1) Draw diagram in time-ordered quantum mechanics
   and Feynman diagram for a+b -> c+d process in t-channel
   explain differences

2) What is the simplest form for Lorentz Invariant Matrix Element.
   Could you explain it?

3) In the QED, cross-section for e+e- -> mu+mu- is calculated
   averaging over initial spin states and summing over the final
   spin states.
   What is the form for the differential cross-section dsigma/dOmega
   could you draw it and explain contributions.
   What is the form for total (integrated) cross-section, how it
   behaves with increasing energy in the centre-of-mass frame of
   annihilating electrons

4) Using as example ATLAS detector at LHC explain what are main components
   of general purpose detectors, gives some representative numbers for
   the performance achieved of different components (eg. resolution)