IceCube Galactic Halo Analysis Carsten Rott Jan-Patrick Huelss CCAPP Mini Workshop Columbus OH August 6, m 2450 m August 6, 20091CCAPP DM Miniworkshop

1450 m 2450 m Very clear ice Dust concentration E reco = 500 TeV August 6, 20092CCAPP DM Miniworkshop

3 August 6, 2009 CCAPP DM Miniworkshop 3 General Detector Capabilities Muon from IC40 Data Tracks Cascades Track-LikeIceCubeAMANDA Time Resolution2 ns5-7 ns Energy Resolution (log 10 E) 0.3 – 0.4 Field of View2π Noise Ratelow Angular resolution<1 o ~ o Cascade-LikeIceCubeAMANDA Time Resolution2 ns5-7 ns Energy Resolution (log 10 E) 0.18 Field of View4π Noise Ratelow Angular resolution30 o ~30-40 o IceCube Angular Resolution < 1°

CCAPP DM Miniworkshop 4August 6, 2009 SolarEarthHalo Neutrino Flux, Scattering cross-section Neutrino Flux, ?Neutrino Flux, Self- annihilation cross-section Muon neutrinos Muon neutrinos, Cascades Background off-source on- source Background simulationsBackground off-source on- source Excess Anisotropy, Spectrum IceCube ( + Deep Core) DeepCore ( + IceCube)

August 6, 2009 CCAPP DM Miniworkshop5 Annihilation rate ∝  2 Galactic Center on Southern hemisphere -30 o -Requires identification of down-going starting events Neutrino signal “least detectable”, hence allows to set conservative limit on the total self- annihilation cross-section [Yuksel, Horiuchi, Beacom, Ando (2007)]‏

August 6, 2009CCAPP DM Miniworkshop6 Galactic center: cos( y )=1 (B=0,L=0)‏ Example: 10 degree zenith angle band mapped in galactic coordinates [L=0,B=0] RA (  )‏   A neutrino flux from annihilations in the Milky way halo might be observable as neutrino flux anisotropy. Use up-going tracks (from the Northern hemisphere) to have access to TeV range neutrinos. Preliminary

August 6, 2009CCAPP DM Miniworkshop7 Preliminary

8 Deep Core Strings  6 strings with high quantum efficiency PMTs, densely spaced  7 “standard” IceCube strings  located in best ice (below 2100 m exceptionally clear)‏  Interstring spacing 72m  Uses high Quantum Efficiency PMTs, that have about 40% higher efficiency  Located in the deep ice  Lower atmospheric muon background  Larger scattering length ~40m 8 August 6, 2009 CCAPP DM Miniworkshop 8

arXiv: Fermi August 6, 2009 CCAPP DM Miniworkshop 9

August 6, 2009CCAPP DM Miniworkshop10 Conclusions IceCube DarkMatter Halo Analysis underway using Northern Hemisphere with 22 string dataset IceCube DarkMatter Halo Analysis underway using Northern Hemisphere with 22 string dataset Access to Southern Hemisphere with IceCube 40 and DeepCore will significantly improve sensitivity Access to Southern Hemisphere with IceCube 40 and DeepCore will significantly improve sensitivity IceCube Neutrino Effective Area not so different from Fermi IceCube Neutrino Effective Area not so different from Fermi

August 6, 2009CCAPP DM Miniworkshop11 gap Spin-dependent WIMP-proton cross-section Spin-dependent WIMP- nucleon cross-section very difficult to access in direct detection experiments

August 6, CCAPP DM Miniworkshop Search for an excess neutrino flux from the direction of the sun Analysis performed with the IceCube 22 string detector and 104 days of livetime (when the sun below the horizon) Cold Dark Matter candidate particle is assumed to be the LSP (neutralino) in MSSM, R-parity conserving scenario Neutralino is a Majorana particle and self-annihilates Consider two annihilation channels: –Hard:  → W + W – →  –Soft:  → bb →  Consider 7 neutralino masses from 50 GeV to 5 TeV Solar WIMPs  Preliminary

(for equilibrium): July 8, 2009Carsten Rott - ICRC09 Lodz13 Solar capture rate: WIMP Annihilation Rate:    or August 6, CCAPP DM Miniworkshop

Look for an excess of (muon) neutrinos in the direction of the sun No evidence for a signal observed Upper limits on muon flux from neutralino annihilations in the Sun Under the assumption of equilibrium condition in the Sun, a limit on the WIMP- Nucleon cross-section can be obtained For spin-dependent couplings, IceCube’s sensitivity is about 2-orders of magnitude better than direct searches arXiv: ( PRL 102, ) August 6, CCAPP DM Miniworkshop Preliminary

August 6, 2009CCAPP DM Miniworkshop15 Preliminary

August 6, AMANDA analysis on-going IceCube analysis on-going Understanding of low energy vertical tracks extremely important CCAPP DM Miniworkshop Dark Matter could be clustered in the centre of the Earth  Annihilation signal might be observable in vertically up-going events Energy and zenith angle of muon neutrino events in the signal region (see also “Search for Atmospheric Oscillations with IceCube”)

August 6, 2009CCAPP DM Miniworkshop17  String Trigger: 5 DOMs hit within a series of 7 DOMs within a time window of 1500ns Preliminary Beginning with 40 string data, IceCube lowered the multiplicity 8 trigger threshold to 5 applying a string trigger Preliminary

August 6, 2009CCAPP DM Miniworkshop18 Under the assumption of equilibrium condition in the Sun (and the assumption that capture is dominated by spin- independent cross-section), a limit on the WIMP-Nucleon cross-section can be obtained IceCube limits are competitive with direct detection experiments at WIMP masses, where IceCube is sensitive

August 6, CCAPP DM Miniworkshop New stringent limit on the WIMP-nucleon scattering cross-section using IceCube 22-string data DeepCore combined with IceCube will allow to probe a large region of SUSY parameter space that is difficult to access in direct detection experiments Preliminary

August 6, 2009 CCAPP DM Miniworkshop 20 SeasonDeployed string strings strings strings strings 04/05 05/06 06/07 07/08 08/09 09/10 10/11 IC40 IC22 IC40 DeepCore

August 6, 2009CCAPP DM Miniworkshop21 Systematic uncertainties on the effective volume: Neutrino oscillation: 4% Neutrino-nucleon cross-section: 3% Muon propagation in ice: <1% Proton propagation & absolute OM sensitivity: 17-24% Spread in OM sensitivity: <5% Time & position calibration: <5% Signal MC statistics: 3-5% Total systematic uncertainty: 19-26% Preliminary