Nuclear and Particle Physics (CSIR (Council of Scientific & Industrial Research) Physical Sciences): Questions 1 - 4 of 13

Consider the four processes,

(i)

(ii)

(iii)

(iv)

Which of the above is/are forbidden for free particles? (December)

If the binding energy B of a nucleus (mass number A and charge Z) is given by,

; where, then the Z for the most stable isobar for a nucleus with is –

(December)

In a classical model, a scalar (spin-0) meson consists of a quark and an antiquark bound by a potential, Where and . If the messes of the quark and antiquark are negligible, the mass of the meson can be estimated as approximately – (June – 2014)

Muons are produced through the annihilation of particle and its antiparticle, namely the process, A muon has a rest mass of and its proper life time is . If the center of mass energy of the collision is in the laboratory frame that coincides with the center – of – mass frame, then the fraction of muons that will decay before they reach a detector placed 6 km away from the interaction point is – (June)