“One of our major concerns is background particles that can mimic the dark matter signature in our detectors.” — Jodi Cooley

SMU physicist Jodi Cooley is a member of the international scientific team that will use a powerful new tool to understand one of the biggest mysteries of modern physics.

The U.S. Department of Energy has approved funding and start of construction for SuperCDMS SNOLAB, a $34 million experiment designed to detect dark matter.

SuperCDMS will begin operations in the early 2020s to hunt for hypothetical dark matter particles called weakly interacting massive particles, or WIMPs.

“Understanding the nature of dark matter is one of the most important scientific puzzles in particle astrophysics today,” said Cooley, an associate professor of experimental particle physics. “The experiment will have unprecedented sensitivity to dark matter particles that are hypothesized to have very low mass and interact very rarely. So they are extremely challenging to detect. This challenge has required us to develop cutting edge detectors.”

Cooley is one of 111 scientists from 26 institutions in the SuperCDMS collaboration. SMU graduate students on the experiment include Matt Stein (Ph.D. ’18) and Dan Jardin; and also previously Hang Qiu (Ph.D. ’17).

Physicists are searching for dark matter because although it makes up the bulk of the universe it remains a mystery. They theorize that dark matter could be composed of dark matter particles, with WIMPs a top contender for the title.

If dark matter WIMP particles exist, they would barely interact with their environment and fly right through regular matter. However, every so often, they could collide with an atom of our visible world, and dark matter researchers are looking for these rare interactions.

The SuperCDMS experiment will be the world’s most sensitive for detecting the relatively light WIMPs.

Cooley and her students in the SMU Department of Physics have been working with Washington-based Pacific Northwest National Laboratory on the challenge of background control and material selection for the experiment’s WIMP detectors.

Understanding background signals in the experiment is a major challenge for the detection of the faint WIMP signals.

“One of our major concerns is background particles that can mimic the dark matter signature in our detectors,” Cooley said. “As such, the experiment is constructed from radiopure materials that are carefully characterized through a screening and assay before they are selected.”

The SMU research team also has performed simulations of background particles in the detectors. READ MORE