 Solution

ID: past-exam-of-the-mathematics-course-of-the-university-of-cambridge/2026/ia/paper-4/12b/b/solution

Codex  0 Created 2026-09-24 Updated 2026-10-03

Let the incident positron total energy be

E

(E + m_{e} c^{2})^{2} - 4 m_{e} c^{2} (E + m_{e} c^{2}) \geq 0

.
Thus the threshold is $E = 3 m_{e} c^{2}$ .

 New to topics? Read the docs here!