1. Neutrino Oscillations at Homestake from Chlorine to the Megadetector Ancient Origins of the Question ~1860 Darwin publishes “On The Origin of Species”- & Kelvin challenges the time scale – The Sun is less than 30 million years – Gravitational Energy BUT – Kelvin was wrong- The Physics is more interesting

2. 1946-Bruno Pontecorvo described a novel neutrino detector Neutrino + 37 Cl  37 Ar + e - ∟  37 Cl + The Atomic Energy Commission classified the paper – This detector could be used to locate Nuclear vessels But the AEC was WRONG The Physics is more interesting e + 37 Cl  37 Ar + e - Reactors emit  e

3. 1965-Ray Davis began construction of the Cl Detector to look for e from H  He fusion in the Sun

4. 1985-The Cl detector observes 2.55 SNU (solar neutrino units) The Solar Model (Bahcall) predicts 8 SNU signal/prediction = 1/3 Conclusion: (a) the measurement is wrong, (b) the model is wrong or (c) both are wrong, The Conclusion is WRONG – The physics is more interesting

5. Neutrinos Oscillate - 3 species Pontecorvo(1967) & MSW(1985) But, Solar Neutrino exps. are complicated – unknown source and unknown physics Remedy – Use a known source Reactors – KAMLAND -  e Accelerators – Fermilab(& CERN, KEK)- μ

7. Neutrino Oscillation Fundamentals 1) Unoscillated interaction rate ~ (Beam power) x (Detector Mass)/L 2 2) Detect & Measure: a) Energy distribution of  after oscillation b) Energy distribution of e due to oscillation 3) Backgnd – e from decay of K +  e + + e &  e from decay of  +  e + +  +  e

8. Fermilab Beam Power Options 1) Present – 0.7 Megawatts ( of protons) 2) SNuMI – 1.2 Megawatts 3) Project X – 2.0 Megawatts

11. Oscillation Lengths For E = 1 GeV, L 23 = 494 km(  disappearance) L 13 = 15,420km ( e appearance) Thus, e amplitude grows linearly with distance over any Earth based oscillation path. Signal/uncertainly is L independent since flux varies as 1/L 2 and uncertainly as (flux) ½. Since e from K + and  + decays ~1% of  flux, want beam path ~ 1/10 L 13 or ~ 1500 km. for signal/bkgnd ~ 10.

14. Large Cavern for Long Base Line Experiment Concept (M. Laurenti) Finished Cavern Helical Drift

15. Large Cavern for Long Base Line Experiment Concept (M. Laurenti) Finished Cavern Helical Drift

16. Large Cavern for Long Base Line Experiment Concept (M. Laurenti) Finished Cavern Helical Drift

17. Large Cavern for Long Base Line Experiment Concept Cross Section Helical Drift 4850L 5000L 53M I.D. 85M I.D.

19. 300 kTand 2 MW generates ~200000 cc evts/yr 300 kT Homestake detector and 2 MW generates ~200000 cc evts/yr

20. Spectra with 300 kT detector and 2MW beam from FNAL Background issues examined by FNAL/BNL study. Background issues examined by FNAL/BNL study. NormalReversed sin²2θ ₁₃ = 0.04, 300kT, 1300 km, ~2MW @ 60 GeV 3yrs neutrinos and 3yrs antineutrinos and 3yrs antineutrinos sig~1214 sig~394 sig~564 sig~564 sig~627 Mark Dierckxsens(UChicago), Mary Bishai(BNL)

21. Ultimate Reach Mark Dierckxsens(UChicago), Mary Bishai(BNL) Mass ordering θ ₁₃ CP Violation 60 GeV, 2MW, 3+3 yrs, 300kT stat+ 5%syst 0.003 0.007 0.007 50% coverage at 3 sigma

22. Technical issues Measure 3-generation parameters without ambiguities. (CP measurement is approximately independent of θ 13 ). Need large detector independent of θ 13 value. 300 kT water Cherenkov detector @DUSEL Measurement of CP phase and Sin²2θ 13 at several points. All ambiguities and mass hierarchy are resolved.

23. Developing Collaboration Proposal for an Experimental Program in Neutrino Physics and Proton Decay in the Homestake Laboratory This is the author list of hep-ex/0608023 August 2006

24. Other Physics with the Megadetector 1) Nucleon decay ~ 10 35 years 2) Supernova prompt neutrinos – ~10 5 from SN in the Galaxy ~10 – 20 from Andromeda 3) Relic SN neutrinos 4) Solar neutrinos – sure & HOW 5) Atmospheric neutrinos – 6) Also, a great bkgnd shield for sensitive insert experiments

25. Nucleon decay Large body of work by HyperK, and UNO. background levels for the positron+Pion mode 3.6/MTon-yr (normal) 0.15/MTon-yr (tight) Expected Sensitivity on K-nu mode is about ~8x10³³ yr Ref: Shiozawa (NNN05) 300kTX10yrs => 7X10³ ⁴ yrs

26. HOPEFULLY THE NEW PHYSICS WILL BE MORE INTERESTING