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2HDM cross section ntuple

Introduction

This is a description on how to access cross sections and BRs for 2HDM benchmark points.

A generic CP-conserving 2HDM with a softly broken $ Z_{2} $ symmetry ($ \Phi _{1} \rightarrow \Phi _{1}, \Phi_{2} $ $ \rightarrow $ $ -\Phi_{2} $) has 7 free parameters:

  • Higgs bosons: 2 CP-even with masses mH and mh; 1 CP-odd with mass mA; two charged scalars with mass mCh
  • a mixing angle among the neutral Higgses, $ \alpha $
  • the ratio of the vevs of the two Higgs doublets $ \tan \beta = u1/u2 $
  • the $ m_{12} $ parameter of the potential, which is the softly breaking term of the $ Z_{2} $ symmetry of the potential.

To define benchmarks we usually set mh = 125 GeV. The rest of the parameters can be assigned in principle arbitrary values. Nevertheless, the mass splitting among the rest of the Higgs bosons cannot be very large (e.g. >200 GeV) due to theoretical considerations. The $ m_{12} $ has also to be finely tuned in order to get a valid model.

In the limit $ \sin(\beta - \alpha) \rightarrow 1 $ then the choice $ m ^{2}_{12} = m ^{2}_{A} \tan \beta / (1 + \tan ^{2} \beta) $ gives always a valid model. This is the SM-like limit of the 2HDM (which is different from the decoupling limit).

Production mechanisms in the 2HDM for neutral Higgs are b-associated production, g-fusion, VBF and VH.

The implementation is realized by a set of scripts available in

https://svnweb.cern.ch/cern/wsvn/lhchiggsxs/repository/2HDM/CrossSectionNtuple2HDM/

To check out the scripts, please do the following

svn co svn+ssh://username@svn.cern.ch/reps/lhchiggsxs/repository/2HDM/CrossSectionNtuple2HDM/

Cross Section & BR ntuple

Contacts:

If you have any problem or any request for the ntuple, please contact Steve Sekula (sekula at physics.smu.edu), Nikos Rompotis (nikolaos.rompotis at cern.ch) and Xiaohu Sun (xiaohu.sun at cern.ch). Previous experts include Driss Charfeddine driss.charfeddine at lal.in2p3.fr.

Ntuple versions 13 TeV

Version 1.6.7_AZH NEW

This is to replace thdm_grid_v165_AZHHZA-mCHmax.root with the bug fixed in bbA/H matching and additional tanbeta scan. The one with mCHmin (mass of charged Higgs equal to the H) will be updated on demand.

  • /afs/cern.ch/user/x/xiaohu/public/2HDM-THEO-NTUP/test-2hdm-AZHHZA-mCHmax-fine_correctmatching-moretb.root

Version 1.6.7 NEW

Bug in 1.6.6: bbA/H xsec was smaller than they should be due to a wrong implementation of Santander matching. Fixed in the following file.

  • /afs/cern.ch/user/x/xiaohu/public/2HDM-THEO-NTUP/thdm_grid_v167.root

Version 1.6.6 (buggy bbA/H xsec)

NOTE: the combined bbA/H xsec is wrong in this version due to a wrong implementation of Santander matching. However, the separate 5FS and 4FS bbA/H xs are correct. One can either do a matching on the fly or simply move to version 1.6.7 .

This is a stable version of the 2HDM ntuple for 13TeV

  • /afs/cern.ch/user/x/xiaohu/public/2HDM-THEO-NTUP/thdm_grid_v166.root

Naming convention:

In the ntuple, xs is stored in leaves such as xsec_X_yy, where X=h/H/A stands for various neutral Higgs bosons, yy=gg/bb/VBF/WH/ZH/ttH for ggF/b-associated/VBF/WH/ZH/t-associated production modes, respectively (NOTE: xsec_A_WH and xsec_A_ZH do not exist). BR is stored in leaves such as br_X_yy, where X=h/H/A/C stands for various neutral or charged Higgs bosons, yy for various decay children. The other parameters are stored in tb for $ \tan \beta $, cba for $ \cos ( \beta - \alpha ) $, sba for $ \sin ( \beta - \alpha ) $, mH for mass of H etc.

Features:

  • SM parameters from LHCHXSWG recommended SM values
  • WH, ZH, VBF and ttH xsections are rescaled from the generic high mass Higgs cross sections provided on LHCHXSWG, among which VH and VBF are only calculated for CP even Higgses
  • ggF and bbH xsection are both calculated in SusHi. bbH xsection is combined with 5FS 4FS santander matching
  • code versions: 2HDMC-1.7.0 SusHi-1.5.0

Mass range: 200 - 1500 (low mass 140 - 200 will come as a patch very soon)

Version 1.6.5_AZHHZA

This is an ntuple for studying A->ZH or H->ZA where there is large mass splitting between the H and the A. The charged Higgs boson is set to either the max(mH,mA) or min(mH,mA) in order for the benchmark to be compatible with precision electroweak tests. The SM-like limit sin(b-a)=1 is assumed, hence h has exactly SM Higgs properties. This is the first of its series.

Ntuples:

  • /afs/cern.ch/user/x/xiaohu/public/2HDM-THEO-NTUP/thdm_grid_v165_AZHHZA-mCHmax.root, mCh = max(mA,mH)
  • /afs/cern.ch/user/x/xiaohu/public/2HDM-THEO-NTUP/thdm_grid_v165_AZHHZA-mCHmin.root, mCh = min(mA,mH)

Notes:

  • SM parameters use the LHC HXSG recommended values
  • WH and ZH xsec are correctly included
  • DO NOT use the VBF cross sections appearing in the ntuple. They are wrong.
  • ttH production, not available
  • Code versions: 2HDMC version 1.7.0, SusHi version 1.5.0
  • Grid setting 
mA or mH: 300, 400, 500, 600, 700, 800, 900, 1000
when A->ZH mH < mA; when H->ZA, mH > mA
tb = 0.5, 1.0, 2.0, 5.0, 10.0, 20.0
sin(b-a) = 1.0
4 types
13 TeV

Version 1.6.5

in test

Software updates: 2HDMC version 1.7.0, SusHi version 1.5.0 Parameter updates (according to https://cds.cern.ch/record/2047636/files/LHCHXSWG-INT-2015-006.pdf version 1, 28 Aug 2015, 09:22): m_t = 1.73300000e+02, m_b = 4.18000000e+00, m_c = 0.98600000e+00, G_F = 1.16637876e-05.

Version 1.6.3_13TeV

This version uses the same set-up as in 8 TeV 1.6.3 :

/afs/cern.ch/user/x/xiaohu/public/2HDM-THEO-NTUP/thdm_grid_v163_13TeV.root

Warning: if you want to use b-associated production, please use ONLY the 5FS cross sections. 4FS aren't available yet.

Ntuple versions: 8 TeV

Version 1.6.4

This is the same version as 1.6.3 bug fix but with the H+ bug fixed:

/afs/cern.ch/user/x/xiaohu/public/2HDM-THEO-NTUP/thdm_grid_v164.root

Version 1.6.3 bug fix

This is the same version as 1.6.3 but type 3 and 4 issue fixed:

/afs/cern.ch/user/x/xiaohu/public/2HDM-THEO-NTUP/thdm_grid_v163_1.root

2HDMC version 1.6.4, SusHi version 1.3.0 In this version type 3 is lepton-specific and type 4 is flipped. This means that the code doesn't use the 2HDMC convention which is the other way round.

BUG found: a bug found that affects the H+->Wh BR that is stored in the ntuple. A new version will be produced with this issue fixed. The rest of the H+ BR (tb and taunu mainly) have been checked and they are ok.

Version 1.6.3

Updated versions of = SusHi-1.3.0 = and = 2HDMC-1.6.4 , extends to higher =mA, denser grid in $ cos (\beta - \alpha) $ :

Grid definition Hide details ... 
mH_array = [
200, 220, 240, 260, 280,
300, 320, 340, 350, 360, 380,
400, 420, 440, 450, 460, 480,
500, 520, 540, 550, 560, 580,
600, 650, 700, 750, 800,
850, 900, 950, 1000,
1100, 1200, 1300, 1400, 1500
]

tb_array = [0.1, 0.12, 0.14, 0.16, 0.18, 0.2, 0.22, 0.24, 0.26, 0.28, 0.30, 0.32, 0.34, 0.36, 0.38, 0.4, 0.42, 0.44, 0.46, 0.48, 0.5, 0.52, 0.54, 0.56, 0.58, 0.6, 0.62, 0.64, 0.66, 0.68, 0.7, 0.72, 0.74, 0.76, 0.78, 0.8, 0.82, 0.84, 0.86, 0.88, 0.9, 0.92, 0.94, 0.96, 0.98, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0, 5.2, 5.4, 5.6, 5.8, 6.0, 6.2, 6.4, 6.6, 6.8, 7.0, 7.2, 7.4, 7.6, 7.8, 8.0, 9.0, 10.0, 15.0, 20.0, 25, 30, 35, 40, 45, 50]

sba_array = [-1.0, -0.999799979995999, -0.9991996797437437, -0.99875, -0.9981983770774224, -0.996794863550169, -0.99499, -0.99498743710662, -0.9927738916792685, -0.9901515035589251, -0.98869, -0.9871170143402452, -0.983666610188635, -0.9798, -0.9797958971132713, -0.9754998718605759, -0.9707728879609278, -0.96825, -0.9656086163658649, -0.96, -0.95394, -0.9539392014169457, -0.9474175425861608, -0.9404254356406998, -0.93675, -0.9329523031752481, -0.9249864863877743, -0.91652, -0.9, -0.89303, -0.86603, -0.8, -0.7, -0.6, -0.5, -0.4, -0.3, -0.2, -0.1, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.86603, 0.89303, 0.9, 0.91652, 0.9249864863877743, 0.9329523031752481, 0.93675, 0.9404254356406998, 0.9474175425861608, 0.9539392014169457, 0.95394, 0.96, 0.9656086163658649, 0.96825, 0.9707728879609278, 0.9754998718605759, 0.9797958971132713, 0.9798, 0.983666610188635, 0.9871170143402452, 0.98869, 0.9901515035589251, 0.9927738916792685, 0.99498743710662, 0.99499, 0.996794863550169, 0.9981983770774224, 0.99875, 0.9991996797437437, 0.999799979995999, 1.0]

/afs/cern.ch/user/x/xiaohu/public/2HDM-THEO-NTUP/thdm_grid_v163.root

Version 1.6.2

This is the same as version 1.6.1 and, but with a denser grid of $ cos (\beta - \alpha) $ :

http://www.physics.smu.edu/sekula/2hdm/thdm_grid_v162.root

Version 1.6.1

This is the same as version 1.6, but with a denser grid of $ \tan \beta $ :

http://www.physics.smu.edu/sekula/2hdm/thdm_grid_v161.root

Version 1.6

The following ntuple contains cross sections and BRs: ntuple version 1.6. Using 2HDMC: 1.6.2, LHAPDF: 5.9 (required by SusHi 1.1.1), SusHi: 1.1.1 .

http://www.physics.smu.edu/sekula/2hdm/thdm_grid_v160.root back up link: /afs/cern.ch/work/r/rompotis/public/HSG6Ntuple/thdm_grid_v160.root

In this version only points with $ m ^{2}_{12} = m ^{2}_{A} \tan \beta / (1 + \tan ^{2} \beta) $ are added for the user's convenience. For this version of the ntuple the convention of 2HDMC where $ -1 < \sin(\beta - \alpha) < 1 $ is still in use, so the users have to switch to the $ -1 < \cos(\beta - \alpha) < 1 $ convention by themselves using the ntuple values: cos(b-a) = cba * sign( sba ), where cba and sba refer to branches in the ntuple.

A major update with respect to the previous version is the implementation of 4FS and 5FS cross sections for b-associated production. In all the previous versions of the ntuple xsec_H_bb, xsec_A_bb, xsec_h_bb denote the 5FS calculated cross sections with SusHi. In this version and all the following versions the same variable names denote the Santander matched 4FS+5FS cross section. The user can recover the 4FS and the 5FS cross sections using the following variables: xsec_H_bb_5FS, xsec_H_bb_4FS etc.

Please handle with care the 4FS and the Santander matched cross sections since it is the very first time they have been implemented. Report any behaviour beyond expectations to us as soon as it is observed.

Version 1.4

The following ntuple contains cross sections and BRs: ntuple version 1.4. Using Sushi-1.1.1 and 2HDMC-1.51

With fine binning as in yellow report 3:
/afs/cern.ch/user/d/dcharfed/public/thdm_ntuples/thdm_grid_v140.root

With coarse binning mH={130,140,150,160,170,180,190,200,220,240,250,260,280,300,320,340,350,360,380,400,450,500,600}:
/afs/cern.ch/user/d/dcharfed/public/thdm_ntuples/thdm_grid_v140_oldBin.root

Other Information

This is valid for 1.4 version of the ntuple, but contains detail that are relevant to subsequent versions too.

Cross sections for b-associated and g-fusion production are calculated with Sushi-1.1.1. There is an estimate of the VBF and VH cross sections by taking the cross sections calculated by the LHC Higgs cross section group here and multiplied simply by $ cos^{2} ( \beta - \alpha ) $ for H and $ sin^{2} ( \beta - \alpha ) $ for h. The mass range for VH is restricted up to 300 GeV. Branching fractions are calculated with 2HDMC-1.51 and should be adequate for WW and ZZ and gamgam BR. It is probably not adequate for A->ttbar and other BRs.

The ntuple contains a variable named status and which should be 0 or 8 for the model to be sound. This flag is a binary number with bits signifying the following: first bit is potential stability, second bit is unitarity, third bit perturbativity and fourth bit LEP constraints as implemented in the version of 2HDM that I have used for the ntuple generation. Bit 0 is all OK, bit 1 signifies a problem. Important notice: Normal users are recommended to check only the first and the second bit of the status number, ie. potential stability and unitarity. The rest of the bits are for completeness and LHC HXS group related studies.

The ntuple has fully implemented the $ \sin(\beta - \alpha) \rightarrow 1 $ SM-like limit, which is interesting for h125 properties. The $ m_{12} = 0 $ model is also implemented. This model suffers from limited parameter space being available due to theoretical constraints. In the future the $ m_{12} $ will be better fine-tuned and valid points will be available for the whole range.

The template for the Sushi calculations of the cross sections is given here. The cross section for SM Higgs production was also calculated with the same parameters as in the 2HDM cross sections calculations and mh = 125 GeV, see here The Sushi output for this calculation is 

8 TeV: 

Block SUSHIggh # Bon appetit
         1     1.99561834E+01   # ggh XS in pb                  
Block SUSHIbbh # Bon appetit
         1     2.15883114E-01   # bbh XS in pb       

7 TeV:

Block SUSHIggh # Bon appetit
         1     1.56607139E+01   # ggh XS in pb                  
Block SUSHIbbh # Bon appetit
         1     1.65628943E-01   # bbh XS in pb

-- MarioPelliccioni - 28 Oct 2014

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