Figure 12-2 shows the production of the first antiproton. It was produced by the reaction p +

Question:

Figure 12-2 shows the production of the first antiproton. It was produced by the reaction p + p → p + p + p + p̅ and required a minimum kinetic energy of 5.6 GeV. (The proton beam energy was actually 25 GeV.) Less energy would be required by either of the following reactions. Why is neither of them a possible alternative? Justify your answer.

(a) p + p → p + e^- + e⁺ + p̅

(b) p + p → p + p̅

Figure 12-2