1. 1 Neutrinos: Past, Present and Future Robert C. Webb Physics Department Texas A&M University Robert C. Webb Physics Department Texas A&M University

2. May 16, 2007RCW PPC 20072 A Brief History of the Neutrino The Early Years……  1930 Pauli proposes a massless neutral particle.  1932 Fermi names the “neutrino”.  1956 The first observation of electron anti- neutrinos by Reines and Cowan.  1957-62 Possibility that neutrinos oscillate proposed by Pontecorvo and Sakata.  1961 The muon neutrino is observed at BNL. The Early Years……  1930 Pauli proposes a massless neutral particle.  1932 Fermi names the “neutrino”.  1956 The first observation of electron anti- neutrinos by Reines and Cowan.  1957-62 Possibility that neutrinos oscillate proposed by Pontecorvo and Sakata.  1961 The muon neutrino is observed at BNL.

3. May 16, 2007RCW PPC 20073 Discovering the Neutrino

4. May 16, 2007RCW PPC 20074 Neutrino Physics 1960-1990  The observation of neutrinos by Reines and Cowan ushered in a new era of the study of these elusive “beasts”  Accelerator based measurements undertaken in the US and Europe.  Solar neutrino experiments begun underground.  The observation of neutrinos by Reines and Cowan ushered in a new era of the study of these elusive “beasts”  Accelerator based measurements undertaken in the US and Europe.  Solar neutrino experiments begun underground.

5. May 16, 2007RCW PPC 20075 The triumph of the Electro-Weak Unification While experimentalists set out to study the neutrino, the theorist were busy trying to find a theory for the weak interactions of the neutrino that fit… Weinberg and Salam develop a possible candidate, but it requires a “neutral” weak current as the charged current already seen. While experimentalists set out to study the neutrino, the theorist were busy trying to find a theory for the weak interactions of the neutrino that fit… Weinberg and Salam develop a possible candidate, but it requires a “neutral” weak current as the charged current already seen.

6. May 16, 2007RCW PPC 20076 Theory is working fine..but  The Solar Neutrino problem emerges.  Ray Davis and collaborators with encouragement from John Bachall search for neutrinos from the sun using a giant tank of “cleaning fluid”. (1968)  However, they “see” too few!!  What’s wrong, the theory or the experiment?? or both!!  The Solar Neutrino problem emerges.  Ray Davis and collaborators with encouragement from John Bachall search for neutrinos from the sun using a giant tank of “cleaning fluid”. (1968)  However, they “see” too few!!  What’s wrong, the theory or the experiment?? or both!!

7. May 16, 2007RCW PPC 20077 New experiments emerge to study this question.  All of these measurements found too few solar neutrinos!!  This question will get the ultimate answer in 2003 from the SNO Collaboration!  All of these measurements found too few solar neutrinos!!  This question will get the ultimate answer in 2003 from the SNO Collaboration!

8. May 16, 2007RCW PPC 20078 It’s not just the solar neutrinos that are mis-behaving..  There is an anomaly in the atmospheric neutrino flux as well.  SuperK along with several other undergound experiments see too few muon neutrinos!!  There is an anomaly in the atmospheric neutrino flux as well.  SuperK along with several other undergound experiments see too few muon neutrinos!!

9. May 16, 2007RCW PPC 20079 Super K’s results (1998)  Things make sense if we allow for neutrinos to “oscillate”…

10. May 16, 2007RCW PPC 200710 Two neutrino mixing

11. May 16, 2007RCW PPC 200711 But neutrinos still aren’t cooperating  If there are only 3 neutrinos then there should only be two mass differences!!

12. May 16, 2007RCW PPC 200712 Neutrino mass and mixing

13. May 16, 2007RCW PPC 200713 “precision” experiments to the rescue  NuMI/MINOS at Fermilab  K2K at KEK and in the future… T2K and NOVA  NuMI/MINOS at Fermilab  K2K at KEK and in the future… T2K and NOVA

14. May 16, 2007RCW PPC 200714 MINOS overview  NUMI Beam Line  Near Detector  Far Detector  Beam running  Data Analysis  NUMI Beam Line  Near Detector  Far Detector  Beam running  Data Analysis

15. May 16, 2007RCW PPC 200715 The NuMI beam : MI protons

16. May 16, 2007RCW PPC 200716 NuMI Beam Protons Delivered

17. May 16, 2007RCW PPC 200717 NuMI Beam Performance  Total Integrated POT as of now: >3 10 20, have run at up to 310kW, and up to 4.0 10 13 protons per pulse

18. May 16, 2007RCW PPC 200718 The 3 NuMI Beam Configurations

19. May 16, 2007RCW PPC 200719 MINOS Near Detector  Faster electronics  Partially instrumented:  282 planes of steel  153 planes of scintillator  (Rear part of detector  only used to track muons )  +…..  1 kton total mass  Same basic design steel, scintillator, etc  Some differences, e.g.:

20. May 16, 2007RCW PPC 200720 Typical Neutrino Beam Event

21. May 16, 2007RCW PPC 200721 Near Detector Events (showing multiple events in spill window)

22. May 16, 2007RCW PPC 200722

23. May 16, 2007RCW PPC 200723 Near Detector CC events

24. May 16, 2007RCW PPC 200724 MINOS Far Detector Running since 2003!!

25. May 16, 2007RCW PPC 200725 The MINOS Far Detector Currently have ~20 kt-yr of Cosmic Ray data. Observing single and multiple muons. LOTS Observed upward going muons (neutrino interaction below the detector). ~300 events in current sample. First physics paper on beam neutrinos submitted to Phys. Rev. Lett. In operation with >2 E 20 Protons on the NuMI target Currently have ~20 kt-yr of Cosmic Ray data. Observing single and multiple muons. LOTS Observed upward going muons (neutrino interaction below the detector). ~300 events in current sample. First physics paper on beam neutrinos submitted to Phys. Rev. Lett. In operation with >2 E 20 Protons on the NuMI target

26. May 16, 2007RCW PPC 200726 A beam neutrino event in the MINOS Far Detector

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30. May 16, 2007RCW PPC 200730 Atmospheric neutrinos

31. May 16, 2007RCW PPC 200731 First results from MINOS

32. May 16, 2007RCW PPC 200732 MINOS data as a function of Energy

33. May 16, 2007RCW PPC 200733 MINOS Sensitivity

34. May 16, 2007RCW PPC 200734 The ultimate sensitivity

35. May 16, 2007RCW PPC 200735 Electron neutrino mixing.. the next target  NOVA and T2K..using accelerator neutrinos.  Daya Bay and Double Chooz…using reactor neutrinos.  NOVA and T2K..using accelerator neutrinos.  Daya Bay and Double Chooz…using reactor neutrinos.

36. May 16, 2007RCW PPC 200736 The Off-Axis concept

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38. May 16, 2007RCW PPC 200738 Beam Location and Far Detector Siting

39. May 16, 2007RCW PPC 200739 NOvA Far Detector  25 ktons  1984 liquid scintillator planes, no additional absorber (~80% active)  Scintillator cells 3.8 x 6.0 x 1570 cm  Read out from one side per plane with APDs  Expected minimum signal 20pe  25 ktons  1984 liquid scintillator planes, no additional absorber (~80% active)  Scintillator cells 3.8 x 6.0 x 1570 cm  Read out from one side per plane with APDs  Expected minimum signal 20pe 15.7m 110 m

40. May 16, 2007RCW PPC 200740 NOvA Event Simulations One unit is 4.9 cm (horizonta l) 4.0 cm (vertical) One unit is 4.9 cm (horizonta l) 4.0 cm (vertical) + A -> p + 3  ± +  0 + e +A→p  +  - e -  + A -> p +  - Particle ID: particularly “fuzzy” e’s long track, not fuzzy  gaps in tracks (  o ?) large energy deposition (proton?)

41. May 16, 2007RCW PPC 200741 NOvA Near Detector  126 tons of scintillator, 83 tons of steel  23 ton fiducial mass  186 liquid scintillator planes in target, 10 in muon ranger, 1m of steel  Same cell size, same minimum signal  Read out from one side per plane with APDs plus faster electronics than in far detector  126 tons of scintillator, 83 tons of steel  23 ton fiducial mass  186 liquid scintillator planes in target, 10 in muon ranger, 1m of steel  Same cell size, same minimum signal  Read out from one side per plane with APDs plus faster electronics than in far detector

42. May 16, 2007RCW PPC 200742 The Far Detector Site

43. May 16, 2007RCW PPC 200743 Upgrading Proton Source for NOvA  Proton Plan goal (present FNAL accelerator upgrade program) is 390kW (have achieved 310kW with MINOS) Proton Plan 2 uses Recycler as a proton pre-injector  Post-collider era: Use Recycler to accumulate protons from Booster while MI is accelerating, saves time  Recycler momentum aperture is large enough to allow slip- stacking operation in Recycler for up to 12 Booster batches injected  Extracted to MI in a single turn and there re-captured and accelerated  Main Injector will run at its design acceleration rate of 240 GeV/s (1.333 s cycle time)  4.3×10 12 p/batch, 95% slip-stacking efficiency  4.9×10 13 ppp at 120 GeV every 1.333s  700 kW, or 6×10 20 protons per year Now part of NOvA Project!  Proton Plan goal (present FNAL accelerator upgrade program) is 390kW (have achieved 310kW with MINOS) Proton Plan 2 uses Recycler as a proton pre-injector  Post-collider era: Use Recycler to accumulate protons from Booster while MI is accelerating, saves time  Recycler momentum aperture is large enough to allow slip- stacking operation in Recycler for up to 12 Booster batches injected  Extracted to MI in a single turn and there re-captured and accelerated  Main Injector will run at its design acceleration rate of 240 GeV/s (1.333 s cycle time)  4.3×10 12 p/batch, 95% slip-stacking efficiency  4.9×10 13 ppp at 120 GeV every 1.333s  700 kW, or 6×10 20 protons per year Now part of NOvA Project!

44. May 16, 2007RCW PPC 200744 Neutrino Summary MINOS data show  disappearance at low energies at 6.21.27x10 20 Protons on Target) The best fit oscillation parameters are (hep-ex 0607088) Systematic uncertainties on m 2 are ~40% of statistical MINOS continues to take data—still to come: cross sections, e appearance, sterile neutrino search MINOS data show  disappearance at low energies at 6.21.27x10 20 Protons on Target) The best fit oscillation parameters are (hep-ex 0607088) Systematic uncertainties on m 2 are ~40% of statistical MINOS continues to take data—still to come: cross sections, e appearance, sterile neutrino search

45. May 16, 2007RCW PPC 200745 NOvA Prospects  NOA look for e /  transitions at m 2 atm  First hint of  13 being non-zero?  CP violation in absence of matter effects  Matter effects in absence of m sol 2  NOA look for e /  transitions at m 2 atm  First hint of  13 being non-zero?  CP violation in absence of matter effects  Matter effects in absence of m sol 2

46. May 16, 2007RCW PPC 200746 Neutrino future outlook what might we expect to see 50 years hence?  New group of precision experiments b eing planned to study electron neutrino-muon neutrino mixing..  Possibility that there is CP violation in the neutrino sector..  Is the neutrino a Majorana particle or not??  Large underground detectors will allow us to use neutrinos for the study of the earth, dark matter candidates, supernovae, and beyond…  New group of precision experiments b eing planned to study electron neutrino-muon neutrino mixing..  Possibility that there is CP violation in the neutrino sector..  Is the neutrino a Majorana particle or not??  Large underground detectors will allow us to use neutrinos for the study of the earth, dark matter candidates, supernovae, and beyond…