LHC DM WG organisers | lhc-dmwg-admin | Uli Haisch, Tim Tait (Theory), Spyros Argyropoulos (ATLAS), Matteo Cremonesi (CMS), Xabier Cid Vidal (LHCb) |
---|---|---|
ATLAS Common Dark Matter subgroup conveners | atlas-phys-gen-common-dark-matter-conveners | Spyros Argyropoulos, Zirui Wang |
CMS Dark matter subgroup conveners | Matteo Cremonesi | Matteo Cremonesi |
LHCb Dark matter subgroup conveners | Xabier | Xabier Cid Vidal |
t-channel contacts | lhc-dmwg-tchannel-contacts | Benjamin Fuks (theory), Benedikt Maier, David Yu (CMS), Rute Pedro (ATLAS) |
The LHCDMWG aims to hold general meetings 3 times per year, nominally January, May, September. Meetings related to ongoing projects (e.g. t-channel) happen more regularly. The list of previous meetings per category can be found below.
LHCDMWG meetings | indico | List of all previous meetings & contributions |
---|---|---|
t-channel meetings | indico | List of all previous meetings & contributions |
General LHCDMWG mailing list | List for meeting general announcments (only administrators can/should post) | lhc-dmwg |
---|---|---|
General contributors | List for technical discussions on all topics (everyone can post) | lhc-dmwg-contributors |
t-channel contributors | For people contributing to t-channel WP (everyone can post) | lhc-dmwg-contributors-tchannel |
Mattermost channel | Mattermost channel (under development) | Subscribe |
A list of DM models can be found at https://github.com/LHC-DMWG/model-repository.
NB: to obtain access you need to subscribe to the lhc-dmwg-material e-group.
NB2: the repository above only serves as a place to collect models. For the official generation of events to be used by experimental collaborations, we invite the contributors to check with the respective conveners listed above.
Under construction
The limits on the branching ratio of Higgs to invisible can be converted into limits on the WIMP-nucleon cross-section, thus allowing to compare the results from the LHC searches for DM to direct detection experiments. We propose 3 comparisons:
The formulae to be used in order to translate the Higgs-to invisible branching ratio (denoted by BR in the following) are given below.
The WIMP-nucleon cross-sections are given by the formulate below for scalar (1), Majorana (2) and vector (3) DM are given below:
(1) |
(2) |
(3) |
(4) |
The latter quantity (fN) parametrises the Higgs-nucleon interaction and has been calculated using lattice QCD in 1708.02245. The above formulae are obtained from Djouadi et al, 1112.3299, with the difference that the Higgs vev is set to 246 GeV (instead of 246/sqrt(2) used in that paper).
For scalar DM the coupling is given by
(5) |
For Majorana DM, the coupling is given by
(6) |
For vector DM, the coupling is given by
(7) |
Various UV complete models for vector dark matter have been proposed in the literature (see Bibliography section below). In these models an extra U(1)' symmetry is introduced, under which the DM is charged. An additional Higgs field h2 spontaneously breaks this U(1)' symmetry, thereby generating the DM mass. The additional Higgs boson associated to the breaking of the extra U(1)' symmetry (hereafter denoted by ) mixes with the SM Higgs boson, with a mixing angle .
The first model we recommend to show is the one from Arcadi et al, 2001.10750, for which the WIMP-nucleon cross-section can be expressed as
(8) |
Two mass of the additional Higgs boson should be varied in order to get a range of predictions. In Zaazoua et al, 2107.01252 it was found that correspond to the maximum and minimum WIMP-nucleon cross-sections for
Todo: Provide script for obtaining the curve for the radiative model
Update information with detailed instructions for MadGraph generation
Recommendations for the production of signatures in the simplified s-channel model have been provided in the white papers listed below. An improved (more accurate) prescription for the generation of certain signatures is being discussed. Details will be posted below, once the prescription is agreed upon.
A tool for rescaling the s-channel limits for arbitrary values of the couplings have been developed and presented in Albert et al, 2203.12035. We recommend following the prescriptions there for the presentation of results with rescaled couplings.
Detailed recommendations for the generation of 2HDMa signal samples for various signatures can be found in the relevant white paper listed below. More information about the model and the existing constraints can be found at the bibliography section.
The 2MDM model, introducing a heavy Z' boson and an additional Higgs boson has recently started being explored by ATLAS and CMS.
Recommendations for the harmonised presentation of results are in progress.
-- MichelangeloMangano - 2023-02-14