Introduction
We have some standard programs to make plots and dump cutflows from the ttH ntuples. These exploit TTree::Draw() to let the user draw quantities or count events with appropriate cross sections and corrections applied. The cuts and plots are specified in files using "yaml" syntax (see a very simple introduction here).
Installing the Software
The software comes as part of the ttH multileptonic code, which is unfortunately a rather large code base. Follow the check out procedures given in the CERN wiki page. The scripts are all in the HWWtthCode/other/stack area. Make sure you set up an athena release and RootCore every time you start a new session working with these scripts.
The Input Data
You can use the files in /data/tth/v4_processed/trigpdf . Any output of our ntupler will be compatible with this software (see 8 TeV tth Analysis for instructions to build and run that ntupler). The ntupler expects the MC files to be provided with names of the form "DSID.root", and the data files to be "period*.root". All files should be in the same directory.
The Configuration and Cross Section Files
The cross sections for all processes are specified in HWWtthCode/XsectionInput/Xsection8TeV_tth_bkg_v2.yaml and Xsection8TeV_tth_sig_v2.yaml. These are autogenerated from the corresponding .txt files in the same directory, which are much easier to read. By default the "priority 1" samples are the ones that are used, although in practice we override these choices with some regularity. When you run either the cutflow dumper or the plotter, they will first print out all the MC files they have loaded, so you can keep track of what is being done.
You are unlikely to ever need to edit config_8TeV.yaml, but for completeness, this is the file that maps the process names given in the cross section files to categories of processes (e.g. "single top" or "diboson"). Effectively it groups the DSIDs and configures how they will be displayed in the cutflows and plots (and what colors the histograms will be). The color choices are the result of a carefully negotiated agreement, don't touch them unless really necessary. This file also contains weights for various Alpgen Z samples which you can mostly ignore.
Making Cutflows
The cuts are specified in yaml files, in lists like:
- name: Three leptons, Mll cut: trilep_type>0&&passEventCleaning&&(lep_Pt_0>10e3&&lep_Pt_1>20e3&&lep_Pt_2>20e3)&&(top_hfor_type!=4)&&Mll01>12e3&&Mll02>12e3&&(abs(lep_ID_1)==13||lep_isVeryTightLH_1)&&(abs(lep_ID_2)==13||lep_isVeryTightLH_2) - name: Trigger cut: trilep_type>0&&passEventCleaning&&(lep_Pt_0>10e3&&lep_Pt_1>20e3&&lep_Pt_2>20e3)&&(top_hfor_type!=4)&&Mll01>12e3&&Mll02>12e3&&(abs(lep_ID_1)==13||lep_isVeryTightLH_1)&&(abs(lep_ID_2)==13||lep_isVeryTightLH_2)&&(lep_Match_EF_mu24i_tight_0||lep_Match_EF_mu36_tight_0||lep_Match_EF_e24vhi_medium1_0||lep_Match_EF_e60_medium1_0||lep_Match_EF_mu24i_tight_1||lep_Match_EF_mu36_tight_1||lep_Match_EF_e24vhi_medium1_1||lep_Match_EF_e60_medium1_1||lep_Match_EF_mu24i_tight_2||lep_Match_EF_mu36_tight_2||lep_Match_EF_e24vhi_medium1_2||lep_Match_EF_e60_medium1_2)
Each cut is specified as a new list item ( - ) which contains a name (description which will be seen in the cutflow tex table) and the cut definition.
The simplest execution of the code isDISPLAY="" python do_cutflow.py standard_3l_cutflow.yaml --filedir '/data/onyisi/tth_8TeV_processed/4/3lep_LCbtag_trigpdf/' --texout mycutflow.tex
This will dump the expected yields for the cuts specified in standard_3l_cutflow.yaml to the output file mycutflow.tex. Since these cuts do not need to have any particular relationship to each other, you can make cutflows, or scan alternative signal regions, or whatever you would like to do.
To get a list of options, runpython do_cutflow.py - --help
(the extra hyphen is needed to tell ROOT not to interpret the --help itself). These options let you change the MC that is being used, tweak the output of the cutflow script, or change the event weights that are being used (this is important for running systematic variations, but not for general running).