[Rivet] Sherpa+Rivet: m_io->fill_next_event fails

[Andy Buckley]

Frank Siegert wrote:
> Frank Siegert, Thursday 26 November 2009:
>> Eike von Seggern, Thursday 26 November 2009:
>>> I'm trying to run Sherpa with the BaBar setup and analyse the events
>>> with Rivet. However, Rivet stops after processing a few events. I
>>> tracked it down to that the m_io->fill_next_event call in
>>> Run::processEvent fails. But no other error message is printed by
>>>  HepMC. Sherpa and Rivet are both built against HepMC 2.05 .
>>>
>>> I attach the Sherpa run card. The Rivet command is:
>>>
>>> rivet -l Rivet=DEBUG -a PDG_HADRON_MULTIPLICITIES babar.hepmc2g
>>>
>>> Has anyone an idea what's going wrong.
>> I don't have a solution, but it might be interesting to know whether it
>> works through Sherpa's internal Rivet interface (in 1.2.0). Our manual
>> describes how you can use that... could you give that a try?
> 
> Actually, I've just tested it, and it doesn't stall, but the analysis 
> isn't going to work for Babar events, since it looks at 2*"mean beam 
> momentum" instead of sqrt(s). This isn't the same for asymmetric beams.

Eike/Frank, does this now work with the updated analysis? If so, then I 
guess this *is* a problem with HepMC I/O. Why asymmetric beams would 
lead to a HepMC read fail I have no idea... but it's possible, and looks 
increasingly probable.

Andy

-- 
Dr Andy Buckley
SUPA Advanced Research Fellow
Particle Physics Experiment Group, University of Edinburgh