GSI Forum: Analysis » PndKinFitter Mass constraints and resolution

Home » PANDA » PandaRoot » Analysis » PndKinFitter Mass constraints and resolution

Show: Today's Messages :: Polls :: Message Navigator

PndKinFitter Mass constraints and resolution [message #15745]

Fri, 22 November 2013 12:16

StefanoSpataro
Messages: 2736
Registered: June 2005
Location: Torino

first-grade participant

From: *to.infn.it

I was checking what is stored by the ana_complete.C macro, and I was taking a look into the jpsi invariant mass after the fitter (PndKinFitter) putting a mass constraint.
Checking the hjpsim_mcf histo, at a first glance the mass peak seems a delta as I would expect, but just increasing the binning and zooming I realized that it has a distribution and a width of 5 MeV. Now the question is: why it is not a delta? If I constraint that the mass is a specific value, I should expect such value, and not a distribution (at least this is what I was finding when running kinematic fitters for hades). It is not
clear to me why there is such behavior, I have received such a question.
Is it possible that the fitter finds local maxima and not the good one? Or maybe it stops after X iterations even if it has not find the set value? Or maybe there is some bug?

index.php?t=getfile&id=7665&private=0

Attachment: jpsi.gif
(Size: 9.96KB, Downloaded 738 times)

Report message to a moderator

Previous Topic:	loop over PndMcTracks
Next Topic:	Talk at Hirschegg 2014 - Perspectives of Open Charm Physics at PANDA

Goto Forum:

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Thu Nov 06 13:49:08 CET 2025

Total time taken to generate the page: 0.00604 seconds