Physicists at Texas A&M University are developing highly sensitive detectors to uncover the nature of dark matter and dark energy, which comprise 95% of the universe. Led by Dr. Rupak Mahapatra, these efforts aim to detect rare particle interactions that occur infrequently. The work, featured in Applied Physics Letters, builds on decades of research into cosmic enigmas.
The universe's composition remains largely mysterious, with only 5% consisting of ordinary matter visible to telescopes and instruments. The remaining 95% is dominated by dark matter, which accounts for about 27% and shapes the structure of galaxies through gravitational effects, and dark energy, making up 68% and accelerating the cosmos's expansion. Neither emits, absorbs, nor reflects light, complicating direct detection, so scientists infer their presence from gravitational influences on galactic movements and large-scale structures.
Dr. Rupak Mahapatra, an experimental particle physicist at Texas A&M University, likens current knowledge to "trying to describe an elephant by only touching its tail. We sense something massive and complex, but we're only grasping a tiny part of it." His team designs advanced semiconductor detectors equipped with cryogenic quantum sensors to capture elusive signals from dark matter particles. These instruments must detect interactions so weak they might happen just once a year or even once a decade. "The challenge is that dark matter interacts so weakly that we need detectors capable of seeing events that might happen once in a year, or even once in a decade," Mahapatra explained.
Mahapatra's group contributes to the TESSERACT experiment, a global dark matter search emphasizing signal amplification amid noise. Over 25 years, he has advanced the SuperCDMS project, including a 2014 breakthrough in Physical Review Letters that enabled detection of low-mass weakly interacting massive particles (WIMPs), prime dark matter candidates. These hypothetical particles interact via gravity and the weak nuclear force, often passing through Earth undetected, requiring ultra-cold sensors near absolute zero for rare collisions with ordinary matter.
A 2022 study co-authored by Mahapatra explored combined strategies like direct detection, indirect methods, and collider searches for WIMPs. "No single experiment will give us all the answers," he noted. "We need synergy between different methods to piece together the full picture." Detecting dark matter could revolutionize physics, revealing fundamental laws and inspiring unforeseen technologies. "If we can detect dark matter, we'll open a new chapter in physics," Mahapatra said.