A search for neutrino signal from dark matter annihilation in the center of the Milky Way with Baikal NT200

TL;DR

This study reanalyzed data from the Baikal NT200 neutrino telescope to search for neutrino signals from dark matter annihilation in the Milky Way's center, setting upper limits on annihilation cross sections.

Contribution

It applies two analysis methods to existing data to constrain dark matter annihilation signals, providing new upper limits on cross sections for various annihilation channels.

Findings

No significant neutrino excess detected from the Galactic Center.

Established 90% CL upper limits on dark matter annihilation cross sections.

Used two complementary analysis approaches for robust results.

Abstract

We reanalyze the dataset collected during the years 1998--2003 by the deep underwater neutrino telescope NT200 in the lake Baikal with the low energy threshold (10 GeV) in searches for neutrino signal from dark matter annihilations near the center of the Milky Way. Two different approaches are used in the present analysis: counting events in the cones around the direction towards the Galactic Center and the maximum likelihood method. We assume that the dark matter particles annihilate dominantly over one of the annihilation channels $b\bar{b}$, $W^+W^-$, $\tau^+\tau^-$, $\mu^+\mu^-$ or $\nu\bar{\nu}$. No significant excess of events towards the Galactic Center over expected neutrino background of atmospheric origin is found and we derive 90% CL upper limits on the annihilation cross section of dark matter.