Les Houches

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Project Acronym: RDM

Interested people: Benj, Andreas Goudelis, Genevieve Belanger, Dipan Sengupta, Aoife Bharucha, José Zurita, Jose Miguel No, Jordan Bernigaud, Jan Heisig, Giacomo Polesello, Priscilla Pani, Biplob Bhattacherjee, Andre Lessa, Cedric Delaunay

[Feel free to add your name here and edit tasks!]

Goal (ambitious): study the interplay between RD anomalies and Dark Matter.

Goal (concrete): use the S1 leptoquark model that solves RD and RD* and study the dark matter aspect.

Setup: Work in a model with 3 new particles (S1, chi1, chi0) and 3 couplings y^L_{3X}, y^{R}_{23} and y_D. S1 is a scalar leptoquark solving the RD anomalies, chi1 and chi0 are fermions, probably close in mass, with chi0 being a SM singlet, hence chi1 has the same SM gauge charges as S1.

Tasks (updated, from 25.06.2019):

1- Expand existing UFO for dark matter: add yD coupling. Make it Micromegas friendly by including tildes for dark particles (see below for details on the model). In charge:JB, DS

2- Check flavor constraints: how much can we relax y^L_{3X}, y^{R}_{23} / mS1^2 = 1/(4 TeV^2)? Interest is to lower mS1 and the couplings as much as possible without colliding with other flavor bounds coming from e.g: D-Dbar mixing (that would apply on combinations of couplings and masses, y^{R}_{23}^2 / mS1^2 ). Persons in charge: MN, JB

3- Monojet bounds on chi1: Assuming that chi1 decays are soft an go undetected, there will be *unavoidable* direct bounds from monojets on the mchi1 mass [Note that in the simplified model chi1 decays 100% into chi0 + SM particles, so there is no branching ratio dillution here). Persons in charge: JZ, DS, AL

4- * NEW *: There will be constraints from gq → l + S1 (also in principle gq → LQ + q + l is possible, but this is suppressed by being a 2→ process instead of a 2→3 one). Persons in charge: GP, AL, JZ

5- Relic density: We will in principle have two possible production freeze-out modes: either co-annihilation (CA) or conversion-driven (CD). Once #1 is solved, this can be investigated with micromegas (CA) or by private Jan's code (CD). Persons in charge: GB, AG, JMN, DS, JH

6- Direct-detection (1-loop induced): This is in principle implemented in Micromegas, so it should be easy to check. Person in charge: GB, AG, DS.

Tasks (from 20.06.2019 meeting):

1- Get a working Lagrangian. From private communication with D. Marzocca we need to have both left handed and right handed couplings to S1. The dark sector includes a chi1 (coloured and charged) and a chi0 (singlet) field. The implementation include LQ couplings to lepton and quark doublets (bL-vL) and LQ couplings to the lepton and quark singlets (cR-tauR). The model finally includes a 3rd coupling (yDM) to the chi1-chi0 pair. Persons in charge: Benjamin, Dipan.

A FeynRules implementation is now available and can be downlaoded from here. The tarball contains the SM implementation (sm.fr), the new physics sector implementation (lqdm.fr) and a toy mathematica notebook (use-LQDM.nb).
The provided mathematica notebook has been used to generate UFO and CalcHep model files.
Here is a note detailing what has been implemented. The TeX version is also available.
Important message from Benj: The model still needs to be double-checked by an independent pair of eyes!

2- RD explained by mS1=2 TeV, and both lq couplings being 1. (From D. Marzocca). Anomaly explained by lambda_bv * lambda_ctau / mS1^2.

3- Study bounds from direct detection. These happen at the 1-loop level, expressions known in literature for the SUSY case. In charge: Genevieve, Andreas, Dipan, Jose Miguel.

4- look into CMS search for LQ + MET (motivated by the “Coannihilation Codex”) and for existing searches constraining chi1. In charge: Aoife, José.

5- study relic density (after 1-4 are done). Jan

References

Zoology of New Physics Models for the Flavour Anomalies