I believe this is just a report that 2 groups have found some of the normal matter that we knew was there but had not detected.
Dark matter unaffected.
why should dark matter be unaffected by this discovery?
dark matter is what scientist called missing/undetected matter. the saw the gravitation effects of missing/undetected matter, but they did not see matter itself. so they called it dark matter.
now this mystery is solved, there is no dark matter anymore. as far as I understood.
Dark matter by definition is stuff which does not interact (or does so extremely weakly) with normal matter (our standard model stuff) except via gravitation.
This stuff they've found is normal matter.
It's hot ferkrissakes - radiating photons. Obviously dark matter doesn't do that.