Dr. Rupak Mahapatra, an experimental particle physicist at Texas A&M University, is involved in global efforts to detect and understand dark matter and dark energy, which are theorized to constitute approximately 95% of the universe. His research group designs and constructs semiconductor detectors equipped with cryogenic quantum sensors, utilized in experiments seeking to identify particles that interact infrequently with ordinary matter.
The Unseen Universe: Dark Matter and Dark Energy
Current cosmological models indicate that visible "ordinary matter" accounts for approximately 5% of the universe's total mass and energy. The remaining 95% is attributed to dark matter and dark energy, whose compositions are largely unknown.
- Dark Matter: Estimated to account for roughly 27% of the universe's total energy content, dark matter is inferred through its gravitational influence on the formation and structure of galaxies and galaxy clusters.
- Dark Energy: Comprising approximately 68% of the universe's total energy content, dark energy is associated with the universe's accelerated expansion.
Neither dark matter nor dark energy emits, absorbs, or reflects light, making direct observation challenging. Their presence is primarily inferred through their gravitational effects on cosmic structures.
Advanced Detection Technologies and Research Initiatives
Dr. Mahapatra's research group at Texas A&M focuses on developing highly sensitive detectors designed to register signals from particles that interact rarely with ordinary matter. The weak interaction strength of dark matter necessitates detectors capable of identifying events that may occur once a year or less.
The team has contributed to several dark matter search initiatives, including the TESSERACT detector project, a global effort in which Texas A&M University is a participating institution. Dr. Mahapatra has also been involved with the SuperCDMS experiment for 25 years. These experiments employ ultra-sensitive detectors, cooled to temperatures near absolute zero, to attempt to observe infrequent interactions between hypothetical dark matter particles and ordinary matter.
Key Contributions and the Search for WIMPs
In 2014, Dr. Mahapatra co-authored a publication in Physical Review Letters detailing the introduction of voltage-assisted calorimetric ionization detection within the SuperCDMS experiment. This development aimed to enhance the sensitivity for detecting low-mass Weakly Interacting Massive Particles (WIMPs), which are considered a leading candidate for dark matter.
WIMPs are hypothetical particles theorized to interact primarily through gravity and the weak nuclear force. Their existence could account for the universe's missing mass. In 2022, Dr. Mahapatra also co-authored a study examining various WIMP detection approaches, including direct detection, indirect detection, and collider searches.
Dr. Mahapatra has noted the challenges in detecting dark matter due to its weak interaction, requiring instruments that can identify extremely rare events. He has also indicated that a comprehensive understanding of dark matter will likely require a synergistic approach involving multiple experimental methods.
Funding and Future Implications
Research efforts in this area receive support from organizations such as the U.S. Department of Energy and the National Science Foundation. The detection of dark matter is considered significant for advancing fundamental physics knowledge and holds potential for unforeseen technological advancements.