The small vacuum-insulated environment of the cryostat device the scientists used to cool their apparatus severely limited the size of the spherical metallic dish they could use in their search. While this allowed the scientists to significantly reduce the minimal signal levels they could detect compared to other experiments using off-the-shelf tech, it came with a major drawback. They searched at temperatures between minus 459 degrees Fahrenheit (minus 272.9 degrees Celsius) and minus 459.6682 degrees F (minus 273.149 degrees C), just a fraction of a degree warmer than the coldest temperature theoretically possible, absolute zero. The team took a different approach in the new study, however, using quantum-limited amplifiers rather than off-the-shelf amplifiers and conducting their dark photon hunt at incredibly low temperatures. "Previous searches that inspired this work, like the SHUKET experiment, generally aimed to maximize the signal strength through having a very large dish while using the best commercially available low-noise amplifiers they had access to," Klimovich explained. The inspiration for the team’s dark photon search comes from a previous attempt to hunt for hidden dark matter called the SHUKET experiment, which uses an electromagnetic telescope. "For hidden photon searches, the amplitude of the dark matter signal scales with the area of the metal dish used, while the minimal detectable signal level is largely determined by the noise level of the amplifiers used to read out the antenna," Klimovich added. "The sensitivity of a hidden photon dark matter experiment depends on the strength of the dark matter signal compared to the smallest signal you can detect," team member Nikita Klimovich, a researcher in Oxford University's Department of Physics, told. And while this new strategy hasn’t yet turned up any of the hypothetical particles, it has placed constraints on their characteristics, which will aid future searches. Now, researchers from the California Institute of Technology (Caltech) have come up with a new detection method for dark photons. This action would explain why the cosmic web, a large-scale structure in the universe linking together galaxies, was hotter than predicted when observed by the Hubble Space Telescope. Dark photons were initially suggested as a dark matter candidate because, theoretically, they would weakly interact with ordinary photons, meaning they could have played a role in heating up the early universe.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |