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Novel Searches for Dark Matter with Neutrino Telescopes

Prospects for the Search for Dark Matter with Fermi Brian L. Winer The Ohio State University Fermi LAT Dark Matter and New Physics Working Group. Novel Searches for Dark Matter with Neutrino Telescopes Center for Cosmology and Astroparticle Physics Nov 17-18 th , 2008.

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Novel Searches for Dark Matter with Neutrino Telescopes

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  1. Prospects for the Search for Dark Matter with Fermi Brian L. Winer The Ohio State University Fermi LAT Dark Matter and New Physics Working Group Novel Searches for Dark Matter with Neutrino Telescopes Center for Cosmology and Astroparticle Physics Nov 17-18th, 2008

  2. WIMP annihilation: gamma-ray yield 200GeV mass WIMP WIMP pair annihilation gamma spectrum

  3. Dark Matter in the gamma ray sky Milky Way Halo simulated by Taylor & Babul (2005) All-sky map of DM gamma ray emission (Baltz 2006) Galactic center Milky Way satellites Milky Way halo Extragalactic sub haloes/clumps Only dm annihilation radiation shown….

  4. Several Different Search Modes

  5. Background to all photons: Charged Particles • Rejection power: • ~105-6 • γ efficiency: • ~0.8 Total GCR protons GCR He GCR electrons albedo protons,pbar albedo positronsalbedo electrons albedo gammas.

  6. Galactic Center Advantage: Largest Source of DM Photons Problems: Astrophysical Sources CR Accelarators High Energy Gamma Sources Behavior at Fermi Energies?? Initial Sensitivity Estimation ROI = 0.5 deg of GC, E > 1 GeV Truncated NFW Profile. Simulate Particle-yield (DarkSUSY) Background: Astrophysical Sources Subtracted GALPROP Represents Diffuse Background Simulate Detector Response. Consider Annihilations: (Done Individually)

  7. Dark Matter From the Galactic Center Simple for Test Statistic. (More sophisticated TS under study) • similar • WW less sensitivity • more sensitive. 5 Years of Sky-Survey 5 Years of Sky-Survey • Current Efforts: • Optimize ROI (Plot) • Understand Source Removal • Need data. • Optimize TS.

  8. Galactic Halo Analysis Advantage: Use the large statistics of the full sky. Challenge: Critically Dependent on Diffuse Background Measure the sensitivity to observing a signal. ROI = R>10o or |b|>10o NFW Profile. Diffuse Background: GALPROP (Conv., Opt.) Simultaneous Fit to bothspatial and energydistributions Mass vs <s v> 1 year of running

  9. Galactic diffuse: conventional and optimized GALPROP model ’conventional’ GALPROP: calibrated with locally measured electron and proton,helium spectra, as well as synchrotron emission Optimized GALPROP: Conventional Optimized Strong, Moskalenko, Reimer, ApJ537, 736, 2000 Strong, Moskalenko, Reimer, ApJ613, 962-976, 2004

  10. Galactic Diffuse Background: Brem b l

  11. Galactic Diffuse Background: Neutral Pion Decay b l

  12. Galactic Diffuse Background: Inverse Compton b l

  13. Galactic Diffuse Background: Total b l

  14. Galactic Halo Analysis Advantage: Use the large statistics of the full sky. Challenge: Critically Dependent on Diffuse Background Measure the sensitivity to observing a signal. ROI = R>10o or |b|>10o NFW Profile. Diffuse Background: GALPROP (Conv., Opt.) Simultaneous Fit to bothspatial and energydistributions Mass vs <s v> 1 year of running

  15. Sensitivity for Galactic Halo Analysis Conventional Diffuse Optimized Diffuse 50 250 50 250 Typical DM Photon Yields (1 year) : 1.5 x 104 (100 GeV/c2) 3 x 103 (250 GeV/c2)

  16. Halo Analysis: Mass Resolution Warning: Statistical Uncertainty ONLY…think of this as a “best case/Lower Limit” 100 For cases where we observer a signal at 5s, we can determine our mass resolution. Error bars represent the 68% CI • Current Efforts: • Work on understanding Diffuse Background. • Optimize ROI • Understand Source Removal • Optimize Fitting. • SYSTEMATICS! SYSTEMATICS! 0 250 100

  17. Search for Sub-halos • In CDM Paradigm, expect MW to contain potentially large number of sub-halos. • Sensitivity: • Assumes Taylor&Babul (05) Distribution • Sub-halo with Truncated NFW Profile • MWIMP=100 GeV • Annihilation • Background: Extragalactic,Galactic Diffuse (GALPROP) • Search for Msub>106 MO • Test Statistic: .

  18. Sub-halos Most Sub-Halos are found a high (|b|) galactic latitude. Once found an attempt can be made to extract the DM parameters. Below are the error ellipses for the case on the previous page. Green: GALPOP optimized Red: GALPROP conventional No. of satellites Fermi 5-yrs 99% CL 90% CL Fermi 1-yr 68% CL <σannihv > * Astrophy Unc. Significance [ σ] WIMP mass [GeV]

  19. Dwarf Spheroidal Galaxies • Advantage: • Could be DM Dominated • Disadvantage: • DM Profile? • Initial Sensitivity • GALPROP used forDiffuse • Test Statistic: • Simple: • Recent: Likelihood • If NFW Profile, sens afactor of 10 less. • Other dSph (e.g. Draco)will also be studied. Sagittarius Dwarf Assumes 5 years of observations. Likelihood TS: Sensitivity Improves by2-4x

  20. Line Search Simulated detector response to δ function in energy • Advantage: ”Smoking Gun” • Backgrounds from data • Challenges: • Small BR <10-3 • Energy Resolution. • Initial Sensitivity Estimation • ROI = Broken Annulus • 20o < R < 35o ; |b|>15o • DM Den High but reduced background • Scan through energy range • Fit Background to exponential • Signal Fit Double Gaussian • Test Statistic: Some recent models predict enhancements. Proposed by Stoehr, et al Example MC Sim.

  21. Line 5σ sensitivity Trials factor included for unknown source. 5 Years of Fermi Data • Current Efforts: • Improved event selection and energy reconstruction. • Optimized ROI • Need data  Measure Diffuse Bkg. • Optimize TS.

  22. Summary • Fermi has many targets for the indirect DM search. • Some are statistics limited. • Some are sys. limited • Other Modes: • Cosmological WIMPS • Extra Dim: KK  HE Electrons • Efforts are on-going to optimize these searches. • Real Data Helps! • The DM Working Group plans an intense effort in the first year of operation. • We are happy finally to be in orbit!

  23. WIMP annihilation: gamma-ray flux

  24. Acknowledgements E Baltz, B. Berenji, E. Bloom, J. Chiang, Y. Edmonds, G. Godfrey, P. Wang, L. Wai, J. Cohen-Tanugi(SLAC/KIPAC) I. Moskalenko (Stanford) A. Morselli, A. Lionetto (INFN Roma/Tor Vergata) E. Nuss (Montpellier) R. Hughes, A. Sander, P. Smith, B. Winer (Ohio State) L. Bergström, T. Bringmann, J. Conrad, J. Edsjö, A. Sellerholm (Stockholm) A. Moiseev (Goddard) G. Bertone (Paris) R. Johnson(Santa Cruz) J. Ormes (Denver) R. Rando (Padova) A. Strong (Max-Planck) Pre-launch Estimates for GLAST Sensitivity to Dark Matter Annihilation SignalsE. A. Baltz, et al JCAP, 07 (2008) 013, arXiv: 0806.2911v2

  25. Parameter Space

  26. Cosmological WIMPS

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