Re: Pythia and generated particles

From: Mario Kadastik <>
Date: Tue, 15 Feb 2005 03:08:57 +0200

Carsten Hof wrote:

>Hi Mario,
>you can access the total cross section via
>Double_t xsection = eg-> GetPARI(1);

Ok, never came to look for it in PARI. I normally used XSEC in pythia.

>For further details you should see the Pythia manual.
>(The methods in Root have similar names to the one in Pythia)#

Well there is no method for GetXSEC in root.

>All the details for writing and reading should be in PythiaExample.C.
>If you want to create your own tree see. The tree0-3 tutorials and the
>manual section are really helpfull.

Well problem is that in none of these examples is an array read back from the tree. Yes there are examples that store it, I haven't found one where an array is restored from tree.

And also there is still the open question on how do I save just a single Float_t variable (like the cross section) to the root file for later analysis. I'd like something like this:

TFile f("file.root","RECREATE")
Float_t xsec = 12.3;

or any other way to write the variable to the root file.

Mario Received on Tue Feb 15 2005 - 02:08:20 MET

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