IceCube & DeepCore Overview and Dark Matter Searches. Matthias Danninger for the IceCube collaboration

IceCube & DeepCore Overview and Dark Matter Searches for the IceCube collaboration

Content Overview: IceCube DeepCore (DOMs, geometry, deep ice properties, trigger & filter) Dark Matter searches: (current limits and prospects) Halo & Galactic Center Sun Conclusions 2

The IceCube neutrino telescope Final Configuration: - 5160 DOMs / 86 strings - ~O(103) neutrinos/day SPS-filter level - ~1.7x108 muons/day - threshold: 10 GeV - angular resolution: 0.4-1deg (~ 10 TeV) In Ice: 4790 DOMs/ 79 strings 3

The IceCube neutrino telescope 4

Deep Core 6 additional strings 60 High Quantum Efficiency PMTs (deployed in deep ice) 7m DOM spacing (17m standard), 72m inter-string spacing. focus energies (few GeV~1TeV) 4π detector using IceCube as an active veto. Southern sky sources (GC) and year round observation for the Sun. 5

Ice structure from dust-logger IceCube DeepCore 10 HQE DOMs 66 (courtesy of P. Hulth) DeepCore 50 HQE DOM 6

High quantum-efficiency PMTs 405 nm The DeepCore DOMs have PMTs with higher quantum efficiency than standard IceCube DOMs. The final gain in situ not yet determined. Noise rate HQE/standard = 1.18 (courtesy of P. Hulth) 7

DeepCore Trigger & Filter DeepCore SMT3 Trigger: Applied to the 13 strings associated with the fiducial volume (bottom 50 DOMs of DeepCore strings and bottom 22 DOMs of IceCube strings) MC predicted rates of ~140 Hz (8 Hz exclusive to IceCube SMT8 rate) Trigger implemented in IC79 configuration with observed rate of 170 Hz. (courtesy of J. Koskinen) 8

DeepCore Trigger & Filter DeepCore SPS Filter Applied to all DeepCore SMT3 triggers the expected rate from single CORSIKA MC is 22.6 Hz, background reduction of 8*10-3 Signal acceptance for atmospheric muon and electron neutrinos >99.5% and >99% for WIMPs. 9

Deep Core events 10

Deep Core events 11

DeepCore scientific goals Low energy electron-neutrinos, tau-neutrino cascades Neutrino oscillations. Observing neutrino sources in the Southern hemisphere. Improve sensitivity for low mass dark matter particles (WIMPS). Overview over DarkMatter searches with IceCube & DeepCore (Earth) (Halo/GC) slides, courtesy of C. Rott & C. Finley (Sun) work in progress, no new results 12

r benchmark model 14

J(Ψ) NFW Kravtsov Yuksel, Horiuchi, Beacom, Ando (2007) Moore r J(Ψ) Line of sight integral 15

Yuksel, Horiuchi, Beacom, Ando (2007) J(Ψ) DarkSUSY Line of sight integral 16

IC-22 Point Source Search, ApJL 701, 47 (2009) S / sqrt(b) no longer improves past 80 from Galactic Center (zenith) 275.70 days livetime after selecting good runs. 5114 selected events 17

IC22-string result Result: no excess in onsource region found, compared with off-source region. Upper Limits: different curves represent dn/de for different annihilation channels; thickness of curves is range due to different halo models 18

crucial for GC analysis is effective veto for downgoing muon events and identify starting tracks within IceCube see DeepCore Veto methods (talk by S. Euler) IC22-string result & IC40-string GC Arxiv:0912.5183 See also J.Huelss, DPG Result: no excess in onsource region found, compared with off-source region. Upper Limits: different curves represent dn/de for different annihilation channels; thickness of curves is range due to different halo models 19

Neutrinos from Dark Matter (Sun) signature: ν excess over background from Sun direction physics uncertainties involved: - relic density calculations - DM distribution in the halo smaller effect for this method mean density ρ l ocal = 0.3 GeV/c2 cm3 - velocity distribution - WIMP properties (MSSM/UED...) - interaction of WIMPs with matter (capture) planetary effects (high masses) background: Sun composition atm µ ~O(109) events/year (downwards) - self interaction (annihilation) atm ν ~O(103) events/year (all directions) 20

Investigated DM candidates arise in extensions of the Standard Model assumed to be stable: relics from the Big Bang mass from few GeV to few TeV candidates: MSSM: lightest super-symmetric particle (LSP) neutralino, χ01 = z11 B + z12 W3 + z13 H01+ z14 H02 simulation of softest and hardest case hard: m(χ01) [35 GeV 5 TeV] (τ + τ / W+W-) soft: m(χ01) [35 GeV 5 TeV] (b b) Universal extra dimensions: Lightest KaluzaKlein particle (LKP), B(1) or γ ( 1) fixed branching ratios: m(γ ( 1 ) [250 GeV 3TeV] R 21

Low Energy neutrino Search Signal MC ν-interaction in the Sun ν-energies of ~ 1 TeV have high interaction probability in Sun Sun becomes ν-opaque low mean muon energy in detector short tracks with few hits 22

Analysis strategy Remove atmospheric muon events until data sample is dominated by atmospheric neutrino events tally n e rim e tity p n x a u E ed q n i a t ob ΓA Φµ Cc ~ σsd 23

Analysis strategy Remove atmospheric muon events until data sample is dominated by atmospheric neutrino events tally n e rim e tity p n x a u E ed q n i a t ob ΓA Φµ Cc ~ σsd Mostly neutrino events in final data sample 24

Analysis strategy Remove atmospheric muon events until data sample is dominated by atmospheric neutrino events Abbasi et al., Physical Review D81 (2010) 057101. tally n e rim e tity p n x a u E ed q n i a t ob ΓA Φµ Cc ~ σsd SVM output value from signal simulations, data and three background components 25

Kaluza-Klein DM (LKP) Abbasi et al., Physical Review D81 (2010) 057101. (IC22 result) IceCube-22 & study: Only used data, when Sun is below the horizon main syst. uncertainty: Photon propagation in the ice & absolute DOM efficiency (~20%) relate muon flux and WIMP-nucleon crosssection: <Eνμ > = 53 GeV 27

Neutralino DM (LSP) Abbasi et al., Phys. Rev. Lett. 102, 201302 (2009) (IC22 result) IceCube-22 & study: Only used data, when Sun is below the horizon main syst. uncertainty: Photon propagation in the ice & absolute DOM efficiency (~20%) relate muon flux and WIMP-nucleon crosssection: 29

WIMP-Model-independent Result Abbasi et al., Physical Review D81 (2010) 057101. (IC22 result) effective area for final event selection as function of Eν in the range 50-1000 GeV, for ν µ and anti-ν µ from the direction of the Sun. The result is an average over the austral winter. With DC down to ~20GeV IC22: Systematic effects are in-cluded at the 1σ level, and statistical uncertainty of the same level are shown with error bars. 31

Conclusion DeepCore layout (top view) AMANDA-II analysis are finishing (full 6y-data result soon) First IceCube results are published IC22 results for searches from Sun & Halo IC40 & IC59 analysis ongoing IC79 incl. DeepCore is taking data DeepCore makes low-energy region 10 ~ 100 GeV accessible for IceCube Looking forward: Including isolated hits and new reconstruction techniques All year search for low WIMP masses (IceCube active veto for DeepCore) WIMP search from Galactic Center String 79 & 80 will create even denser DeepCore array 32

Conclusion DeepCore layout (top view) AMANDA-II analysis are finishing (full 6y-data result soon) First IceCube results are published IC22 results for searches from Sun & Halo IC40 & IC59 analysis ongoing IC79 incl. DeepCore is taking data DeepCore makes low-energy region 10 ~ 100 GeV accessible for IceCube 79 & 80 Looking forward: Including isolated hits and new reconstruction techniques All year search for low WIMP masses (IceCube active veto for DeepCore) WIMP search from Galactic Center String 79 & 80 will create even denser DeepCore array 33

Additional Slides 34