1. PPEG plan for development of physics case for RDR IDS-NF plenary meeting October 19-21, 2011 Arlington, VA, USA Walter Winter Universität Würzburg TexPoint fonts used in EMF: AAAAA A A A

2. 2 Contents  The setting and consequences: the “big three” physics topics 2011:  T2K hint for nonzero  13  Evidence for sterile neutrinos?  Superluminal neutrinos at OPERA?  Other activity: PINGU  Summary [apologize for not citing all talks of our WG, but not directly a summary talk …]

3. T2K hint for nonzero  13

4. 4 T2K hint for non-zero  13 ? Source: T2K June 15, 2011: “Indication of Electron Neutrino Appearance from an Accelerator-produced off-axis Muon Neutrino Beam“ 2.5  exclusion of  13 =0

5. 5 Consequences of T2K hint  Parameter space for  CP starts to become constrained; CP violation difficult (need to exclude  CP =0 and  )  Need new facility! Huber, Lindner, Schwetz, Winter, 2009

6. 6 When will T2K be confirmed?  Example: Double Chooz  If T2K best-fit confirmed, data already on tape?  Expect significant results in 2012! (M. Lindner, TAUP 2011)

7. 7 Impact on Neutrino Factory?  Staging: built low-luminosity (1/25) option first?  Optimization of accelerator, given existing equipment? Costing??? (P. Huber)

8. 8 Impact on theory?  Non-zero  13  degree to which  -  -symmetry is broken?  Tri-bimaximal mixings perhaps no attractive starting point anymore? Challenges:  13 and  12 deviations from TBM values!  Some flavor symmetries (A 4 etc) disfavored?  Quark-lepton connections? GUTs?  Non-zero  13 ~ Anarchy?  Or: Anarchy + some structure  Froggatt-Nielsen? (R. Mohapatra vs. H. Murayama)

9. 9 Plans and consequences Plans:  Study of optimization and systematics for large  13  Impact of prior knowledge of  13 ?  Precision physics case for NuFact?  Quantification of “staging scenarios“  Follow model building for large  13  Interesting quantities/relationships?  Clues for required precision? Consequences:  Establish physics case for NuFact compared to alternatives; luminosity-staging? Muon collider program: what do they need/want [physics, accelerator]?  No decision on final RDR strategy before  13 hint confirmed/established!? Then maybe even RDR = LOI?

10. Evidence for sterile neutrinos?

11. 11 Evidence for sterile neutrinos?  LSND/MiniBooNE antineutrinos  Reactor anomaly  Global fits (arXiv:1007.1150) (B. Fleming, TAUP 2011) (Kopp, Maltoni, Schwetz, 1103.4570)

12. 12 Arbitrary sterile s  Cosmology: upper bound O(1 eV)  However: sterile neutrinos even preferred, if light enough  Cannot exclude that light sterile neutrinos “hide“ among the actives (Hamann et al, Phys.Rev.Lett. 105 (2010) 181301) m1m1 m2m2 m3m3 m 4 ?

13. 13 Generalized exclusion limits … without any constraints on  m 41 2 (Meloni, Tang, Winter, arXiv:1007.2419) From e disppearance From  disppearance From LBL-  disppearance (higher order effect) 90% CL, 2 d.o.f. Precision physics case for NuFact in presence of sterile neutrinos?

14. 14 Sterile s: Consequences  VLENF  Physics and optimization?  Can VLENF and LL-LENF be the same thing? How would that look like?  Evidence on “very light steriles“?  Would help the precision physics case  Need to be followed further

15. Superluminal neutrinos at OPERA?

16. 16 OPERA superluminal neutrinos?  Time of flight measurement of muon neutrinos  Comparison of proton waveform with neutrino events  Advanced wrt speed of light by  t=60.7 ns (6  ), which cannot be accounted for otherwise (out of the 1048.5 ns) (OPERA, arXiv:1109.4897; submitted Sept. 22, 2011)

17. 17 Convincing theories?  Have to take into account SN 1987A observations; confirm MINOS results  Either strong energy-dependence of effects, or flavor dependence  Violation of Lorentz invariance implied?  However, so far no convincing theory (too pre-mature)  No of papers discussing OPERA results: 93 up to date (average: 3.4 per day)  Need to follow this development

18. 18 Some comments on possible explanations  Common prejudice: rising and falling edges relevant for statistical significance of effect  However: Any description leading to deviations from proton waveform shape affects g.o.f.  Examples:  Smearing from proton to neutrino waveform  Shortcuts of steriles through extra dimension  … (Dotted: 200ns Gaussian filter, arXiv:1110.0424)

19. 19 OPERA: Consequences  HENF can test this phenomena, in principle; compared to alternatives (right energies, right channels); but: bunches?  Important for physics case of NuFact, if confirmed  Higher precision through more statistics, longer baseline, neutrino-antineutrino, …? 2 x BCT M. Dracos, J. Diaz

20. New ideas/other activities

21. 21 Other activity: PINGU (“Phased IceCube Next Generation Upgrade“)  Decrease spacing of IceCube DOMs at South Pole  huge mass already at 1 GeV  Supernova neutrinos?  Proton decay?  Atmospheric neutrinos? Beams? (V eff from J. Koskinen, PINGU phase I only, preliminary; Tang, Winter, to appear) FNAL/CERN-IceCube

22. 22 NF beam to PINGU?  Key issue: energy resolution (non- magnetized detector); need 10-20% E (see Huber, Schwetz, arXiv:0805.2019)  Applications: (Tang, Winter, to appear)  Replace magic baseline (small  13 )  Single-baseline LENF (large  13 ) (avoid tau contamination by low E , which is a serious issue for a non-magnetized detector!)

23. 23 Summary and conclusions  Need to follow and interpret developments of big three “discoveries“ this year:  Large  13  Sterile neutrinos  Superluminal motion of neutrinos  Large  13 requires  Systematics study  Precision physics case?  Definition of setup comparable to LBNE? Staging? LL-LENF?

24. BACKUP

25. 25 OPERA: Model constraints Fraction of superluminal neutrinosGaussian smearing (arXiv:1110.0424)