SBNW11 Summary June 23, 2011 Louis – Experimental Results & Theoretical Interpretations Van de Water – Future Facilities & Experiments

109 Registrants 44 Institutions Talks are on Web Page ent/sbnw2011

What is Short Baseline? “Short” refers to L /E and not just L  Note that L /E  is proportional to the lifetime in its CM frame Our definition of “Short” is L /E ~ 1 (km/GeV or m/MeV) This definition includes radioactive source experiments (~1 m/1 MeV), reactor experiments (~5 m/5 MeV), accelerator experiments (~1 km/1 GeV), & IceCube atmospheric (~1000 km/1 TeV)

Motivation for SBNW11 Tantalizing results from short (& long) baseline experiments (LSND, MiniBooNE, MINOS, Reactor Antineutrinos, Radioactive Neutrino Sources, etc.) may possibly have a profound impact on our understanding of particle & nuclear physics. Neutrino cross sections are very interesting: nuclear effects, short- range correlations, pion exchange currents, pion absorption, initial state interactions, & final state interactions make this a rich and compelling area of study. Nuclear effects can affect neutrinos and antineutrinos differently and affect CP violation interpretations.

5 A.A. Aguilar-Arevalo et al., Phys. Rev. Lett. 102, (2009)

6 A.A. Aguilar-Arevalo et al., Phys. Rev. Lett. 105, (2010)

Extremely surprising result - CCQE     C)>6    n) How can this be? Not seen before, requires correlations. Fermi Gas has no correlations and should be an overestimate. A possible explanation involves short-range correlations & 2-body pion- exchange currents: Joe Carlson et al., Phys.Rev.C65, (2002) & Gerry Garvey. These nuclear effects could have a big effect on searches for CP Violation.  CCQE Scattering - (Carlson) A.A. Aguilar-Arevalo, Phys. Rev. D81, (2010). 7

Initial MINOS  Disappearance Results in Mode (Thomas) Expect  disappearance above 10 GeV for LSND neutrino oscillations. “The probability that the underlying  and  parameters are identical is 2.0%.” (arXiv: )

Initial MINOS  Disappearance Results in Mode Expect  disappearance above 10 GeV for LSND neutrino oscillations.

10 arXiv: R=

11 Giunti & Laveder, arXiv: SAGE, PRC 73 (2006) arXiv:nucl-ex/ R=

Theoretical Interpretations Sterile neutrinos (3+N models with CP violation) - Ignarra Non-standard interactions – Kopp & Friedland Lorentz violation - Diaz CPT violation Sterile decay - Gninenko

13 Christina Ignarra; Updated from G. Karagiorgi et al., PRD80, (2009) Kopp, Maltoni, & Schwetz, arXiv: all & 3+1 only Key test is a search for  disappearance!

Non Standard Interactions (Kopp)

Sterile Decay? (Gninenko) The decay of a ~50 MeV sterile  has been shown to accommodate the LSND & MiniBooNE excesses – Gninenko, PRL 103, (2009) arXiv:

Lorentz Violation? (Diaz) arxiv:

Conclusions World antineutrino data agree very well with a 3+1 model Key test of 3+1 is a search for  disappearance World neutrino + antineutrino data can be explained somewhat well by a 3+2 model with CP violation, although there is tension between appearance and disappearance experiments Other models are possible besides 3+N: NSI, sterile neutrino decay, Lorentz violation, CPT violation, etc. Knowledge of cross sections important for interpretations of short and long baseline oscillations

SBNW11: R. Van de Water (LANL) ◦ Key questions ◦ Requirements for future beam experiments ◦ Future experiments/facilities  Short term  Mid term  Long term ◦ Summary 22

SBNW11: R. Van de Water (LANL) ◦ Need to make smoking gun measurement.  How do we do it quickly?  v μ disappearance?? ◦ Need to make a >5 sigma measurement at L/E ~1 to convince ourselves and the community of new physics. ◦ Not sure of underlying physics, so need an experiment (or set of experiments) with diverse capabilities that can test many ideas. ◦ Cross section effects are important, and can change interpretation of oscillation results. 23

SBNW11: R. Van de Water (LANL) Need to measure neutrino properties to the few percent level. Rate = Flux x Cross Section x detector response Flux: Intense source -> Booster/MI, CERN-PS, SNS, cyclotrons, LBNE, Project X. Measure flux insitu using H/D 2 targets. Cross Section: Need better models, especially to measure correct neutrino energy. Much data on Carbon, need more data for Ar. Detector Response: LAr would allow separation of electrons and gamma-rays. Want good tracking and magnetic fields. Two detectors or long detector to measure L/E effects. 24

SBNW11: R. Van de Water (LANL) ◦ Keep running Miniboone to improve antineutrino oscillation statistics (collect ~1.5E21 POT). ◦ Complete SB/MB v μ disappearance. ◦ Oscillation updates from Minos (v μ disappearance, antinu NC, LV). ◦ Analyze IceCube data, look for v μ disappearance. ◦ Make more cross section measurements with Minerva, Minos, Miniboone, ArgoNeut. ◦ Develop better cross section models. ->Apply to recent oscillation results, i.e. shift in reconstructed neutrino energy. Could it explain the difference in Miniboone v e and v e appearance result? 25

SBNW11: R. Van de Water (LANL) 26 - They are working on full systematics and will have results in the future. (Warren Huelsnitz)

SBNW11: R. Van de Water (LANL) ◦ Run uBooNE to test MB low energy anomaly. ◦ Build BooNE (near detector) – decisive (~5 sigma), quick, inexpensive, on Carbon (measure disappearance/appearance). ◦ Minos+ running to search for sterile nu, NSI, etc. ◦ NOvA 2 nd near detector (L/E ~1) and SciNova cross sections. ◦ Build and run two detector LAr experiments at CERN and FNAL to make definitive test of appearance, disappearance, nu decay, etc. ◦ Build OscSNS/cyclotron experiment (stop pion source) to retest LSND directly >5 sigma. ◦ Katrin results (look for kinks in E distribution above end point). ◦ Develop Muon Storage ring, Reactor (SCRAAM) and Source (LENS, Ga, Borexino) experiments. 27

SBNW11: R. Van de Water (LANL) As a counting experiment: translates to 5σ sensitivity if excess is ν e, 4σ if excess is γ  e/γ separation capability removes ν μ induced single γ backgrounds  electron neutrino efficiency: ~x2 better than MiniBooNE  sensitivity at low energies (down to tens of MeV compared to 200 MeV on MiniBooNE) 28 Low energy excess above background if excess is electrons Low energy excess above background if excess is photons

SBNW11: R. Van de Water (LANL) 29 Neutrino mode appearanceAntineutrino mode appearance - Also >5σ disappearance sensitivity in both modes.

SBNW11: R. Van de Water (LANL) 30 MINOS+ disappearance NoVA with a second near detector -NoVA has also considered a off axis near detector. -Given the similar energies and signal, NoVA is taking seriously SB oscillations/physics as a source of background they need to understand.

SBNW11: R. Van de Water (LANL) 31 (Stat errors only) > Project X feeding the BNB could significantly (~ x10) reduce the required run time! Assumes 2-3E20 POT/yr (Stat errors only)

SBNW11: R. Van de Water (LANL) 32 -CERN Science council is seriously considering the proposal and will make a recommendation soon (June 28) whether to proceed with real design and costing work.

SBNW11: R. Van de Water (LANL) OscSNS at ORNL: A Smoking Gun Measurement of Active-Sterile Neutrino Oscillations  -> e ; e p -> e + n => re-measure LSND an order of magnitude better.  -> s ; Monoenergetic  ;  C ->  C*(15.11) => search for sterile ν OscSNS would be capable of making precision measurements of e appearance &  disappearance and proving, for example, the existence of sterile neutrinos! (see Phys. Rev. D72, (2005)). Flux shapes and cross sections are known very well. SNS: ~1 GeV, ~1.4 MW 1kton LS detector At 60m MB like detector at the SNS

SBNW11: R. Van de Water (LANL) ◦ If smoking gun found, then design/build a series of experiments with Project X to explore in detail the source of new physics:  DIF ( kW at 3GeV with a new accumulator)  times more flux with reduced Kaon background.  DIF (25-50kW at 8GeV with antiproton accumulator) directly into BNB.  DAR difficult due to long duty cycle.  Beam dump exotics - axions, paraphotons, etc.  Cross sections. 34

SBNW11: R. Van de Water (LANL) ◦ The conference succeeded in starting to build a community to investigate physics at the L/E ~1 scale. ◦ We need to find a smoking gun soon:  More MB running, SB/MB disappearance, BooNE, uBooNE, IceCube. ◦ LAr will play a crucial role in the future, and can test in detail many of the models such as 3+N, nu decay, nuclear effects, LV, etc. ◦ We need to continue work on cross sections for Carbon and Ar.  Nuclear effects are important, especially to energy determination, which can affect oscillation parameters. ◦ Whatever technology/experiments we do, we need overwhelming statistics (protons) to understand details of the new physics.  Project X would be an outstanding opportunity for short baseline physics. 35

SBNW11: R. Van de Water (LANL) Backup

SBNW11: R. Van de Water (LANL) 37 Updated from G. Karagiorgi et al., PRD80, (2009) Kopp, Maltoni, & Schwetz, arXiv: all & 3+1

MiniBooNE v e Appearance Oscillations Current: 5.66E20 POT: E > 475 MeV Future Projections 8.58E20 POT We have reprocessed up to 8.58E20 POT and are currently analyzing the data. We will release updated oscillation results soon (this summer) - 50% more POT and new K+ constraint from SciBooNE. Joint SciBooNE/MiniBooNE v μ disappearance analysis ongoing with results in the fall.