Describe what is meant by a virtual particle.

Draw a Feynman diagram which represents this interaction.

Explain whether this interaction involves the \({{\text{W}}^ - }\), \({{\text{W}}^ + }\) or \({{\text{Z}}^{\text{0}}}\) boson.

a particle that mediates one of fundamental forces / a particle that appears as an intermediate particle in a Feynman diagram / a particle that is not observed and may violate energy and momentum conservation at a vertex;

electron and positron directions and symbols shown correctly;

muon and antimuon directions and symbols shown correctly;

\({{\text{Z}}^0}\) boson, no charge has been transferred/neutral current;

Generally well answered.

Generally well answered.

Generally well answered.