Syntax conflict between mg5amc and madspin in 3.1.x and 3.2.x

Hi,

To my point of view only syntax #1 should work with MadSpin, the rest is indeed not supported syntax.
(Obviously a better error message would be nicer).

Will look at fixing #1 and having better crash for the other option

Cheers,

Olivier

> On 5 Oct 2021, at 20:31, Richard Ruiz <email address hidden> wrote:
>
> Public bug reported:
>
> Hi Folks,
>
> I am not entirely sure this is a bug but guidance is appreciated either
> way. In short, it seems like the new "recommended" syntax for mg5amc in
> 3.1.x and 3.2.x is not yet compatible with MadSpin. (Though maybe it is
> and I am just doing something silly.)
>
> Using the following script (a simple charged current Drell-Yan
> production of a sterile neutrino), I can generate events with mg5amc but
> MadSpin fails to compile or understand the process banner. I have tried
> different variations of "generate" with different responses from MadSpin
> (see below).
>
> Let me know if more details are needed.
>
> cheers,
> richard
>
>
> Script:
> -----------------------------
> define ee = e+ e-
> generate p p > n1 ee QED=2 QCD=0 [QCD] #option 1 <~~~ see below
> #generate p p > n1 ee QED^2=4 QCD^2=0 [QCD] #option 2 <~~~ see below
> #generate p p > n1 ee EW^2=4 QCD^2=0 [QCD] #option 3 <~~~ see below
> #generate p p > n1 ee EW=2 aS=0 [QCD] #option 4 <~~~ see below
> output HeavyN_CCDY_Test
> launch HeavyN_CCDY_Test
> order=lo
> shower=py8
> madspin=onshell
> set LHC 13
> set pdlabel lhapdf
> set nevents 100
> set no_parton_cut
> set VeN1 1
> set mn1 40
> decay n1 > ee j j
> done
>
> ----------------------------------------------------
> #option 1
>
> Everything works with this syntax when using version 3.1.0(bzr) but not
> when using 3.2.x
>
> ----------------------------------------------------
> #option 2
>
> mg5amc works but madspin fails to acknowledge syntax for 3.1.x and
> 3.2.x. The terminal output is:
>
> ...
> ...
> ...
> INFO: generating the production square matrix element for onshell
> INFO: generating the full matrix element squared (with decay)
> INFO: generate matrix element for decay only (1 - > N).
> Command "launch auto " interrupted with error:
> InvalidCmd : model order 2 not valid for this model (valid one are: QCD, QED, EW, EW^2, aEW, aS). Please correct
> Please report this bug on https://bugs.launchpad.net/mg5amcnlo
>
>
> ----------------------------------------------------
> #option 3
>
>
> mg5amc works but madspin fails to acknowledge syntax for 3.1.x and 3.2.x. The terminal output is:
>
> ...
> ...
> ...
> INFO: generating the production square matrix element for onshell
> INFO: generating the full matrix element squared (with decay)
> INFO: generate matrix element for decay only (1 - > N).
> Command "launch auto " interrupted with error:
> InvalidCmd : model order 2 not valid for this model (valid one are: QCD, QED, EW, EW^2, aEW, aS). Please correct
> Please report this bug on https://bugs.launchpad.net/mg5amcnlo
>
>
> ----------------------------------------------------
> #option 4
>
> mg5amc works but madspin fails to generate a matrix element for 3.1.x
> and 3.2.x. The terminal output is:
>
> ...
> ...
> ...
> INFO: generating the pr...