MCatNLO Step 1
We will produce MCatNLO events starting from scratch. In step 1 we will download the MCatNLO program, configure it to our needs and perform the integration step. Once that has been done, we will produce the executable that will be used later to generate events.
1) Prepare your working directory
(this dir will be referred to as /scratch/MyMCatNLO in future)
cd scratch mkdir MyMCatNLO
2)Download the package and the PDF libraries
Download the program itself
cd /scratch/MyMCatNLO mkdir MyMCatNLO_EXECUTABLE cd MyMCatNLO_EXECUTABLE
Go to the MCatNLO webpage and download the package (called Package231.tar.gz). Then untar it.
tar -xzvf Package231.tar.gz
Download the PDF libraries Go to the MCatNLO webpage and download the package (called grid-files)
mkdir PDF cd PDF
Go to the MCatNLO webpage and download the pdf librarie sthat come with MCalNLO. (On the web-page they are listed as: grid files). Then untar it.
tar -xvf data.tar
Note: These libraries are simply ascii files and since MCatNLO is a NLO MC it requires NLO PDFs. For technical reasons we decided for the Rome production to use cteq5m1.
3) Tailor the MCatNLO program to your wishes
The MCatNLO.inputs is the main steering script. It can work in two different operating modes. Either just produce the event files (i.e. only produce the top and additional gluon), or also put them through Herwig.
BASES = ON
This signals that the integration step will be performed. When generating events in step (2) we will set this variable to OFF since the integration needs to be done only once.
4)Perform the integration step
Note that the integration step can take a long time (>2 hours). The results will be 3 files: (2 files with .data extension and 1 files with .integral extension)
5)Save the important results for event generation
The results of the integration step is contained in three files that are located in the current working directory (2 files with .data extension and 1 files with .integral extension). The files contain information on the spikes in phase space that have to be taken in to account when generating events.
So, create a directory in your MyMCatNLO directory and save the files related to the integration step by copying them there:
mkdir ./../MyMCatNLO_BasicInfo_CTEQ5M1 cp TTbarBase_a_bs.data ./../MyMCatNLO_BasicInfo_CTEQ5M1/ cp TTbarBase_b_bs.data ./../MyMCatNLO_BasicInfo_CTEQ5M1/ cp TTbarBase.integrals ./../MyMCatNLO_BasicInfo_CTEQ5M1/ cp cteq5m1 ./../MyMCatNLO_BasicInfo_CTEQ5M1/