By counting the number of neutral and charged current events at high energy, it is possible to show that electromagnetic force does (or does not!) unify at high energy. Our group have therefore analysed data from the HERA experiment and plotted a graph to investigate the number of neutral and charged current events at high energy (neutral current events represents electromagnetic interaction and charged current events represents weak interaction).

The graph shows the relation between energy and the number of events and energy. The vertical axis is the number of events whereas the horizontal axis is a variable called Q2, which can be thought of as the energy of the exchanged particle. We can see from the graph that, at low energy, there are much more neutral current events than charged current events, however, as energy increase, the number of neutral current events is decreasing faster than the number of charged current events and the number of the two events gets near. This can be thought of as the two forces being indistinguishable at high energy, which means that they are unifying at high energy.