220 likes | 341 Views
Neutrino Physics - Lecture 5. Steve Elliott LANL Staff Member UNM Adjunct Professor 505-665-0068, elliotts@lanl.gov. Lecture 5 Outline. Finish Solar Neutrinos Neutrinos from the Atmosphere The neutrinos Past experiments What we know and what we want to learn. The hierarchy question.
E N D
Neutrino Physics - Lecture 5 Steve Elliott LANL Staff Member UNM Adjunct Professor 505-665-0068, elliotts@lanl.gov
Lecture 5 Outline • Finish Solar Neutrinos • Neutrinos from the Atmosphere The neutrinos Past experiments What we know and what we want to learn Steve Elliott, UNM Seminar Series
The hierarchy question Normal Inverted Steve Elliott, UNM Seminar Series
The “Dark Side” of solar neutrinos Two “flavors” are involved in solar neutrino oscillations. e and a linear combination of and . Steve Elliott, UNM Seminar Series
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. Steve Elliott, UNM Seminar Series
Solar Neutrino Resultsthere is no dark side Early fit to solar neutrino data. Note solution space for tan>1. Phys.Lett. B490 (2000) 125 Steve Elliott, UNM Seminar Series
The addition of KamLAND Steve Elliott, UNM Seminar Series
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 7Be fluxes poorly known. • With constraint, 7Be 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? Steve Elliott, UNM Seminar Series
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. Steve Elliott, UNM Seminar Series
The Vacuum-matter transition This classic LMA oscillation probability curve might be altered by NSI. About 2 MeV hep-ph/0305159 Vacuum Matter Steve Elliott, UNM Seminar Series
Future Solar Neutrino Experiments Steve Elliott, UNM Seminar Series
Future Experiments Steve Elliott, UNM Seminar Series
Atmospheric NeutrinosUp vs. Down Steve Elliott, UNM Seminar Series
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 Steve Elliott, UNM Seminar Series
SuperK • 1000 m underground • 50,000 tons of water • 12,000 pmts Steve Elliott, UNM Seminar Series
Results Steve Elliott, UNM Seminar Series
L/E analysis (Ishitsuka: NOON 2004) Steve Elliott, UNM Seminar Series
L/E results Steve Elliott, UNM Seminar Series
Maximal mixing and the future If sin213 is different than 0, Earth matter effects can resonantly enhance the subdominate transitions depending on the sign of m232. Steve Elliott, UNM Seminar Series
Future Experiments Steve Elliott, UNM Seminar Series
SNO is “small” but deep Steve Elliott, UNM Seminar Series