1. Neutrino Physics - Lecture 5 Steve Elliott LANL Staff Member UNM Adjunct Professor 505-665-0068, elliotts@lanl.gov

2. Spring 2007Steve Elliott, UNM Seminar Series2 Lecture 5 Outline Finish Solar Neutrinos Neutrinos from the Atmosphere The neutrinos Past experiments What we know and what we want to learn

3. Spring 2007Steve Elliott, UNM Seminar Series3 The hierarchy question Normal Inverted

4. Spring 2007Steve Elliott, UNM Seminar Series4 The “Dark Side” of solar neutrinos Two “flavors” are involved in solar neutrino oscillations. e and a linear combination of   and .

5. Spring 2007Steve Elliott, UNM Seminar Series5 The “Dark Side” of solar neutrinos II For  <  /4, 1 is mostly e. But for  ’ =  /2 -  /4, 1 is mostly  + . Thus, although oscillations in a vacuum cannot distinguish between  and  ’, matter oscillations can. That is cos2  changes sign.

6. Spring 2007Steve Elliott, UNM Seminar Series6 Solar Neutrino Results there is no dark side Early fit to solar neutrino data. Note solution space for tan  >1. Phys.Lett. B490 (2000) 125

7. Spring 2007Steve Elliott, UNM Seminar Series7 The addition of KamLAND

8. Spring 2007Steve Elliott, UNM Seminar Series8

9. Spring 2007Steve Elliott, UNM Seminar Series9 What’s left to do? Is our model of neutrino mixing and oscillation complete, or are there other mechanisms at work? –Without luminosity constraint, pp and 7 Be fluxes poorly known. –With constraint, 7 Be is still poorly known. Is nuclear fusion the only source of the Sun’s energy and is it steady state? What is the correct hierarchial ordering of the neutrino masses?

10. Spring 2007Steve Elliott, UNM Seminar Series10 Non-Standard Interactions and New Properties Do neutrinos have non-standard interactions? Are there unexpected properties? Non-standard interactions of neutrinos with matter would lead to modifications of matter effects in oscillations. NSI on order of 10-30% of SM weak interaction are possible and compatible with accelerator and oscillation data. Such large effects would affect solar neutrino data. Since NSI must mimic SM behavior in the matter dominated region, but be small in the vacuum region, the transition region is a good place to look.

11. Spring 2007Steve Elliott, UNM Seminar Series11 The Vacuum-matter transition This classic LMA oscillation probability curve might be altered by NSI. VacuumMatter About 2 MeV hep-ph/0305159

12. Spring 2007Steve Elliott, UNM Seminar Series12 Future Solar Neutrino Experiments ExperimentTargetReactionThreshold Borexino ~300 t liq. Scint. ES~250 keV KamLAND ~600 t liq scint. ES~250 keV LENS 60 t In load in scint CC HERON68 m 3 LHeES~45 keV CLEAN40 t liq. NeES~35 keV MOON Few t of 100 Mo CC168 keV

13. Spring 2007Steve Elliott, UNM Seminar Series13 Future Experiments

14. Spring 2007Steve Elliott, UNM Seminar Series14 Atmospheric Neutrinos Up vs. Down

15. Spring 2007Steve Elliott, UNM Seminar Series15 IMB and Kamiokande Previous large water Cherenkov detectors Built to look for proton decay, atmospheric neutrinos are a significant background: hence lots of study Kamiokande was able to lower threshold to see solar neutrinos Saw SN1987A, but not pdk Statistically weak indication of atmospheric neutrino oscillations Led to plan for Very Large SuperK

16. Spring 2007Steve Elliott, UNM Seminar Series16 SuperK 1000 m underground 50,000 tons of water 12,000 pmts

17. Spring 2007Steve Elliott, UNM Seminar Series17 Results

18. Spring 2007Steve Elliott, UNM Seminar Series18 L/E analysis (Ishitsuka: NOON 2004)

19. Spring 2007Steve Elliott, UNM Seminar Series19 L/E results

20. Spring 2007Steve Elliott, UNM Seminar Series20 Maximal mixing and the future If sin 2  13 is different than 0, Earth matter effects can resonantly enhance the subdominate transitions depending on the sign of  m 23 2.

21. Spring 2007Steve Elliott, UNM Seminar Series21 Future Experiments ExperimentTargetStatus SuperK50 kt waterContinue on SNO1 kt heavy waterJust completed MINOS Iron magnetized calorimeter Operating INO 30-50kt magnetized tracking calorimeter proposal UNO/HyperK Mt class waterproposal

22. Spring 2007Steve Elliott, UNM Seminar Series22 SNO is “small” but deep