Jan. 2 () –
Scientists from the LHAASO cosmic ray observatory in China have restricted the lifetime of heavy dark matter particles with masses between 100,000 and a billion gigaelectronvolts.
These are the first results in this field obtained during 1.5 years of observation with the Large High Altitude Air Shower Observatory (LHAASO), specialized in gamma rays.
The study has recently been published as a featured letter in Physics Review Letters.
Until now, the mysteries of dark matter and its basic properties have not ceased to be revealed.. The gravitational model of the Milky Way shows that there is a very high density of dark matter at the galactic center, and the gamma rays produced by the decay of this dark matter will radiate from the galactic center to the surroundings for hundreds of light-years or even thousands. of light years. However, for a long time, the observation of ultra-high energy gamma rays produced by heavy dark matter has faced great challenges, mainly due to the presence of other background radiation.
Thanks to its unprecedented detection sensitivity for ultra-high energy gamma rays, LHAASO has unique potential to observe gamma rays that break up heavy dark matter. LHAASO can remove background events by nearly six orders of magnitude above 100 teraelectronvolts, significantly reducing background interference and improving the ability to capture gamma rays, according to a statement from the Chinese Academy of Sciences.
Using data from the LHAASO ‘subarray KM2A’ element, the scientists measured the intensity of ultra-high-energy gamma rays beyond the galactic plane and placed one of the strongest limits yet for the lifetime of heavy dark matter. . The limit is almost 10 times higher than previous results. This study shows that dark matter with a mass PeV (measure petaelectronvolts) has a lifetime of at least a thousand trillion trillion years (10^21 years).
LHAASO’s gamma-ray observations greatly complement other dark matter search experiments (such as neutrino observation experiments). As the full set of LHAASO runs stably and accumulates data, this limit will increase, the statement added.
