Is there a resting frame in the universe? A proposed experimental test based on a precise measurement of particle mass

According to the Special Theory of Relativity, there should be no resting frame in our universe. Such an assumption, however, could be in conflict with the Standard Model of cosmology today, which regards the vacuum not as an empty space. Thus, there is a strong need to experimentally test whether there is a resting frame in our universe or not. We propose that this can be done by precisely measuring the masses of two charged particles moving in opposite directions. If all inertial frames are equivalent, there should be no detectable mass difference between these two particles. If there is a fixed resting frame in the universe, one will observe a mass difference that is dependent on the orientation of the laboratory frame. This can be tested by repeating the experiment at different times of the day (or on different days of the season). The detailed experimental setup is discussed in this paper. Our analysis suggests that, with the existing technological limits, the proposed measurement should have sufficient accuracy to determine if there is a resting frame or not.