Dark matter constraints from an observation of dSphs and the LMC with the Baikal NT200

TL;DR

This study uses five years of Baikal NT200 neutrino data to search for dark matter annihilation signals from dwarf spheroidal galaxies and the LMC, finding no excess and setting upper limits on annihilation cross sections.

Contribution

It provides new constraints on dark matter annihilation cross sections using neutrino observations from multiple astrophysical sources.

Findings

No excess neutrino signal detected from targets.

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

Combined analysis improves constraints over individual source analysis.

Abstract

In present analysis we complete search for a dark matter signal with the Baikal neutrino telescope NT200 from potential sources in the sky. We use five years of data and look for neutrinos from dark matter annihilations in the dwarfs spheroidal galaxies in the Southern hemisphere and the Large Magellanic Cloud known as the largest and close satellite galaxy of the Milky Way. We do not find any excess in observed data over expected background from the atmospheric neutrinos towards the LMC or any of tested 22 dwarfs. We perform a joint likelihood analysis on the sample of five selected dwarfs and found a concordance of the data with null hypothesis of the background-only observation. We derive 90% CL upper limits on the cross section of annihilating dark matter particles of mass between 30 GeV and 10 TeV into several channels both in our combined analysis of the dwarfs and in a particular analysis towards the LMC.