English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We consider a decaying scalar dark matter (DM) with mass $m_\chi$ in therange 10 GeV - 10 TeV and vary the branching ratios of all possible two-body SMfinal states (excluding and including $\nu\bar{\nu}$) in the range $0\%-100\%$to derive constraints on the total decay width $\Gamma$ using the datacollected by several astrophysical and cosmological observations. We find that,$\Gamma \lesssim 10^{-26} - 10^{-27}\,{\rm s}^{-1}$ (excluding $\nu\bar{\nu}$)and $\Gamma \lesssim 10^{-24} - 10^{-26}\,{\rm s}^{-1}$ (including$\nu\bar{\nu}$) are allowed, depending on the values of $m_\chi$, which aremost robust upper limits on $\Gamma$ for a generic decaying scalar DM. We theninvestigate the prospect of the upcoming Square Kilometre Array (SKA) radiotelescope in detecting the DM decay induced radio signals originating insidethe dwarf spheroidal (dSph) galaxies. We have classified the DM parameterspace, allowed by the existing observations, independently of the branchingratio of each individual two-body SM final state, based on the detectability atthe SKA. Excluding the $\nu\bar{\nu}$ decay mode, we find that, throughout theDM mass range considered, $\Gamma \gtrsim 10^{-30}\,{\rm s}^{-1} -10^{-29}\,{\rm s}^{-1}$ is detectable for all possible branching ratiocombinations at the SKA (assuming 100 hours of observation time), withconservative choices for the relevant astrophysical parameters. On the otherhand, when arbitrary branching ratios are allowed also for the $\nu\bar{\nu}$decay mode, DM decays can be probed independently of the branching ratio ofeach SM final state for $\Gamma \gtrsim 2 \times 10^{-29}\,{\rm s}^{-1}$,provided DM masses are greater than a few hundreds of GeV.

A general study of decaying scalar dark matter: existing limits and projected radio signals at the SKA