試題詳解

9.Initially, there are two pairs of electron and positron moving under two conditions: one pair of electronpositron move at the same velocity of 0.6c, side-by-side in the same direction, the other pair of electron and positron move toward each other in an opposite direction with the velocity of -0.6c and 0.8c (c : light velocity). Finally, in the same system, each pair of electron and positron merge together, thus annihilate each other, and totally two photons are generated. Calculate the energies momenta and de-Broglie wavelengths of the electron and positron, two photons move in the same or opposite directions? the momenta of two photons, p₁ and p₂, the wavelengths λ₁ and λ₂, and the energies of two photons  

(A) For positron v = 0.8c: = 408.87 KeV / c, ; v= 0.6c:  = 306.65 KeVIc 

(B) For electron v = 0.6c: = 638.86 KeV, = 383.32 KeV / c,

(C) Two photons move off in the opposite directions p₁ = 894.4 KeV/ c, p₂ = -596.3 KeV /c

(D) Two photons move off p₁ = 1022 KeV/ c, p₂ = -255.5 KeV/ c; = 1022 KeV, = 255.5 KeV

(E) Two photons move off in the opposite directions p₁ = 1.9166 MeV /c, p₂ =-851.8 KeV/c,