  In a previous work, it was found that the Light Dark Matter (LDM) scenario
could be a possible explanation to the 511 keV emission line detected at the
centre of our galaxy. Here, we show that hints of this scenario may also have
been discovered in particle physics experiments. This could explain the
discrepancy between the measurement of the fine structure constant and the
value written in the CODATA. Finally, our results indicate that some of the LDM
features could be tested in accelerators. Their discovery might favour N=2
supersymmetry.
