That Feynman diagram is on its side, unless that's an antiparticle moving backwards in time. The Y axis of Feynman diagrams seems to be a time axis as well as a spatial axis.
https://www.youtube.com/watch?v=3a1c_1TIGGw
https://www.youtube.com/watch?v=0xkD3GjJMNs
>>135699181
go to sleep