problem in using MadSpin

Hi,

This is clearly not expected.
We do not have access on lxplus.

Could you copy paste the full log?
In particular, I would be interested to know what is the width of the top in this case.
Could you also include the full event banner and the full madspin card?
(and/or put them in publicly available place)

Cheers,

Olivier

> On Oct 7, 2016, at 10:23, antares <email address hidden> wrote:
>
> Question #402834 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/402834
>
> Description changed to:
> Dear experts,
>
> I generated ttbb events at 8TeV using madragph5_aMCatNLO. These events
> are not decayed, I then want to decay them I use MadSpin. Altough in the
> past MadSpin gave me no problems, even for ttbb at 13 TeV, now my output
> is as follows:
>
> INFO: Estimating the maximum weight
> INFO: *****************************
> INFO: Probing the first 75 events
> INFO: with 400 phase space points
> INFO:
> INFO: Event 1/75 : 0.77s
> INFO: Event 6/75 : 14.2s
> INFO: Event 11/75 : 18.2s
> INFO: Event 16/75 : 33.9s
> INFO: Event 21/75 : 41s
> INFO: Event 26/75 : 54.6s
> INFO: Event 31/75 : 1m 10s
> INFO: Event 36/75 : 1m 25s
> INFO: Event 41/75 : 1m 51s
> INFO: Event 46/75 : 2m 6s
> INFO: Event 51/75 : 2m 45s
> INFO: Event 56/75 : 3m 1s
> INFO: Event 61/75 : 3m 4s
> INFO: Event 66/75 : 3m 8s
> INFO: Event 71/75 : 3m 27s
> INFO:
> INFO: Decaying the events...
>
> Then the process runs without any further output for >24h, which ever
> happened to me before.
>
> I am asking you if this behaviour is expected or not, and in case it is
> not normal, I would like to know how I can solve this problem.
>
> I am decaying the events with the madspin configuration:
>
> decay t > w+ b, w+ > mu+ vmu
> decay t~ > w- b~, w- > mu- vmu~
> launch
>
> but I tried with different decays and I always get the same issue.
> A copy of the events I would like to decay is in lxplus:
>
> /afs/cern.ch/work/m/mmantoan/public/group.phys-
> gener.ttbb_aMCatNLOHerwig_8TeV_v2_2_3._00105.events.tar.gz
>
> thank you very much in advance for your help
>
> Matteo
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

Hi Oliver,
thank you for your answer.
I just run MadSpin in this way, from the directory of MG5_aMC_v2_3_2_2

./MadSpin/madspin
decay t > w+ b, w+ > mu+ vm
decay t~ > w- b~, w- > mu- vm~
launch

I copy here the full output.

INFO: process: p p > t t~ b b~
INFO: options:
Set group_subprocesses to Auto
Note that you need to regenerate all processes
set loop optimized output to True
set loop color flows to False
Passing to gauge unitary.
INFO: detected model: loop_sm. Loading...
INFO: Restrict model loop_sm with file models/loop_sm/restrict_default.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~
Defined multiparticle all = g gh gh~ d u s c d~ u~ s~ c~ a ve vm vt e- mu- ve~ vm~ vt~ e+ mu+ b t b~ t~ z w+ h w- ta- ta+
Set group_subprocesses to Auto
Note that you need to regenerate all processes
set loop optimized output to True
set loop color flows to False
Passing to gauge unitary.
INFO: Restrict model /afs/cern.ch/work/m/mmantoan/submit/MG5_aMC_v2_3_2_2/models/loop_sm with file models/loop_sm/restrict_default.dat .
INFO: Run "set stdout_level DEBUG" before import for more information.
INFO: Change particles name to pass to MG5 convention
Kept definitions of multiparticles l- / j / vl / l+ / p / vl~ unchanged
Defined multiparticle all = g gh gh~ d u s c d~ u~ s~ c~ a ve vm vt e- mu- ve~ vm~ vt~ e+ mu+ b t b~ t~ z w+ h w- ta- ta+
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~
INFO: Will use seed 126819709
WARNING: set the mass of the b-quark to its value in the param_card.dat: 4.95 GeV
INFO:
INFO: decay channels for t~ : ( width = 1.32 GeV )
INFO: BR d1 d2
INFO: 1.000000e+00 w- b~
INFO:
INFO:
INFO: decay channels for w- : ( width = 2.085 GeV )
INFO: BR d1 d2
INFO: 3.377000e-01 u~ d
INFO: 3.377000e-01 c~ s
INFO: 1.082000e-01 ve~ e-
INFO: 1.082000e-01 vm~ mu-
INFO: 1.082000e-01 vt~ ta-
INFO:
INFO:
INFO: decay channels for w+ : ( width = 2.085 GeV )
INFO: BR d1 d2
INFO: 3.377000e-01 u d~
INFO: 3.377000e-01 c s~
INFO: 1.082000e-01 ve e+
INFO: 1.082000e-01 vm mu+
INFO: 1.082000e-01 vt ta+
INFO:
INFO:
INFO: decay channels for t : ( width = 1.32 GeV )
INFO: BR d1 d2
INFO: 1.000000e+00 w+ b
INFO:
INFO: generating the production square matrix element
INFO: generate p p > t t~ b b~ --no_warning=duplicate;define pert_QCD = -4 -3 -2 -1 1 2 3 4 21;add process p p > t t~ b b~ pert_QCD --no_warning=duplicate;
INFO: Done 16.46
INFO: generating the full square matrix element (with decay)
INFO: generate p p > t t~ b b~ , (t~ > b~ w- , w- > mu- vm~ QCD=99), (t~ > b~ w- , w- > mu- vm~ QCD=99), (t > b w+ , w+ > mu+ vm QCD=99), (t > b w+ , w+ > mu+ vm QCD=99) --no_warning=duplicate;define pert_QCD = -4 -3 -2 -1 1 2 3 4 21;add process p p > t t~ b b~ pert_QCD, (t~ > b~ w- , w- > mu- vm~ QCD=99), (t~ > b~ w- , w- > mu- vm~ QCD=99), (t > b w+ , w+ > mu+ vm QCD=99), (t > b w+ , w+ > mu+ vm QCD=99) --no_warning=duplicate;
INFO: Done 21.91
INFO: generate matrix element for decay only (1 - > N).
INFO: output standalone_msF /afs/cern.ch/work/m/mmantoan/submit/MG5_aMC_v2_3_2_2/decay_me
INFO: Done 1.425
INFO: Compiling code
INFO: detect independant decays
INFO: Done in 0.0654630661011s
INFO:
INFO: Estimating the maximum weight
INFO: *****************************
INFO: Probing the first 75 events
INFO: with 400 phase space points
INFO:
INFO: Event 1/75 : 0.65s
INFO: Event 6/75 : 12.4s
INFO: Event 11/75 : 15.8s
INFO: Event 16/75 : 27.7s
INFO: Event 21/75 : 32s
INFO: Event 26/75 : 43.5s
INFO: Event 31/75 : 54.5s
INFO: Event 36/75 : 1m 6s
INFO: Event 41/75 : 1m 27s
INFO: Event 46/75 : 1m 38s
INFO: Event 51/75 : 2m 7s
INFO: Event 56/75 : 2m 18s
INFO: Event 61/75 : 2m 20s
INFO: Event 66/75 : 2m 24s
INFO: Event 71/75 : 2m 37s
INFO:
INFO: Decaying the events...

and then it seems to freeze.

I put the LHE file to decay in a google Drive public space:

https://drive.google.com/open?id=0B7bEZhwoF9_FTkJDQjVxRGQtd0k

Thank you again for your help

Matteo

Hi Matteo,

The problem is related to some inconsistent behavior in the handling of the b-mass.
in aMC@NLO the b final state will be set to the mass related to the shower and not the matrix element mass for the b.
MadSpin tries to keep the b mass when this one is specified.

So one solution to your problem is to edit the banner and set the b mass to 4.75 in the param_card.
such that the shower mass and the one of the banner matches to each other and this allow to fix your problem.

Cheers,

Olivier

Thank you very much Oliver. If I change such parameter, shall I redo the LHE file from scratch or it doesn't matter for the final result?

Thank you very much again
Matteo

Dear Matteo,

re-doing the lhe file with that mass for the b is certainly safer.
But expcept if you hare very sensitve on the b mass for some key observable is should not matter.

Cheers,

Olivier

Dear Oliver, this solved my problem. Thank you very much for all the precious help and support