The reaction e⁺ + e^- → A) describes the annihilation of a positron and an electron. B) has a large probability of occurrence only if the positron is at rest or nearly at rest. C) requires two photons moving in opposite directions to conserve linear momentum. D) conserves the electron lepton number. E) All of these are correct.

Question

Quizplus · Accepted Answer

A) The reaction involves the annihilation of a positron and an electron, as indicated by the presence of "+" and "-" charges on the reactants.
B) The reaction has a higher probability of occurring if the positron is nearly at rest, as this will reduce the kinetic energy of the particles and increase the likelihood of the electrons being in the same place at the same time.
C) The reaction requires the conservation of both energy and momentum, which can only be achieved if two photons of equal energy and opposite momentum are produced.
D) The reaction does conserve the lepton number, as the lepton number of the positron and electron are both +1 and -1 respectively, and the lepton number of the photons is 0. Therefore, the initial and final lepton numbers are equal. 
Overall, all of these statements are correct and support the answer of E.

The Reaction E+ + E- →

The Reaction E⁺ + E^- →