The particle nature of dark matter is a driving question of contemporary physics, with astrophysical experiments leading the search for dark matter annihilation or decay signatures. In an era of ever-tightening constraints on Weakly-interacting massive particles (WIMPs), there is increasing interest in light (<1 GeV) dark matter candidates. Sterile neutrinos, which could provide an elegant solution to the puzzle of the observed active neutrino masses and mixing, are among the most well-motivated light dark matter candidates, with astrophysical X-ray observations offering the best opportunity for discovery. In this talk, I will review the status of X-ray searches for sterile neutrinos, including the candidate sterile neutrino signal at ~3.5 keV. In particular, I will describe the novel use of the NuSTAR X-ray satellite observatory to provide the leading constraints in much of the mass range ~10-50 keV, improving upon previous limits at some masses by over an order of magnitude and reducing the available parameter space for sterile neutrinos in the simplest models by almost two-thirds.
About the speaker
Kerstin Perez's research involves using cosmic particles to look for beyond the Standard Model physics, in particular evidence of dark matter interactions. She leads the silicon detector program for the GAPS experiment, a balloon-borne instrument that aims to detect antideuteron and antiproton evidence of dark matter annihilation in the Galactic halo. As the first optimized experiment to search for low-energy antideuterons, which have been discussed for over a decade as a particularly low-background signature of dark matter, GAPS is poised to make a major contribution to the field. In addition, she is head of the analysis of high-energy X-ray emission in the inner parsecs of the Galaxy using the NuSTAR telescope array, and is involved in searches for X-ray signatures of exotic particle physics processes. She has also begun work on the prototype X-ray optics for the International Axion Observatory (IAXO), the upgrade to the CAST solar axion helioscope experiment.
In addition to mentoring students in research, Kerstin has a passion for science education and outreach, placing particular emphasis on connecting with students who, because of cultural factors or lack of exposure, have not considered the career paths that a science education opens.
More details on Kerstin's research can be found here.