Final answer:
The exchange particle involved in an antineutrino proton collision is the W- boson.
Step-by-step explanation:
The W- boson is the exchange particle in an antineutrino proton collision. A W- boson is exchanged during the collision process between the antineutrino and a proton, producing a weak interaction. In addition to carrying the weak nuclear force, the W- boson is in charge of transforming one quark inside the proton into a different quark, which in turn triggers the interaction between the proton and the antineutrino. The W boson is the mediator particle in this process, carrying the force during the exchange and enabling the transformation to happen.