Re: Extended particle list in TGeant3

From: Ivana Hrivnacova <ihrivnac_at_mail.cern.ch>
Date: Fri, 7 Jan 2005 12:11:22 +0100 (CET)

 Hi all,

 I think that this part of code in TGeant3 should  better go in a user application.

 Some time ago we have interfaced the
 Gspart() function as TVirtualMC::DefineParticle()  and added the function TVirtualMCApplication::AddParticles()  where use can define own particles via this function.  However we have not interfaced the Gsdk() function yet  which will be necessary here.

 It does not look to be difficult,
 user will have to pass the particles PDG codes instead of  G3 particles codes. The implementation for G3 should be then  trivial, for Geant4 it shouldn't be a problem, too.  Let me know what do you think about such solution.

 I haven't find anywhere a call to function  TVirtualMC::SetUserDecay(). I searched for it in AliRoot and  in geant3.
 Andreas, could you, please, clarify, if this function is  still used (and if so, where)? Thanks.

 Best regards,

 Ivana

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e-mail: Ivana.Hrivnacova_at_cern.ch
address: Institut Physique Nucleaire, 91406 Orsay, France phone: (33) 01 69 15 65 94

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On Fri, 7 Jan 2005, Yuri Kharlov wrote:

> Dear Rene and Adreas,
>
> Please find attached tha patch to TGeant3.cxx (cvs version 1.39) what I
> propose to modify concerning quarkonia decays. Apply it by
> "patch TGeant3.cxx TGeant3.cxx.diff".
> Could you please look if it does not contradict to external decayers
> (now all quarkonia will decay into mu+mu-)? Probably, external decayer
> users will need to declare J/psi as stable. If you feel it not
> convenient, let us not apply my changes and let users declare needed
> decays manually.
>
> Best regards,
> Yuri.
>
> Rene Brun wrote:
>
> >Andreas, Yuri,
> >
> >Could one of you send me the fix for this problem?
> >
> >Rene
> >
> >Andreas Morsch wrote:
> >
> >
> >>Dear Yuri,
> >>I agree, if you un-comment the code it will be wrong.
> >>The particle id's in comment have not evolved with the compiled code.
> >>So if you need to uncomment this part you should perform you proposed
> >>corrections.
> >>
> >>Best regards - Andreas.
> >>
> >>
> >>
> >>>Dear Andreas,
> >>>
> >>>I agree that external decayers for J/psi and other vector mesons is more
> >>>correct as simple isotropic decay. Unfortunately, not all applications
> >>>have their external decayer yet (besides aliroot).
> >>>
> >>>As to decay definition in TGeant3.cxx v.1.34, in this and even in the
> >>>head version, some misleading comments about J/psi and Upsilon decay do
> >>>present, but actually they decay non-existing particles 113 and 114 into
> >>>mu+mu-. It is this code which confused me.
> >>>
> >>>Best regards,
> >>>Yuri.
> >>>
> >>>
> >
> >
> >
>
>

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Received on Fri Jan 07 2005 - 12:11:30 MET