[Rivet] Question about WFinder

[Andy Buckley]

On 24/02/10 17:37, Piergiulio Lenzi wrote:
> Dear Rivet developers,
>     I'm trying to use the WFinder projection, and I noticed that the pt 
> cut and eta  range are actually applied both to the charged lepton and 
> the neutrino. Can you confirm this?
> I'm not sure whether this is the expected behavior or not, especially 
> the eta cut on the neutrino is not something that one can apply in an 
> experiment. 
> If I had to choose, I would prefer not to check the neutrino eta and pt 
> at all when building the W candidate, and then reproduce the experiment 
> MET cut with a cut on TotalVisibleMomentum.
> What do you think about that?

Hi Giulio,

I completely agree. I wrote the WFinder as a partial clone of the
ZFinder, really only modified to make sure that photons aren't clustered
in a cone around the neutrino. It would make sense to also take this
more realistic approach to MET and lepton pT cuts for W reconstruction.

I was hoping that I could make this fix quickly, but the
InvMassFinalState projection takes a single FinalState projection as a
constructor argument so it's not immediately easy to make the change.
I'll see if I can neatly enhance the InvMassFinalState to be able to be
directly supplied with particles, which seems the easiest approach: I'm
not immediately sure if this will screw up the caching system. Any other
ideas, e.g. from Frank?

Andy

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