Recently, dark matter hunters from around the world gathered at the University of California, Los Angeles for "Dark Matter 2014." The annual conference is one of the largest of its kind aimed at discussing the latest progress in the quest to identify dark matter, the unknown stuff that makes up more than a quarter of the universe yet remains a mystery.
So where does the hunt stand? Between sessions, three leading physicists at the conference spent an hour discussing the search for dark matter on several fronts.
"This conference has highlighted the progression of larger and larger experiments with remarkable advances in sensitivity," says Blas Cabrera, Professor of Physics at Stanford University and Member of the Kavli Institute for Particle Astrophysics and Cosmology at Stanford. "What we're looking for is evidence of a dark matter particle, and ... we believe (this particle) interacts with ordinary matter only very rarely."
Says Dan Hooper, Associate Professor in the Department of Astronomy and Astrophysics at the University of Chicago, and Senior Member of the Kavli Institute for Cosmological Physics at the university: "Four and a half years ago, I wrote my first paper on searching for evidence of dark matter at the center of the Milky Way galaxy. And now we think we have the most compelling results to date."
Tim Tait, Professor of Physics and Astronomy at the University of California Irvine is involved in looking for evidence of dark matter by colliding subatomic particles at the Large Hadron Collider, or LHC, in Europe. Says Tait: "Supersymmetry proposes there are mirror particles that shadow all the known fundamental particles, and in this shadow world may lurk the dark matter particle. So, by smashing together protons in the LHC, we've tried to reveal these theoretical supersymmetric particles. So far, though, the LHC hasn't found any evidence for supersymmetry."
What would a discovery mean? Says Cabrera: "We would have identified the dominant form of matter in the universe that seeded structure and led to galaxies, solar systems and planets, and ultimately to our Earth with intelligent life."