6533b7cffe1ef96bd1259a40
RESEARCH PRODUCT
Enumerating higher-dimensional operators with on-shell amplitudes
Camila S. MachadoG. Durieuxsubject
PhysicsHigh Energy Physics - TheorySpinor010308 nuclear & particles physicsLorentz transformationGravitonFOS: Physical sciencesComputer Science::Digital Libraries01 natural sciencesHelicitysymbols.namesakeHigh Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)High Energy Physics - Theory (hep-th)Dimension (vector space)0103 physical sciencessymbolsEffective field theory010306 general physicsMathematical physicsGauge symmetrySpin-½description
We establish a simple formula for the minimal dimension of operators leading to any helicity amplitude. It eases the systematic enumeration of independent operators from the construction of massless non-factorizable on-shell amplitudes. Little-group constraints can then be solved algorithmically for each helicity configuration to extract a complete set of spinor structures with lowest dimension. Occasionally, further reduction using momentum conservation, on-shell conditions and Schouten identities is required. A systematic procedure to account for the latter is presented. Dressing spinor structures with dot products of momenta finally yields the independent Lorentz structures for each helicity amplitude. We apply these procedures to amplitudes involving particles of spins 0,1/2,1,2. Spin statistics and elementary selection rules due to gauge symmetry lead to an enumeration of operators involving gravitons and standard-model particles, in the effective field theory denoted GRSMEFT. We also list the independent spinor structures generated by operators involving standard-model particles only. In both cases, we cover operators of dimension up to eight.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2020-05-15 |