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Re: Difference of neutral candidate between Geant4 and Geant3 [message #17721 is a reply to message #15844]

Fri, 09 January 2015 22:21

StefanoSpataro
Messages: 2736
Registered: June 2005
Location: Torino

first-grade participant

From: 93.49.202*

Hi,
I did some recent changed triggered by the fact that currently geant4 simulation is faster than geant3.

I simulated the standard psi(2S)->J/psipi+pi- events and compared the emc digi multiplicity with geant3, geant4, and geant4 setting off the "special cuts" and "special controls", i.e. the emulation of geant3 cuts in energy.
This is what I get:

index.php?t=getfile&id=8230&private=0

I understand that the lower multiplicity of geant4 comes not from geant itself but from the special cuts in energy that we use by default. If we remove the flag from gconfig/g4Config.C the computing time increases a lot, become a factor 2 slower than g3, and the multiplicity is higher than geant3 as expected.

At the end, I understand this is just a fact of cuts, and only a comparison with experimental data can help to find the better thresholds.

Attachment: emcdigi_mult.gif
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[Message index]

		Difference of neutral candidate between Geant4 and Geant3 By: donghee on Thu, 31 October 2013 10:12
		Re: Difference of neutral candidate between Geant4 and Geant3 By: StefanoSpataro on Fri, 01 November 2013 12:41
		Re: Difference of neutral candidate between Geant4 and Geant3 By: donghee on Mon, 11 November 2013 13:46
		Re: Difference of neutral candidate between Geant4 and Geant3 By: StefanoSpataro on Mon, 11 November 2013 18:04
		Re: Difference of neutral candidate between Geant4 and Geant3 By: donghee on Tue, 12 November 2013 10:53
		Re: Difference of neutral candidate between Geant4 and Geant3 By: donghee on Fri, 15 November 2013 15:34
		Re: Difference of neutral candidate between Geant4 and Geant3 By: StefanoSpataro on Fri, 15 November 2013 16:15
		Re: Difference of neutral candidate between Geant4 and Geant3 By: Dima Melnychuk on Thu, 06 February 2014 11:56
		Re: Difference of neutral candidate between Geant4 and Geant3 By: StefanoSpataro on Fri, 07 February 2014 19:46
		Re: Difference of neutral candidate between Geant4 and Geant3 By: StefanoSpataro on Fri, 09 January 2015 22:21

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