Gregory D. Mack, The Ohio State University Dept. of Physics

PASCOS 2006 September 13, 2006

Gregory D. Mack, The Ohio State University Dept. of Physics

PASCOS 2006 September 13, 2006

DM Annihilation Cross DM Annihilation Cross Section LimitsSection Limits DM density profiles … cusps or cores?DM density profiles … cusps or cores?

Kaplinghat, Knox, and Turner (KKT)* proposed Kaplinghat, Knox, and Turner (KKT)* proposed a large enough cross section to turn a cusp into a large enough cross section to turn a cusp into a core.a core.

Brings question of Brings question of “How big can <“How big can <σσ v> be?” v> be?”

Hui’s** Hui’s** unitarityunitarity boundbound is the only strict, is the only strict, model-independent upper limitmodel-independent upper limit

* : Kaplinghat, Knox, and Turner, PRL 88, 3335 (2000); ** Hui PRL 86, 3467 (2001)* : Kaplinghat, Knox, and Turner, PRL 88, 3335 (2000); ** Hui PRL 86, 3467 (2001)

DisappearanceDisappearance of DM corresponds to of DM corresponds to appearanceappearance of productsof products

Invisible vs. visible … Invisible vs. visible … nothing SM is invisiblenothing SM is invisible KKT requires Br(photons) < 10KKT requires Br(photons) < 10-10-10

Conservatively constrain total dark matter Conservatively constrain total dark matter annihilation cross section by looking at neutrino annihilation cross section by looking at neutrino appearance instead of photon appearance …. appearance instead of photon appearance …. Br(neutrino) = 100%Br(neutrino) = 100%

What Products Should What Products Should We Look For?We Look For?

Galactic Center is problematic at bestGalactic Center is problematic at best Look at diffuse contribution from all galaxiesLook at diffuse contribution from all galaxies Annihilation signal depends on density Annihilation signal depends on density

squared … “squared … “clumpinessclumpiness” matters” matters

Adapted from Ullio, Bergstrom, Edsjo, and Lacey PRD 66, 123502 (2002) and Adapted from Ullio, Bergstrom, Edsjo, and Lacey PRD 66, 123502 (2002) and Bergstrom, Edsjo and Ullio PRL 87, 251301 (2001)Bergstrom, Edsjo and Ullio PRL 87, 251301 (2001)

ΔΔ22 for NFW: 2 x 10 for NFW: 2 x 1055 ; Moore: 2 x 10 ; Moore: 2 x 1066 or or higher… clumpiness relative to smooth DMhigher… clumpiness relative to smooth DM

Diffuse Neutrino FluxDiffuse Neutrino Flux

Look for redshift-Look for redshift-smeared bump on the smeared bump on the atmospheric neutrino atmospheric neutrino background, from background, from monoenergetic monoenergetic neutrinosneutrinos

Analyze in half-order Analyze in half-order of magnitude bins of magnitude bins

Require finding 100% Require finding 100% of signal in the binof signal in the bin

Atmospheric Neutrino Atmospheric Neutrino BackgroundBackground

Beacom, Bell, Mack astro-ph/0608090

AMANDA and SK data support the AMANDA and SK data support the prohibition of such a signalprohibition of such a signal

Atmospheric Neutrino Atmospheric Neutrino BackgroundBackground

Munich (AMANDA), astro-ph/0509330

Ashie, et al (Super-K)PRD 71, 112005 (2005),Fully-contained events

Rules outRules out KKT, KKT, large annihilation large annihilation cross sectionscross sections

Covers large Covers large range of masses range of masses until Unitarity until Unitarity takes overtakes over

New Model New Model Independent Independent ConstraintConstraint

Beacom, Bell, Mack astro-ph/0608090

Created a new, model independent bound on the Created a new, model independent bound on the dark matter annihilation cross section, extending dark matter annihilation cross section, extending over an interesting mass rangeover an interesting mass range

Rules out cusps being able to be modified by Rules out cusps being able to be modified by annihilation; corresponds to creating a core within annihilation; corresponds to creating a core within only the inner 1 pc of a Milky Way, NFW galaxyonly the inner 1 pc of a Milky Way, NFW galaxy

Analysis can be improved greatly through various Analysis can be improved greatly through various methods (being less conservative, stricter limits methods (being less conservative, stricter limits on data …)on data …)

ConclusionsConclusions