[Rivet] Leading neutrinos?

[Jonathan Butterworth]

Hi both,

Since the experimental calibrations generally go to the "hadron" or 
"final state particle" level, they generally include a correction, at 
least on average, for particles from hadronic decays, including 
neutrinos and muons.

Since in the MC used to do these corrections, the neutrino from the W is 
~always the leading particle, I think using this is actually correct, 
and is what the experiments measure, even if they call it the "neutrino 
from the W".

Well, I guess more correct might be "all particles which only interact 
weakly and which don't come from SM hadron decays"

I think timescales involved are such that the post/pre hadronisation 
distinction is physically meaningful.

Or?

Cheers,
Jon

On 28/02/2011 17:31, Frank Siegert wrote:
> HI David,
>
> On 28/02/11 16:57, David Grellscheid wrote:
>> ATLAS_2010_S8919674 (W+jets) uses a LeadingParticlesFS to make up
>> pTmiss. Does that make sense? Shouldn't I add all neutrinos? How would I
>> even know how the experimental pTmiss divides over the neutrinos?
>
> Unfortunately this analysis (like some others) corrects to
> pTmiss="neutrino from the W" for the particle level distributions.
> Since that is not possible to implement in a generator-independent
> analysis I used the leading neutrino as closest match. This seems to be
> a very good approximation, as I validated the analysis by reproducing
> the Sherpa predictions in the paper using the same ATLAS-internal MC
> samples.
>
> Cheers,
> Frank
> _______________________________________________
> Rivet mailing list
> Rivet at projects.hepforge.org
> http://www.hepforge.org/lists/listinfo/rivet

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Prof. Jonathan Butterworth,              http://www.hep.ucl.ac.uk/~jmb/
Physics and Astronomy Department                  Tel: +44 20 7679 3444
ATLAS, CERN                                       Tel: +41 22 76  72340
University College London                 Gower St, London WC1E 6BT, UK
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~