Virtual particles do not necessarily have an invariant mass. That's why you can find examples of typically huge particles inside protons. That's why a beta decay of a neutron can involve the production of a virtual W- boson that has an invariant mass that's 86 times more massive than the neutron.
https://profmattstrassler.com/2022/09/09/protons-and-charm-q...
Virtual particles do not necessarily have an invariant mass. That's why you can find examples of typically huge particles inside protons. That's why a beta decay of a neutron can involve the production of a virtual W- boson that has an invariant mass that's 86 times more massive than the neutron.