PhD course "EFT fitting in Standard Model measurements"

26.06.2023     repo

    This is a simple tutorial showcasing how to use SMEFTsim in MadGraph, simulating the decay of the Higgs boson
    h → e- νe μ+ νμ

Pre-requisites

  1. MadGraph5_aMC@NLO v2.6 to v2.9, including the reweight module.
  2. ROOT with PyROOT (for python2)
    3. alternatively:
  3. Docker
  4. Install the docker image following instructions given here

Material and Instructions

  1. Download material by cloning the github repository https://github.com/IlariaBrivio/SMEFTsim_tutorial_June23.git
  2. Follow instructions in the Readme file.
  3. If you are using docker, make sure to download all the material from within the image.

Solutions

  1. The repository contains a zip folder with the product of the tutorial.
  2. Some physics to look for in the plots:
    • quadratic terms are all much smaller than the linear ones. This is because the decay is kinematically limited.
    • operators entering only through input shifts (cll1, cHbox) give exact rescalings of the SM rate → the SMEFT/SM ratio is perfectly flat.
    • the operators cHW, cHl3 give different kinematics compared to SM → the SMEFT/SM ratio has a non-flat shape.
    • propagator corrections are non-negligible only in the kinematic regions where one of the two W is on-shell.
      here, they are of the same order as the linear corrections from vertex insertions.

Reinterpretation forum

17.02.2021     Indico page

    The tutorial will be in two parts: a short one about the usage of SMEFTsim in FeynRules and a longer one about the usage for MC event generation. They are completely independent.

Part 1: SMEFTsim in FeynRules

Pre-requisites

  1. Mathematica 12.
    If you do not have a license from your home institute, you can get a 15-day trial license from the Wolfwam website
  2. FeynRules

Material

  1. Download the SMEFTsim FeynRules source from the GitHub repository

Part 2: SMEFTsim in MadGraph5

Pre-requisites

  1. MadGraph5_aMC@NLO v2.6 or more recent, including the reweight module.
  2. ROOT with PyROOT (for python2.7)
    3. alternatively:
  3. VirtualBox
  4. The virtual machine Delphes2020.vdi available here . Please follow the installation instructions provided. Note that the machine is about 4GB, so it might take some time to download.

Material

  1. We will use the latest version of the UFO model SMEFTsim_U35_MwScheme_UFO.
    You can either download it from the GitHub repository and copy it into the MADGRAPH/models/ directory or import it from the FeynRules database: after opening MadGraph, type import model SMEFTsim_U35_MwScheme_UFO The model will be automatically downloaded.
  2. A tarball with some scripts. Download with wget https://www.dropbox.com/s/nr1pm0ijxu1es5f/Material.tar

    3. If you are using the Virtual Machine, make sure to download all the material within the virtual environment.

Other Tutorials and Talks

    Here you can find links to other tutorials and talks about SMEFTsim

Tutorials and Hands-on

  1. 2021 EFT School on Collider Phenomenology (April 2021). A broad session with tutorials on several EFT tools, including MadGraph, SMEFT@NLO, MadAnalysis. instructions and material available.
  2. PREFIT School (March 2020) the lectures "EFT UFO: hands-on", "Madgraph and Parton Shower: hands on", "SMEFT: hands on" use SMEFTsim in FeynRules/Mathematica and in MadGraph5. Instructions and recordings available.

Talks

  1. SMEFT-Tools 2022 (September 2022) [slides here]
  2. Area 2 meeting of the LHC EFT WG (December 2020)
  3. SMEFT-Tools 2019 (June 2019)