Juan Abel Barrio
Professor of Atomic, Molecular, and Nuclear Physics in the Department of Structure of Matter, Thermal Physics, and Electronics at the Complutense University of Madrid (UCM) and researcher in Gamma Ray Astrophysics at the Institute of Particle Physics and Cosmos (IPARCOS) at UCM
"The search for dark matter, whose existence in particle form is only a hypothesis without experimental evidence, is one of the most difficult searches that physics has faced in the last 100 years; it is one of the ‘holy grails’ of physics that, to date, has proved fruitless. NASA's Fermi gamma-ray satellite has been operating for more than 15 years, one of its objectives being to identify gamma rays hypothetically produced by the annihilation of dark matter particles. The Fermi international collaboration, made up of approximately 150 scientists from around the world (not just NASA), is one of the groups that knows the experiment best and has spent the most time studying the region of the galaxy referred to in the article. It is a particularly complicated region due to the number of ‘standard’ sources and processes that can give rise to gamma rays that could mimic those coming from dark matter.
This collaboration has been searching for evidence of dark matter in different regions of the sky, including our galaxy, for all this time, carrying out very careful analyses, verified by dozens of experts. And it has found no statistically significant evidence of gamma rays coming from dark matter. If it had, the announcement would have come officially from NASA, it would have been sent to Nature, and it would have meant a Nobel Prize the following year.
That said, the Fermi international collaboration makes the information on all the gamma rays it has observed publicly available so that researchers outside the collaboration, such as the author of this paper, can analyze them. On some occasions, one of these researchers has found a ‘minor’ detection (unrelated to dark matter) that had been overlooked by the Fermi collaboration researchers, but given that this is such a coveted search, I would find it very strange if this detection of gamma rays produced by dark matter particles had been overlooked.“
Is the research of good quality?
”Not really."
Does it fit with the existing evidence?
“No. The author himself says that the average he obtains is outside the exclusion limits obtained by the Fermi collaboration.”
What are the implications of this finding?
“If it were officially confirmed by the Fermi collaboration, which I highly doubt, and which is the only one I would personally trust, it would effectively be finding one of the holy grails of physics, opening the door to physics beyond the Standard Model of particle physics, etc.”
Is it correct to say, as in the press release, that this could be the “first time that dark matter has been ‘seen’”?
“No, in the sense that it has not been seen, but rather proposed as evidence, which I would consider unreliable. And there have already been more indications of dark matter in the last 20 years, which have ultimately been ruled out.”