= Heavy charged Higgs production =

This page contains the code to generate events for charged Higgs production at the LHC.

'''Authors :  Celine Degrande, Maria Ubiali, Marius Wiesemann, Marco Zaro'''

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''Reference:'' 

Heavy charged Higgs boson production at the LHC[[BR]]
C. Degrande, M. Ubiali, M. Wiesemann, M. Zaro. Jul 9, 2015. 32 pp.[[BR]]
e-Print: arXiv:1507.02549 [hep-ph] 


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''Instructions:''

The process folders have to be placed directly inside the main folder (of the proper version) of MadGraph5_aMC@NLO (​[https://launchpad.net/mg5amcnlo MG5_aMC homepage]). Please extract the downloadable archive there or move the process folders there (do not copy the folder, since this may destroy the symbolic links).

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= Charged Higgs production in the intermediate mass range =

This page contains instructions how to use the NLO predictions for charged Higgs production in the intermediate mass range and combine them with event generation at LO.

'''Authors :  Celine Degrande, Rikkert Frederix, Valentin Hirschi, Maria Ubiali, Marius Wiesemann, Marco Zaro'''

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''Reference:'' 

Accurate predictions for charged Higgs production: closing the m,,H^±^,,∼mt window[[BR]]
C. Degrande, R. Frederix, V. Hirschi, M. Ubiali, M. Wiesemann, M. Zaro.[[BR]]
e-Print: arXiv:1607.05291 [hep-ph] 


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''Instructions:''

The best we can do currently to model a charged Higgs signal in the intermediate mass range for this involved process (pp > b b H W) is to use the available NLO predictions for the total cross section and combine them with event generation at LO.

1) The state-of-the-art NLO predictions in the intermediate mass range, excluding contributions from scalar Higgses, can be downloaded for tan(beta) values of 0.1 to 60 for both type I and type II 2HDMs from the [https://twiki.cern.ch/twiki/bin/view/LHCPhysics/LHCHXSWGMSSMCharged#Intermediate_mass_145_200_GeV_ch twiki page of the LHCHXSWG (charged Higgs subgroup)]

2) Generate the process at LO without neutral Higgses to compute dσ,,LO,,^no-neutral^. Use the model file attached to this page (2HDMtypeIIymbMSbar.tar.gz) and extract it into the models folder.[[BR]]
 __details how to generate it with MG5_aMC:__[[BR]]
 MG5_aMC>import model 2HDMtypeIIymbMSbar[[BR]]
 MG5_aMC>generate p p > h+ w- b b~ / h1 h2 h3[[BR]]
 MG5_aMC>output HWbb_no-neutral[[BR]]
 MG5_aMC>exit[[BR]]

 The parameters in the cards should be chosen according to the LHC Higgs cross section working group recommendations.


3) Generate the process at LO including neutral Higgses to compute dσ,,LO,,^with-neutral^[[BR]]
 __details how to generate it with MG5_aMC:__[[BR]]
 MG5_aMC>import model 2HDMtypeIIymbMSbar[[BR]]
 MG5_aMC>generate p p > h+ w- b b~[[BR]]
 MG5_aMC>output HWbb_with-neutral[[BR]]
 MG5_aMC>exit[[BR]]

 The parameters in the cards should be chosen according to the LHC Higgs cross section working group recommendations.


4) Combine all contributions: reweight LO without neutral Higgses to NLO cross section and add neutral Higgs contribution at LO without reweighting:

''' dσ,,final,, =  dσ,,LO,,^no-neutral^*σ,,NLO,,^no-neutral^/σ,,LO,,^no-neutral^+(dσ,,LO,,^with-neutral^-dσ,,LO,,^no-neutral^) '''