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Calorimetry (GeV-EeV) in AMANDA and IceCube Neutrino Telescopes

Calorimetry (GeV-EeV) in AMANDA and IceCube Neutrino Telescopes. Neutrino Astronomy & Exotic Physics New Measurements from AMANDA Predictions for IceCube Conclusions Punch line… Energy determination is critical to doing Neutrino Astronomy. Neutrino Astronomy. Stable particles: p, g, e , n

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Calorimetry (GeV-EeV) in AMANDA and IceCube Neutrino Telescopes

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  1. Calorimetry (GeV-EeV) in AMANDA and IceCube Neutrino Telescopes • Neutrino Astronomy & Exotic Physics • New Measurements from AMANDA • Predictions for IceCube • Conclusions Punch line… Energy determination is critical to doing Neutrino Astronomy. Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  2. Neutrino Astronomy • Stable particles: p, g, e, n p + X  hadrons p+ nm + m+ • Astrophysical Sources: • AGN, GRB, Galaxy/Sag-A • GZK ( p + CMB g) • Topological defects • Cosmic-Rays: • Atmospheric Muons • Atmospheric Neutrinos Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  3. Neutrino Astronomy • Upper bounds to Neutrino Fluxes already exist from cosmic rays. Waxman & Bachall (WB) PRD,64,023002 Manheim, Protheroe & Rachen (MPR) PRD, 63, 023003 1 particle per m2-second Gaiser, astro-ph/0011525 Knee 1 particle per m2-year Cosmic Ray Flux Ankle 1 particle per km2-year GeV TeV PeV EeV Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  4. Neutrino Astronomy Albuquerque, Lamoureux, Smoot, hep-ph/0109177 • Diffuse flux: WB, MPR, GZK, galaxy Atmospheric nm • Point sources: AGN, Sgr-A, galactic center Background * 1 deg/40,000 deg • Variable sources: • GRB Background * 1 deg/40,000 deg * time coincidence factor. En dFn/dEn (km-2 yr-1 sr-1) TeV PeV EeV Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  5. Exotic Physics • Dark matter clumps at the center of galaxies, stars and planets. • Primary WIMP candidate is the neutralino: lightest super symmetric particle in MSSM. c + c  n + n, W + W, Z + Z, H + H, W + H, Z + H, q + q Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  6. Neutrino Rates 101 • Deep Inelastic Scattering • Charge current nm + p m + X ne + p e + X • Neutral current • + p n + X • Neutrino flux is attenuated as it passes through the earth. Albuquerque, Lamoureux, Smoot, hep-ph/0109177 COS(qz) = 0 COS(qz) = 1 COS(qz) Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  7. Muon Calorimetry 101 Albuquerque, Lamoureux, Smoot, hep-ph/0109177 • Muons radiate energy as they travel through ice. • Cerenkov light is a small fraction of the ionization component described by Bethe-Bloch equation. • Above 1 TeV other processes dominate: Bremstraahlung Photons Electron Pairs Photo-nuclear • Radiation deposited in the detector depends on the energy of the muon as it passes near the detector Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  8. Photon Transport 101 • Cerenkov Light • PMTs are sensitive to 300 nm to 600 nm wavelengths • Muons and secondaries radiate Cerenkov light. • Cascades – tracks radiate Cerenkov light. Hadronic component is 0.8*<EM>. • Scattering is depth dependent • See Kael Hanson’s talk in the calibration session. • Calorimetry in AMANDA & IceCube depends on the relation between photons detected and muon or cascade energy. J. Ahrends, et. al,submitted PRD Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  9. Calorimetry in Ice • Absorption length ~100 m • Scattering length ~25 m • Light is isotropized well before it is absorbed. • To first order, sampling is insensitive to geometric position or PMT orientation. • Current arrays sample a very small fraction of the total Cerenkov light… Total PMT area/ detector surface area ~ 10-5 for AMANDA and IceCube. • PMTs on a string… ~20 m spacing between PMTs String spacing… ~100 m spacing between strings. • String spacing determines energy threshold. Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  10. Atmospheric Neutrinos in AMADNA J. Ahrends, et. al,submitted PRD Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  11. Atmospheric Neutrinos in AMANDA • Primary quality cuts: • Likelihood of track fit high • High fraction of unscattered hits • Long track length • Hits spread smoothly along track • Hits aren’t spherically distributed • Low prob of being down-going J. Ahrends, et. al,submitted PRD Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  12. Atmospheric Neutrinos in AMANDA J. Ahrends, et. al,submitted PRD • Angular distributions of events are consistent with Atmospheric Neutrinos. • 204 candidates with 10% background • Rate is 0.65 (+0.65 –0.3) times the predicted rate. Vertical Up-going Horizon J. Ahrends, et. al,submitted PRD Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  13. Atmospheric Neutrino Spectrum in AMANDA J. Ahrends, et. al,submitted PRD AMANDA measures flux in the energy range: 66 GeV < En < 3.4 TeV En = 50 GeV Simulated Energy Thresholds Em (center) = 20 GeV Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  14. Atmospheric Neutrino Spectrumin AMANDA Energy resolution is estimated by a gaussian: s = 0.4*log(Egen) Predrag Miocinovic, PhD Thesis Reconstructed E = Generated E PRELIMINARY PRELIMINARY Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  15. Atmospheric Neutrino Spectrumin AMANDA PRELIMINARY Predrag Miocinovic, PhD Thesis • At low cut levels, misreconstructed background is evident. • Above cut level 7, normalization of data is 65% as before. • Spectrum shape is in good agreement with prediction. Cut levels 1-3 Cut levels 4-6 Cut levels 7-9 TeV Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  16. SPASE-AMANDA Cosmic Ray Composition • Lateral shower distribution is sensitive to the cosmic ray energy and composition. • Spase array is 15 deg. From AMANDA Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  17. SPASE-AMANDA Cosmic Ray Composition • Radiated light is multiplied by the number of muons in the bundle at the shower core. K50 ~ N photons 50 m from core. • Spase array at the Pole measures the lateral distribution of the shower. S30 = N electrons 30 m from core. • Comparison of muons in the core to the electrons 30 m from the core. Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  18. SPASE-AMADNA Cosmic Ray Composition • SIBYLL MC predicts a shift in the muon abundance vs electron abundance. • Differences between SIBYLL and QGSJET Are taken as a systematic uncertainty. • Smaller systematics • Muon propogation • Ice properties • Electronics Katherine Rawlins, PhD Thesis PRELIMINARY Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  19. SPASE-AMANDACosmic Ray Composition • A is the mean nucleon mass number of the cosmic ray spectrum. • Composition above the knee is constent with higher mass cosmic rays. • Energy resolution is better for bundles than single muons. • PeV energies measured. PRELIMINARY Katherine Rawlins, PhD Thesis 65% proton / 35% iron 90% proton / 10% iron PeV Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  20. WIMP Search in AMANDA J. Ahrens et al. Submitted PRD astro-ph/0202370 • Neutralino Mass is 5 times average muon energy. • Muon threshold is 50 GeV. Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  21. The Future… IceCube • IceCube: 80 strings 60 PMTs/string Depth: 1.4-2.4 Km Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  22. IceCube Concept IceTop AMANDA South Pole Skiway 1400 m 2400 m • IceTop: 2 PMTs in a “pool” at the top of each string. 3D air-shower detector Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  23. Simulated IceCube Events 10 TeV Muon 375 TeV Electron PeV Tau 6 PeV Muon Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  24. IceCube – Sensitivity (>10 GeV) • WIMPs from the center of the earth and the sun. Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  25. IceCube – Sensitivity (>TeV) Albuquerque, Lamoureux, Smoot, hep-ph/0109177 • Diffuse flux as a function of energy deposited in the detector. • IceCube sensitive to 1/3rd of WB limit after 1 yr. 1/5th of WB limit after 2-3 yrs • If diffuse flux is comes from <10 sources, IceCube will identify them. • GRB: Atm flux/(20000*DT) = back-free 15 events/year • Sagittarius A East • Center of the Galaxy is above the horizon at the South Pole. • 0 to 40 events/year at Mediterranean latitudes. Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  26. IceCube – Sensitivity(>EeV) • GZK n have Ultra High Energy • Above the horizon at EeV. • Radiated energy is enormous. • Without reconstructing tracks: number of photons in the detector gives lower limit to muon energy. • Effective volume grows with energy 1 km2 @ E=1015 GeV 8 km2 @ E=1020 GeV • Fewer than 2.5 events/(km2 yr) expected from GZK. Engel, Stanev, astro-ph/0101216 EeV Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

  27. Conclusions • First analyses of AMANDA-B10 calorimetry are encouraging. • Atmospheric neutrino rate and spectrum are consistent within systematic uncertainties of theoretical predictions. • Cosmic ray composition is consistent with higher mass cosmic rays above the knee. • WIMP limit confirms other direct measurement results. • IceCube is a discovery instrument • Astrophysical fluxes are small but detectable if experiment is efficient. (no descoping, need near 100% duty cycle) • WIMPS will provide a good cross check of Direct Detection limits. • Source detection depends on understanding the energy resolution well. • Trigger & cut thresholds • Spectrum measurement. • Real physical insight comes from the energetics of the neutrino spectrum. Jodi Lamoureux, LBNL/NERSC Calor 2002 – Cal Tech., Pasadena, CA

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