Limits on a muon flux from neutralino annihilations in the Sun with the IceCube 22-string detector

TL;DR

Upper limits have been obtained on the annihilation rate of captured neutralinos in the Sun and converted to limits on the weakly interacting massive particle (WIMP) proton cross sections for WIMP masses in the range 250-5000 GeV.

Abstract

A search for muon neutrinos from neutralino annihilations in the Sun has been performed with the IceCube 22-string neutrino detector using data collected in 104.3 days of live-time in 2007. No excess over the expected atmospheric background has been observed. Upper limits have been obtained on the annihilation rate of captured neutralinos in the Sun and converted to limits on the WIMP-proton cross-sections for WIMP masses in the range 250 - 5000 GeV. These results are the most stringent limits to date on neutralino annihilation in the Sun.

Figures (4)

• Figure 1: The product $Q_{1}\times Q_{2}$ of the output values of the two SVMs for the experimental data, a simulated signal ($m_{\tilde{\chi}^{0}_{1}}$ = 1000 GeV, hard spectrum) and the background. The background has been scaled to match the data rate and it is shown divided into three components: atmospheric neutrinos and single and coincident atmospheric muons.
• Figure 2: Cosine of the angle between the reconstructed track and the direction of the Sun, $\Psi$, for data (squares) with one standard deviation error bars, and the atmospheric background expectation from atmospheric muons and neutrinos (dashed line). Also shown is a simulated signal ($m_{\tilde{\chi}^{0}_{1}}$ = 1000 GeV, hard spectrum) scaled to $\mu_{s}=6.8$ events (see Table I).
• Figure 3: Upper limits at the 90% confidence level on the muon flux from neutralino annihilations in the Sun for the soft ($b\overline{b}$) and hard ($W^{+}W^{-}$) annihilation channels, adjusted for systematic effects, as a function of neutralino mass. The shaded area represents MSSM models not disfavoured by direct searches cdmsxenon10. A muon energy threshold of 1 GeV was used when calculating the flux. Also shown are the limits from MACRO macro, Super-K superk, and AMANDA sunWimp.
• Figure 4: Upper limits at the 90% confidence level on the spin-dependent neutralino-proton cross-section $\sigma^{\it{SD}}$ for the soft ($b\overline{b}$) and hard ($W^{+}W^{-}$) annihilation channels, adjusted for systematic effects, as a function of neutralino mass. The shaded area represents MSSM models not disfavoured by direct searches cdmsxenon10 based on $\sigma^{\it{SI}}$. Also shown are the limits from CDMS cdms, COUPP coupp, KIMS kims and Super-K superk.