An operator basis for the Standard Model with an added scalar singlet

Abstract

Motivated by the possible di-gamma resonance at 750 GeV, we present a basis of effective operators for the Standard Model plus a scalar singlet at dimensions 5, 6, and 7. We point out that an earlier list at dimensions 5 and 6 contains two redundant operators at dimension 5.

Comments: 8 pages and 2 tables. v2: removed redundant operator from dimension 7 list. v3: fixed bug in colour coding of CP properties and updated to match published version