RPV stop production "Survey return zero cross section"

Hi,

For the meaning of the model. I would suggest to contact the model author.
Otherwise you can just read the paper SLHA1 and SLHA2 format: http://home.fnal.gov/~skands/slha/

For you zero result, I guess that this is linked that one of the coupling associate to your process vanishes for your new values.

Cheers,

Olivier

On Mar 23, 2014, at 1:21 AM, alefisico <email address hidden> wrote:

> New question #245907 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/245907
>
> Hi
>
> I am trying to generate an RPV decay using this model: http://feynrules.irmp.ucl.ac.be/wiki/RPVMSSM
> In Madgraph 1.5.11, I am doing this:
> import model RPVMSSM_UFO
> define f = u c d s u~ c~ d~ s~ l+ l- vl vl~ ta- ta+ b b~
> generate p p > cl cl~, ( cl > ul z, ul > j j, z > f f ), ( cl~ > ul~ z, ul~ > j j, z > f f )
>
> When I run with the default values in the param_card, it works fine but checking a previous LHE file from a similar process (that I didn't generate it) I realize that the values in the bloc usqmix were change to:
> ###################################
> ## INFORMATION FOR USQMIX
> ###################################
> Block usqmix
> 1 3 0.000000e-01 # RRu13
> 1 6 10.00000e-01 # RRu16
> 2 3 10.00000e-01 # RRu23
> 2 6 0.000000e-01 # RRu26
> 3 5 1.000000e+00 # RRu35
> 4 4 1.000000e+00 # RRu44
> 5 1 1.000000e+00 # RRu51
> 6 2 1.000000e+00 # RRu62
>
> If I change this values, I got this error message:
> .........
> INFO: All jobs finished
> End survey
> Survey return zero cross section.
> Typical reasons are the following:
> 1) A massive s-channel particle has a width set to zero.
> 2) The pdf are zero for at least one of the initial state particles
> or you are using maxjetflavor=4 for initial state b:s.
> 3) The cuts are too strong.
> Please check/correct your param_card and/or your run_card.
> Zero result detected: See https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/FAQ-General-14
>
> quit
>
>
> in my run_card.dat the value of maxjetflavor is 5 and I am not making any cuts. For this process should I have to change the usqmix bloc or can I leave it with the default values? Also, I could not find any information about what this usqmix bloc means, could you explain me a little bit please?
>
> cheers,
>
>
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