1. November 19, 2005 Sergio Palomares-Ruiz Physics of Atmospheric Neutrinos: Perspectives for the Future Topical Workshop on Physics at Henderson DUSEL Fort Collins, CO, November 18-19, 2005

2. November 19, 2005 Sergio Palomares-Ruiz GOALS Leading effects Measuring the mixing parameters in the (2,3) sector: |  m 2 31 | and sin 2 2  23 Determining L/E pattern Sub-leading effects Solar sector effects (sub-GeV neutrinos) Matter effects (multi-GeV neutrinos) Limits on oscillations into sterile neutrinos New physics

3. November 19, 2005 Sergio Palomares-Ruiz Experiments Super-K UNOHyper-K MINOS (and INO?) (magnetized) Present Early future Future Liquid Argon Detector ?

4. November 19, 2005 Sergio Palomares-Ruiz Parameters in (2,3) sector From K2K: sin 2 2  23 =1 |  m 2 31 | = 2.8 x 10 -3 eV 2 Atmospheric neutrinos (SK) Y. Suzuki, TAUP 2005 E. Aliu et al., Phys. Rev. Lett.94:081802, 2005

5. November 19, 2005 Sergio Palomares-Ruiz L/E behavior Super-KamiokandeMore statistics: e.g., UNO Not only does it demonstrate the oscillatory pattern, but also improves the measurement of the mixing parameters Y.Ashie et al., Phys. Rev. Lett. 93:101801, 2004 UNO Collaboration

6. November 19, 2005 Sergio Palomares-Ruiz What we don’t know  No clue, so far, on the type of hierarchy (sign of  m 2 31 ), the octant of  23 (>45º or < 45º) and  CP   13 constrained by CHOOZ and SK: sin 2  13 < 0.067 G.L. Fogli et al., Phys. Rev. D 69, 017301 (2004)

7. November 19, 2005 Sergio Palomares-Ruiz Measuring  13 Reactor and LBL experiments Determining sign (  m 2 31 ) and  CP LBL (appearance) experiments New ideas: Super-NO A, detectors in Korea-Japan, etc Reactor exp. will help in resolving degeneracies (  ) 0 decay experiments Can atmospheric neutrinos help? YES! Determining octant of  23 Unique to atmospheric and VLB experiments if  13 very small

8. November 19, 2005 Sergio Palomares-Ruiz Sub-leading effects 2-   m 2 21 L / 2E = 0 and U e3 = sin  13 e i  cp = 0 3- :   m 2 21 effect in sub-GeV neutrinos  U e3 effect in sub-GeV and multi-GeV neutrinos  Difference between Normal and Inverted Hierarchy in multi-GeV neutrinos

9. November 19, 2005 Sergio Palomares-Ruiz Sub-GeV neutrinos O.L.G. Peres and A. Yu. Smirnov, Phys. Lett. B456 (1999) 204 and Nucl. Phys. B680 (2004) 479 P 2 = sin 2 2  12,m sin 2  m /2 = s 13 (1+2EV/  m 2 31 ) R 2 = - sin 2  12,m cos 2  12,m sin 2  m /2 I 2 = -1/2 sin 2  12,m sin  m sin 2  12,m  m ~ VL E sub-GeV > E R Matter dominated regime  m 2 21 contribution N e > N e o if  23 < 45º N e 45º U e3 interference  CP dependence |U e3 | 2 contribution (opposite sign) No inteference between  m 2 31 and  m 2 21 6% 3% 2%

10. November 19, 2005 Sergio Palomares-Ruiz  m 2 21 contribution O.L.G. Peres and A. Yu. Smirnov, Nucl. Phys. B680 (2004) 479 Effect proportional to (  m 2 21 ) 2 Sensitivity to deviations from maximal  23 Sensitivity to octant of  23 Peres and Smirnov, 99, 03; Fogli, Lisi and Marrone 01; González-García and Maltoni, 02 ; González-García, Maltoni and Smirnov, 04

11. November 19, 2005 Sergio Palomares-Ruiz  13 contribution O.L.G. Peres and A. Yu. Smirnov, Nucl. Phys. B680 (2004) 479 The excess increases with decrease of sin  13

12. November 19, 2005 Sergio Palomares-Ruiz Analysis of present SK data Hollow regions:  m 2 21 = 0 M.C. González-García, M. Maltoni and A. Yu. Smirnov, Phys. Rev. D70:093005, 2004. Colored regions:  m 2 21 = 8.2 x 10 -5 eV 2 and tan 2  12 = 0.42  13 = 0  13 free SK + CHOOZ

13. November 19, 2005 Sergio Palomares-Ruiz r sin 2  23 -1 ' ¤ Sub-GeV: r ' 2 ! r sin 2  23 -1 ' 0 ; sin 2  23 = 0.5 0.28 ; sin 2  23 = 0.64 r sin 2  23 -1 ' ¤ Multi-GeV : r ' 2.6 - 4.5 ! r sin 2  23 -1 ' 0.3 ; r = 2.6 1.25 ; r = 4.5 Multi-GeV neutrinos sin 2  23 = 0.5 Petcov 98; Chizhov and Petcov 99,00,01; Akhmedov, Dighe, Lipari and Smirnov 99; Bañuls, Barenboim and Bernabéu 01; Bernabéu, Pérez, SPR and Petcov 01; Bernabéu, SPR and Petcov 03; SPR and Petcov 04; Indumathi and Murthy 04; Gandhi, Ghosal, Goswami, Mehta and Uma Sankar 04 and 05   13 -driven matter effects

14. November 19, 2005 Sergio Palomares-Ruiz Earth Effect Constant density ! MSW effect Thus, Mantle interaction  Normal (Inverted) hierarchy ! the effect is enhanced for (anti)neutrinos sin 2  23  Effect larger for larger sin 2  23  Very small for sub-GeV (r ' 2 and non-resonant)

15. November 19, 2005 Sergio Palomares-Ruiz Earth Effect L = 3000 km L = 8000 km Mantle interaction Non-resonant Resonant M. C. Bañuls, J. Bernabéu and G. Barenboim, Phys. Lett. B513:391, 2001

16. November 19, 2005 Sergio Palomares-Ruiz Earth Effect Two layers of different density New resonant effects E R(c) < E R < E R(m) Mantle-Core interaction sin 2 2  13  m 2 31 / E [10 -  eV  / GeV] M. V. Chizhov and S. T. Petcov, Phys. Rev. D63 (2001) 073003 J. Bernabéu, SPR, A. Pérez and S.T. Petcov, Phys. Lett. B531:90, 2002

17. November 19, 2005 Sergio Palomares-Ruiz Earth Effect Mantle-Core interaction J. Bernabéu, SPR, A. Pérez and S.T. Petcov, Phys. Lett. B531:90, 2002

18. November 19, 2005 Sergio Palomares-Ruiz Water-Cherenkov detectors No discrimination of the charge of the produced lepton. Measurement of N  and N e events. Could we then distinguish the type of mass spectrum with these detectors? YES! Different neutrino and antineutrino cross sections N ~ 2/3 N( -like events) + 1/3 N( -like events) Effect larger for Normal hierarchy N e Multi-GeV sample: Increase of N e and decrease N  of N  ! Should consider N  /N e

19. November 19, 2005 Sergio Palomares-Ruiz N  /N e E = [2, 10] GeV cos  n = [0.4, 1.0] J. Bernabéu, SPR, S. T. Petcov, Nucl. Phys. B669:255,2003

20. November 19, 2005 Sergio Palomares-Ruiz Magnetized detectors Discrimination of the charge of the produced muon N  + : distinction between neutrinos and antineutrinos Measurement of N  - and N  + : distinction between neutrinos and antineutrinos Neutrino energy determination CPT-matter induced asymmetry is measurable

21. November 19, 2005 Sergio Palomares-Ruiz Mantle interaction Different  13 M. C. Bañuls, J. Bernabéu and G. Barenboim, Phys. Lett. B513:391, 2001

22. November 19, 2005 Sergio Palomares-Ruiz Mantle-Core interaction J. Bernabéu, SPR, A. Pérez and S.T. Petcov, Phys. Lett. B531:90, 2002

23. November 19, 2005 Sergio Palomares-Ruiz We can distinguish  + -like events from  - -like events ! distinction of  from  Observable:

24. November 19, 2005 Sergio Palomares-Ruiz Mantle |  m 2 31 | = 2 10 -3 eV 2 E = [2, 10] GeV SPR and S. T. Petcov, Nucl. Phys. B712:392, 2005

25. November 19, 2005 Sergio Palomares-Ruiz Core |  m 2 31 | = 2 10 -3 eV 2 E = [2, 10] GeV SPR and S. T. Petcov, Nucl. Phys. B712:392, 2005

26. November 19, 2005 Sergio Palomares-Ruiz Future Deviations from maximal mixing M.C. González-García, M. Maltoni and A. Yu. Smirnov, Phys. Rev. D70:093005, 2004. S. Antusch et al., Phys. Rev. D70:097302, 2004. Water-Cherencov LBL accelerator neutrinos Atmospheric neutrinos Magnetized ICAL S. Choubey and P. Roy, hep-ph/0509197

27. November 19, 2005 Sergio Palomares-Ruiz M.C. González-García, M. Maltoni and A. Yu. Smirnov, Phys. Rev. D70:093005, 2004. S. Choubey and P. Roy, hep-ph/0509197 Future Water-CherencovMagnetized ICAL Discrimination of the octant of  23

28. November 19, 2005 Sergio Palomares-Ruiz Future sin 2 2  23 = 0.96 sin 2 2  23 = 0.99sin 2 2  23 = 0.96 sin 2 2  23 = 0.99 Discrimination of the octant of  23 M. Shiozawa, RCCN04

29. November 19, 2005 Sergio Palomares-Ruiz Water-Cherencov detectors: SK 20 yrs Statistical significance for non-zero  13 T. Kajita, NOON2004 Future

30. November 19, 2005 Sergio Palomares-Ruiz Future Statistical significance for non-zero  13 T. Tabarelli de Fatis, Eur. Phys. J. C 24 (2002)43 Magnetized detectors

31. November 19, 2005 Sergio Palomares-Ruiz Future Water-Cherencov detectors SK 80 yrs Normal Hierarchy Inverted Hierarchy T. Kajita, NOON2004 Statistical significance for the mass hierarchy

32. November 19, 2005 Sergio Palomares-Ruiz Future Statistical significance for the mass hierarchy T. Tabarelli de Fatis, Eur. Phys. J. C 24 (2002)43 Magnetized detectors

33. November 19, 2005 Sergio Palomares-Ruiz Sensitivity to  CP Future  CP =  /4  CP = 5  /4 sin 2  13 = 0.04sin 2  13 = 0.02sin 2  13 = 0.01 SK 80 yrs M. Shiozawa, RCCN04

34. November 19, 2005 Sergio Palomares-Ruiz Conclusions Future atmospheric neutrino experiments can provide additional information and help in resolving degeneracies in LBL neutrino experiments (P. Huber, M. Maltoni and T. Schwetz, Phys. Rev. D71:053006, 2005). Determination of the deviation of  23 from 45º from leading and sub- leading  m 2 21 and  13 effects (sub- and multi-GeV). Determination of the octant of  23 from sub-leading  m 2 21 and  13 effects (sub- and multi-GeV). Unique opportunity if  13 is very small. Determination of the type of hierarchy from sub-leading  13 -driven matter effects (multi-GeV). Determination of possible CP-violation in the lepton sector from the interference of  m 2 21 and  13 sub-leading effects (sub-GeV). Limits on sterile admixture and new physics.