1. Physics working group summary 2 nd ISS Meeting KEK, Tsukuba, Japan January 23-25, 2006 Walter Winter Institute for Advanced Study, Princeton For the ISS physics working group

2. Jan. 24+25, 2006ISS KEK Summary - Walter Winter2 Contents Introduction Introduction Meeting summary: Meeting summary: –Theory (… and muon physics) –Phenomenology: Non-accelerator measurements and “new physics” –Physics with a superbeam, beta beam, neutrino factory Towards the final product: Performance indicators and presentation of results? Towards the final product: Performance indicators and presentation of results? Open questions, next steps Open questions, next steps Summary Summary

3. Jan. 24+25, 2006ISS KEK Summary - Walter Winter3 Three-flavor oscillations: Requirements Coupling strength:  13 Atmospheric oscillation: Amplitude:  23 Frequency:  m 31 2 Solar oscillation: Amplitude:  12 Frequency:  m 21 2 Sub- leading effect:  CP Neutrino oscillation parameters (1  ):  m 21 2 ~ 8.2 10 -5 eV 2 +- 5% sin 2 2  12 ~ 0.83 +- 5% |  m 31 2 | ~ (2 – 2.5) 10 -3 eV 2 sin 2 2  23 ~ 1+- 7% sin 2 2     CP  Mass hierarchy? Neutrino oscillation parameters (1  ):  m 21 2 ~ 8.2 10 -5 eV 2 +- 5% sin 2 2  12 ~ 0.83 +- 5% |  m 31 2 | ~ (2 – 2.5) 10 -3 eV 2 sin 2 2  23 ~ 1+- 7% sin 2 2     CP  Mass hierarchy? (see e.g. Bahcall et al, hep-ph/0406294; Super-K, hep-ex/0501064; CHOOZ+solar papers) Key to subleading effects (CP violation, mass hierarchy) Superbeam/ -factory/ Beta Beam

4. Theory (plus some muon physics) Why are the parameters, which we want to study, interesting at all? (more specific versions of “big questions”) (Murayama)

5. Jan. 24+25, 2006ISS KEK Summary - Walter Winter5 Flavor symmetry? Same gauge quantum numbers, but mass hierarchy and small mixings “unnatural” (for quarks, charged leptons)  Hidden quantum number?  Same for neutrino generations, different for charged leptons, quarks? Break flavor symmetry by small VEV  Hierachies, e.g., m u :m c :m t ratio Atmospheric mixing maximal+two large mixing angles  How big quantitatively? From anarchy:  13 not too small? (Murayama) Symmetry “Flavor symmetry” Emmy Noether Conserved quantity Hidden quantum number

6. Jan. 24+25, 2006ISS KEK Summary - Walter Winter6 Quark-Lepton complementarity? Understand phenomenological relationships between quarks and leptons at deeper level Understand phenomenological relationships between quarks and leptons at deeper level Example: Example: Deeper underlying reason or accidental? Deeper underlying reason or accidental? Note: CKM/MNS matrix is composited of two parts Note: CKM/MNS matrix is composited of two parts  Implement QLC? Important in future: parameter precision measurements! (Minakata)

7. Jan. 24+25, 2006ISS KEK Summary - Walter Winter7 Massive neutrinos in cosmology Two applications: Leptogenesis and mass bounds Two applications: Leptogenesis and mass bounds Evolution of large scale structure well understood; massive neutrinos damp fluctuations on horizon scale; power spectrum! Evolution of large scale structure well understood; massive neutrinos damp fluctuations on horizon scale; power spectrum! Bounds from different combinations of CMB, galaxy clustering, cluster abundance, grav. Lensing, Lyman  Bounds from different combinations of CMB, galaxy clustering, cluster abundance, grav. Lensing, Lyman  Limits: 2 eV (CMB alone, robust) 0.42 eV (use of Lyman  ) – but: systematics issue? Limits: 2 eV (CMB alone, robust) 0.42 eV (use of Lyman  ) – 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)

8. Jan. 24+25, 2006ISS KEK Summary - Walter Winter8 Flavor physics to establish SUSY? Probe origin of SUSY breaking terms and models beyond MSSM from studies of flavor and CP violation Probe origin of SUSY breaking terms and models beyond MSSM from studies of flavor and CP violation Charged LFV (e.g.  -> e  ) + neutrino oscillations provide independent information on see-saw; large mixing angles might enhance charged LFV; especially  13 measurement would allow predictions of charged LFV Charged LFV (e.g.  -> e  ) + neutrino oscillations provide independent information on see-saw; large mixing angles might enhance charged LFV; especially  13 measurement would allow predictions of charged LFV Good example for accumulating complementary hints from different experiments to obtain clearer picture of physics Good example for accumulating complementary hints from different experiments to obtain clearer picture of physics (Hisano)

9. Jan. 24+25, 2006ISS KEK Summary - Walter Winter9 (Towards) search for charged lepton mixing at NuFact Charged lepton mixing from many different models Charged lepton mixing from many different models Many diff. Processes, e.g.  -> e  Some processes detector limited, others beam limited Many diff. Processes, e.g.  -> e  Some processes detector limited, others beam limited Polarized muons useful to reduce backgrounds and discriminate models produce e.g. by pion decay at rest + change spin by crossing field Polarized muons useful to reduce backgrounds and discriminate models produce e.g. by pion decay at rest + change spin by crossing field Many beam requirements: intensity, pulsed or continuous beam (dep. on process), low pion contamination, narrow energy spread Many beam requirements: intensity, pulsed or continuous beam (dep. on process), low pion contamination, narrow energy spread (Kuno) NF Frontend: 10 14 muons/s Current proton drivers: 10 8 muons/s (MEG) few MW PD: 10 11-12 muons/s (PRISM)

10. Jan. 24+25, 2006ISS KEK Summary - Walter Winter10 LFV in DIS processes Motivation: E. g. Slepton mixing (SUSY) introduces LFV at one loop Motivation: E. g. Slepton mixing (SUSY) introduces LFV at one loop  -associated LFV interesting for Higgs-boson mediated processes  -associated LFV interesting for Higgs-boson mediated processes Use DIS process: e.g.  N ->  X at neutrino factory O(10 2 ) events for 50 GeV Also possible: neutrino beam? Use DIS process: e.g.  N ->  X at neutrino factory O(10 2 ) events for 50 GeV Also possible: neutrino beam? Cross section increases with energy! Therefore: argument for as large E  as possible Cross section increases with energy! Therefore: argument for as large E  as possible Problem: Misidentification of events/Backgrounds; MC in progress Problem: Misidentification of events/Backgrounds; MC in progress (Kanemura)

11. Phenomenology (+ some Theory) … of neutrino oscillations Non-accelerator neutrino property measurements Non-accelerator neutrino property measurements Non-standard physics Is there anything else beyond three-flavor oscillations? What possible mechanisms? How does one test those? Non-standard physics Is there anything else beyond three-flavor oscillations? What possible mechanisms? How does one test those?

12. Jan. 24+25, 2006ISS KEK Summary - Walter Winter12 Prospects on properties … from non-accelerator sources  m 21 2 from KamLAND; but wrong baseline for  12 New reactor experiment?  m 21 2 from KamLAND; but wrong baseline for  12 New reactor experiment? Gadolinium-loaded SK for solar parameters? Gadolinium-loaded SK for solar parameters? Atmospheric parameters: Large magn. iron detector? Precision comparable to LBL; Also: Deviations from maximal mixing, octant degeneracy Atmospheric parameters: Large magn. iron detector? Precision comparable to LBL; Also: Deviations from maximal mixing, octant degeneracy (Choubey)

13. Jan. 24+25, 2006ISS KEK Summary - Walter Winter13 Unitarity triangles for lepton sector Similar to quark sector: Use unitarity triangles Similar to quark sector: Use unitarity triangles In see-saw mechanism: 6x6-Matrix unitary; in all realistic scenarios: active mixing unitary In see-saw mechanism: 6x6-Matrix unitary; in all realistic scenarios: active mixing unitary Matter effects change unitarity triangles Matter effects change unitarity triangles Example: Higher E makes sides comparable; Example: Higher E makes sides comparable;  Easier to calculate area  Easier to establish CP viol. (Xing)

14. Jan. 24+25, 2006ISS KEK Summary - Walter Winter14 Status of 3+2 scheme Can accommodate all data Can accommodate all data Implies: Too low BG for superbeams, wrong near detector non-osc. assumption Implies: Too low BG for superbeams, wrong near detector non-osc. assumption Eventually checked by MiniBOONE !? Eventually checked by MiniBOONE !? If confirmed: Some new interesting physics: Two new very similar osc. Frequencies introduced; CP violation by different phases? Then probably new SBL experiment needed … If confirmed: Some new interesting physics: Two new very similar osc. Frequencies introduced; CP violation by different phases? Then probably new SBL experiment needed … (Sorel)

15. Jan. 24+25, 2006ISS KEK Summary - Walter Winter15 Lepton flavor violation? May appear in production, propagation, or detection May appear in production, propagation, or detection Neutrinos propagate “off-shell” Neutrinos propagate “off-shell”  Interference effects if same in/out states Strong correlations between osc. and new physics parameters Strong correlations between osc. and new physics parameters Different for different types of exp Different 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)

16. Physics with a superbeam, beta beam, neutrino factory

17. Jan. 24+25, 2006ISS KEK Summary - Walter Winter17 T2KK Idea: “Double Chooz” of superbeams? Idea: “Double Chooz” of superbeams? In addition: Stronger CP phase dependence + matter effects at longer baseline In addition: Stronger CP phase dependence + matter effects at longer baseline 10% systematics hardly problem anymore … 10% systematics hardly problem anymore … Substantially improved mass hierarchy reach Substantially improved mass hierarchy reach (Kajita)

18. Jan. 24+25, 2006ISS KEK Summary - Walter Winter18 Facilities using a Water Cherenkov detector Principle advantage of beta beam: No intrinsic beam BG Principle advantage of beta beam: No intrinsic beam BG New efficiency and BG matrices for migration New efficiency and BG matrices for migration High gamma beta beam best alternative (even “low flux”) High gamma beta beam best alternative (even “low flux”) (Couce) Two different options!

19. Jan. 24+25, 2006ISS KEK Summary - Walter Winter19 Better neutrino factory detector?  13 sensitivity Better detector threshold makes L=2000-3000 km very efficient  13 -baseline for exclusion limit  13 sensitivity Better detector threshold makes L=2000-3000 km very efficient  13 -baseline for exclusion limit Mass hier., CP violation All of the following help: Mass hier., CP violation All of the following help: –Better threshold (especially) –Better energy resolution –Smaller matter density uncertainty (for large  13 ) “Magic baseline” (Winter)

20. Towards the final product: Performance indicators and presentation of results?

21. Jan. 24+25, 2006ISS KEK Summary - Walter Winter21 Performance indicators Many, many in circulation Many, many in circulation Need to be identical to compare results Need to be identical to compare results Matter of Matter of –Definition –Tested hypothesis –Purpose –Taste –Computation power

22. Jan. 24+25, 2006ISS KEK Summary - Walter Winter22  xample:  13 performance indicators  13 exclusion limit (sensitivity limit):  13 exclusion limit (sensitivity limit):  Describes the new  13 limit for the hyopthesis of no signal (  13 =0)  Correspond to new limit after the experiment has been (unsuccessfully) performed  13 discovery reach:  13 discovery reach:  Describes if  13 =0 can be excluded for the hypothesis of a certain set of parameters (  13 >0) CP fraction plots often used for discovery potentials!

23. Jan. 24+25, 2006ISS KEK Summary - Walter Winter23 Example:  CP -performance indicators Examples Examples –Allowed region in  -  13 -plane Identify how much parameter space remains for specific hypotheses of true values –Sensitivity to max. CP violation  /2 or 3  /2 Can CP violation be detected for the hypothesis of max. CP violation? –Sensitivity to “any” CP violation For what fraction of CP violating values can CP violation be detected? (CP fraction plots)! –Precision of  How precisely can one measure  (only defined in the high precision limit, since  cyclic; also: not Gaussian!) –CP coverage How precisely can one measure  or what fraction of the parameter space can be excluded? Which one(s) useful for ISS study? Level of condensation, computation time True values: Few examples True values: Complete relevant space Purpose: Risk minimization Purpose: Looks like result

24. Jan. 24+25, 2006ISS KEK Summary - Walter Winter24 Towards the presentation of results: Build strong physics case! Main objectives? Main objectives? –Find  13 –Establish mass hierarchy –Search for leptonic CP violation Important physics limits: Important physics limits: –  13 large? Neutrino factory physics case? Or vice verse: Only if  13 small? Better detector key component? –Physics for  13 zero? Such as by some symmetry … May be important for funding agencies! E. g. mass hierarchy, MSW effect… (Fig. from Huber, Lindner, Winter, hep-ph/0412199) Theory needed: Why are these parameters interesting at all?

25. Jan. 24+25, 2006ISS KEK Summary - Walter Winter25 More physics can be done! Include other possible physics; qualitatively or quantitatively? How? Include other possible physics; qualitatively or quantitatively? How? Examples: Examples: –Measure  13 precisely as soon as found –Measure  CP precisely as soon as found –Measure leading atmospheric parameters –Deviations from maximal atmospheric mixing –Resolution of octant degeneracy –Test unitarity –New physics ad-mixtures? –MSW effect sensitivity –Matter density measurements? –… Certainly good theoretical motivation, e.g., quark-lepton- complementarity, mass models etc.

26. Jan. 24+25, 2006ISS KEK Summary - Walter Winter26 Example: Optimization for large  13 Mass hierarchy no problem for L >> 1000 km Mass hierarchy no problem for L >> 1000 km CP fraction for CP violation (3  “Standard” “Optimal appearance” L=1000 km/E  =20 GeV possible alternative? CP fraction for CP violation (3  “Standard” “Optimal appearance” L=1000 km/E  =20 GeV possible alternative? (Huber, Lindner, Rolinec, Winter, to appear)

27. Jan. 24+25, 2006ISS KEK Summary - Walter Winter27 Example: New physics tests How can this be done by “simple” experimental strategies? Theory/Phenomenology: Link specific models (e.g. LFV) with general tests? Or: Just wait until some inconsistency discovered? Examples:   detection P ee +P e  +P e  = 1? Requires action! (“Wait and see” does not work here …) 2. Neutral currents (hard, but maybe competitive to 1. ?) 3. Spectral signature from effects on probability level (decay, …) Advantage: Characteristic depletion/enhancement in certain regions of spectrum, oscillation nodes not shifted 4. More complicated: Hamiltonian-level effects (LFV etc.) Problem: Shifts oscillation nodes, confusion with “standard” parameters Note: At least 1. and 2. sufficient but not necessary for new physics! See many talks in this workshop for specific possible effects! E.g. Hisano, Kanemura, Sato, Sorel, Xing

28. Jan. 24+25, 2006ISS KEK Summary - Walter Winter28 Some biased conceptualities … How to present multiple options, such as for detector etc? How to present multiple options, such as for detector etc? –Avoid too many options mixed up (confusing) –Discuss different options in one section and choose one “representative” for main line of argumentation? –Need that representative asap if September goal!!! Problem: Computation time for more complex calculations: GLoBES on parallel cluster! So far: used mainly opportunistic systems Problem: Computation time for more complex calculations: GLoBES on parallel cluster! So far: used mainly opportunistic systems At the end: Very small number of meaningful key figures required At the end: Very small number of meaningful key figures required

29. Open questions Physics – Detector Physics – Accelerator Detector – (Physics) – Accelerator

30. Jan. 24+25, 2006ISS KEK Summary - Walter Winter30 Open questions: Physics-Detector Ken Long: “close loop” Need now best possible detector concept (such as in glb-files) with 1. Better low energy efficiences 2. Better energy resolution? Ken Long: “close loop” Need now best possible detector concept (such as in glb-files) with 1. Better low energy efficiences 2. Better energy resolution? Can be either one detector or hybrid technology (same site) Can be either one detector or hybrid technology (same site) Better detector = key component in large  13 discussion!? Better detector = key component in large  13 discussion!? In addition: e detection, silver channel concepts + Relevance for physics, optimization, baselines In addition: e detection, silver channel concepts + Relevance for physics, optimization, baselines

31. Jan. 24+25, 2006ISS KEK Summary - Walter Winter31 Open 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  13,  CP, mass hier.: Example: 40 GeV for  13,  CP, mass hier.: Physics: How large can flux uncertainty be? (Scott Berg) Physics: How large can flux uncertainty be? (Scott Berg)

32. Jan. 24+25, 2006ISS KEK Summary - Walter Winter32 Storage ring+possible NF program? t=0 yr: Start with one baseline, two polarities, “golden channel”, L=3,000 km E  = 20 GeV, m D =50kt, 2 MW proton driver? t=0 yr: Start with one baseline, two polarities, “golden channel”, L=3,000 km E  = 20 GeV, m D =50kt, 2 MW proton driver? t=3 yr: First data analysis Problem: not in fortunate region in param. space Decision: Go to “magic” baseline + silver channel after five more years of data taking t=3 yr: First data analysis Problem: not in fortunate region in param. space Decision: Go to “magic” baseline + silver channel after five more years of data taking t=5 yr: Upgrade, still at L=3,000 km E  = 40 GeV, m D =100kt, 4 MW proton driver t=5 yr: Upgrade, still at L=3,000 km E  = 40 GeV, m D =100kt, 4 MW proton driver t=8 yr: Stop data taking; connect new storage ring t=8 yr: Stop data taking; connect new storage ring t=10 yr: Start at “magic” baseline+silver channel (new baseline) with one polarity (neutrino appearance only) t=10 yr: Start at “magic” baseline+silver channel (new baseline) with one polarity (neutrino appearance only) t=13 yr: Data analysis: Signal! Start precision measurement t=13 yr: Data analysis: Signal! Start precision measurement t=15 yr: Decide to change polarity t=15 yr: Decide to change polarity t=20 yr: End of program t=20 yr: End of program ++ -- ++ -- silver MB Flexible storage ring concept? Physics: How many baselines?

33. Jan. 24+25, 2006ISS KEK Summary - Walter Winter33 Open questions: Detector-Accelerator (maybe not our business …) 3  sensitivity to sin 2 2  13 3  sensitivity to sin 2 2  13 Optimization: Better detector versus higher muon energy? Optimization: Better detector versus higher muon energy? Better EresBetter thresholdBetter Eres+thresh. (Huber, Lindner, Rolinec, Winter, to appear)

34. Jan. 24+25, 2006ISS KEK Summary - Walter Winter34 Next steps: Goals for Boston Conceptual cases? Link to theory? Examples: Conceptual cases? Link to theory? Examples: –Large  13 : sin 2 2  13 > 0.01 (Physics case for NuFact at all? vs. Superbeams?) –Small  13 : 10 -4 < sin 2 2  13 < 10 -1 (NuFact’s “golden age”?) –“Zero”  13 : sin 2 2  13 << 10 -4 (What physics can be done? What does that mean?) How to deal with a positive MiniBOONE signal? Disaster or “golden age” of neutrino physics? Last-minute changes or matter of argumentation? How to conceptualize “new physics” tests and post-MiniBOONE physics? How to deal with a positive MiniBOONE signal? Disaster or “golden age” of neutrino physics? Last-minute changes or matter of argumentation? 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. Jan. 24+25, 2006ISS KEK Summary - Walter Winter35 Summary Theory/phenomenology: very rich information collected from many different sources Theory/phenomenology: very rich information collected from many different sources  Next steps: How to conceptualize/order that? General approaches to new physics tests? Experiment simulations and muons: Experiment simulations and muons: –Partly work in progress (superbeams, beta beams, etc.) –But: At this put input from detector (+accelerator) WG required (best to come up with) –Some open questions (such as channel requirements)  Next steps: Concept! Work on physics cases... Think about “final product” …