off shell production

Asked by Md.Raju on 2019-11-10

Sorry for incomplete question .
As you have said that for off_shell production we can impose the off-shell condition by $ syntax for loop induced production but here Iam facing some problem to understand the interference between box and triangluer diagrams.I want to mention the situation clearly Iam trying to generate the process g g > h h [QCD] now I should get two type of diagramme box and triangular and the triangular give diagramme like g g > H > hh [QCD] and it will negatively interfer with box .But it is not working in the mass range of H 100 to 4000 gev.
I have checked that madgraph actually doing first it produce Heavy higgs by g g > H and decay it H > h h and multiply the cross section with decay width . Is it right ?

I want to know what actually madgraph mean by off-shell production

Question information

Language:
English Edit question
Status:
Answered
For:
MadGraph5_aMC@NLO Edit question
Assignee:
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Last query:
2019-11-12
Last reply:
2019-11-12

Hi,

The notion of off-shell/on-shell is related to the parameter
"bwcutoff" of the run_card.
We consider "onshell" case where the invariant mass is at most bwcutoff times the width away from the pole mass. (otherwise this is consider off-shell).

> I have checked that madgraph actually doing first it produce Heavy higgs by g g > H and decay it H > h h and multiply the cross section with decay width . Is it right ?

No this is certainly wrong. Madgraph never use the branching ratio information.
(Only MadSpin does).
So even with the syntax
generate p p > H , H > h h
we will not use the branching ratio for the computation of that process.

Now I have try to check in the 2HDM if I can find such issue.
However when I'm doing:
import model 2HDM_NLO
generate g g > h1 h1 / h3 [noborn=QCD]
output
launch
set mh1 125
set mh2 600
set wh2 Auto
set wh1 Auto

I do not have any particle "h2" consider as onshell for that process.
Do you know a benchmark who would be dominated by the onshell h2?

Cheers,

Olivier

> On 10 Nov 2019, at 16:27, Md.Raju <email address hidden> wrote:
>
> New question #685728 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/685728
>
> Sorry for incomplete question .
> As you have said that for off_shell production we can impose the off-shell condition by $ syntax for loop induced production but here Iam facing some problem to understand the interference between box and triangluer diagrams.I want to mention the situation clearly Iam trying to generate the process g g > h h [QCD] now I should get two type of diagramme box and triangular and the triangular give diagramme like g g > H > hh [QCD] and it will negatively interfer with box .But it is not working in the mass range of H 100 to 4000 gev.
> I have checked that madgraph actually doing first it produce Heavy higgs by g g > H and decay it H > h h and multiply the cross section with decay width . Is it right ?
>
> I want to know what actually madgraph mean by off-shell production
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Md.Raju (rahi199065) said : #2

Dear madgraph expert
I am working with this bench value
generate g g > h h [noborn=QCD]
output
launch
###################################
## INFORMATION FOR CKMBLOCK
###################################
Block ckmblock
    1 2.250000e-01 # lamC
    2 8.110000e-01 # AC
    3 1.310000e-01 # rhoCb
    4 3.450000e-01 # etaCb

###################################
## INFORMATION FOR HIGGSINPUTS
###################################
Block higgsinputs
    1 20.00 # tanb
    2 5000.00 # LHhh

###################################
## INFORMATION FOR LOOP
###################################
Block loop
    1 9.118800e+01 # MU_R

###################################
## INFORMATION FOR MASS
###################################
Block mass
    1 1380.000 # MD
    2 1430.000 # MU
    3 1.010000e-01 # MS
    4 1.270000e+00 # MC
    5 4.700000e+00 # MB
    6 1.760000e+02 # MT
   11 5.110000e-04 # Me
   13 1.056600e-01 # MMU
   15 1.777000e+00 # MTA
   23 9.118760e+01 # MZ
   25 1.260000e+02 # MHl
   37 1900.00 # MCh
  300 1500.00 # MHh
  301 2800.00 # MPs
## Dependent parameters, given by model restrictions.
## Those values should be edited following the
## analytical expression. MG5 ignores those values
## but they are important for interfacing the output of MG5
## to external program such as Pythia.
  12 0.000000 # ve : 0.0
  14 0.000000 # vm : 0.0
  16 0.000000 # vt : 0.0
  21 0.000000 # g : 0.0
  22 0.000000 # a : 0.0
  24 79.824660 # w+ : cmath.sqrt(MZ__exp__2/2. + cmath.sqrt(MZ__exp__4/4. -
(aEW*cmath.pi*MZ__exp__2)/(Gf*sqrt__2)))
  9000002 91.187600 # ghZ : MZ
  9000003 79.824660 # ghWp : MW
  9000004 79.824660 # ghWm : MW

###################################
## INFORMATION FOR SMINPUTS
###################################
Block sminputs
    1 1.32000e+02 # aEWM1
    2 1.166390e-05 # Gf
    3 1.180000e-01 # aS

###################################
## INFORMATION FOR YUKAWA
###################################
Block yukawa
    1 1380.00 # ymdo
    2 1430.00 # ymup
    3 1.010000e-01 # yms
    4 1.270000e+00 # ymc
    5 4.700000e+00 # ymb
    6 1.760000e+02 # ymt
   11 5.110000e-04 # yme
   13 1.056600e-01 # ymm
   15 1.777000e+00 # ymtau

###################################
## INFORMATION FOR DECAY
###################################
DECAY 6 1.508336e+00 # WT
DECAY 23 2.495200e+00 # WZ
DECAY 24 2.085000e+00 # WW
DECAY 25 Auto # WHl
DECAY 37 1.000000e+00 # WCh
DECAY 300 Auto # WHh
DECAY 301 1.000000e+00 # WPs
DECAY 1 0.000000 # d : 0.0
DECAY 2 0.000000 # u : 0.0
DECAY 3 0.000000 # s : 0.0
DECAY 4 0.000000 # c : 0.0
DECAY 5 0.000000 # b : 0.0
DECAY 11 0.000000 # e- : 0.0
DECAY 12 0.000000 # ve : 0.0
DECAY 13 0.000000 # mu- : 0.0
DECAY 14 0.000000 # vm : 0.0
DECAY 15 0.000000 # ta- : 0.0
DECAY 16 0.000000 # vt : 0.0
DECAY 21 0.000000 # g : 0.0
DECAY 22 0.000000 # a : 0.0

but I don't change the bwcutoff parameter in run card it is in the default
value 15.0 .Does this parameter effect the result.

On Mon, Nov 11, 2019 at 1:39 AM Olivier Mattelaer <
<email address hidden>> wrote:

> Your question #685728 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/685728
>
> Status: Open => Answered
>
> Olivier Mattelaer proposed the following answer:
> Hi,
>
> The notion of off-shell/on-shell is related to the parameter
> "bwcutoff" of the run_card.
> We consider "onshell" case where the invariant mass is at most bwcutoff
> times the width away from the pole mass. (otherwise this is consider
> off-shell).
>
> > I have checked that madgraph actually doing first it produce Heavy
> higgs by g g > H and decay it H > h h and multiply the cross section
> with decay width . Is it right ?
>
> No this is certainly wrong. Madgraph never use the branching ratio
> information.
> (Only MadSpin does).
> So even with the syntax
> generate p p > H , H > h h
> we will not use the branching ratio for the computation of that process.
>
> Now I have try to check in the 2HDM if I can find such issue.
> However when I'm doing:
> import model 2HDM_NLO
> generate g g > h1 h1 / h3 [noborn=QCD]
> output
> launch
> set mh1 125
> set mh2 600
> set wh2 Auto
> set wh1 Auto
>
> I do not have any particle "h2" consider as onshell for that process.
> Do you know a benchmark who would be dominated by the onshell h2?
>
> Cheers,
>
> Olivier
>
>
> > On 10 Nov 2019, at 16:27, Md.Raju <email address hidden>
> wrote:
> >
> > New question #685728 on MadGraph5_aMC@NLO:
> > https://answers.launchpad.net/mg5amcnlo/+question/685728
> >
> > Sorry for incomplete question .
> > As you have said that for off_shell production we can impose the
> off-shell condition by $ syntax for loop induced production but here Iam
> facing some problem to understand the interference between box and
> triangluer diagrams.I want to mention the situation clearly Iam trying to
> generate the process g g > h h [QCD] now I should get two type of diagramme
> box and triangular and the triangular give diagramme like g g > H > hh
> [QCD] and it will negatively interfer with box .But it is not working in
> the mass range of H 100 to 4000 gev.
> > I have checked that madgraph actually doing first it produce Heavy higgs
> by g g > H and decay it H > h h and multiply the cross section with decay
> width . Is it right ?
> >
> > I want to know what actually madgraph mean by off-shell production
> >
> > --
> > 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/685728/+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/685728
>
> You received this question notification because you asked the question.
>

Only in the way the lhe events is written for this syntax (and for the optimisation of the code)

Cheers,

Olivier

> On 12 Nov 2019, at 08:38, Md.Raju <email address hidden> wrote:
>
> Question #685728 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/685728
>
> Status: Answered => Open
>
> Md.Raju is still having a problem:
> Dear madgraph expert
> I am working with this bench value
> generate g g > h h [noborn=QCD]
> output
> launch
> ###################################
> ## INFORMATION FOR CKMBLOCK
> ###################################
> Block ckmblock
> 1 2.250000e-01 # lamC
> 2 8.110000e-01 # AC
> 3 1.310000e-01 # rhoCb
> 4 3.450000e-01 # etaCb
>
> ###################################
> ## INFORMATION FOR HIGGSINPUTS
> ###################################
> Block higgsinputs
> 1 20.00 # tanb
> 2 5000.00 # LHhh
>
> ###################################
> ## INFORMATION FOR LOOP
> ###################################
> Block loop
> 1 9.118800e+01 # MU_R
>
> ###################################
> ## INFORMATION FOR MASS
> ###################################
> Block mass
> 1 1380.000 # MD
> 2 1430.000 # MU
> 3 1.010000e-01 # MS
> 4 1.270000e+00 # MC
> 5 4.700000e+00 # MB
> 6 1.760000e+02 # MT
> 11 5.110000e-04 # Me
> 13 1.056600e-01 # MMU
> 15 1.777000e+00 # MTA
> 23 9.118760e+01 # MZ
> 25 1.260000e+02 # MHl
> 37 1900.00 # MCh
> 300 1500.00 # MHh
> 301 2800.00 # MPs
> ## Dependent parameters, given by model restrictions.
> ## Those values should be edited following the
> ## analytical expression. MG5 ignores those values
> ## but they are important for interfacing the output of MG5
> ## to external program such as Pythia.
> 12 0.000000 # ve : 0.0
> 14 0.000000 # vm : 0.0
> 16 0.000000 # vt : 0.0
> 21 0.000000 # g : 0.0
> 22 0.000000 # a : 0.0
> 24 79.824660 # w+ : cmath.sqrt(MZ__exp__2/2. + cmath.sqrt(MZ__exp__4/4. -
> (aEW*cmath.pi*MZ__exp__2)/(Gf*sqrt__2)))
> 9000002 91.187600 # ghZ : MZ
> 9000003 79.824660 # ghWp : MW
> 9000004 79.824660 # ghWm : MW
>
> ###################################
> ## INFORMATION FOR SMINPUTS
> ###################################
> Block sminputs
> 1 1.32000e+02 # aEWM1
> 2 1.166390e-05 # Gf
> 3 1.180000e-01 # aS
>
> ###################################
> ## INFORMATION FOR YUKAWA
> ###################################
> Block yukawa
> 1 1380.00 # ymdo
> 2 1430.00 # ymup
> 3 1.010000e-01 # yms
> 4 1.270000e+00 # ymc
> 5 4.700000e+00 # ymb
> 6 1.760000e+02 # ymt
> 11 5.110000e-04 # yme
> 13 1.056600e-01 # ymm
> 15 1.777000e+00 # ymtau
>
> ###################################
> ## INFORMATION FOR DECAY
> ###################################
> DECAY 6 1.508336e+00 # WT
> DECAY 23 2.495200e+00 # WZ
> DECAY 24 2.085000e+00 # WW
> DECAY 25 Auto # WHl
> DECAY 37 1.000000e+00 # WCh
> DECAY 300 Auto # WHh
> DECAY 301 1.000000e+00 # WPs
> DECAY 1 0.000000 # d : 0.0
> DECAY 2 0.000000 # u : 0.0
> DECAY 3 0.000000 # s : 0.0
> DECAY 4 0.000000 # c : 0.0
> DECAY 5 0.000000 # b : 0.0
> DECAY 11 0.000000 # e- : 0.0
> DECAY 12 0.000000 # ve : 0.0
> DECAY 13 0.000000 # mu- : 0.0
> DECAY 14 0.000000 # vm : 0.0
> DECAY 15 0.000000 # ta- : 0.0
> DECAY 16 0.000000 # vt : 0.0
> DECAY 21 0.000000 # g : 0.0
> DECAY 22 0.000000 # a : 0.0
>
>
> but I don't change the bwcutoff parameter in run card it is in the default
> value 15.0 .Does this parameter effect the result.
>
> On Mon, Nov 11, 2019 at 1:39 AM Olivier Mattelaer <
> <email address hidden>> wrote:
>
>> Your question #685728 on MadGraph5_aMC@NLO changed:
>> https://answers.launchpad.net/mg5amcnlo/+question/685728
>>
>> Status: Open => Answered
>>
>> Olivier Mattelaer proposed the following answer:
>> Hi,
>>
>> The notion of off-shell/on-shell is related to the parameter
>> "bwcutoff" of the run_card.
>> We consider "onshell" case where the invariant mass is at most bwcutoff
>> times the width away from the pole mass. (otherwise this is consider
>> off-shell).
>>
>>> I have checked that madgraph actually doing first it produce Heavy
>> higgs by g g > H and decay it H > h h and multiply the cross section
>> with decay width . Is it right ?
>>
>> No this is certainly wrong. Madgraph never use the branching ratio
>> information.
>> (Only MadSpin does).
>> So even with the syntax
>> generate p p > H , H > h h
>> we will not use the branching ratio for the computation of that process.
>>
>> Now I have try to check in the 2HDM if I can find such issue.
>> However when I'm doing:
>> import model 2HDM_NLO
>> generate g g > h1 h1 / h3 [noborn=QCD]
>> output
>> launch
>> set mh1 125
>> set mh2 600
>> set wh2 Auto
>> set wh1 Auto
>>
>> I do not have any particle "h2" consider as onshell for that process.
>> Do you know a benchmark who would be dominated by the onshell h2?
>>
>> Cheers,
>>
>> Olivier
>>
>>
>>> On 10 Nov 2019, at 16:27, Md.Raju <email address hidden>
>> wrote:
>>>
>>> New question #685728 on MadGraph5_aMC@NLO:
>>> https://answers.launchpad.net/mg5amcnlo/+question/685728
>>>
>>> Sorry for incomplete question .
>>> As you have said that for off_shell production we can impose the
>> off-shell condition by $ syntax for loop induced production but here Iam
>> facing some problem to understand the interference between box and
>> triangluer diagrams.I want to mention the situation clearly Iam trying to
>> generate the process g g > h h [QCD] now I should get two type of diagramme
>> box and triangular and the triangular give diagramme like g g > H > hh
>> [QCD] and it will negatively interfer with box .But it is not working in
>> the mass range of H 100 to 4000 gev.
>>> I have checked that madgraph actually doing first it produce Heavy higgs
>> by g g > H and decay it H > h h and multiply the cross section with decay
>> width . Is it right ?
>>>
>>> I want to know what actually madgraph mean by off-shell production
>>>
>>> --
>>> 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/685728/+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/685728
>>
>> You received this question notification because you asked the question.
>>
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

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