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2019:groups:bsm:fislhc [2019/06/27 10:07]
giacomo.polesello
2019:groups:bsm:fislhc [2019/06/27 11:59] (current)
andreas.goudelis
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 [Please add (or remove!) your name and feel free to edit tasks!] [Please add (or remove!) your name and feel free to edit tasks!]
  
-**Goal** : study if it's possible to test scenarios of freeze-in ​in which DM is produced through scattering of SM particles ​(as opposed ​to production ​from decays ​of a heavier ​bath particle).+**Goal** ​(generalised following discussion on 26/​6/​2019) ​: study if it's possible to realise ​freeze-in ​with much-stronger-than-feeble couplings and test the corresponding scenarios at the LHC (and direct/​indirect detection experiments). 
 + 
 +---- 
 +The answer appears to be positive according to our - preliminary - findings and estimates, and the trick is to assume a low reheating temperature. We discussed two effects ​(corresponding ​to regimes which can also overlap):  
 + 
 +* The reheating temperature being below the dark matter mass. In this case, in order to get the relic right one needs to increase the DM couplings since DM production ​relies on the tails of the distributions of the thermal ​bath particles. 
 + 
 +* The reheating temperature being below the mediator mass. In this case, even for large-ish couplings, the mediator is not produced on-shell and the effective interaction can be feeble. 
 + 
 +Of all models that one can think of, we agreed to consider three simple scenarios:  
 +* The singlet scalar model  
 +* A 2HDM + pseudoscalar singlet model 
 +* A t-channel model, like the ones in [[https://​arxiv.org/​abs/​1811.05478]] or https://​arxiv.org/​abs/​1705.09292
  
 **Tasks**: **Tasks**:
  
-1) Adopt a concrete freeze-in ​model and see to which extent it's possible to increase the coupling of DM to the visible sector (e.g. by lowering the reheating temperature and, generically,​ by playing with the ratio of the mediator mass and the reheating temperature). Jose Miguel has proposed to start with the simple singlet scalar model and lower the reheating temperature below the Higgs mass.+1) Write model files for all models
  
-2) Depending on the findings of 1) we'll see how to proceed.+2) Compute ​the freeze-in DM abundance by varying the model parameters and the reheating temperature. For the latter, an indicative interval could be between ​GeV (such that we're roughly above the QCD scaleand 1 TeV (such that we don't go far above LHC-accessible masses).
  
 +3) Compute direct detection constraints. The t-channel model, in particular, has a loop-induced contribution which must be calculated
 +
 +4) Consider "​peripheral"​ constraints,​ such as flavour constraints in the t-channel model
 +
 +5) Compute LHC constraints (presumably quite a few channels, depending on the model)
  
 **UFO files for different benchmark models**: **UFO files for different benchmark models**:
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 Feynrules file (with some restrictions w.r.t. Uli's) for 2HDM + pseudoscalar $a$  {{ :​2019:​groups:​bsm:​typeii2hdm_pseudoportal_dm.fr.tar.gz |2HDM+a .fr file }} . Feynrules file (with some restrictions w.r.t. Uli's) for 2HDM + pseudoscalar $a$  {{ :​2019:​groups:​bsm:​typeii2hdm_pseudoportal_dm.fr.tar.gz |2HDM+a .fr file }} .
  
 +Feynrules files for the t-channel model considered in [[https://​arxiv.org/​abs/​1811.05478]]:​ [[https://​feynrules.irmp.ucl.ac.be/​wiki/​FICPLHC]]
  
  
2019/groups/bsm/fislhc.1561622846.txt.gz · Last modified: 2019/06/27 10:07 by giacomo.polesello