Simulation with PLUTO for pp@1.25GeV

Here, I will present the status of pp@1.25GeV PLUTO simulation. The generated events are very close to the events from Anja and Witek. There are just some small changes.
Just to remind : Page from Witek and Anja
In our simulation, we do not have 2 pion events, which should vanish with missing mass cut. But all other cross section values are taken in the same table. The second difference is about the momentum smearing. We use either the standard Geydar's parametrisation or the Geydar's factors adjusted to real resolution. Otherwise, all the parameters for generation are equivalent.

Ideal Resolution Realistic Resolution
missing mass ideal resolution missing mass realistic resolution
We apply an asymmetric cut on the missing mass. This reduces more the pi0 contribution because the missing mass is higher than for delta Dalitz decay.
invariant mass after missing mass cut ideal resolution invariant mass after missing mass cut realistic resolution
invariant mass after missing mass cut and missing energy cut ideal resolution invariant mass after missing mass cut and missing energy cut realistic resolution
correlation missing energy-mass ideal resolution correlation missing energy-mass realistic resolution
effect of missing energy cut on missing mass ideal resolution effect of missing energy cut on missing mass realistic resolution
The black line represent all pe+e- combinations
The red line represent pe+e- combinations, from events with delta Dalitz decay, calculated with the proton from the delta decay (top left hand corner for 2D-hist)
The green line represent pe+e- combinations, from events with delta Dalitz decay, calculated with the proton which is not from the delta(top right hand corner)
The blue line represent pe+e- combinations, from events with pi0 Dalitz decay, calculated with the proton from the delta decay(bottom left hand corner)
The pink line represent pe+e- combinations, from events with pi0 Dalitz decay, calculated with the proton which is not from the delta
We can see that the acceptance is quite the same for both proton from the delta decay and the other one in case of delta Dalitz decay and for small missing masses in case of pi0.(bottom right hand corner)

We can notice also that the effect of resolution is bigger for low missing energies than for higher one. This can be understood by the fact that, if the missing energy is low, the momentum of the detected proton must be high. So, the error on the momentum will be high.

With the actual resolution, the missing mass cut is not enough to reduce pi0 contribution. The missing energy cut allows a better reduction of the pi0. It seems however important to improve the resolution as the first step.

-- EmilieMoriniere - 08 Feb 2007
Topic attachments
I Attachment Action Size Date Who Comment
invmass_cut_id.gifgif invmass_cut_id.gif manage 149.6 K 09 Feb 2007 - 09:44 EmilieMoriniere invariant mass after missing mass cut and missing energy cut ideal resolution
invmass_cut_re.gifgif invmass_cut_re.gif manage 148.2 K 09 Feb 2007 - 09:44 EmilieMoriniere invariant mass after missing mass cut and missing energy cut realistic resolution
invmass_id.gifgif invmass_id.gif manage 152.5 K 09 Feb 2007 - 09:43 EmilieMoriniere invariant mass after missing mass cut ideal resolution
invmass_re.gifgif invmass_re.gif manage 159.2 K 09 Feb 2007 - 09:43 EmilieMoriniere invariant mass after missing mass cut realistic resolution
missmass__enecut_id.gifgif missmass__enecut_id.gif manage 277.9 K 13 Feb 2007 - 09:17 EmilieMoriniere effect of missing enrgy cut on missing mass ideal resolution
missmass__enecut_re.gifgif missmass__enecut_re.gif manage 277.6 K 13 Feb 2007 - 09:18 EmilieMoriniere effect of missing energy cut on missing mass realistic resolution
missmass_id.gifgif missmass_id.gif manage 208.9 K 09 Feb 2007 - 09:42 EmilieMoriniere missing mass ideal resolution
missmass_re.gifgif missmass_re.gif manage 201.6 K 09 Feb 2007 - 09:42 EmilieMoriniere missing mass realistic resolution
missmiss_id.gifgif missmiss_id.gif manage 241.5 K 14 Feb 2007 - 16:22 EmilieMoriniere correlation missing energy-mass ideal resolution
missmiss_re.gifgif missmiss_re.gif manage 241.5 K 14 Feb 2007 - 16:40 EmilieMoriniere correlation missing energy-mass realistic resolution
Topic revision: r7 - 23 Feb 2007, EmilieMoriniere
 
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