Description of the UFO models to generate Dirac magnetic monopoles

Dirac magnetic monopoles can be generated by Drell-Yan process or photon fusion process. The UFO models shown here describe both the processes and generate the corresponding LHE files. These models were tested for three spin cases (0, 1/2 and 1) and two processes (photon fusion and Drell-Yan). In the models attached in this page, there are two different couplings used:

1. velocity independent coupling models: mono_spinzero, mono_spinhalf and mono_spinone.
2. velocity dependent coupling models: mono_spinzero_beta, mono_spinhalf_beta, mono_spinone_beta.

[ For spin half beta dependent case, the SM case follows kappamon=0. One needs to set the value of this parameter to be 0 in the param_card ]

Details of these models can be found in ​arXiv:1808.08942.

A. Instructions to run Drell-Yan spin zero model:

1. Part 1 of the script to run spin zero monopole model (put the following snippet in a text file named 'Spin0ScriptDY.txt'):

import model mono_spinzero_beta
generate p p > a > mm+ mm-
output Pre5For

2. Part 2 of the script to run spin zero monopole model (put the following snippet in a textfile named 'Spin0ScriptDY2.txt'):

launch Pre5For
analysis=MADANALYSIS_4
set run_card ebeam1 6500
set ebeam2 6500
set lpp1 1
set lpp2 1
set pdlabel nn23lo1 ### one can choose different pdf set here
set lhaid 230000    ### one can choose different pdf set here
set nevents 1000    ### change the number of events here
set dynamical_scale_choice -1
set fixed_couplings False
set param_card mass 25 125
set mass 4110000 6000 ### change the mass here
set decay 4110000 0.000000e+0
set gch 1 1.0

3. Run the part 1 of the script: ./bin/mg5_aMC Spin0ScriptDY.txt

4. A new folder named Pre5For will be generated.

5. Go to Pre5For/Sources and open genps.inc.

6. Use the absolute path of 'maxparticles.inc' on line 5.

7. Run the part 2 of the script: ./bin/mg5_aMC Spin0ScriptDY2.txt

8. If you don't change the part 1 of the script at all (you only need to change it to import different monopole models), then you just need to use steps c-f only once. After that, in step g, change the mass parameter in script 2 and run for different mass points.

1. 'For different spin models, one just needs to import those corresponding models in part 1 of the script.'

B. Instructions to run photon fusion spin zero model:

1. Part 1 of the script to run spin zero monopole model (put the following snippet in a textfile named 'Spin0Script.txt'):

   import model mono_spinzero_beta
   generate a a > mm+ mm-
   output Pre5
   
   

2. Part 2 of the script to run spin zero monopole model (put the following snippet in a textfile named 'Spin0Script2.txt'):

launch Pre5
analysis=madanalysis5
set run_card ebeam1 6500
set ebeam2 6500
set lpp1 2
set lpp2 2
set pdlabel lhapdf ### one can choose different pdf set here
set lhaid 82000    ### one can choose different pdf set here
set nevents 1000   ### change the number of events here
set dynamical_scale_choice -1
set fixed_couplings False
set param_card mass 25 125
set mass 4110000 6000  ### change the mass here
set decay 4110000 0.000000e+0
set gch 1 1.0

3. Run the part 1 of the script: ./bin/mg5_aMC Spin0Script.txt

4. A new folder named Pre5 will be generated.

5. Go to Pre5/Sources and open genps.inc.

6. Use the absolute path of 'maxparticles.inc' on line 5.

7. Run the part 2 of the script: ./bin/mg5_aMC Spin0Script2.txt

8. If you don't change the part 1 of the script at all (you only need to change it to import different monopole models), then you just need to use steps c-f only once. After that, in step g, change the mass parameter in script 2 and run for different mass points.

1. 'For different spin models, one just needs to import those corresponding models in part 1 of the script.'