Scientists have been looking for sign of dark matter for decades. While it is believed to make up a significant portion of the universe’s mass, but it is not directly detected till the date. However, researchers continue to push the boundaries of what is possible, and a recent study has made significant strides in detecting light dark matter.
In a report published by Xuyang Ning and colleagues in 2023, a sensitive search for light dark matter was conducted using the PandaX-4T detector. The study aimed to detect dark matter originating from cosmic ray inelastic collision with the atmosphere. The kinetic energy of the produced light dark matter carries some of the meson mass and can be boosted to several hundred MeV, which yield sizeable nuclear recoil signatures in the direct detection experiments.
The authors conducted a full and dedicated simulation of both elastic and quasi-elastic processes of the Earth attenuation effect on the dark matter flux arriving at the PandaX-4T detector. The attenuation effect occurs when dark matter particles pass through the Earth before reaching the detector. By simulating this effect, the authors were able to determine the strength of the dark matter-nucleon scattering cross-section.
In particular for those boosted dark matter particles, the authors discovered that quasi-elastic scattering was crucial for assessing the attenuation impact. For a scalar mediator with mS = 300 MeV/c2 and BR( 0S) = 1.0 105, the study calculated limits on the reference cross-section vs dark matter mass with 90% confidence level.
The results of the study showed that the PandaX-4T detector can generate comparable results for light dark matter flux produced by cosmic rays. It also emphasises the significance of calculating the Earth attenuation effect, which can provide valuable insights into the nature of dark matter.
While the search for dark matter is still ongoing, studies like this are critical in advancing our understanding of the universe’s mysteries. The study’s findings demonstrate the importance of continued research in this area, which could one day lead to a direct detection of dark matter and a better understanding of our universe’s composition.