Physics 215 A QFT Fall 2017
نویسنده
چکیده
(a) Draw the Feynman diagram which gives the leading contribution to the process φφ→ φφ. (b) Derive the correct sign of the amplitude by considering the relevant matrix elements of powers of the interaction hamiltonian. (c) Evaluate the diagram in terms of a spinor trace and a momentum integral. Do not do the momentum integral. Suppose that the integral is cutoff at large k by some cutoff Λ. Estimate the dependence on Λ.
منابع مشابه
Physics 215 A QFT Fall 2017 Assignment
(a) What symmetries do these charges generate (i.e. how do the fields transform)? Show that they are symmetries of S. (b) If you want to, show that [Q, H] = 0, where H is the Hamiltonian. (c) Evaluate [Q, Q]. Hence, non-Abelian. (d) To complete the circle, find the Noether currents J i μ associated to the symmetry transformations you found in part 1a. (e) Generalize to the case of N scalar fields.
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