1. H. Ray Los Alamos National Laboratory The Future of Neutrino Physics in a Post-MiniBooNE Era

2. H. Ray2 Outline  Introduction to neutrino oscillations  LSND : The motivation for MiniBooNE  MiniBooNE Overview & Current Status  The Spallation Neutron Source

3. H. Ray3 Standard Model of Physics

4. H. Ray4 Standard Model of Physics Neutrino Oscillations Observed Assume Neutrinos Have Mass Introduce mass into SM via RH field (Sterile Neutrinos) which mix w/ LH fields (SM ) Use Oscillations to find Sterile Neutrinos Neutrino Oscillations Observed Assume Neutrinos Have Mass Introduce mass into SM via RH field (Sterile Neutrinos) which mix w/ LH fields (SM ) Use Oscillations to find Sterile Neutrinos

5. H. Ray5 Neutrino Oscillations  e = Weak stateMass state 1 2 cos  -sin  sin  |  (0)> = -sin  | 1 > + cos  | 2 >

6. H. Ray6 Neutrino Oscillations  e = Weak stateMass state 1 2 cos  -sin  sin  |  (t)> = -sin  | 1 > + cos  | 2 > e- iE1t e -iE2t

7. H. Ray7 Neutrino Oscillations P osc = | | 2 P osc =sin 2 2  sin 2 1.27  m 2 L E

8. H. Ray8 Neutrino Oscillations P osc =sin 2 2  sin 2 1.27  m 2 L E Distance from point of creation of neutrino beam to detection point  Is the mixing angle  m 2 is the mass squared difference between the two neutrino states E is the energy of the neutrino beam

9. H. Ray9 LSND  800 MeV proton beam + H 2 0 target, Copper beam stop  167 ton tank, liquid scintillator, 25% PMT coverage  E =20-52.8 MeV  L =25-35 meters  e + p  e + + n  n + p  d +  (2.2 MeV)

10. H. Ray10 The LSND Result  Different from other oscillation signals  Higher  m 2  Smaller mixing angle  Much smaller probability (very small signal) ~0.3%

11. H. Ray11 The LSND Problem P osc =sin 2 2  sin 2 1.27  m 2 L E  m 2 ab = m a 2 - m b 2  Something must be wrong!  Flux calculation  Measurement in the detector  Both  Neither Reminiscent of the great Ray Davis Homestake missing solar neutrino problem!

12. H. Ray12 Confirming LSND P osc =sin 2 2  sin 2 1.27  m 2 L E  m 2 ab = m a 2 - m b 2  Want the same L/E  Want higher statistics  Want different sources of systematic errors  Want different signal signature and backgrounds

13. H. Ray13 MiniBooNE

14. H. Ray14 MiniBooNE Neutrino Beam  Start with an 8 GeV beam of protons from the booster Fermilab

15. H. Ray15 MiniBooNE Neutrino Beam  The proton beam enters the magnetic horn where it interacts with a Beryllium target  Focusing horn allows us to run in neutrino, anti- neutrino mode  Collected ~6x10 20 POT, ~600,000 events  Running in anti- mode now, collected ~1x10 20 POT Fermilab World record for pulses pre-MB = 10M MB = 100M+

16. H. Ray16 MiniBooNE Neutrino Beam  p + Be = stream of mesons ( , K)  Mesons decay into the neutrino beam seen by the detector  K + /  +   + +   +  e + +  + e Fermilab

17. H. Ray17 MiniBooNE Neutrino Beam  An absorber is in place to stop muons and un-decayed mesons  Neutrino beam travels through 450 m of dirt absorber before arriving at the MiniBooNE detector Fermilab

18. H. Ray18 MiniBooNE Detector  12.2 meter diameter sphere  Pure mineral oil  2 regions  Inner light-tight region, 1280 PMTs (10% coverage)  Optically isolated outer veto-region, 240 PMTs

19. H. Ray19 Observing Interactions  Don’t look directly for neutrinos  Look for products of neutrino interactions  Passage of charged particles through matter leaves a distinct mark  Cerenkov effect / light  Scintillation light

20. H. Ray20 Cerenkov and Scintillation Light  Charged particles deposit energy in the medium  Isotropic, delayed  Charged particles with a velocity greater than the speed of light * in the medium* produce an E-M shock wave  v > c/n  Similar to a sonic boom  Prompt light signature

21. H. Ray21 Event Signature

22. H. Ray22 MiniBooNE  Lots of e in MiniBooNE beam vs ~no e in LSND beam  Complicated and degenerate light sources  Require excellent data to MC agreement in MiniBooNE MB :   e LSND :   e  Lots of e in MiniBooNE beam vs ~no e in LSND beam  Complicated and degenerate light sources  Require excellent data to MC agreement in MiniBooNE

23. H. Ray23 The Monte Carlo  Cerenkov light  Scintillation light  Fluorescence from Cerenkov light that is absorbed/re-emitted  Reflection  Tank walls, PMT faces, etc.  Scattering off of mineral oil  Raman, Rayleigh  PMT Properties Sources of LightTank Effects

24. H. Ray24 Step 1 : External Measurements  Start with external desktop measurements IU Cyclotron 200 MeV proton beam Extinction rate = 1 / Extinction Length

25. H. Ray25 Step 2 : Internal Samples  Identify internal samples which isolate various components of the OM  UVF, Scint are both isotropic, same wave- shifting/time constants  Low-E Neutral Current Elastic events below Cerenkov threshold

26. H. Ray26 Step 3 : Verify MC Evolution Calibration Sample Provide e Constraint Background to CCQE Sample Mean = 1.80, RMS = 1.47 Mean = 1.19, RMS = 0.76 Mean = 20.83, RMS = 25.59 Mean = 3.48, RMS = 3.17 Mean = 16.02, RMS = 25.90 Mean = 3.24, RMS = 2.94  Examine cumulative  2 /NDF distributions across many physics samples, many variables

27. H. Ray27 The Monte Carlo Chain External Measurements and Laser Calibration First Calibration with Michel Data Calibration of Scintillation Light with NC Events Final Calibration with Michel Data Validation with Cosmic Muons,  CCQE, e NuMI, etc.

28. H. Ray28 Quasi-Elastic  Events Constrain the intrinsic e flux - crucial to get right!

29. H. Ray29 Signal Region e Events PRELIMINARY

30. H. Ray30 MiniBooNE Current Status  MiniBooNE is performing a blind analysis (closed box)  Some of the info in all of the data  All of the info in some of the data  All of the info in all of the data Public Announcement April 11 th

31. H. Ray31 Final Outcomes Confirm LSNDInconclusiveReject LSND

32. H. Ray32 Final Outcomes Confirm LSNDInconclusiveReject LSND Need to determine what causes oscillations

33. H. Ray33 Final Outcomes Confirm LSNDInconclusiveReject LSND Need to collect more data / perform a new experiment

34. H. Ray34 Final Outcomes Confirm LSNDInconclusiveReject LSND Need to determine what causes oscillations Need to collect more data / perform a new experiment SN S

35. H. Ray35 Final Outcomes Confirm LSNDInconclusiveReject LSND

36. H. Ray36 Final Outcomes Confirm LSNDInconclusiveReject LSND SN S

37. H. Ray37 All Roads Lead to the SNS Confirm LSNDInconclusiveReject LSND Need to determine what causes oscillations Need to collect more data / perform a new experiment SN S

38. H. Ray38 What is the SNS? Accelerator based neutron source in Oak Ridge, TN Spallation Neutron Source

39. H. Ray39 The Spallation Neutron Source  1 GeV protons  Liquid Mercury target  First use of pure mercury as a proton beam target  60 bunches/second  Pulses 695 ns wide  LAMPF = 600  s wide,  FNAL = 1600 ns wide  Neutrons freed by the spallation process are collected and guided through beam lines to various experiments Hg Neutrinos come for free!

40. H. Ray40 The Spallation Neutron Source Target Area  - absorbed by target  + DAR Mono-Energetic!  = 29.8 MeV E range up to 52.8 MeV (Liquid Mercury (Hg+) target)

41. H. Ray41 The Spallation Neutron Source   +   + +    = 26 ns   +  e + +  + e   = 2.2  s  Pulse timing, beam width, lifetime of particles = excellent separation of neutrino types Simple cut on beam timing = 72% pure 

42. H. Ray42 The Spallation Neutron Source   +   + +    = 26 ns   +  e + +  + e   = 2.2  s  Mono-energetic   E = 29.8 MeV  , e = known distributions  end-point E = 52.8 MeV MiniBooNE SNS GeV

43. H. Ray43 The Spallation Neutron Source Neutrino spectrum in range relevant to astrophysics / supernova predictions!

44. H. Ray44 Proposed Experiments Osc-SNS Sterile Neutrinos -SNS Supernova Cross Sections

45. H. Ray45 -SNS Near Detectors  Homogeneous, Segmented  Primary function = cross sections for astrophysics  Most relevant for supernova neutrino detection = 2 H, C, O, Fe, Pb Full proposal submitted to DOE in August, 2005

46. H. Ray46 Osc-SNS Far Detector  MiniBooNE/LSND-type detector  Higher PMT coverage (25% vs 10%)  Mineral oil + scintillator (vs pure oil)  Faster electronics (200 MHz vs 10 MHz)  ~60m upstream of the beam dump/target  Removes DIF bgd

47. H. Ray47 Neutrino Interactions Elastic Scattering Quasi-Elastic Scattering Single Pion Production Deep Inelastic Scattering MeV GeV SNS Allowed Interactions

48. H. Ray48 Neutrino Interactions @ SNS  All neutrino types may engage in NC interactions

49. H. Ray49 Neutrino Interactions @ SNS  All neutrino types may engage in NC interactions  Muon mass = 105.7 MeV, Electron mass = 0.511 MeV  Muon neutrinos do not have a high enough energy at the SNS to engage in CC interactions!

50. H. Ray50 Appearance Osc. Searches  2 oscillation searches at SNS can be performed with CC interactions to look for flavor change  Appearance :   e (ala LSND)  e + p  e + + n  n + p  d + 2.2 MeV photon  Appearance :   e  e + 12 C  e - + 12 N gs  12 N gs  12 C + e + (~8 MeV) + e  MiniBooNE uses e + n  e - + p lower E e vs higher E e

51. H. Ray51 Neutrino Interactions @ SNS  Appearance :   e  e + 12 C  e - + 12 N  12 N  12 C + e + (~8 MeV) + e Intrinsic e vs mono-energetic e from  E of e - (MeV)

52. H. Ray52 Why the SNS? Beam Width S:BOsc. Candidates LSND   e 600  s 1:135 (observed R > 10) FNAL   e 1600 ns1:3~400 SNS   e 695 ns5:1~448/year Expected for LSND best fit point of : sin 2 2  =0.004 dm 2 = 1 May be < 500 ns!

53. H. Ray53 Sterile Neutrinos  Sterile neutrinos = RH neutrinos, don’t interact with other matter (LH = Weak)  Use super-allowed NC interactions to search for oscillations between flavor states and sterile neutrinos  Disappearance :   e   + C   + C *  C *  C + 15.11 MeV photon  One detector : look for deficit in x events  Two detectors : compare overall x event rates

54. H. Ray54 Sterile Neutrinos Near Detector onlyNear + Far Detector

55. H. Ray55 Sterile Neutrinos “There are several indirect astrophysical hints in favor of sterile neutrinos at the keV scale. Such neutrinos can explain the observed velocities of pulsars, they can be dark matter, and they can play a role in star formation and reionization of the universe.” Kusenko, hep-ph/0609158

56. H. Ray56 Sterile Neutrinos  R-process nucleosynthesis  Balantekin and Fuller, Astropart. Phys. 18, 433 (2003)  Pulsar kicks  Kusenko, Int. J. Mod. Phys. D 13, 2065 (2004)  Dark matter  Asaka, Blanchet, Shaposhnikov, Phys. Lett. B 631, 151 (2005)  Formation of supermassive black holes  Munyaneza, Biermann, Astron and Astrophys., 436, 805 (2005)  Play impt. role in Big Bang nucleosynthesis  Smith, Fuller, Kishimoto, Abazajian, astro-ph/0608377

57. H. Ray57 … but that’s not all! CP/CPT Violation  CPT violation (or CP + sterile neutrinos) allows different mixing for, anti-  Possible explanation for positive LSND, null MiniBooNE  Compare, anti- measured oscillation probabilities  CP :   e    e  CPT :   X    X

58. H. Ray58 Mass Varying Neutrinos  All positive oscillation signals occur in matter (K2K, KamLAND, LSND); no direct information on oscillation parameters in air/vacuum  Impose relationship between nus + dark E through scalar field  Scalar field couples to matter field = different osc parameters in vacuum & mediums  MaVaNus + 1 Sterile nu = LSND yes, MB no!  Require a path to detector which can be vacated/filled with dirt to test  Barger, Marfalia, Whisnant. Phys. Rev. D 73, 013005 (2006)  Schwetz, Winter. Phys. Lett. B633, 557-562 (2006)

59. H. Ray59 Why the SNS? Confirm LSNDInconclusiveReject LSND Looking for new physics Need much higher statistics Need to perform analysis with anti-neutrinos to completely rule out LSND Precise, well-defined neutrino/anti-neutrino beam with very high statistics and low backgrounds

60. H. Ray60 Why the SNS?  SNS : well known E spectrum to allow precise measurements  SNS : simultaneous measurements in neutrino, anti-neutrino modes  SNS : different systematics to LSND, MB  Second cross check of LSND  SNS : can perform beyond the standard model searches not open to MB  Sterile neutrino search, CP/CPT, MaVaNus

61. H. Ray61 The Global Picture  The Neutrino Matrix  APS Multi-Divisional Neutrino Study, Nov 2004  www.aps.org/policy/reports/multidivisional/neutrino/upload/main.pdf Pg ii

62. H. Ray62 The Global Picture  The Neutrino Matrix  APS Multi-Divisional Neutrino Study, Nov 2004  www.aps.org/policy/reports/multidivisional/neutrino/upload/main.pdf Pg iii

63. H. Ray63 The Global Picture  The Neutrino Matrix  APS Multi-Divisional Neutrino Study, Nov 2004  www.aps.org/policy/reports/multidivisional/neutrino/upload/main.pdf Pg 27

64. H. Ray64 The Global Picture  The Neutrino Matrix  APS Multi-Divisional Neutrino Study, Nov 2004  www.aps.org/policy/reports/multidivisional/neutrino/upload/main.pdf Pg 27

65. H. Ray65 Summary  SNS is about to become the best neutrino based facility in the US  DOE proposal for 2 near detectors awaiting funding  LANL white paper produced for far detector  Waiting on MiniBooNE result to go forward with a proposal  Regardless of the outcome of MiniBooNE, the future of *precision* neutrino measurements in the US lies at the SNS!

66. Backup Slides

67. H. Ray67 A Brief History of Neutrinos  1930 : Postulated by Pauli  1950-60 : First detection by Reines- Cowan, inverse beta decay  ~1935 : First nu mass experiments  1972 Bergkvist, mass upper limit  1980 - 85 : Soviet ITEP, mass up&low limit  Infamous 17 keV neutrino

68. H. Ray68 SNS Stats  ~17% of incident protons produce pions  2.3 x 10 -5  - decay before capture   + stopped <0.3 ns  1.3 GeV protons produce :  0.098  +, 0.061  -  For 9.6 x 10 15 protons/sec on target get 0.94 x 10 15 of each flavor : , Anti- , e  Anti- e / Anti-  < 3 x 10 -4  Flux @ 50 m from target = 3 x 10 6 s -1 cm -2

69. H. Ray69 Sterile Neutrinos  Near detector : ~2056 events/year (25 ton)  Far detector : ~3702 events/year (500 ton)  + C   + C * C *  C + 15.11 MeV photon Event rates only for 

70. H. Ray70 Event Rates per Year 250 ton detector @ 60 m, 100% eff e 12 C  e - 12 N gs 9378 e 12 C  e - 12 N * 4294 Total e 12 C  e - X 13,672  12 C   12 C * 15.11 3702  12 C   12 C * 15.11 7504 e 12 C  e 12 C * 15.11 6186 Total 12 C  12 C * 15.11 17,392

71. H. Ray71 Lorentz Violation  LSND, Atm, Solar oscillations explained by small Lorentz violation  Size of violation consistent with size of effects emerging from underlying unified theory at Planck scale  Kostelecky, Mewes. hep-ph/0406255 (2004)  Oscillations depend on direction of propagation  Don’t need to introduce neutrino mass!  Look for sidereal variations in oscillation probability

72. H. Ray72 Neutron Background  10 9 neutrons/day pass through near detectors  CC measurements = bgd free  neutron bgds greatly suppressed for t > ~1  s after start of beam spill  production is governed by  lifetime (~2.2  s )

73. H. Ray73 Near Detector Rates  Segmented (10 ton fiducial mass)  Iron = 3200 CC/year  Lead = 14,000  Al = 3,100  Homogeneous  Carbon = 1,000  Oxygen = 450

74. H. Ray74 Minos  120 GeV proton beam  Graphite target  2 movable horns  1.27x10 20 POT  Next up :   e osc search

75. H. Ray75 MINER A  Placed in NuMi beamline, directly upstream of Minos  Segmented solid scintillator detector, use Minos as  det  C, Fe, Pb targets  Quasi-Elastic Q 2, CC Coherent  prod. at very high E (6, 20 GeV)  Construction complete by 2009  4 yr run plan

76. H. Ray76 NO A  Off-Axis detector  Near & Far Detectors