[Rivet] Question about WFinder

[Piergiulio Lenzi]

Hi Andy,
    thanks for your answer,
I actually found a trick to do the job (well something still has to be 
refined).
The idea is to run the InvMassFinalState on a MergedFinalState produced 
out of two IdentifiedFinalState's, one with all the charged leptons, 
with pt and eta cuts, and one with all the neutrinos.
The only problem is that IdentifiedFinalState doesn't take a vector of 
eta ranges, but I think this is easily fixable.
I'm attaching a patch file that I produced on top of 1.2.0b. I hope this 
is a good starting point .
Thanks!
Giulio



Andy Buckley wrote:
> 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
>
>   
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