Les Houches

Fix the m(h+/-) and A masses to be equal to $M$ and related to the $H^\prime$ mass via $(540 GeV)^4 = M_{H^\prime}^4 + 3M^4$, and scan over $0.1 < \tan\beta < 10$ and $150 < M < 410$GeV.

As you can see, the measurements disfavour $\tan\beta > 1$ regardless of $M = M_A$. There is some increase in sensitivity at high $M_A$. We can also plot the same data as a function of $M_{H^\prime}$:

The binning is equally spaced in $M$, so gets distorted in $M_{H^\prime}$ (can do another scan in $M_{H^\prime}$ if useful). However, even here we can see the increased sensitivity at high $M_A$ corresponds to $M_{H^\prime} < 250$GeV or so.

We can look at the sensitivity plots for different signatures. The sensitivity that reaches to lowest $\tan\beta$ comes from dilepton+X measurements around the $Z$ pole (so $Z+$jet and similar measurements). See below:

Lepton+MET+X measurements (mostly $W$+jet or top) also have their best sensitivity at quite $M$, but a bit lower than the dileptons, so at intermediate $M_{H^\prime}$, see below the same scan plotted against the two different masses.

The inclusive $\gamma$ measurements also have some sensitivity, which shows a sharp cutoff once $M_A > 350$ GeV. (See below.)

This needs to be understood. Next, we should try and identify exactly which processes and which cross section measurements drive these sensitivities to check whether they makes sense.

Trying this 2HDM: https://feynrules.irmp.ucl.ac.be/wiki/2HDM

Quick test run for 13TeV with these parameters:

   set /Herwig/FRModel/Particles/h2:NominalMass 150*GeV  
   set /Herwig/FRModel/Particles/h3:NominalMass 410*GeV
   set /Herwig/FRModel/Particles/h+:NominalMass 410*GeV
   set /Herwig/FRModel/Particles/h-:NominalMass 410*GeV
   set /Herwig/FRModel/FRModel:tanbeta 0.5
   set /Herwig/FRModel/FRModel:sinbma 1.0

I think h2 = H', and h3 = A in Ken's language. Not sure which way up $\tan\beta$ is.

Herwig output:

• subprocess cross sections are in here:lhc.out.2hdm1.txt
• branching fractions/widths are in here:lhc.log.2hdm1.txt
• Contur output here: http://www.hep.ucl.ac.uk/~jmb/LH/2HDM/contur-plots-2hdm1/

Seems to be some sensitivity in the CMS top and W+jets measurements and the ATLAS Z+jets…to be checked. Note this run is only 1000 events, will do more once we agree whether it looks sensible. Then also plan to fix $[2 M_{h^\pm}^4 + M_{h3}^4 + M_{h2}^4] = 540^4$ GeV and scan in $\tan\beta$ and $M_{h2}$.

Same run but with

   set /Herwig/FRModel/FRModel:tanbeta 2.0

Herwig output:

• subprocess cross sections are in herelhc.out.2hdm2.txt
• branching fractions/widths are in herelhc.log.2hdm2.txt
• Contur output here: http://www.hep.ucl.ac.uk/~jmb/LH/2HDM/contur-plots-2hdm2/

Same as above, swith

   set /Herwig/FRModel/FRModel:tanbeta 0.5

Herwig output:

• subprocess cross sections are in herelhc.out.2hdm1ws.txt
• branching fractions/widths are in herelhc.log.2hdm1ws.txt
• Contur output here: http://www.hep.ucl.ac.uk/~jmb/LH/2HDM/contur-plots-2hdm1ws/

Same as above, still with

   set /Herwig/FRModel/FRModel:tanbeta 2.0

Herwig output:

• subprocess cross sections are in herelhc.out.2hdm2ws.txt
• branching fractions/widths are in herelhc.log.2hdm2ws.txt
• Contur output here: http://www.hep.ucl.ac.uk/~jmb/LH/2HDM/contur-plots-2hdm2ws/

TODO add the resonant modes gg→h2 etc