[Rivet] Rivet with asymmetric beams

[Eike von Seggern]

On Wed, Dec 09, 2009 at 14:52 +0000, Andy Buckley wrote:
> Eike von Seggern wrote:
> > On Fri, Dec 04, 2009 at 18:21 +0000, Andy Buckley wrote:
> >> Eike von Seggern wrote:
> >>> Hi Andy et al.,
> >>>
> >>> following up on a thread a few days ago. I set up a directory on
> >>> hepforge with an example data file. The problem is that with the
> >>> PDG_HADRON_MULTIPLICITIES analysis 23 events of 10000 are processed. The
> >>> problem is (afaik) that the _io->fill_next_event(_evt.get()) call in
> >>> Run::readEvent() fails. So I'm not sure if it's a HepMC problem or a
> >>> rivet bug.
> >> Hi Eike,
> >>
> >> You need to let me know *where* on HepForge you've put your example file 
> >> ;) This is certainly one to get sorted before 1.2.0 (i.e. SOON!)
> > 
> > Hi Andy et al.,
> > 
> > I think, the problem is in HepMC. My suspect is now that the 
> > 
> > *m_istr >> *evt;
> > 
> > call on line 132 in HepMC-2.05.00/src/IO_GenEvent.cc fails. And
> > _io->error_message() gives me:
> > 
> > "input stream encountered invalid data"
> > 
> > Has any of you encountered this earlier?
> 
> No... that seems very odd. Can you mock up a very small test example 
> that reproduces the problem (check the HepMC ASCII produced by Sherpa 
> for any bugs, and see if a mocked-up asymmetric event shows the same 
> problem), and submit it as a HepMC bug on the LCG Savannah tracker, 
> linked from the HepMC web page. Something problematic like this should 
> be back-ported to production versions of HepMC.
> 
> Andy
> 
> -- 
> Dr Andy Buckley
> SUPA Advanced Research Fellow
> Particle Physics Experiment Group, University of Edinburgh
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So the bug was actually that the cross-section error wasn't
correctly passed to HepMC in Sherpa. That's fixed now. I couldn't find a
ticket. If there was one for this issue, it can be closed.

Cheers,
    eike