Yu-tin Huang (National Taiwan U)
Implications of locality and unitarity for massive S-matrix
|Tue, May 09, 2017, 13:15 - 14:30
Seminar Room A
The advent of modern S-matrix analysis was greatly inspired by the spinor-helicity formalism for massless particles, as well as its embedding in twistor theory. In this talk we will generalise the formalism to massive particles. This provides a natural basis to categorise all possible three-particle interactions. Employing perturbative unitarity and locality, puts constraint on consistent interactions between massive higher spin states and massless states. As a result we will derive the statement that fundamental particles with spin greater than 1 cannot be charged, and those greater than 2 cannot be consistently coupled to gravity. We will also demonstrate the utility of this new formalism by considering loop corrections to g-2 for spin-1/2 and 1, and the derivation of the beta function.