2. A new, exotic particle (not necessarily a Standard Model particle), X, is discovered which decays weakly as follows X →π μ' Determine the following properties of X, or explain why it is not possible to deter- mine the property from the information given. (i) Lepton numbers (ii) Baryon number (iii) Electric charge (iv) Quark flavour

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5. Pion beams (*) are used to treat cancer in radiation therapy. The energy comes from the decay of the pions. Negative pions usually decay into a muon and a muon antineutrino. (a) (b) Write out the complete decay of a л into stable particles. How much energy is released from a complete decay? Assume the neutrino masses are negligible. (c) How many pions need to decay to give a dose of 50.0 Gy to 10.0 grams of tissue?

2. Draw a Feynman diagram for each of the following reactions, provided it is allowed. If the reaction is forbidden explain why. μ → eveVμ τ' →μνμύτ Vμе- → Veft- Vμe+ → Vel+ Vμe+ → Vef+ Vμnμp VμP →μ+n eté → VμVμ ete- →T+T- e¯e → ee

5. How much energy is released in the decay + → µt + v„? 6. How much energy is required to produce a neutron-antineutron pair?

Determine the quark composition of the B+, B-, and B0 mesons