We develop an effective field theory of a generic massive particle of any spin and, as an example, apply this to study higher-spin dark matter (DM). Our formalism does not introduce unphysical degrees of freedom, thus avoiding the potential inconsistencies that may appear in other field-theoretical descriptions of higher spin. Being a useful reformulation of the Weinberg's original idea, the proposed effective field theory allows for consistent computations of physical observables for general-spin particles, although it does not admit a Lagrangian description. As a specific realization, we explore the phenomenology of a general-spin singlet with Z2 -symmetric Higgs portal couplings, a setup which automatically arises for high spin, and show that higher spin particles with masses above O (10 ) TeV can be viable thermally produced DM candidates. Most importantly, if the general-spin DM has purely parity-odd couplings, it naturally avoids all DM direct detection bounds, in which case, its mass can lie below the electroweak scale. Our formalism reproduces the existing results for low-spin DM and allows one to develop consistent higher-spin particle physics phenomenology for high- and low-energy experiments and cosmology.
Physical Review D
- Pub Date:
- December 2020
- High Energy Physics - Phenomenology;
- High Energy Physics - Theory
- References added. Corrections in formulae involving multispinor contractions. Results qualitatively the same. Matches version published in PRD