fixed target deep inelastic scattering

Asked by ouseph cj on 2020-11-03

Dear MadGraph experts,

 I am trying to calculate the cross sections for p v > p v (mediated by Zp, v= vl vl~).
 is it possible consider the collision of neutron and proton with neutrino simultaneously.
 if it is what will be the script.

Best
Melbin

Question information

Language:
English Edit question
Status:
Answered
For:
MadGraph5_aMC@NLO Edit question
Assignee:
No assignee Edit question
Last query:
2020-11-04
Last reply:
2020-11-08

This question was reopened

You have two ways:

1) Use lhapdf dedicated ion beam PDF
in that case in the run_card you have to set
set pdlabel = lhapdf
set lhaid = XXXXX # niumber of the pdf set that you want to use

2) use a rescaled proton pdf
by filling this section of the run_card (which is not present by default, you can force the display via the command: "update ion_pdf")

#*********************************************************************
# Heavy ion PDF / rescaling of PDF *
#*********************************************************************
  1 = nb_proton1 # number of proton for the first beam
  0 = nb_neutron1 # number of neutron for the first beam
  -1.0 = mass_ion1 # mass of the heavy ion (first beam)
# Note that seting differently the two beams only work if you use
# group_subprocess=False when generating your matrix-element
  1 = nb_proton2 # number of proton for the second beam
  0 = nb_neutron2 # number of neutron for the second beam
  -1.0 = mass_ion2 # mass of the heavy ion (second beam)

Cheers,

Olivier

> On 3 Nov 2020, at 14:15, ouseph cj <email address hidden> wrote:
>
> New question #693802 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/693802
>
> Dear MadGraph experts,
>
> I am trying to calculate the cross sections for p v > p v (mediated by Zp, v= vl vl~).
> is it possible consider the collision of neutron and proton with neutrino simultaneously.
> if it is what will be the script.
>
>
> Best
> Melbin
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

ouseph cj (ouseph444) said : #2

Dear Oliver
*Where to set the following parameters.*

#*********************************************************************
# Heavy ion PDF / rescaling of PDF *
#*********************************************************************
  1 = nb_proton1 # number of proton for the first beam
  0 = nb_neutron1 # number of neutron for the first beam
  -1.0 = mass_ion1 # mass of the heavy ion (first beam)
# Note that seting differently the two beams only work if you use
# group_subprocess=False when generating your matrix-element
  1 = nb_proton2 # number of proton for the second beam
  0 = nb_neutron2 # number of neutron for the second beam
  -1.0 = mass_ion2 # mass of the heavy ion (second beam)

*In my run card, I only have the following parameters,*

#*********************************************************************
# MadGraph5_aMC@NLO *
# *
# run_card.dat MadEvent *
# *
# This file is used to set the parameters of the run. *
# *
# Some notation/conventions: *
# *
# Lines starting with a '# ' are info or comments *
# *
# mind the format: value = variable ! comment *
# *
# To display more options, you can type the command: *
# update full_run_card *
#*********************************************************************
#
#*********************************************************************
# Tag name for the run (one word) *
#*********************************************************************
  tag_1 = run_tag ! name of the run
#*********************************************************************
# Number of events and rnd seed *
# Warning: Do not generate more than 1M events in a single run *
#*********************************************************************
  10000 = nevents ! Number of unweighted events requested
  0 = iseed ! rnd seed (0=assigned automatically=default))
#*********************************************************************
# Collider type and energy *
# lpp: 0=No PDF, 1=proton, -1=antiproton, 2=photon from proton, *
# 3=photon from electron *
#*********************************************************************
     1 = lpp1 ! beam 1 type
     0 = lpp2 ! beam 2 type
     6500.0 = ebeam1 ! beam 1 total energy in GeV
     1000.0 = ebeam2 ! beam 2 total energy in GeV
#*********************************************************************
# Beam polarization from -100 (left-handed) to 100 (right-handed) *
#*********************************************************************
     0.0 = polbeam1 ! beam polarization for beam 1
     100.0 = polbeam2 ! beam polarization for beam 2

#*********************************************************************
# PDF CHOICE: this automatically fixes also alpha_s and its evol. *
#*********************************************************************
     nn23lo1 = pdlabel ! PDF set
     230000 = lhaid ! if pdlabel=lhapdf, this is the lhapdf number
# To see heavy ion options: type "update ion_pdf"
#*********************************************************************
# Renormalization and factorization scales *
#*********************************************************************
 False = fixed_ren_scale ! if .true. use fixed ren scale
 False = fixed_fac_scale ! if .true. use fixed fac scale
 91.188 = scale ! fixed ren scale
 91.188 = dsqrt_q2fact1 ! fixed fact scale for pdf1
 91.188 = dsqrt_q2fact2 ! fixed fact scale for pdf2
 -1 = dynamical_scale_choice ! Choose one of the preselected dynamical
choices
 1.0 = scalefact ! scale factor for event-by-event scales
#*********************************************************************
# Type and output format
#*********************************************************************
  False = gridpack !True = setting up the grid pack
  -1.0 = time_of_flight ! threshold (in mm) below which the invariant
livetime is not written (-1 means not written)
  average = event_norm ! average/sum. Normalization of the weight in
the LHEF
# To see MLM/CKKW merging options: type "update MLM" or "update CKKW"

#*********************************************************************
#
#*********************************************************************
# handling of the helicities:
# 0: sum over all helicities
# 1: importance sampling over helicities
#*********************************************************************
   0 = nhel ! using helicities importance sampling or not.
#*********************************************************************
# Generation bias, check the wiki page below for more information: *
# 'cp3.irmp.ucl.ac.be/projects/madgraph/wiki/LOEventGenerationBias' *
#*********************************************************************
 None = bias_module ! Bias type of bias, [None, ptj_bias, -custom_folder-]
 {} = bias_parameters ! Specifies the parameters of the module.
#
#*******************************

# Parton level cuts definition *
#*******************************
#
#
#*********************************************************************
# BW cutoff (M+/-bwcutoff*Gamma) ! Define on/off-shell for "$" and decay
#*********************************************************************
  15.0 = bwcutoff ! (M+/-bwcutoff*Gamma)
#*********************************************************************
# Standard Cuts *
#*********************************************************************
# Minimum and maximum pt's (for max, -1 means no cut) *
#*********************************************************************
 20.0 = ptj ! minimum pt for the jets
 0.0 = misset ! minimum missing Et (sum of neutrino's momenta)
 -1.0 = ptjmax ! maximum pt for the jets
 -1.0 = missetmax ! maximum missing Et (sum of neutrino's momenta)
 {} = pt_min_pdg ! pt cut for other particles (use pdg code). Applied on
particle and anti-particle
 {} = pt_max_pdg ! pt cut for other particles (syntax e.g. {6: 100, 25:
50})
#
# For display option for energy cut in the partonic center of mass frame
type 'update ecut'
#
#*********************************************************************
# Maximum and minimum absolute rapidity (for max, -1 means no cut) *
#*********************************************************************
 5.0 = etaj ! max rap for the jets
 {} = eta_min_pdg ! rap cut for other particles (use pdg code). Applied on
particle and anti-particle
 {} = eta_max_pdg ! rap cut for other particles (syntax e.g. {6: 2.5, 23:
5})
#*********************************************************************
# Minimum and maximum DeltaR distance *
#*********************************************************************
#*********************************************************************
# Minimum and maximum invariant mass for pairs *
#*********************************************************************
 {} = mxx_min_pdg ! min invariant mass of a pair of particles X/X~ (e.g.
{6:250})
 {'default': False} = mxx_only_part_antipart ! if True the invariant mass
is applied only
                       ! to pairs of particle/antiparticle and not to pairs
of the same pdg codes.
#*********************************************************************
# Inclusive cuts *
#*********************************************************************
#*********************************************************************
# maximal pdg code for quark to be considered as a light jet *
# (otherwise b cuts are applied) *
#*********************************************************************
 4 = maxjetflavor ! Maximum jet pdg code
#*********************************************************************
#
#*********************************************************************
# Store info for systematics studies *
# WARNING: Do not use for interference type of computation *
#*********************************************************************
   True = use_syst ! Enable systematics studies
#
systematics = systematics_program ! none, systematics [python], SysCalc
[depreceted, C++]
['--mur=0.5,1,2', '--muf=0.5,1,2', '--pdf=errorset'] =
systematics_arguments ! see:
https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/Systematics#Systematicspythonmodule
# Syscalc is deprecated but to see the associate options type'update
syscalc'

Best
Ouseph

On Tue, Nov 3, 2020 at 9:30 PM Olivier Mattelaer <
<email address hidden>> wrote:

> Your question #693802 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/693802
>
> Status: Open => Answered
>
> Olivier Mattelaer proposed the following answer:
> You have two ways:
>
> 1) Use lhapdf dedicated ion beam PDF
> in that case in the run_card you have to set
> set pdlabel = lhapdf
> set lhaid = XXXXX # niumber of the pdf set that you want to use
>
> 2) use a rescaled proton pdf
> by filling this section of the run_card (which is not present by default,
> you can force the display via the command: "update ion_pdf")
>
> #*********************************************************************
> # Heavy ion PDF / rescaling of PDF *
> #*********************************************************************
> 1 = nb_proton1 # number of proton for the first beam
> 0 = nb_neutron1 # number of neutron for the first beam
> -1.0 = mass_ion1 # mass of the heavy ion (first beam)
> # Note that seting differently the two beams only work if you use
> # group_subprocess=False when generating your matrix-element
> 1 = nb_proton2 # number of proton for the second beam
> 0 = nb_neutron2 # number of neutron for the second beam
> -1.0 = mass_ion2 # mass of the heavy ion (second beam)
>
> Cheers,
>
> Olivier
>
> > On 3 Nov 2020, at 14:15, ouseph cj <email address hidden>
> wrote:
> >
> > New question #693802 on MadGraph5_aMC@NLO:
> > https://answers.launchpad.net/mg5amcnlo/+question/693802
> >
> > Dear MadGraph experts,
> >
> > I am trying to calculate the cross sections for p v > p v (mediated by
> Zp, v= vl vl~).
> > is it possible consider the collision of neutron and proton with
> neutrino simultaneously.
> > if it is what will be the script.
> >
> >
> > Best
> > Melbin
> >
> > --
> > You received this question notification because you are an answer
> > contact for MadGraph5_aMC@NLO.
>
> --
> If this answers your question, please go to the following page to let us
> know that it is solved:
>
> https://answers.launchpad.net/mg5amcnlo/+question/693802/+confirm?answer_id=0
>
> If you still need help, you can reply to this email or go to the
> following page to enter your feedback:
> https://answers.launchpad.net/mg5amcnlo/+question/693802
>
> You received this question notification because you asked the question.
>

You have that line in your run_card:

# To see heavy ion options: type "update ion_pdf"

That shows that you indeed support those options.
if you type the line "update ion_pdf" when you have the following questions:

Do you want to edit a card (press enter to bypass editing)?
/------------------------------------------------------------\
| 1. param : param_card.dat |
| 2. run : run_card.dat |
| 3. madanalysis5_parton : madanalysis5_parton_card.dat |
\------------------------------------------------------------/
 you can also
   - enter the path to a valid card or banner.
   - use the 'set' command to modify a parameter directly.
     The set option works only for param_card and run_card.
     Type 'help set' for more information on this command.
   - call an external program (ASperGE/MadWidth/...).
     Type 'help' for the list of available command
 [0, done, 1, param, 2, run, 3, madanalysis5_parton, enter path]

Then the line, that I described above will be added to your run_card (you can also add them by hand if prefer a pure manual edition of the card.

Cheers,

Olivier

> On 3 Nov 2020, at 14:50, ouseph cj <email address hidden> wrote:
>
> # To see heavy ion options: type "update ion_pdf"

ouseph cj (ouseph444) said : #4

Dear Oliver,
I have the following questions,

1. If I used the second method *(use a rescaled proton pdf) *that you
proposed. Do I need to touch the PDF label, Can I proceed with the default
value?

2. If i follow the following script,

 1 = nb_proton1 # number of proton for the first beam
 1 = nb_neutron1 # number of neutron for the first beam

does it account the both collision (p+neutrino and n+neutrino)
does the madgraph will give the combined cross-section (M1(Proton
+neutrino)+M2(Neutron+neutrino)), For my case I need to calculate collision
of both proton and neutron with Neutrino.

Thanking you with Anticipation
Melbin

On Tue, Nov 3, 2020 at 9:30 PM Olivier Mattelaer <
<email address hidden>> wrote:

> Your question #693802 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/693802
>
> Status: Open => Answered
>
> Olivier Mattelaer proposed the following answer:
> You have two ways:
>
> 1) Use lhapdf dedicated ion beam PDF
> in that case in the run_card you have to set
> set pdlabel = lhapdf
> set lhaid = XXXXX # niumber of the pdf set that you want to use
>
> 2) use a rescaled proton pdf
> by filling this section of the run_card (which is not present by default,
> you can force the display via the command: "update ion_pdf")
>
> #*********************************************************************
> # Heavy ion PDF / rescaling of PDF *
> #*********************************************************************
> 1 = nb_proton1 # number of proton for the first beam
> 0 = nb_neutron1 # number of neutron for the first beam
> -1.0 = mass_ion1 # mass of the heavy ion (first beam)
> # Note that seting differently the two beams only work if you use
> # group_subprocess=False when generating your matrix-element
> 1 = nb_proton2 # number of proton for the second beam
> 0 = nb_neutron2 # number of neutron for the second beam
> -1.0 = mass_ion2 # mass of the heavy ion (second beam)
>
> Cheers,
>
> Olivier
>
> > On 3 Nov 2020, at 14:15, ouseph cj <email address hidden>
> wrote:
> >
> > New question #693802 on MadGraph5_aMC@NLO:
> > https://answers.launchpad.net/mg5amcnlo/+question/693802
> >
> > Dear MadGraph experts,
> >
> > I am trying to calculate the cross sections for p v > p v (mediated by
> Zp, v= vl vl~).
> > is it possible consider the collision of neutron and proton with
> neutrino simultaneously.
> > if it is what will be the script.
> >
> >
> > Best
> > Melbin
> >
> > --
> > You received this question notification because you are an answer
> > contact for MadGraph5_aMC@NLO.
>
> --
> If this answers your question, please go to the following page to let us
> know that it is solved:
>
> https://answers.launchpad.net/mg5amcnlo/+question/693802/+confirm?answer_id=0
>
> If you still need help, you can reply to this email or go to the
> following page to enter your feedback:
> https://answers.launchpad.net/mg5amcnlo/+question/693802
>
> You received this question notification because you asked the question.
>

hi,

As said in the other question:
1. You can use that default PDF set (NN23LO) or choose another one. NN23LO is a bit old but has the advantages that you do not need to install/link the lhapdf library.

2. Yes this will give you the sum. The best is always to check obviously:
So I ran the following script:
generate p e- > p ve
output
launch
set ebeam1 6500
launch
set nb_proton1 0
set nb_neutron1 1
launch
set nb_proton1 1
set ebeam1 2*6500

and the three cross-section are:
  === Results Summary for run: run_01 tag: tag_1 ===

     Cross-section : 744.7 +- 1.891 pb
     Nb of events : 10000

  === Results Summary for run: run_02 tag: tag_1 ===

     Cross-section : 697.8 +- 2.219 pb
     Nb of events : 10000

  === Results Summary for run: run_03 tag: tag_1 ===

     Cross-section : 1442 +- 3.703 pb
     Nb of events : 10000

Cheers,

Olivier

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