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Neutrino Physics - Lecture 7

Neutrino Physics - Lecture 7. Steve Elliott LANL Staff Member UNM Adjunct Professor 505-665-0068, elliotts@lanl.gov. Lecture 7 Outline. Accelerator Neutrinos - short - medium baseline The neutrinos Past experiments What we know and what we want to learn Most slides from Bill Louis.

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Neutrino Physics - Lecture 7

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  1. Neutrino Physics - Lecture 7 Steve Elliott LANL Staff Member UNM Adjunct Professor 505-665-0068, elliotts@lanl.gov

  2. Lecture 7 Outline • Accelerator Neutrinos - short - medium baseline The neutrinos Past experiments What we know and what we want to learn Most slides from Bill Louis Steve Elliott, UNM seminar series

  3. The LSND Puzzle and MiniBOONE Steve Elliott, UNM seminar series

  4. The Evidence for Neutrino Oscillations Steve Elliott, UNM seminar series

  5. Requires a 3rdm2 Steve Elliott, UNM seminar series

  6. Current State of Neutrino Oscillation Evidence Expt. Type Dm2 (eV2) sin22q LSNDnm->ne~1 ~3x10-3 Atm.nm->nx~2x10-3 ~1 Solar ne->nx~8x10-5 ~0.8 Steve Elliott, UNM seminar series

  7. MiniBooNE Neutrino Oscillation Update • Neutrino Oscillations & the 3 m2 Problem!?! (Sterile Neutrinos?) • MiniBooNE: A Definitive Test of the LSND Neutrino Oscillation Signal • Future Neutrino Experiments: BooNE & OscSNS Steve Elliott, UNM seminar series

  8. If MiniBooNE Confirms LSND: Physics Beyond the Standard Model & Connections with Astrophysics! 3+2 Sterile Neutrinos Sorel, Conrad, & Shaevitz (PRD70(2004)073004) Explain Pulsar Kicks? Explain R-Process in Supernovae? Explain Dark Matter? MaVaNs & 3+1 Hung (hep-ph/0010126) Sterile Neutrino Kaplan, Nelson, & Weiner (PRL93(2004)091801) Explain Dark Energy? CPT Violation & 3+1Barger, Marfatia, & Whisnant (PLB576(2003)303) Sterile Neutrino Explain Baryon Asymmetry in the Universe? Quantum Decoherence Barenboim & Mavromatos (PRD70(2004)093015) Lorentz Violation Kostelecky & Mewes (PRD70(2004)076002) Katori, Kostelecky, Tayloe (hep-ph/0606154) Extra Dimensions Pas, Pakvasa, & Weiler (PRD72(2005)095017) Sterile Neutrino Decay Palomares-Ruiz, Pascoli, & Schwetz (JHEP509(2005)48) Steve Elliott, UNM seminar series

  9. Probability of Neutrino Oscillations Pab = dab - 4SiSj |UaiU*bi U*ajUbj | sin2(1.27Dmij2L/En) As N increases, the formalism gets rapidly more complicated! N #Dmij2 #qij #CP Phases 2 1 10/1 3 2 3 1/3 6 5 1510/15 Steve Elliott, UNM seminar series

  10. MiniBooNE: A Definitive Test of the LSND Evidence for Oscillations: Search for nm-> ne Completely different systematic errors than LSND Much higher energy than LSND Blind Analysis Alabama, Bucknell, Cincinnati, Colorado, Columbia, Embry-Riddle, Fermilab, Indiana, Los Alamos, LSU, Michigan, Princeton, St. Mary's, Western Illinois, Yale Steve Elliott, UNM seminar series

  11. Steve Elliott, UNM seminar series

  12. MiniBooNE Highlights • MiniBooNE began taking data in September 2002 and has collected ~750K neutrino events from ~7E20 Protons on Target; Oscillation analysis will use ~600K events from ~5.7E20 POT • Experiment is working well (99% livetime & 99% of PMT channels working well) • Clearly reconstructing CCQE, CCPI+, NCPI0, & NCEL events • First focussing horn was replaced during 2004 fall shutdown after setting a world record of 96M pulses (previous record set at BNL with 13M pulses); Second horn now has >100M pulses • Now taking data with Antineutrinos (since January 2006) Steve Elliott, UNM seminar series

  13. MiniBooNE Neutrino Flux HARP at CERN E910 at BNL Steve Elliott, UNM seminar series

  14. Expected MiniBooNE Events Steve Elliott, UNM seminar series

  15. After nePID Selection (from proposal) Steve Elliott, UNM seminar series

  16. Expected MiniBooNE Sensitivity (from proposal) (from proposal) Steve Elliott, UNM seminar series

  17. Measurement of Oscillation Parameters (from proposal) Steve Elliott, UNM seminar series

  18. Likelihoods for Contained NuMI 1 Sub-Events Good agreement between data and MC! Preliminary! Steve Elliott, UNM seminar series

  19. Backgrounds • Non-ne Backgrounds • Beam Off • CC Inclusive • NCp0 • NCD->Ng • NC Coherentg • NC Radiativeg • Intrinsic-ne Backgrounds • From m -> ne decay • From K-> ne decay • From p -> ne decay Steve Elliott, UNM seminar series

  20. Beam-Off Background is Negligible! Neutrino Signal to Cosmic-Ray Background ~ 5000 to 1! Steve Elliott, UNM seminar series

  21. Good PID Agreement for CC Inclusive Events Preliminary! CC inclusive events tagged by Michel electrons 92% of m- decay 8% of m- capture MC is correctly estimating CC inclusive background Steve Elliott, UNM seminar series PID

  22. MiniBooNE NC p0Events are Measured DMp ~ 20 MeV Steve Elliott, UNM seminar series

  23. Gamma Backgrounds • NCD->Ng: BR ~ 0.56% at peak; small but non-negligible background; now properly handled by modified version of NUANCE • NCCoherentg : Calculated from Rein & Sehgal (Phys. Lett. 104B (1981) 394) & estimated to be negligible • NC Radiativeg: Two sources have been considered, and both are negligible: (1) Bremsstrahlung Term, where g emanates from recoil proton; (2) Contact Term, where g emanates from the interaction vertex Steve Elliott, UNM seminar series

  24. IntrinsicneBackgrounds • From m -> ne decay : Well determined from nm CCQE events • From K-> ne decay : Measure kaon-induced neutrino flux at high energies & extrapolate to low energies • From p -> ne decay : Well determined from nm CCQE events Steve Elliott, UNM seminar series

  25. Expectations for 5E20 Protons on Target Preliminary! Steve Elliott, UNM seminar series

  26. MiniBooNE Schedule • Continue Antineutrino Run • Complete Neutrino Oscillation Analysis (Estimate systematic errors from neutrino flux, cross sections, detector MC) • Open “Box” and Present Results • If MiniBooNE Confirms LSND => Physics Beyond the Standard Model! Steve Elliott, UNM seminar series

  27. Future Experiments: BooNE & OscSNS What new physics is there Beyond the Standard Model? BooNE would involve a second “MiniBooNE-like” detector (~$8M) at FNAL at a different distance; with 2 detectors, many of the systematics would cancel OscSNS would involve building a “MiniBooNE-like” detector (~$12M) with higher PMT coverage at a distance of ~60 m from the SNS beam stop at ORNL Steve Elliott, UNM seminar series

  28. BooNE at FNAL Two identical detectors at different distances Search for sterile neutrinos via NCPI0 scattering & NCEL scattering Problem: imprecise n energy determination smears oscillations! Steve Elliott, UNM seminar series

  29. OscSNS at ORNL SNS: ~1 GeV, ~1.4 MW nm -> neD(L/E) ~ 3% ; ne p -> e+ n nm -> nsD(L/E) < 1% ; Monoenergetic nm!; nm C -> nm C*(15.11) OscSNS would be capable of making precision measurements of ne appearance & nm disappearance and proving, for example, the existence of sterile neutrinos! (see Phys. Rev. D72, 092001 (2005)). Flux shapes are known perfectly and cross sections are known very well. Steve Elliott, UNM seminar series

  30. OscSNS nm -> neExperiment vs LSND (assuming Dm2 < 1 eV2) • More Detector Mass (x5) • Higher Intensity Neutrino Source (x2) • Lower Duty Factor (x100) (less cosmic bkgd) • No DIF Background (backward direction) • Lower Neutrino Background (x4) (60 m vs 30 m) • Better Signal/Background (x4) • Better L/E Resolution (x2) (more scint & better PMTs) • For LSND parameters, expect ~350ne oscillation events & <50 background events per year! Steve Elliott, UNM seminar series

  31. Search for Sterile Neutrinos with OscSNS Via Measurement of NC Reaction: nm C -> nm C*(15.11) Garvey et al., Phys. Rev. D72 (2005) 092001 Steve Elliott, UNM seminar series

  32. KARMEN Measurement ofnm C -> nmC*(15.11) sNC = (3.2+-0.5+-0.4)x10-42 cm2 (B. Armbruster et al., Phys. Lett. B423 (1998) 15) sNC ~2.8x10-42 cm2 (Kolbe, Langanke, & Vogel, Nucl. Phys. A652 (1999) 91) Steve Elliott, UNM seminar series

  33. Measurement of 3+2 Model with OscSNS (Sorel et al., Phys. Rev. D70 (2004) 073004) Steve Elliott, UNM seminar series

  34. Conclusions • MiniBooNE will soon test the LSND Oscillation Signal • If the LSND Signal is Confirmed, then Future Oscillation Experiments Would Provide a Great Opportunity for Neutrino Physics: BooNE at FNAL & OscSNS at ORNLMake Precision Measurements of Oscillation Parameters • Resolve 3 m2 Paradox & Explore Physics Beyond the Standard Model! (e.g. Sterile Neutrinos) Steve Elliott, UNM seminar series

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