1000 Solved Problems in Modern Physics

544 10 Particle Physics – II matrix element, the general form being (q^2 +m^2 )−^1 , where m is the mass of the exchanged partic ...

10.2 Problems 545 (iv)μ++μ−→τ++τ− (v) p→e++π^0 (vi)π^0 →γ+γ (vii)π−+p→K++Σ− (viii)π−+p→K−+Σ+ 10.5 Theρ^0 meson is known to have ...

546 10 Particle Physics – II 10.10 Show that (a)ρ→η+πis forbidden as a decay through strong interaction. (b)ω→η+πis forbidden as ...

10.2 Problems 547 π++p→π++p (1) π−+p=π−+p (2) π−+p=π^0 +n (3) Show that ifa 1 / 2 a 3 / 2 thenσ 1 :σ 2 :σ 3 =9:1:2andifa 1 / 2 ...

548 10 Particle Physics – II 10.26 Consider the formation of the resonanceΔ(1,236) due to the incidence of π+andπ−onp. Assuming ...

10.2 Problems 549 Show that the number of chargedΣ’s will be equal to twice the number of neutralΣ’s. 10.32 In the rest system o ...

550 10 Particle Physics – II (a)π^0 π^0 (b)π+π+ (c)π+π− (d)Λπ^0 (e)Σ^0 π^0 (f)π−π−? 10.2.3 Quarks............................... ...

10.2 Problems 551 10.51 (a) What are the quark constituents of the statesΔ−,Δ^0 ,Δ+,Δ++? (b) Assuming the quarks are in states o ...

552 10 Particle Physics – II dσ dΩ = α^2 ^2 c^2 4 E^2 CM (1+cos^2 θ) whereECMis the total centre of mass energy andθis the scat ...

10.2 Problems 553 10.68 Use lepton universality and lepton-quark symmetry to estimate the branching fraction for the decayτ−→e−+ ...

554 10 Particle Physics – II neutrino energy was spread between 5 and 15 MeV over a period of 4 s. Estimate the upper limit for ...

10.2 Problems 555 10.83 Classify the following semileptonic decays of theD+(1,869)=cdmeson as Cabibbo-allowed, Cabibbo-suppresse ...

556 10 Particle Physics – II 10.91 The neutral kaonsK^0 andK^0 are the charge conjugate of each other and are distinguished by t ...

10.2 Problems 557 10.98 Sketch the Feynman diagrams and replace the symbolslwith the correct leptons or anti-leptons in the foll ...

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 diagram ...

10.3 Solutions 559 (v) Fig. 10.2(c)AEM interaction Fig. 10.2(d)Weak interaction 10.2 (i) Weak interaction because neutrino is in ...

560 10 Particle Physics – II SubstitutingmK=498 MeV/c^2 and mπ=140 MeV/c^2 , we get p 0 = 142 .8MeV/c^2 10.4 (i) Does not occur ...

10.3 Solutions 561 (f)σ.E→−σ.Eunder both P and T-operations. (g) Similarlyσ.B→−σ.Bunder both p-operation and under T-operation. ...

562 10 Particle Physics – II (c) Decay via strong or electromagnetic interaction is forbidden because of violation of cp invaria ...

10.3 Solutions 563 (b) Each photon will carry 67.5 MeV λ= 1241 67. 5 × 106 nm= 18. 385 × 10 −^6 nm= 1. 84 × 10 −^14 m 10.3.2 Str ...