NLO predictions for the production of a spin-two particle at the LHC

Abstract

We obtain predictions accurate at the next-to-leading order in QCD for the production of a generic spin-two particle in the most relevant channels at the LHC: production in association with coloured particles (inclusive, one jet, two jets and $t\bar t$), with vector bosons ($Z,W^\pm,\gamma$) and with the Higgs boson. We present total and differential cross sections as well as branching ratios as a function of the mass and the collision energy also considering the case of non-universal couplings to standard model particles. We find that the next-to-leading order corrections give rise to sizeable $K$ factors for many channels, in some cases exposing the unitarity-violating behaviour of non-universal couplings scenarios, and in general greatly reduce the theoretical uncertainties. Our predictions are publicly available in the MadGraph5\_aMC@NLO framework and can, therefore, be directly used in experimental simulations of spin-two particle production for arbitrary values of the mass and couplings.Comment: 10 pages, 5 figures, 1 table; v2: update references, rewrite the introduction, add mass scanning, remove all 750 GeV references, the model file can be found http://feynrules.irmp.ucl.ac.be/wiki/NLOModel

Simplified dark matter models with a spin-2 mediator at the LHC

“…1 One may also assign independent coupling parameters for each flavour, especially for heavy flavours [28].…”

“…In [28], the SM sector of the above model was implemented in FeynRules/NloCT [32,33] (based on [34][35][36]), and the Y 2 production and decay rates at next-to-leading order (NLO) QCD accuracy were presented. In this work, we include the three DM species (X R , X D , X V ) with the corresponding interactions, and add the model into the DMsimp framework [37] as the simplified DM model with a spin-2 mediator.…”

“…Since the radiation of an initial-state photon (Z /W ) can only occur in the quark-initiated process, Y 2 + photon (Z /W ) production is very much suppressed as compared to Y 2 + jet production. This is also the reason that the process has a huge K factor especially in the low-mass region [28]. 5 In the context of DM searches, the monojet signature is expected to give important constraints on the model.…”

The two-loop QCD correction to massive spin-2 resonance $$ \rightarrow q \bar{q} g $$ → q q ¯ g

“…Moreover, the signature can also be found in tri-gauge boson productions [19][20][21][22][23]. Recently all the important processes are fully automatized [24] in Mad-Graph5aMC framework [25] with NLO+PS accuracy for a generic spin-2 particle. Nevertheless the NLO corrections are often very large, resulting in large K-factors and large scale uncertainties.…”

Production of $$\tau \tau jj$$ττjj final states at the LHC and the TauSpinner algorithm: the spin-2 case

“…This is in contrast to, for example Ref. [23], where the X field is coupled to the energy momentum tensor of quantised SM. After the electroweak symmetry breaking, operators in Eq.…”