A new proposal suggests using existing synchrotron safety equipment to hunt for dark photons—a leading candidate for dark matter—without the need for dedicated facilities.
Tokyo, Japan — A researcher from Tokyo Metropolitan University has proposed a novel method to search for dark photons, a hypothetical particle that could constitute dark matter. The idea leverages the X-ray beams and standard radiation monitoring equipment already in place at synchrotron facilities, offering a low-cost, complementary approach to traditional experiments.
Key Details of the Proposal
- Innovative Setup: The proposed experiment uses the X-ray beam from a synchrotron undulator and a standard Geiger-Muller counter positioned behind safety shielding. This creates a "light-shining-through-a-wall" (LSW) experiment, which looks for particles that can pass through barriers normal photons cannot.
- No Dedicated Facility Required: Because the setup relies on existing infrastructure, it can run concurrently with other experiments at the synchrotron, requiring no dedicated beam time or facility modifications.
- Stringent New Constraints: Dr. Wen Yin, the researcher behind the proposal, modeled the generation and detection of dark photons. For dark photon masses between 1 and 50 electronvolts, his model yields an upper limit on the mixing parameter—which governs how dark photons interact with normal photons—of less than 0.00001 times the strength of photon-photon interaction. This is more stringent than previous LSW experiments in the same mass range.
Background on Dark Photons
Dark photons are a proposed explanation for dark matter, the invisible substance that makes up roughly 85% of the universe's mass but does not interact with electromagnetic forces, making it extremely difficult to detect.
Traditional LSW experiments, such as the ALPS experiment at DESY in Hamburg, require dedicated setups involving powerful lasers and magnetic fields. This new proposal offers a complementary path by repurposing equipment at synchrotron radiation facilities.
Support and Funding
The work was supported by JSPS KAKENHI Grant Numbers 22K14029 and 23K22486, as well as the Tokyo Metropolitan University Grant for Young Researchers.