Production of the SM Higgs Boson in the Gluon-Gluon Fusion and VBF processes

Hi,

For the moment, you can use the HEFT model. which has the low energy limit of the loop.
In the next version, you should be able to integrate the loop-induced process with full mass effect (and interference with the bottom)

Cheers,

Olivier

On 23 Mar 2015, at 20:11, amine shady <email address hidden> wrote:

> New question #264071 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/264071
>
> Hi there,
>
> I'm studying the phenomenology of the Higgs Boson. I was using calcHEP but now I am using MadGraph5_aMC@NLO Generator in my research.
> The problem is that I can not generate event in Gluon-Gluon fusion channel. generate p p > h > mu+ mu- gives me and error message.
> Also for the VBF process, if I try generate p p > w+ w- h I won't get the w+ w- fusion feynman diagram.
>
> I wish somebody can give me a hint on how to produce such events. I'd be grateful.
>
> Cheers,
> Amine
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi,

Thanks for the reply. I actually tried importing heft and heft_v4 and generate the processes but it gave me the same error messages.
For example:

For Gluon-Gluon Fusion:
MG5_aMC>generate p p > h > mu+ mu-
INFO: Checking for minimal orders which gives processes.
INFO: Please specify coupling orders to bypass this step.
INFO: Trying process: g g > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
INFO: Trying process: u u~ > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
INFO: Trying process: u c~ > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
INFO: Trying process: c u~ > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
INFO: Trying process: c c~ > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
INFO: Trying process: d d~ > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
INFO: Trying process: d s~ > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
INFO: Trying process: s d~ > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
INFO: Trying process: s s~ > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
INFO: Trying process: u~ u > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
INFO: Trying process: c~ c > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
INFO: Trying process: d~ d > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
INFO: Trying process: s~ s > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
Command "generate p p > h > mu+ mu-" interrupted with error:
InvalidCmd : No amplitudes generated from process Process: g/u/c/d/s/u~/c~/d~/s~ g/u/c/d/s/u~/c~/d~/s~ > h> mu+ mu- HIG=1 HIW=1 WEIGHTED=4. Please enter a valid process

For the VFB:
I did: generate p p > h w+ w- , it gave me all the Feynman diagrams which include the W Bosons but not the Weak Boson Fusion process.

Hi,

To have the higgs decay to muon
you actually need to use the heft-full specification of the model.
since otherwise the muon is massless and therefore do not couple to Higgs.

> For the VFB:
> I did: generate p p > h w+ w- , it gave me all the Feynman diagrams which include the W Bosons but not the Weak Boson Fusion process.

This is “normal” since your command is understood as
> generate p p > h w+ w- QED<=MINIMAL_POSSIBLE_VALUE

See here:
https://answers.launchpad.net/mg5amcnlo/+faq/1942

Cheers,

Olivier

On 23 Mar 2015, at 22:16, amine shady <email address hidden> wrote:

> Question #264071 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/264071
>
> Status: Answered => Open
>
> amine shady is still having a problem:
> Hi,
>
> Thanks for the reply. I actually tried importing heft and heft_v4 and generate the processes but it gave me the same error messages.
> For example:
>
> For Gluon-Gluon Fusion:
> MG5_aMC>generate p p > h > mu+ mu-
> INFO: Checking for minimal orders which gives processes.
> INFO: Please specify coupling orders to bypass this step.
> INFO: Trying process: g g > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
> INFO: Trying process: u u~ > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
> INFO: Trying process: u c~ > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
> INFO: Trying process: c u~ > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
> INFO: Trying process: c c~ > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
> INFO: Trying process: d d~ > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
> INFO: Trying process: d s~ > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
> INFO: Trying process: s d~ > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
> INFO: Trying process: s s~ > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
> INFO: Trying process: u~ u > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
> INFO: Trying process: c~ c > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
> INFO: Trying process: d~ d > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
> INFO: Trying process: s~ s > h > mu+ mu- WEIGHTED=4 HIW=1 HIG=1
> Command "generate p p > h > mu+ mu-" interrupted with error:
> InvalidCmd : No amplitudes generated from process Process: g/u/c/d/s/u~/c~/d~/s~ g/u/c/d/s/u~/c~/d~/s~ > h> mu+ mu- HIG=1 HIW=1 WEIGHTED=4. Please enter a valid process
>
>
> For the VFB:
> I did: generate p p > h w+ w- , it gave me all the Feynman diagrams which include the W Bosons but not the Weak Boson Fusion process.
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi,

I'm sorry but I am still struggling with the syntax. I used import model (path-to-)heft-full
I don't understand why the muons are massless. And how can I redefine them to have mass?

My biggest problem is how to obtain a process where the Gluon Fusion is done with Top Quark Loop.

For VBF, I used generate p p > h w+ w- QED=2(and also QED=3) but still don't get the Weak Boson Fusion process!!

Thanks for your help, I really need to get rid of this step in my research project ASAP.

Cheers,
Amine

Hi again,

It seems that there is a big difference between Mad_Graph4 and MadGraph5_aMC@NLO Generator.
In this tutorial page http://www.niu.edu/spmartin/madgraph/madhiggs.html , I tried their example:
generate p p > h, h > a a but it didn't work for me. I did generate p p > h a a and it worked.
So maybe my problem is just a question of syntax.

Thanks,
Amine

Hi,

> I'm sorry but I am still struggling with the syntax. I used import model (path-to-)heft-full
> I don't understand why the muons are massless. And how can I redefine them to have mass?

I thought that heft-full has it but it is not the case.
You should check then the model available here:
https://cp3.irmp.ucl.ac.be/projects/madgraph/attachment/wiki/Models/HiggsEffective/Higgs_Effective_Couplings_UFO.tgz

> For VBF, I used generate p p > h w+ w- QED=2(and also QED=3) but still
> don’t get the Weak Boson Fusion process!!

Which processes do you want exactly?
Here I’m surprised by the lack of jet in the final state. How can you have a WBF process without any jet in the final state?

Do you want the following?

generate p p > h w+ w- j j QCD=0

Cheers,

Olivier

On 24 Mar 2015, at 01:01, amine shady <email address hidden> wrote:

> Question #264071 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/264071
>
> Status: Answered => Open
>
> amine shady is still having a problem:
> Hi,
>
> I'm sorry but I am still struggling with the syntax. I used import model (path-to-)heft-full
> I don't understand why the muons are massless. And how can I redefine them to have mass?
>
> My biggest problem is how to obtain a process where the Gluon Fusion is
> done with Top Quark Loop.
>
> For VBF, I used generate p p > h w+ w- QED=2(and also QED=3) but still
> don't get the Weak Boson Fusion process!!
>
> Thanks for your help, I really need to get rid of this step in my
> research project ASAP.
>
> Cheers,
> Amine
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi Amine,

> generate p p > h, h > a a but it didn't work for me. I did generate p p > h a a and it worked.

Note that this is two completely different process (with nothing in common).
The first syntax is valid if your model has a Higgs to 2 photon interaction. (which is not the case in the sm model, but well in the heft model).

Please read https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/Models/HiggsEffective
for limitation of the accuracy of the model

> In this tutorial page http://www.niu.edu/spmartin/madgraph/madhiggs.html

This is not an official madgraph tutorial (not done by any member of our code).
If you want an official tutorial, please look at:
https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/Lund2014

Cheers,

Olivier

On 24 Mar 2015, at 01:07, amine shady <email address hidden> wrote:

> Question #264071 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/264071
>
> amine shady gave more information on the question:
> Hi again,
>
> It seems that there is a big difference between Mad_Graph4 and MadGraph5_aMC@NLO Generator.
> In this tutorial page http://www.niu.edu/spmartin/madgraph/madhiggs.html , I tried their example:
> generate p p > h, h > a a but it didn't work for me. I did generate p p > h a a and it worked.
> So maybe my problem is just a question of syntax.
>
> Thanks,
> Amine
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi Olivier,

Thanks for your reply, this time I learned a lot, and I started to understand better how Mad_Graph works.

I went through a lot of tutorials and of course the ones you gave me but I will have a problem.
I can not produce an event with Gluon-Gluon-Top Quark fusion to Higgs.
I can not produce an event with Weak Boson Fusion to Higgs neither. I tried so many times and the last thing I did is
generate p p > h w+ w- j j / z a u d s c s~ c~ QCD=0
I got many Feynman diagrams but the Higgs is always produced via w+ w+ or w- w- or w+ or w-.

To be clear, I want to produce these two processes:
http://universe-review.ca/I15-70-Higgsproduction.jpg

I'd be thankful if you give me a hint on how to produce such processes.
Cheers,
Amine

Hi Amine,

What Final state do you want?

In order to produce the diagram that you send in your previous thread this are the correct syntax:

the one on left:
import model sm
generate p p > h j j QCD=0
which contains your diagram.

For the one of the right:
import model heft
generate g g > h

Cheers,

Olivier

On 25 Mar 2015, at 04:11, amine shady <email address hidden> wrote:

> Question #264071 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/264071
>
> Status: Answered => Open
>
> amine shady is still having a problem:
> Hi Olivier,
>
> Thanks for your reply, this time I learned a lot, and I started to
> understand better how Mad_Graph works.
>
> I went through a lot of tutorials and of course the ones you gave me but I will have a problem.
> I can not produce an event with Gluon-Gluon-Top Quark fusion to Higgs.
> I can not produce an event with Weak Boson Fusion to Higgs neither. I tried so many times and the last thing I did is
> generate p p > h w+ w- j j / z a u d s c s~ c~ QCD=0
> I got many Feynman diagrams but the Higgs is always produced via w+ w+ or w- w- or w+ or w-.
>
> To be clear, I want to produce these two processes:
> http://universe-review.ca/I15-70-Higgsproduction.jpg
>
> I'd be thankful if you give me a hint on how to produce such processes.
> Cheers,
> Amine
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi Olivier,

import model sm
generate p p > h j j QCD=0
gives me just Z Z fusion to Higgs and not W+ W- to Higgs
I tried
generate p p > h j j /z QCD=0 but it gives me either W+ W+ to Higgs or W- W- to Higgs but not W+ W- to Higgs

import model heft
generate g g > h
gives me gluon gluon fusion in one point to the Higgs and not gluon gluon fusion via Top quark to Higgs

Something in missing, and apparently it's obvious, but I didn't figure it out.

Cheers,
Amine

Hi Olivier,

Last question. in "Process results.html" when there are a lot of Feynman diagrams I have something like

P0_qq_hwpwmqq

      s= 461.29 ± 2.79 (pb)

Graph Cross-Section ↓ Error Events (K) Unwgt Luminosity
G4 84.96 1.51 254001.0 1374.0 16.2
G9 63.49 0.5 254001.0 2291.0 36.1
G29 62.17 1.41 126001.0 242.0 3.89
G8 60.62 0.934 126001.0 776.0 12.8
G25 60.52 0.788 126001.0 593.0 9.8
G21 50.73 0.579 510001.0 981.0 19.3
G23.06 35.32 0.888 62001.0 197.0 5.58
G17 11.37 0.193 126001.0 414.0 36.4
G19 9.453 0.518 126001.0 115.0 12.2
G35.02 5.24 0.111 126001.0 952.0 182
.
.
.
etc.

How can I determine which partial cross section is related to a specific Feynman diagram. Should I count from top to P0_qq_hwpwmqq

      s= 461.29 ± 2.79 (pb)

Graph Cross-Section ↓ Error Events (K) Unwgt Luminosity
G4 84.96 1.51 254001.0 1374.0 16.2
G9 63.49 0.5 254001.0 2291.0 36.1
G29 62.17 1.41 126001.0 242.0 3.89
G8 60.62 0.934 126001.0 776.0 12.8
G25 60.52 0.788 126001.0 593.0 9.8
G21 50.73 0.579 510001.0 981.0 19.3
G23.06 35.32 0.888 62001.0 197.0 5.58
G17 11.37 0.193 126001.0 414.0 36.4
G19 9.453 0.518 126001.0 115.0 12.2
G35.02 5.24 0.111 126001.0 952.0 182

etc.
How can I determine which partial cross section is related to a specific Feynman diagram? Should I count from top to P0_qq_hwpwmqq

      s= 461.29 ± 2.79 (pb)

Graph Cross-Section ↓ Error Events (K) Unwgt Luminosity
G4 84.96 1.51 254001.0 1374.0 16.2
G9 63.49 0.5 254001.0 2291.0 36.1
G29 62.17 1.41 126001.0 242.0 3.89
G8 60.62 0.934 126001.0 776.0 12.8
G25 60.52 0.788 126001.0 593.0 9.8
G21 50.73 0.579 510001.0 981.0 19.3
G23.06 35.32 0.888 62001.0 197.0 5.58
G17 11.37 0.193 126001.0 414.0 36.4
G19 9.453 0.518 126001.0 115.0 12.2
G35.02 5.24 0.111 126001.0 952.0 182
.
.
.
etc

How could I determine which partial cross section is related to a specific Feynman diagram? Should I count from top to bottom and from left to right in every line? Because there are symbols near each partial cross section like G4 G9 G29 etc and it's bleak for me. Sometimes I'd like to take just the cross sections of the feynman diagrams that interest me.

Cheers,
Amine

Sorry for pasting many times the same thing. My question at the bottom.

Hi,

You will find all the details in this thread:
https://answers.launchpad.net/mg5amcnlo/+question/187387

Let me insist that those number are NOT the physical contribution of a single Feynman Diagram to the process.
They are no guarantee that those number are even gauge/lorentz invariant.
Only the sum of the channel is for sure physical.

The use of those number is therefore STRONGLY discourage but by very expert user of MadGraph
and those number can certainly NOT be use for a publication/analysis, only to give some intuition of what is happening.

Cheers,

Olivier

On 25 Mar 2015, at 23:51, amine shady <email address hidden> wrote:

> Question #264071 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/264071
>
> Status: Answered => Open
>
> amine shady is still having a problem:
> Hi Olivier,
>
> Last question. in "Process results.html" when there are a lot of Feynman
> diagrams I have something like
>
> P0_qq_hwpwmqq
>
> s= 461.29 ± 2.79 (pb)
>
> Graph Cross-Section ↓ Error Events (K) Unwgt Luminosity
> G4 84.96 1.51 254001.0 1374.0 16.2
> G9 63.49 0.5 254001.0 2291.0 36.1
> G29 62.17 1.41 126001.0 242.0 3.89
> G8 60.62 0.934 126001.0 776.0 12.8
> G25 60.52 0.788 126001.0 593.0 9.8
> G21 50.73 0.579 510001.0 981.0 19.3
> G23.06 35.32 0.888 62001.0 197.0 5.58
> G17 11.37 0.193 126001.0 414.0 36.4
> G19 9.453 0.518 126001.0 115.0 12.2
> G35.02 5.24 0.111 126001.0 952.0 182
> .
> .
> .
> etc.
>
> How can I determine which partial cross section is related to a specific
> Feynman diagram. Should I count from top to P0_qq_hwpwmqq
>
> s= 461.29 ± 2.79 (pb)
>
> Graph Cross-Section ↓ Error Events (K) Unwgt Luminosity
> G4 84.96 1.51 254001.0 1374.0 16.2
> G9 63.49 0.5 254001.0 2291.0 36.1
> G29 62.17 1.41 126001.0 242.0 3.89
> G8 60.62 0.934 126001.0 776.0 12.8
> G25 60.52 0.788 126001.0 593.0 9.8
> G21 50.73 0.579 510001.0 981.0 19.3
> G23.06 35.32 0.888 62001.0 197.0 5.58
> G17 11.37 0.193 126001.0 414.0 36.4
> G19 9.453 0.518 126001.0 115.0 12.2
> G35.02 5.24 0.111 126001.0 952.0 182
>
> etc.
> How can I determine which partial cross section is related to a specific Feynman diagram? Should I count from top to P0_qq_hwpwmqq
>
> s= 461.29 ± 2.79 (pb)
>
> Graph Cross-Section ↓ Error Events (K) Unwgt Luminosity
> G4 84.96 1.51 254001.0 1374.0 16.2
> G9 63.49 0.5 254001.0 2291.0 36.1
> G29 62.17 1.41 126001.0 242.0 3.89
> G8 60.62 0.934 126001.0 776.0 12.8
> G25 60.52 0.788 126001.0 593.0 9.8
> G21 50.73 0.579 510001.0 981.0 19.3
> G23.06 35.32 0.888 62001.0 197.0 5.58
> G17 11.37 0.193 126001.0 414.0 36.4
> G19 9.453 0.518 126001.0 115.0 12.2
> G35.02 5.24 0.111 126001.0 952.0 182
> .
> .
> .
> etc
>
>
> How could I determine which partial cross section is related to a specific Feynman diagram? Should I count from top to bottom and from left to right in every line? Because there are symbols near each partial cross section like G4 G9 G29 etc and it's bleak for me. Sometimes I'd like to take just the cross sections of the feynman diagrams that interest me.
>
> Cheers,
> Amine
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi Olivier,

Problems solved. Thank you for your time. I really appreciate it.

Cheers,
Amine

Thanks Olivier Mattelaer, that solved my question.