[Rivet] Rivet with asymmetric beams

[Andy Buckley]

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