[Hps] Possible interaction between baryons and dark-matter particles revealed by the first stars

[mdiamond at physics.utoronto.ca]

Hi folks,

As a follow-up, I spotted this on arXiv today:
https://urldefense.proofpoint.com/v2/url?u=https-3A__arxiv.org_abs_1803.02804&d=DwIBaQ&c=lz9TcOasaINaaC3U7FbMev2lsutwpI4--09aP8Lu18s&r=hGEVsUzUB5ml8iDt6EuOdg&m=hHoFrBHOldiI4sQ8xYaFHgSYfS-PVNBirDF4NbeoTEs&s=0KCgkqy6UcDKQJWao7ieHHcHVoGXt5vQLAPIv6lRyFk&e= 
Severely Constraining Dark Matter Interpretations of the 21-cm Anomaly
Asher Berlin, Dan Hooper, Gordan Krnjaic, Samuel D. McDermott
"The EDGES Collaboration has recently reported the detection of a  
stronger-than-expected absorption feature in the global 21-cm  
spectrum, centered at a frequency corresponding to a redshift of z ~  
17. This observation has been interpreted as evidence that the gas was  
cooled during this era as a result of scattering with dark matter. In  
this study, we explore this possibility, applying constraints from the  
cosmic microwave background, light element abundances, Supernova  
1987A, and a variety of laboratory experiments. After taking these  
constraints into account, we find that the vast majority of the  
parameter space capable of generating the observed 21-cm signal is  
ruled out. The only range of models that remains viable is that in  
which a small fraction, ~ 0.3-2%, of the dark matter consists of  
particles with a mass of ~ 10-80 MeV and which couple to the photon  
through a small electric charge, epsilon ~ 10^{-6}-10^{-4}.  
Furthermore, in order to avoid being overproduced in the early  
universe, such models must be supplemented with an additional  
depletion mechanism, such as annihilations through a L_{\mu}-L_{\tau}  
gauge boson or annihilations to a pair of rapidly decaying hidden  
sector scalars."

-- Miriam


Quoting Omar Moreno <email at omarmoreno.net>:

> Hi Everyone,
>
> Here is a link to the paper that was mentioned in the meeting:
>
> https://urldefense.proofpoint.com/v2/url?u=https-3A__www.nature.com_articles_nature25791&d=DwIBaQ&c=lz9TcOasaINaaC3U7FbMev2lsutwpI4--09aP8Lu18s&r=hGEVsUzUB5ml8iDt6EuOdg&m=NjUf0M-e0XnLmHwKW6jtdHcLcSh00tzqtXne2YyNe7c&s=w2koHjwsbFkSBipdjhphQz-AMn_AArMzIyjIkSgWjWA&e=
>
> Best,
>
> --Omar Moreno