Results from MiniBooNE and SciBooNE Users Meeting 2010 Joseph Walding College of William and Mary 2nd June 2010 Outline Joseph Walding Fermilab Users Meeting 2nd June 2010 ● MiniBooNE and SciBooNE Refresher Course ● Physics Results From The Last Year... – Neutrino Cross-sections – Neutrino Oscillations ● Summary 2 MiniBooNE Collaboration Joseph Walding Fermilab Users Meeting 2nd June 2010 ● University of Alabama ● Saint Mary's University of Minnesota ● Bucknell University ● Virginia Tech. ● University of Cincinnati ● Western Illinois University ● University of Colorado, Boulder ● Yale University ● Columbia University ● Embry-Riddle Aeronautical University ● Fermi National Accelerator Laboratory ● University of Florida ● University of Illinois ● Indiana University ● Los Alamos National Laboratory ● Louisiana State University ● MIT ● University of Michigan 3 ● Princeton University SciBooNE Collaboration Users Meeting 2010 ● Universitat Autonoma de Barcelona ● Purdue University Calumet ● University of Cincinnati ● Universita degli Studi di Roma "La Sapienza" & INFN ● University of Colorado, Boulder ● Saint Mary's University of Minnesota ● Columbia University ● Tokyo Institute of Technology ● Fermi National Accelerator Laboratory ● Unversitat de Valencia ● High Energy Accelerator Research Organization (KEK) ● Imperial College London A selection of SciBooNE collaborators at the ● Indiana University London Collaboration Meeting. March 2008 ● Institute for Cosmic Ray Research (ICRR) ● Kyoto University ● Kamioka Observatory ● Los Alamos National Laboratory ● Louisiana State University ● MIT 4 Outline Joseph Walding Fermilab Users Meeting 2nd June 2010 ● MiniBooNE and SciBooNE Refresher Course ● Physics Results From The Last Year... – Neutrino Cross-sections – Neutrino Oscillations ● Summary 5 The Booster n Experiments Joseph Walding Fermilab Users Meeting 2nd June 2010 50 m 440 m SciBooNE MiniBooNE ● Booster Proton accelerator: 8 GeV protons sent to target ● Target Hall: Beryllium target. 174kA magnetic horn with reversible horn polarity ● 50m decay volume: Mesons decay to m & n . Short decay pipe minimises m®ne decay m 6 ● SciBooNE: 100m baseline; MiniBooNE: 540m baseline Neutrino Beam Joseph Walding Fermilab Users Meeting 2nd June 2010 ● Use HARP experiment pBe®p± production data to predict our neutrino flux – ● Kaon production: Primary source of ne's ● Reversible horn polarity used to sign select mesons – Run in neutrino or anti-neutrino mode MiniBooNE Neutrino-Mode Flux MiniBooNE Antineutrino-Mode Flux ν ν µ ν µ µ ν µ ν ν e e ν e ν e 7 Wrong sign flux: ~6% Wrong sign flux: ~18% Intrinsic ne flux: ~0.5% Intrinsic ne flux: ~0.5% SciBooNE Joseph Walding Fermilab Users Meeting 2nd June 2010 SciBar Electron-Catcher (EC) 14,336 Scintillator bars 'Spaghetti' Calorimeter 15 tons (10 tons F.V.) 2 planes (x&y) 11X p/p separation using dE/dx 0 0 identify p & ne Muon Range Detector (MRD) 12 2” iron planes 362 scintillator panels stop m's with p < 1.2 GeV/c n beam All detectors have X&Y views SciBar & EC used at K2K 4m MRD 'new' detector built at FNAL 2008 DOE P2* Environmental Award 2m 8 MiniBooNE Joseph Walding Fermilab Users Meeting 2nd June 2010 Cherenkov Detector Specification Events identified using: 12 m diameter tank Ring topology 900 tons mineral oil (CH2) m-decay Michel signal 1280 inner PMTs (signal region) Scintillation light 240 outer PMTs (veto region) Able to distinguish nm from ne Physics Goals: Principally a neutrino oscillation experiment. Also able to measure neutrino cross-sections 9 Huge data-set in neutrino and antineutrino mode Data Sets Joseph Walding Fermilab Users Meeting 2nd June 2010 MiniBooNE SciBooNE ) 30 T O P mode 6 1 E 4 / ( n mode 20 _ e t a n _ r t mode n n e mode v E 10 mode mode 0 J un J ul Oct Nov Dec J an Feb Mar Apr May J un J ul Aug '07 '08 Date 0 1 ● 20 2n: 0.99x10 POT _ ● n: 1.53x1020 POT ● n: 6.5x1020 POT _ ● 95% POT efficiency ● n: 5.8x1020 POT _ Thank you to the Beams Division! ● Currently running in n mode 10 – Approved for 1x1021 POT Outline Joseph Walding Fermilab Users Meeting 2nd June 2010 ● MiniBooNE and SciBooNE Refresher Course ● Physics Results From The Last Year... – Neutrino Cross-sections – Neutrino Oscillations ● Summary 11 Neutrino Cross-Sections Joseph Walding Fermilab Users Meeting 2nd June 2010 _ ● Previous measurements from ● No measurements of sub-GeV n 1970's-1980's cross-sections ● Mostly H2 & D2 targets ● Important for CP studies _ ● Small sample sizes (100's of events) ● n and : n Different oscillation probabilities _ n CC cross-section G. Zeller n CC cross-section G. Zeller T2K NOvA T2K NOvA 12 LBNE LBNE Neutrino Cross-Sections Joseph Walding Fermilab Users Meeting 2nd June 2010 Good understanding of high E cross-sections (DIS) Low E is different regime: Quasi-elastic (QE) and single pion (1p) events dominate Important for future neutrino oscillation experiments _ n CC cross-section G. Zeller n CC cross-section G. Zeller T2K NOvA T2K NOvA 13 LBNE LBNE Neutrino Cross-Sections Joseph Walding Fermilab Users Meeting 2nd June 2010 Expected statistic error (T2K) K. Hiraide 5% systematic 20% systematic Wish to know T2K cross-sections better than 10% n CC cross-section G. Zeller quasi-elastic (QE) signal NC π 0 (background to ν e appearance) CC π + T2K NOvA (background to 14 ν disappearance) LBNE µ Quasi-Elastic Scattering Joseph Walding Fermilab Users Meeting 2nd June 2010 'Typical' muon ring in MiniBooNE - nm m CCQE W+ n p ● MiniBooNE uses muon kinematics to describe event ● Identify muons from decay signature ● Measuring total and differential cross- sections – Not ratios with respect to Charged 15 Current inclusive events Quasi-Elastic Scattering Joseph Walding Fermilab Users Meeting 2nd June 2010 eff 2 MA = 1.35 ± 0.17 GeV/c cf. K2K: MA = 1.20 ± 0.12 (SciFi) MA = 1.14 ± 0.11 (SciBar) ● Very different from light target experiments and for higher energy interactions ● First double differential CCQE cross-section – Model Independent 146,070 events: 77.0% purity, 26.6% efficiency J.Phys. G28 , R1 (2002) , R1 16 T. Katori: arXiv:1002.2680, accepted by PRD Quasi-Elastic Scattering Joseph Walding Fermilab Users Meeting 2nd June 2010 'Typical' 2-track CCQE event in SciBooNE - nm m CCQE W+ m n p p ● SciBooNE uses muon and proton kinematics to describe event ● Identify muons using MRD or from decay signature 17 Quasi-Elastic Scattering Joseph Walding Fermilab Users Meeting 2nd June 2010 ● Extraction of CCQE absolute cross-section J. Alcaraz – MRD-matched sample MRD-Matched Sample: 13,585 1-track events: 66.2% purity, 10.8% efficiency 2,915 2-track events: 68.5% purity, 2.3% efficiency Preliminary SciBar-Contained SciBar-Contained 1-track sample 2-track sample ● SciBar-contained 1-track (m) sample: Excess in backwards muon tracks ● Not seen in 2-track (m+p) sample 18 J. Walding: Thesis Quasi-Elastic Scattering Joseph Walding Fermilab Users Meeting 2nd June 2010 ● SciBooNE and MiniBooNE data in good agreement ● Low to high energy discrepancy – Minerva to fill in the gaps... Minerva, MINOS Preliminary 19 NC-Elastic Scattering Joseph Walding Fermilab Users Meeting 2nd June 2010 n n m m ● Neutral Current – NCE Z0 SciBooNE: Proton track – MiniBooNE: Scintillation light ● Proton typically below n,p n,p Cherenkov threshold ● SciBooNE: – NC/CCQE ratio calculation in progress – watch this space! 20 NC-Elastic Scattering Joseph Walding Fermilab Users Meeting 2nd June 2010 d ● Extracted dQ2 ● MiniBooNE CCQE value for MA better description of data than world average ● Isolating a Cherenkov proton sample – Ratio: p p / N N Preliminary – Strange spin component of the nucleon, Ds ● Ds= 0.08±0.26, systematics limited D. Perevalov: arXiv D. 0909.4617Perevalov: Preliminary Preliminary 21 NC p 0 Production Joseph Walding Fermilab Users Meeting 2nd June 2010 nm nm Z0 p0 n,p n,p ● SciBooNE: Two measurements – Inclusive NC p0 – Coherent NC p0 22 Inclusive NC p 0 Production Joseph Walding Fermilab Users Meeting 2nd June 2010 ● Charged current events rejected by looking for muon decay signature ● Vertex reconstruction used to reject external neutrino events (dirt events) from sample ● Able to reconstruct the p0 mass ● Extract_ model independent cross-section ratio (En = 0.8 GeV): 657 events selected, 240 expected background events 0 0 0 NC NC NC N obs −N bck CC = CC CC CC − 0 N obs N bck NC Y. Kurimoto: Phys. Rev. D81, 033004 Kurimoto: Phys. Rev. Y. =7.7±0.5stat±0.5sys×10−2 cf. MC prediction = 6.8x10-2 23 Error < 10% Coherent NC p 0 Production Joseph Walding Fermilab Users Meeting 2nd June 2010 ν Without vertex activity µ ν µ π0 ● Neutrino interacts coherently with whole nucleus – No nucleon recoil, forward tracks only – SciBar sensitive to proton recoil ● Not possible in MiniBooNE With vertex activity ● Define region around reconstructed vertex to look for proton recoil activity ● Extract model-dependent coherent fraction ● Fraction of NC π0 events from coherent channel: 17.9% (cf. MiniBooNE: 19.5%) – Agrees with Rein-Sehgal (RS) prediction – CC (K2K, SciBooNE): No evidence of coherent 24 production - disagrees with RS prediction by PRD accepted Kurimoto: arXiv 1005.0059, Y. MB: NC p0 Production Joseph Walding Fermilab Users Meeting 2nd June 2010 nm nm Z0 p0 n,p n,p ● Cross-section extraction in neutrino and antineutrino mode 25 MB: NC p0 Production Joseph Walding Fermilab Users Meeting 2nd June 2010 ● More model-independent measurements _ ● Flux averaged differential cross-sections (n and n mode) – Already being used by T2K! 26 C. Anderson: Phys. Rev. D81, 013005 CC p Production Joseph Walding Fermilab Users Meeting 2nd June 2010 n m- m ● + CC-p : Background to nm disappearance – If pion not identified event looks W+ CCQE-like p – Mis-reconstruction of neutrino energy n,p n,p ● For T2K need to know CC-p+ cross- section to <10% ● CC-p0: Not an oscillation background – Completes p production picture 27 MB: CC p + Production Joseph Walding Fermilab Users Meeting 2nd June 2010 ● Ability to separate pion and muon tracks Kink point – Hadronic interactions ® kinked tracks ● Absolute and multiple differential cross-sections calculated: Model ∂ ∂ ∂ ∂ ∂2 ∂2 Independent , , , , , ∂KE ∂cos ∂KE ∂ cos ∂ KE ∂cos ∂KE∂cos Model ∂ E , dependent ∂Q2 Preliminary Preliminary M.