SBNW11 Summary June 23, 2011

SBNW11 SummaryJune 23, 2011

• Louis – Experimental Results & Theoretical Interpretations

• Van de Water – Future Facilities & Experiments

109 Registrants44 Institutions

Talks are on WebPage https://indico.fnal.gov/event/sbnw2011

What is Short Baseline?

• “Short” refers to Ln/En and not just Ln

• Note that Ln/En is proportional to the n lifetime in its CM frame

• Our definition of “Short” is Ln/En ~ 1 (km/GeV or m/MeV)• This definition includes radioactive n source experiments (~1 m/1 MeV), reactor n experiments (~5 m/5 MeV), accelerator n experiments (~1 km/1 GeV), & IceCube atmospheric n (~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.

MiniBooNE Neutrino Results – (Mills)

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A.A. Aguilar-Arevalo et al., Phys.

Rev. Lett. 102, 101802 (2009)

LSND & MiniBooNE Antineutrino Results

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A.A. Aguilar-Arevalo et al., Phys.

Rev. Lett. 105, 181801 (2010)

Extremely surprising result - CCQE nC)>6 nn)

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, 024002 (2002) & Gerry Garvey. These nuclear effects could have a big effect on searches for CP Violation.

n CCQE Scattering - (Carlson)A.A. Aguilar-Arevalo, Phys. Rev. D81, 092005 (2010).

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Initial MINOS n Disappearance Results in n Mode(Thomas)

Expect n disappearance above10 GeV for LSND neutrino oscillations.

“The probability that the underlying n and n parameters are identical is 2.0%.” (arXiv:1104.0344)

Initial MINOS n Disappearance Results in n Mode

Expect n disappearance above10 GeV for LSND neutrino oscillations.

Reactor Antineutrino Anomaly(Mention)

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arXiv: 1101.2755

R=0.937+-0.027

Radioactive Neutrino Sources(Gavrin)

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Giunti & Laveder, arXiv:1006.3244SAGE, PRC 73 (2006) 045805arXiv:nucl-ex/0512041

R=0.86+-0.05

Theoretical Interpretations

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

Global Fits to World n Data(Ignarra)

(LSND, KARMEN, MiniBooNE, Reactor, MINOS, CDHS, etc.)

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Christina Ignarra; Updated from G. Karagiorgi et al., PRD80, 07300 (2009)

Kopp, Maltoni, & Schwetz, arXiv:1103.4570

all n & n

3+1

n only

Key test is a search for n disappearance!

Non Standard Interactions (Kopp)

Sterile n Decay?(Gninenko)

• The decay of a ~50 MeV sterile n has been shown to accommodate the LSND & MiniBooNE excesses– Gninenko, PRL 103, 241802 (2009)

arXiv:1009.5536

Lorentz Violation? (Diaz)

arxiv: 1012.5985

Conclusions• World antineutrino data agree very well with a 3+1 model

• Key test of 3+1 is a search for n 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

WorkShop Summary of Future Experiments and Facilities:

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◦ Need to make smoking gun measurement. How do we do it quickly? vμ 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.

Some Key Questions:

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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/D2 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.

Requirements for next beamline experiments:

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◦ Keep running Miniboone to improve antineutrino oscillation statistics (collect ~1.5E21 POT).

◦ Complete SB/MB vμ disappearance.◦ Oscillation updates from Minos (vμ disappearance,

antinu NC, LV). ◦ Analyze IceCube data, look for vμ 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 ve and ve appearance result?

Near Term Goals (~few years)Search for smoking gun:

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IceCube (L/E ~10TeV/10,000km ~1)

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- They are working on full systematics and will have results in the future.

(Warren Huelsnitz)


◦ 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 2nd 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.

Mid Term Possibilities (3-7 years)Make Detailed measurements to begin understanding the underlying physics:

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SBNW11: R. Van de Water (LANL) 28

MicroBooNE's LArTPC detection technique extremely powerfulSensitivities in neutrino mode (R. Guenette)

As a counting experiment: translates to 5σ sensitivity if excess is νe, 4σ if excess is γ

e/γ separation capability removes νμ 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)

Low energy excess above background if excess is electrons

Low energy excess above background if excess is photons


BooNE: MB like near detector at 200m, 1E20 POT each mode (only 1 year running) – Full systematics (Mills)

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Neutrino mode appearance Antineutrino mode appearance

- Also >5σ disappearance sensitivity in both modes.


Minos+ and NoVA (J. Thomas, R. Patterson, J. Cooper)

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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.


uBoonE and LaLAr on the BNB (Roxanne Guenette)

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(Stat errors only)

> Project X feeding the BNB could significantly (~ x10) reduce the required run time!

Assumes 2-3E20 POT/yr

(Stat errors only)


Moving ICARUS (600T LAr) to CERN, build a near detector (150T LAr) and rebuild the PS neutrino source (F. Pietropaola).

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- 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.


OscSNS at ORNL: A Smoking Gun Measurement of Active-Sterile Neutrino Oscillations

n -> ne ; ne p -> e+ n => re-measure LSND an order of magnitude better.

n -> ns ; Monoenergetic n ; n C -> n C*(15.11) => search for sterile ν

OscSNS would be capable of making precision measurements of ne appearance & n disappearance and proving, for example, the existence of sterile neutrinos! (see Phys. Rev. D72, 092001 (2005)). Flux shapes and cross sections are known very well.

SNS: ~1 GeV, ~1.4 MW

1kton LSdetectorAt 60m

MB like detector at the SNS


◦ If smoking gun found, then design/build a series of experiments with Project X to explore in detail the source of new physics: DIF (300-600kW at 3GeV with a new accumulator) 15-30 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.

Long Term Possibilities (>8 years)Make Precision measurements of new physics:

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◦ 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.

SBNW11 Workshop Summary:

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Backup


Global Fits to World n Data

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Updated from G. Karagiorgi et al., PRD80, 07300 (2009)

Kopp, Maltoni, & Schwetz, arXiv:1103.4570

all n & n

3+1

MiniBooNE ve Appearance OscillationsCurrent: 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 vμ disappearance analysis ongoing with results in the fall.

Documents

SBNW11 Summary June 23, 2011