Problem decaying NLO gluon fusion higgs events in madspin (with spinmode=None)

[Josh Bendavid]

Have produced some lhe files with the HC_NLO_X0_UFO model
http://feynrules.irmp.ucl.ac.be/wiki/HiggsCharacterisation

Trying to decay the higgs with madspin and spinmode=none results in an error as below related to validation of the model.
Example lhe file and madspin card are attached.
(Trying to use spinmode=none in order to have the H -> 4 lepton decays with interference, etc)

************************************************************
* *
* W E L C O M E to M A D S P I N *
* *
************************************************************
MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>INFO: process: p p > x0
INFO: options: / t
Set group_subprocesses to Auto
Note that you need to regenerate all processes
set loop optimized output to True
INFO: detected model: HC_NLO_X0_UFO-heft. Loading...
INFO: Please read carefully the README of the model file for instructions/restrictions of the model.
INFO: Restrict model HC_NLO_X0_UFO with file ../models/HC_NLO_X0_UFO/restrict_heft.dat .
INFO: Run "set stdout_level DEBUG" before import for more information.
INFO: Change particles name to pass to MG5 convention
Defined multiparticle p = g u c d s u~ c~ d~ s~
Defined multiparticle j = g u c d s u~ c~ d~ s~
Defined multiparticle l+ = e+ mu+
Defined multiparticle l- = e- mu-
Defined multiparticle vl = ve vm vt
Defined multiparticle vl~ = ve~ vm~ vt~
Pass the definition of 'j' and 'p' to 5 flavour scheme.
Defined multiparticle all = g gh gh~ d u s c b d~ u~ s~ c~ b~ a ve vm vt e- mu- ve~ vm~ vt~ e+ mu+ t t~ z w+ x0 w- ta- ta+
Set group_subprocesses to Auto
Note that you need to regenerate all processes
set loop optimized output to True
Complex mass already desactivated.
Defined multiparticle p = g u c d s u~ c~ d~ s~
Defined multiparticle j = g u c d s u~ c~ d~ s~
Defined multiparticle l+ = e+ mu+
Defined multiparticle l- = e- mu-
Defined multiparticle vl = ve vm vt
Defined multiparticle vl~ = ve~ vm~ vt~
Defined multiparticle p = g u c d s b u~ c~ d~ s~ b~
Defined multiparticle j = g u c d s b u~ c~ d~ s~ b~
MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>Defined multiparticle ell+ = e+ mu+ ta+
MadSpin>Defined multiparticle ell- = e- mu- ta-
MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>INFO: Will use seed 328523370
INFO: generate 10 decay event for particle x0
Command "launch" interrupted with error:
InvalidParamCard : parameter frblock: 14 is not at zero
Please report this bug to developers

           More information is found in 'MS_debug'.

           Please attach this file to your report.
MadSpin>MadSpin>

[Josh Bendavid (joshbendavid)]

(n.b if I try similarly with LO gluon fusion higgs with the built in heft model, or with LO l+ l- h with the sm then when I try to do the decay I get instead an error like)

WARNING: Order of particle in the event did not agree with parent/child order. This might be problematic for some code.
Command "launch" interrupted with error:
IndexError : list index out of range
Please report this bug to developers

           More information is found in 'MS_debug'.

           Please attach this file to your report.

[Olivier Mattelaer (olivier-mattelaer)]

Hi Rik,

Any news on this one?

Olivier

[Rikkert Frederix (frederix)]

Hi Olivier,

Not really. I don't really understand this part of the MadSpin code. I think you know this much better than me. Could you please have a look?

Cheers,
Rik

[Olivier Mattelaer (olivier-mattelaer)]

Hi Josh,

Concerning the
"""
WARNING: Order of particle in the event did not agree with parent/child order. This might be problematic for some code.
Command "launch" interrupted with error:
IndexError : list index out of range
"""
I guess that i fixed that yesterday: See https://bugs.launchpad.net/mg5amcnlo/+bug/1480989, where you can find the associate patch.

Concerning
"""InvalidParamCard : parameter frblock: 14 is not at zero"""
is this still current? I made a patch for you at some point with the restriction card, is that not the same problem?

Cheers,

Olivier

[Josh Bendavid (joshbendavid)]

Ok,
I didn't think that was the same issue, but I'll try this again with that patch and let you know.

You're talking about this one right?
https://github.com/cms-sw/genproductions/blob/mg230/bin/MadGraph5_aMCatNLO/patches/mgfixes.patch#L13-L24

[Olivier Mattelaer (olivier-mattelaer)]

Hi,

Yeah i was talking about that patch.
I’m not fully sure that this is the same bug but It might be.

thanks,

Olivier

On 04 Aug 2015, at 10:59, Josh Bendavid <email address hidden> wrote:

> Ok,
> I didn't think that was the same issue, but I'll try this again with that patch and let you know.
>
> You're talking about this one right?
> https://github.com/cms-sw/genproductions/blob/mg230/bin/MadGraph5_aMCatNLO/patches/mgfixes.patch#L13-L24
>
> --
> You received this bug notification because you are a bug assignee.
> https://bugs.launchpad.net/bugs/1473767
>
> Title:
> Problem decaying NLO gluon fusion higgs events in madspin (with
> spinmode=None)
>
> Status in MadGraph5_aMC@NLO:
> Triaged
>
> Bug description:
> Have produced some lhe files with the HC_NLO_X0_UFO model
> http://feynrules.irmp.ucl.ac.be/wiki/HiggsCharacterisation
>
> Trying to decay the higgs with madspin and spinmode=none results in an error as below related to validation of the model.
> Example lhe file and madspin card are attached.
> (Trying to use spinmode=none in order to have the H -> 4 lepton decays with interference, etc)
>
> ************************************************************
> * *
> * W E L C O M E to M A D S P I N *
> * *
> ************************************************************
> MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>MadSpin>INFO: process: p p > x0
> INFO: options: / t
> Set group_subprocesses to Auto
> Note that you need to regenerate all processes
> set loop optimized output to True
> INFO: detected model: HC_NLO_X0_UFO-heft. Loading...
> INFO: Please read carefully the README of the model file for instructions/restrictions of the model.
> INFO: Restrict model HC_NLO_X0_UFO with file ../models/HC_NLO_X0_UFO/restrict_heft.dat .
> INFO: Run "set stdout_level DEBUG" before import for more information.
> INFO: Change particles name to pass to MG5 convention
> Defined multiparticle p = g u c d s u~ c~ d~ s~
> Defined multiparticle j = g u c d s u~ c~ d~ s~
> Defined multiparticle l+ = e+ mu+
> Defined multiparticle l- = e- mu-
> Defined multiparticle vl = ve vm vt
> Defined multiparticle vl~ = ve~ vm~ vt~
> Pass the definition of 'j' and 'p' to 5 flavour scheme.
> Defined multiparticle all = g gh gh~ d u s c b d~ u~ s~ c~ b~ a ve vm vt e- mu- ve~ vm~ vt~ e+ mu+ t t~ z w+ x0 w- ta- ta+
> Set group_subprocesses to Auto
> Note that you need to regenerate all processes
> set loop optimized output to True
> Complex mass already desactivated.
> Defined multiparticle p = g u c d s u~ c~ d~ s~
> Defined multiparticle j = g u c d s u~ c~ d~ s~
> Defined multiparticle l+ = e+ mu+
> Defined multiparticle l- = e- mu-
> Defined multiparticle vl = ve vm vt
> Defined multiparticle vl~ = ve~ vm~ vt~
> Defined multiparticle p = g u c d s b u~ c~ d~ s~ b~
> Defined multiparticle j = g u c d s b u~ c~...

[Josh Bendavid (joshbendavid)]

Thanks,
With this plus the patch from https://bugs.launchpad.net/mg5amcnlo/+bug/1480989 now it's working as expected.

I do still get a warning
WARNING: Order of particle in the event did not agree with parent/child order. This might be problematic for some code.
but that doesn't seem to cause any problems.

[Josh Bendavid (joshbendavid)]

As a helpful reminder to anyone who wants to do this in the future.

Doing higgs -> 4l decays like
define ell+ = e+ mu+ ta+
define ell- = e- mu- ta-
#
set spinmode=none
decay x0 > ell+ ell- ell+ ell-

requires setting the tau yukawa to zero to avoid h -> tau tau diagrams with radiated gamma* -> l l
(and at least running without setting the tau yukawa to zero was prohibitively slow, probably because of the divergence for mll->0)

Not relevant for this process once removing that contribution, but in general is it possible to specify an mll cut in the decays?
(This would be interesting eg for Higgs->gamma l+ l-)

[Olivier Mattelaer (olivier-mattelaer)]

Hi Josh,

concerning the warning, I keep it on even if in principle I automatically correct for that situation now. The reason is that I'm not 100% sure that my fix cover correctly all the potential pathological case.

Not relevant for this process once removing that contribution, but in general is it possible to specify an mll cut in the decays?
(This would be interesting eg for Higgs->gamma l+ l-)

If you run within the standard mode, it is very difficult to implement. On the other hand, this is pretty easy to do within "spinmode=none". I attach a patch allowing to define cut in the decay with the following syntax:
set run_card mmll=5
Note that those cut are applied in the rest-frame of the decaying particle. So it does not make sense to use cut like pt/...
But it is perfectly fine for mmll.

Cheers,

Olivier

[Josh Bendavid (joshbendavid)]

Thanks, with that patch higgs > gamma mu+ mu- decays are indeed working with an appropriate mll cut.