Searching for Physics Beyond the Standard Model with Accelerator ν Experiments W.C Louis, LANL. MiniBooNE Status FNAL ORNL

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1 Searching for Physics Beyond the Standard Model with Accelerator ν Experiments W.C Louis, LANL MiniBooNE Status FNAL ORNL

2 Happy 75 th Birthdays to Frank Avignone, Ettore Fiorini, & Peter Rosen! We owe a great debt of gratitude to Peter Rosen for helping to make our MiniBooNE experiment a reality! We owe a great debt of gratitude to Frank Avignone for pushing for OrLAND, which has opened our eyes to the SNS and we hope will lead to OscSNS!

3 MiniBooNE Status Alabama, Bucknell, Cincinnati, Colorado, Columbia, Embry-Riddle, Fermilab, Indiana, Los Alamos, LSU, Michigan, Princeton, Saint Mary s, Virginia Tech, Yale

4 MiniBooNE was designed to test the LSND signal A 3 neutrino picture requires Δm 2 13 = Δm Δm 2 23 increasing (mass) 2 Δm 23 2 = m 2 2 -m 3 2 Δm 12 2 = m 1 2 -m 2 2 The three oscillation signals cannot be reconciled without introducing Beyond Standard Model Physics

5 MiniBooNE s Design Strategy Keep L/E same as LSND while changing systematics, energy & event signature P(ν μ ν e )= sin 2 2θ sin 2 (1.27Δm 2 L/Ε) target and horn decay region absorber dirt detector Booster K + π ν + μ ν e??? primary beam secondary beam tertiary beam (protons) (mesons) (neutrinos) Order of magnitude higher energy (~500 MeV) than LSND (~30 MeV) Order of magnitude longer baseline (~500 m) than LSND (~30 m)

6 CCQE Scattering A. A. Aguilar-Arevalo et al., PRL100, (2008) From Q 2 fits to MB ν μ CCQE data: M A eff -- effective axial mass E lo SF -- Pauli Blocking parameter From electron scattering data: E b -- binding energy p f -- Fermi momentum Model describes CCQE ν μ data well M A = GeV E lo = data/mc~1 across all angle vs.energy after fit Kinetic Energy of muon

7 NCpi0 Scattering A. A. Aguilar-Arevalo et al., to be published in Phys. Lett. B coherent fraction= %

8 MiniBooNE observes a low-energy excess! A. A. Aguilar-Arevalo et al., PRL98, (2007); (Update & paper soon on low-energy excess!)

9 Oscillation Limit Energy fit: 475<E ν QE <3000 MeV Simple 2-neutrino oscillations excluded at 98% C.L.

10 Allowed Region Energy Fit : 300< E ν QE < 3000 MeV

11 Global Fit Results-2D Fits 2 Colors represent Δχ arxiv: The star is the point of maximum compatibility LSND, KARMEN2, MB + BUGEY Assuming simple 2-ν oscillations with CP conservation!

12 Global Fits to Experiments LSND MB neutrino Bugey antineutrino KARMEN antineutrino antineutrino Max Compat % Delta M2 Sinsq theta X X X X X X X X X X X X X X X X X

13 Events from NuMI detected at MiniBooNE p beam π, K θ MiniBooNE detector is 745 meters downstream of NuMI target. MiniBooNE detector is 110 mrad off-axis from the target along NuMI decay pipe. Flux MB ~0.5% Event rates Energy similar to MB as off angle NuMI event composition at MB ν μ -81%, ν e -5%, ν μ -13%, ν e -1%

14 Excess Also Observed in NuMI Data! ν e Systematic errors will be reduced plus 3x as much data. ν μ

15 Possible Explanations for the Low-Energy Excess Anomaly Mediated Neutrino-Photon Interactions at Finite Baryon Density: Jeffrey A. Harvey, Christopher T. Hill, & Richard J. Hill, arxiv: CP-Violation 3+2 Model: Maltoni & Schwetz, arxiv: Extra Dimensions 3+1 Model: Pas, Pakvasa, & Weiler, Phys. Rev. D72 (2005) Lorentz Violation: Katori, Kostelecky, & Tayloe, Phys. Rev. D74 (2006) CPT Violation 3+1 Model: Barger, Marfatia, & Whisnant, Phys. Lett. B576 (2003) 303 New Gauge Boson with Sterile Neutrinos: Ann E. Nelson & Jonathan Walsh, arxiv: Other data sets (NuMI, antineutrino, SciBooNE) may provide an explanation!

16 Future Understand the low-energy excess of events! Excess is very interesting in its own right & crucial for T2K & NOvA longbaseline neutrino experiments. (T2K has a very similar neutrino energy distribution & will be affected by the same low-energy excess!) Analyze antineutrino data, NuMI data, & SciBooNE data. MiniBooNE is approved to run through 2009 with antineutrinos. Have already collected ~1E21 POT (~7.5 E20 POT in neutrino mode & ~2.5 E20 POT in antineutrino mode) If low-energy excess is consistent with a signal, new experiments at FNAL (BooNE) and/or ORNL (OscSNS) will be proposed to search/explore physics Beyond the Standard Model.

17 Future Experiments: BooNE & OscSNS Search/Explore physics 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

18 BooNE at FNAL Two identical detectors at different distances Search for ν e appearance & ν μ disappearance Search for sterile neutrinos via NCPI0 scattering & NCEL scattering Problem: imprecise ν energy determination smears oscillations!

19 OscSNS at ORNL Very high neutrino flux! Very low background! Beam is free! ν μ -> ν e Δ(L/E) ~ 3% ; ν e p -> e + n SNS: ~1 GeV, ~1.4 MW ν μ -> ν s Δ(L/E) < 1% ; Monoenergetic ν μ!; ν μ C -> ν μ C*(15.11) OscSNS would be capable of making precision measurements of ν e appearance & ν μ disappearance and proving, for example, the existence of sterile neutrinos! (see Phys. Rev. D72, (2005)). Flux shapes are known perfectly and cross sections are known very well

20 Search for Sterile Neutrinos with OscSNS Via Measurement of NC Reaction: ν μ C -> ν μ C*(15.11) Garvey et al., Phys. Rev. D72 (2005)

21 KARMEN Measurement of ν μ C -> ν μ C*(15.11) σ NC = ( )x10-42 cm 2 (B. Armbruster et al., Phys. Lett. B423 (1998) 15) σ NC ~2.8x10-42 cm 2 (Kolbe, Langanke, & Vogel, Nucl. Phys. A652 (1999) 91)

22 Measurement of 3+2 Model with OscSNS Garvey et al., Phys. Rev. D72 (2005) ν μ > ν s

23 OscSNS Physics Goals ν e appearance (ν 12 e C -> e -12 N gs + β) ν e appearance (ν e p -> e + n + γ) ν μ disappearance & search for sterile ν (ν 12 μ C -> ν μ C* + γ) νe >νe elastic scattering (μ ν?) νc cross sections

24 Conclusions LSND observes evidence for ν e appearance (which will be tested by MiniBooNE antineutrino data) MiniBooNE observes with neutrino data an unexplained excess at lower energies (γ radiative process or ν e appearance?) BooNE and/or OscSNS can search with high sensitivity for ν e appearance, ν μ disappearance, & sterile neutrinos