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EvtGenDirec/PHOTOS [message #22633]

Tue, 22 May 2018 13:57

Alaa Dbeyssi
Messages: 16
Registered: June 2012

occasional visitor

From: *emp.him.uni-mainz.de

Hi,

I am generating the process ppbar->e+e- using EvtGenDirect and switching on PHOTOS (release Dec17p1, macros from /pandaroot/macro/run, p=1.5 GeV).
It seems that PHOTOS is not working properly here since the invariant mass of the e+e- is alway equal to the theoretical value 2.254 GeV (no radiative tail and no photon emission). There is also warning from PHOTOS:

WARNING from PHOTOS: "Momentum not conserved in the vertex". The log file is attached. By switching on PHOTOS, means I don't write "noPhotos" in the decay file. Is this correct?

thank you for your help.
Alaa
///////////////////
The decay file is:

Decay pbarpSystem
1.0 e+ e- PHSP;
Enddecay

End
///////////////////

Attachment: myjob0.1199595.x2257.out
(Size: 426.32KB, Downloaded 579 times)

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Re: EvtGenDirec/PHOTOS [message #22647 is a reply to message #22633]

Wed, 23 May 2018 10:25

Ralf Kliemt
Messages: 508
Registered: May 2007
Location: GSI, Darmstadt

first-grade participant

From: *gsi.de

Hi Alaa,

I believe the "noPhotos" is the default. Please try "yesPhotos" in the beginning to switch it on manually.

Cheers!
Ralf

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Re: EvtGenDirec/PHOTOS [message #22648 is a reply to message #22647]

Wed, 23 May 2018 10:39

StefanoSpataro
Messages: 2736
Registered: June 2005
Location: Torino

first-grade participant

From: 130.192.155*

Or in theory

Decay pbarpSystem
1.0 e+ e- PHSP PHOTOS;
Enddecay

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Re: EvtGenDirec/PHOTOS [message #22651 is a reply to message #22647]

Wed, 23 May 2018 12:08

Alaa Dbeyssi
Messages: 16
Registered: June 2012

occasional visitor

From: *emp.him.uni-mainz.de

Dear Ralf and Stefano,

thank you for your answers.
I tried both methods, but still the generated events are without photons.
From the log files one can see that PHOTOS is switched on.

Best regards,
Alaa

Attachment: myjob0yesPhotos.out
(Size: 414.98KB, Downloaded 449 times)

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Re: EvtGenDirec/PHOTOS [message #22652 is a reply to message #22651]

Wed, 23 May 2018 12:41

StefanoSpataro
Messages: 2736
Registered: June 2005
Location: Torino

first-grade participant

From: 130.192.155*

Can you plot from the simulation file the following:

cbmsim->Draw("MCTrack.fPdgCode","MCTrack.fMotherID==-1");

and attach the plot?

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Re: EvtGenDirec/PHOTOS [message #22655 is a reply to message #22652]

Wed, 23 May 2018 12:57

Alaa Dbeyssi
Messages: 16
Registered: June 2012

occasional visitor

From: *emp.him.uni-mainz.de

Hi Stefano,

here are the plots for the generated 100 events.

best regards,

Alaa

Attachment: Fig1.png
(Size: 11.50KB, Downloaded 905 times)
Attachment: Fig2.png
(Size: 8.51KB, Downloaded 788 times)

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Re: EvtGenDirec/PHOTOS [message #22658 is a reply to message #22655]

Wed, 23 May 2018 13:01

StefanoSpataro
Messages: 2736
Registered: June 2005
Location: Torino

first-grade participant

From: *ip44.fastwebnet.it

Absolutely no photons...

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Re: EvtGenDirec/PHOTOS [message #22660 is a reply to message #22658]

Wed, 23 May 2018 13:10

Alaa Dbeyssi
Messages: 16
Registered: June 2012

occasional visitor

From: *emp.him.uni-mainz.de

yes this problem appears with the new versions of PANDAROOT (feb17p1, dec17p1).
However checking the previous results with an old version of PANDAROOT (revision 25544), PHOTOS works properly by just not adding noPhotos in the decay file.

Best regards,
Alaa

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