558 10 Particle Physics – II
10.109 Draw Feynman diagrams for the processes
(a)e+e−→qq
(b)νμ+N→νμ+X.
10.110 Draw Feynman diagrams for the decays
(a)Ξ−→Λ+π−
(b)K+→π+π+π−
10.111 (a) Draw the Feynman diagram for the semi leptonic decay ofD+→K^0 +
l+ ̄l.
(b) Draw Feynman diagram for the tauon decayτ−→π−+ντ
10.112 Draw Feynman diagrams for (a) Two-photon annihilation (b) Three-photon
annihilation of positronium.
10.113 Draw the Feynman diagram for the decayΛ→p+π−
10.3 Solutions..................................................
10.3.1 ConservationLaws.................................
10.1 (i) Weak decayFig. 10.2(a)
(ii) Forbidden because Baryon number is violated
(iii) Charge current weak interactionFig. 10.2(b)
(iv) Forbidden because energy is not conserved