neutrino physics - lecture 7

Neutrino Physics - Lecture 7Steve ElliottLANL Staff MemberUNM Adjunct Professor505-665-0068, [email protected]

Steve Elliott, UNM seminar series

Lecture 7 OutlineAccelerator Neutrinos - short - medium baselineThe neutrinosPast experimentsWhat we know and what we want to learn

Most slides from Bill Louis


The LSND Puzzle and MiniBOONE


The Evidence for Neutrino Oscillations


Requires a 3rd m2


Current State of Neutrino Oscillation EvidenceExpt.TypeDm2 (eV2) sin22q

LSNDnm->ne ~1 ~3x10-3

Atm. nm->nx~2x10-3~1

Solarne->nx ~8x10-5~0.8


MiniBooNE Neutrino Oscillation UpdateNeutrino Oscillations & the 3 m2 Problem!?! (Sterile Neutrinos?)MiniBooNE: A Definitive Test of the LSND Neutrino Oscillation SignalFuture Neutrino Experiments: BooNE & OscSNS


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+1Hung (hep-ph/0010126)Sterile NeutrinoKaplan, Nelson, & Weiner (PRL93(2004)091801) Explain Dark Energy?CPT Violation & 3+1 Barger, Marfatia, & Whisnant (PLB576(2003)303)Sterile NeutrinoExplain Baryon Asymmetry in the Universe?Quantum DecoherenceBarenboim & Mavromatos (PRD70(2004)093015)Lorentz ViolationKostelecky & Mewes (PRD70(2004)076002)Katori, Kostelecky, Tayloe (hep-ph/0606154)Extra DimensionsPas, Pakvasa, & Weiler (PRD72(2005)095017)Sterile Neutrino DecayPalomares-Ruiz, Pascoli, & Schwetz (JHEP509(2005)48)


Probability of Neutrino OscillationsPab = dab - 4SiSj |Uai U*bi U*aj Ubj | sin2(1.27Dmij2L/En) As N increases, the formalism gets rapidly more complicated!N#Dmij2#qij#CP Phases

2 1 10/1

3 2 31/3

6 515 10/15


MiniBooNE: A Definitive Test of the LSND Evidence for Oscillations: Search for nm -> neAlabama, Bucknell, Cincinnati, Colorado, Columbia, Embry-Riddle, Fermilab, Indiana, Los Alamos, LSU, Michigan, Princeton, St. Mary's, Western Illinois, YaleCompletely differentsystematic errors than LSND

Much higher energythan LSND

Blind Analysis


MiniBooNE HighlightsMiniBooNE 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 POTExperiment is working well (99% livetime & 99% of PMT channels working well) Clearly reconstructing CCQE, CCPI+, NCPI0, & NCEL eventsFirst 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 pulsesNow taking data with Antineutrinos (since January 2006)


MiniBooNE Neutrino FluxHARP at CERNE910 at BNL


Expected MiniBooNE Events


After ne PIDSelection(from proposal)


Expected MiniBooNE Sensitivity(from proposal)(from proposal)


Measurement of Oscillation Parameters(from proposal)


Likelihoods for Contained NuMI 1 Sub-Events Good agreement between data and MC!Preliminary!


BackgroundsNon- ne BackgroundsBeam OffCC InclusiveNC p0NC D->NgNC Coherent gNC Radiative gIntrinsic- ne BackgroundsFrom m -> ne decayFrom K-> ne decayFrom p -> ne decay


Beam-Off Background is Negligible! Neutrino Signal to Cosmic-Ray Background ~ 5000 to 1!


Good PID Agreement for CC Inclusive Events PIDCC inclusive events tagged by Michel electrons

92% of m- decay8% of m- capture

MC is correctlyestimating CCinclusive background

Preliminary!


MiniBooNE NC p0 Events are MeasuredDMp ~ 20 MeV


Gamma BackgroundsNC D->Ng : BR ~ 0.56% at peak; small but non-negligible background; now properly handled by modified version of NUANCENC Coherent g : Calculated from Rein & Sehgal (Phys. Lett. 104B (1981) 394) & estimated to be negligibleNC Radiative g : 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


Intrinsic ne BackgroundsFrom m -> ne decay : Well determined from nm CCQE eventsFrom K-> ne decay : Measure kaon-induced neutrino flux at high energies & extrapolate to low energiesFrom p -> ne decay : Well determined from nm CCQE events


Expectations for 5E20 Protons on TargetPreliminary!


MiniBooNE ScheduleContinue Antineutrino RunComplete Neutrino Oscillation Analysis (Estimate systematic errors from neutrino flux, cross sections, detector MC)Open Box and Present ResultsIf MiniBooNE Confirms LSND => Physics Beyond the Standard Model!


Future Experiments: BooNE & OscSNSWhat 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 cancelOscSNS 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


BooNE at FNALTwo identical detectors at different distances

Search for sterileneutrinos via NCPI0scattering & NCEL scattering

Problem: imprecise n energy determinationsmears oscillations!


OscSNS at ORNLnm -> ne D(L/E) ~ 3% ; ne p -> e+ nnm -> ns D(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.SNS: ~1 GeV, ~1.4 MW


OscSNS nm -> ne Experiment vs LSNDMore 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 ~350 ne oscillation events &

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


KARMEN Measurement of nm C -> nm C*(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)


Measurement of 3+2 Model with OscSNS (Sorel et al., Phys. Rev. D70 (2004) 073004)


ConclusionsMiniBooNE will soon test the LSND Oscillation SignalIf 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 ParametersResolve 3 m2 Paradox & Explore Physics Beyond the Standard Model! (e.g. Sterile Neutrinos)


neutrino physics - lecture 7

Documents

unm seminar seriesrequires

unm seminar serieslecture

unm seminar seriesif

unm seminar seriesthe

miniboonesteve elliott

bnlsteve elliott

m2steve elliott

boone oscsnssteve elliott