Adding some physics model descriptions

docs/part2/bsm-higgs-models.md

@@ -0,0 +1,51 @@
+# Physics Models for Extended Higgs Sector Searches
+
+This page lists the physics models that can be used to perform searches for additional Higgs boson measurements at the LHC, when the SM-like Higgs boson should be accounted for in the data.
+
+## Two Higgs Models
+
+These models are for the case where there are just Two Higgs bosons, one of which is the SM-like Higgs boson that was discovered at the LHC. The two Higgs models are implemented in the python file [`TwoHiggsModels.py`](https://github.com/cms-analysis/HiggsAnalysis-CombinedLimit/blob/main/python/TwoHiggsModels.py). For each of these models, we assume that the SM-like Higgs boson has mass specified by `MH_SM`, while the additional boson has mass `MH`.
+
+You can produce the model by including the  following option in the `text2workspace.py` command:
+
+```sh
+-P HiggsAnalysis.CombinedLimit.TwoHiggsModels:model
+```
+
+| |`model`|<div style="width:160px">`--PO`</div>|<div style="width:160px">POIs</div>|<div style="width:590px">Description</div>|
+| --- | ------------ | -------------------- | ---------------------- | --------------------------------------------------------------------------------------------------------- |
+| Two Higgs bosons  | `twoHiggsUnconstrained`    |   N/A       | `r`, `r_SM`                   | The SM-like Higgs boson signal strength will be `r_SM` and its mass will be assumed to be `MH_SM` (default value 125.8), while the additional Higgs boson signal strength will be scaled by `r` and assumed to have mass `MH`. |
+| Singlet Mixing Model | `singletMixing` |  `--PO BSMDecays`,`--PO UseVisibleMu` | `r`,`BR_BSM` | Without any options, the SM like Higgs boson will have signal strength `r`, while the additional Higgs boson is scaled by `1-r` and `BR_BSM` will not be a POI. If the option `BSMDecays` is included, the additional boson's signal strength will be `r(1-BR_BSM)` and the SM like Higgs boson will have signal strength of `1-r`. If the option `UseVisibleMu` is included too, then instead, the additional Higgs boson will get a signal strength `r` while the SM one will have `1-r(1-BR_BSM)`. |
+| Singlet Mixing Model for Exclusions | `singletMixingInvisible` |  `--PO BSMDecays` | `r`,`x`,`BR_BSM` | The SM like Higgs boson will be scaled by `r*x` while the additional boson is scaled by `r*(1-x)`. If the option `BSMDecays` is included, then `BR_BSM` is also a POI and the additional Higgs boson signal strength is scaled accounting for this BSM branching fraction `r*(1-x)*(1-BR_BSM)`.|
+| Two Higgs bosons with $c_{V}$, $c_{F}$ couplings | `twoHiggsCvCf` | N/A | `CV`, `CF` | Both Higgs bosons signal strengths scale accoring to the coupling to vector bosons `CV` and fermions `CF` where the scaling is determined for each contributing production/decay vertex. In this case, the additioal boson is assumed to follow the same coupling structure (i.e the SM like Higgs boson couplings). |
+
+## Two Higgs Doublet Models
+
+In these models, the couplings of the SM-like Higgs boson are modified according to the type of 2HDM with parameters $\cos(\beta-\alpha)$ and $\tan\beta$. The two Higgs doublet models are implemented in the python file [`AdditionalModels.py`](https://github.com/cms-analysis/HiggsAnalysis-CombinedLimit/blob/main/python/AdditionalModels.py).  In this model, the Higgs boson mass is `MH`, and it can be promoted to a POI by including the option `--PO higgsMassRange=[low,high]`.
+
+You can produce the model by including the  following option in the `text2workspace.py` command:
+
+```sh
+-P HiggsAnalysis.CombinedLimit.AdditionalModels:model_name
+```
+
+| |`model`|<div style="width:160px">`--PO`</div>|<div style="width:160px">POIs</div>|<div style="width:590px">Description</div>|
+| --- | ------------ | -------------------- | ---------------------- | --------------------------------------------------------------------------------------------------------- |
+| 2HDM Type-1 | `twohdm` |    `--PO thdmtype=1`    | `cosbma`,`tanbeta` | The couplings of the Higgs boson to fermions and vector bosons are modified by the parameters `cosbma` ($\cos(\beta-\alpha)$) and `tanbeta` ($\tan\beta$). The couplings dependencies are $\kappa_V = \sqrt(1-\cos^{2}(\beta-\alpha))$, $\kappa_{u}=\kappa_{d}=\cos(\alpha)/\sin(\beta)$. |
+| 2HDM Type-2 | `twohdm` |    `--PO thdmtype=2`    | `cosbma`,`tanbeta` | The couplings of the Higgs boson to fermions and vector bosons are modified by the parameters `cosbma` ($\cos(\beta-\alpha)$) and `tanbeta` ($\tan\beta$). The couplings dependencies are $\kappa_V = \sqrt(1-\cos^{2}(\beta-\alpha))$, $\kappa_{u}=\cos(\alpha)/\sin(\beta)$, $\kappa_{d}=-\sin(\alpha)/\cos(\beta)$. |
+| 2HDM Type-3 | `twohdm` |    `--PO thdmtype=3`    | `cosbma`,`tanbeta` | The couplings of the Higgs boson to quarks, leptons and vector bosons are modified by the parameters `cosbma` ($\cos(\beta-\alpha)$) and `tanbeta` ($\tan\beta$). The couplings dependencies are $\kappa_V = \sqrt(1-\cos^{2}(\beta-\alpha))$, $\kappa_{u}=\kappa_{d}=\cos(\alpha)/\sin(\beta)$, $\kappa_{l}=-\sin(\alpha)/\cos(\beta)$. |
+| 2HDM Type-4 | `twohdm` |    `--PO thdmtype=4`    | `cosbma`,`tanbeta` | The couplings of the Higgs boson to quarks, leptons and vector bosons are modified by the parameters `cosbma` ($\cos(\beta-\alpha)$) and `tanbeta` ($\tan\beta$). The couplings dependencies are $\kappa_V = \sqrt(1-\cos^{2}(\beta-\alpha))$, $\kappa_{u}=\kappa_{l}=\cos(\alpha)/\sin(\beta)$, $\kappa_{d}=-\sin(\alpha)/\cos(\beta)$. |
+
+## Fermiophobic Higgs Model
+
+This model is for the case where the additional Higgs boson does not couple to fermions. The fermiophobic Higgs model is implemented in the python file [`HiggsFermiophobic.py`](https://github.com/cms-analysis/HiggsAnalysis-CombinedLimit/blob/main/python/HiggsFermiophobic.py). In this model, the Higgs boson mass is `MH`, and it can be promoted to a POI by including the option `--PO higgsMassRange=[low,high]`.
+
+You can produce the model by including the  following option in the `text2workspace.py` command:
+
+```sh
+-P HiggsAnalysis.CombinedLimit.HiggsFermiophobic:model_name
+```
+
+| |`model`|<div style="width:160px">`--PO`</div>|<div style="width:160px">POIs</div>|<div style="width:590px">Description</div>|
+| --- | ------------ | -------------------- | ---------------------- | --------------------------------------------------------------------------------------------------------- |
+| Fermiophobic Higgs  | `fp`    |   N/A       | `r`                   | The Higgs boson signal strength will be `r` for any production/decay that involves vector boson couplints only. The branching ratios are recalculated assuming no Higgs boson couplings to fermions.|