[Rivet] Rivet and HepMC units [Re: Rivet!!]

Ben Waugh waugh at hep.ucl.ac.uk
Fri Oct 29 17:05:29 BST 2010


Hi David,

I think your summary is correct. We should probably use generators 
linked with the newer HepMC, but I think realistically we are better off 
sticking with the older HepMC for now.

By the way, the bug in src/Projections/NeutralFinalState.cc is still 
present in the Svn trunk, although Sercan has fixed it in our local 
installation. Can this be fixed for version 1.3.1?

Many thanks,
Ben

On 29/10/10 16:30, David Grellscheid wrote:
> Hi again,
> 
> To follow up, I would reconstruct Sercan's observations as follows:
> 
>  >>>
>  >>> _Rivet 1.3.0 with HepMC_2.03.11 and Boost_1.42_
>  >>>
>  >>> Leading jet: pT = _7.07939 GeV
> 
> The producer was also linked to HepMC 2.03 and implicitly produced 
> GEV/MM output. Rivet reads this output and implicitly assumes GEV/MM. By 
> accident it works.
> 
>  >>>
>  >>> _Rivet 1.3.0 with HepMC_2.06.01 and Boost_1.44_
>  >>>
>  >>> Leading jet: pT = _0.00707939 GeV
> 
> The same input file was used, i.e. no unit information available. HepMC 
> then assumes its configuration defaults
> 
>  >> and includes "--with-momentum=MEV"
> 
> Rivet reads the number 7.07939 from the file and is told it's in MeV.
> When Rivet prints the number back out, it says (in a way correctly):
> 
>  >>> 0.00707939 GeV
> 
> Hope that helps,
> 
>    David

-- 
Dr Ben Waugh                                   Tel. +44 (0)20 7679 7223
Dept of Physics and Astronomy                  Internal: 37223
University College London
London WC1E 6BT


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