Abstract
We show that a natural spinor-helicity formalism that can describe massive scattering amplitudes exists in D = 6 dimensions. This is arranged by having helicity spinors carry an index in the Dirac spinor 4 of the massive little group, SO(5) ∼ Sp(4). In the high energy limit, two separate kinds of massless helicity spinors emerge as required for consistency with arXiv:0902.0981, with indices in the two SU(2)’s of the massless little group SO(4). The tensors of 4 lead to particles with arbitrary spin, and using these and demanding consistent factorization, we can fix 3− and 4-point tree amplitudes of arbitrary masses and spins: we provide examples. We discuss the high energy limit of scattering amplitudes and the Higgs mechanism in this language, and make some preliminary observations about massive BCFW recursion.
Highlights
The philosophy that one can fix a theory based largely on consistency conditions is an old one and its incarnation in S-matrix bootstrap is sometimes considered to be the roots from which string theory arose
We show that a natural spinor-helicity formalism that can describe massive scattering amplitudes exists in D = 6 dimensions
Quantum fields on the other hand transform as tensors of the Lorentz group, and it has become increasingly plausible in recent years that working with little group covariant objects might be a more natural and simpler way to construct scattering amplitudes, since they deal directly with particles
Summary
The philosophy that one can fix a theory based largely on consistency conditions (like unitarity, locality, Lorentz invariance) is an old one and its incarnation in S-matrix bootstrap is sometimes considered to be the roots from which string theory arose. Quantum fields (which are introduced as a tool for ensuring manifest locality) on the other hand transform as tensors of the Lorentz group, and it has become increasingly plausible in recent years that working with little group covariant objects (spinor helicity variables) might be a more natural and simpler way to construct scattering amplitudes, since they deal directly with particles. If our goals are truly ambitious, and we are trying to derive a UV completion like string theory from our general expectations about scattering amplitudes, it is evident that we are likely to require the ability to deal with massive particle as well In such a set up, scattering amplitudes of massive particles should be understandable in terms of IR deformations of massless scattering amplitudes.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
