Consider a particle coupled to a field, the total action of which is given by mc2 1 do (ct, I) S a6(ct, x) 2 p(x) - krio(ct, x) + + dedt C at where m is the mass of the particle, p(x) = 6(x - To) is its density function, c the speed of light, y the Lorentz factor, * the coupling constant, r the particle position, and o(ct, x) the field function. (a) Calculate the canonical momentum for the particle. [5 marks]