Project Description

→ Comparisons of SMEFTsim and SMEFTatNLO running both at LO to check the consistency Especially for ttH and ZH→ the operators affecting these production channels will appear in ggZH. The definition of operators in the NLO model can be found in http://feynrules.irmp.ucl.ac.be/attachment/wiki/SMEFTatNLO/definitions.pdf and in page 49 of https://arxiv.org/pdf/1709.06492.pdf for the LO model. The main difference in the implementation is for complex operators, in SMEFT LO there is a phase and an absolute value whereas only one real value can be modified in the NLO model.

→ Study of ggH and ggZH at NLO. Similar studies published:

 https://arxiv.org/pdf/1601.08193.pdf (ggZH, limited set of operators studied)
 https://arxiv.org/pdf/1708.00460.pdf (ggH)

For the generation of the interference term we need to interfere tree level (from the EFT) with loop-induced processes (from the SM). Madgraph is not able to do it for the official versions, but some documentation on how to do it has been gathered:

 https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/LoopInducedTimesTree

It can be also done using the reweighting module. Link to the STXT Rivet routine:

 https://gitlab.cern.ch/LHCHIGGSXS/LHCHXSWG2/STXS/Classification 

that also provides histograms of common kinematic variables.

Interested Participants

María Moreno Llacer, Marco Delmastro, Ana Cueto, Nicolas Berger, Paolo Francavilla, Saskia Falke, Daniel de Florian, Mauro Donega, Josh McFayden, Add your name :)