But: At this put input from detector (+accelerator) WG But: At this put input from detector (+accelerator) WG

required (best to come up with)required (best to come up with)– Some open questions (such as channel requirements)Some open questions (such as channel requirements)

Next steps: Concept! Work on physics cases ... Next steps: Concept! Work on physics cases ... Think about “final product” …Think about “final product” …

physics working group summary 2 nd iss meeting kek, tsukuba, japan january 23-25, 2006 walter winter...

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