Space telescopes narrow hunt for mysterious dark matter particles
Researchers used data from orbiting observatories and NASA's Voyager spacecraft to rule out several hypothetical dark matter candidates that would decay into electron-positron pairs. The findings tighten constraints on where scientists should look next, potentially accelerating the search for physics beyond current theory.
Originaltitel: INTEGRAL, eROSITA and Voyager constraints on light bosonic dark matter: ALPs, dark photons, scalars, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>B</mml:mi> <mml:mo>−</mml:mo> <mml:mi>L</mml:mi> </mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:msub> <mml:mi>L</mml:mi> <mml:mi>i</mml:mi> </mml:msub> <mml:mo>−</mml:mo> <mml:msub> <mml:mi>L</mml:mi> <mml:mi>j</mml:mi> </mml:msub> </mml:math> vectors
The decay of light bosonic dark matter particles can produce a bright electron/positron ( <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:msup> <a:mi>e</a:mi> <a:mo>+</a:mo> </a:msup> <a:msup> <a:mi>e</a:mi> <a:mo>−</a:mo> </a:msup> </a:math> ) flux that can be strongly constrained by local Voyager observations of the direct <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"> <c:msup> <c:mi>e</c:mi> <c:mo>+</c:mo> </c:msup> <c:msup> <c:mi>e</c:mi> <c:mo>−</c:mo> </c:msup> </c:math> flux, as well as 511 keV line and x-ray continuum observations of <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"> <e:msup> <e:mi>e</e:mi> <e:mo>+</e:mo> </e:msup> <e:msup> <e:mi>e</e:mi> <e:mo>−</e:mo> </e:msup> </e:math> emission. We carefully analyze the <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"> <g:msup> <g:mi>e</g:mi> <g:mo>+</g:mo> </g:msup> <g:msup> <g:mi>e</g:mi> <g:mo>−</g:mo> </g:msup> </g:math> yield and resulting cosmic ray and x-ray spectra from theoretically well-motivated light dark matter models, including (a) electrophilic axion-like particles, (b) dark photons, (c) scalars, and (d) <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"> <i:mi>B</i:mi> <i:mo>−</i:mo> <i:mi>L</i:mi> </i:math> and <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"> <k:msub> <k:mi>L</k:mi> <k:mi>i</k:mi> </k:msub> <k:mo>−</k:mo> <k:msub> <k:mi>L</k:mi> <k:mi>j</k:mi> </k:msub> </k:math> vector bosons. We use the morphology and spectrum of the INTEGRAL 511 keV line data, the eROSITA x-ray continuum spectrum and the Voyager <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"> <m:msup> <m:mi>e</m:mi> <m:mo>+</m:mo> </m:msup> <m:msup> <m:mi>e</m:mi> <m:mo>−</m:mo> </m:msup> </m:math> spectrum to constrain the decay lifetime and coupling of each dark matter model. We find that 511 keV observations typically set world-leading limits on bosonic dark matter decay below masses of <o:math xmlns:o="http://www.w3.org/1998/Math/MathML" display="inline"> <o:mo>∼</o:mo> <o:mn>1</o:mn> <o:mtext> </o:mtext> <o:mtext> </o:mtext> <o:mi>GeV</o:mi> </o:math> , while eROSITA observations provide the strongest constraints in the range from 1–10 GeV. Finally, we forecast future limits from 21 cm line searches with next-generation HERA data.