| EvtGenDirec/PHOTOS [message #22633] | 
			Tue, 22 May 2018 13:57   | 
		 
		
			
				
				
				
					
						  
						Alaa Dbeyssi
						 Messages: 16 Registered: June 2012 
						
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					occasional visitor  | 
					From: *emp.him.uni-mainz.de
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		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 
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The decay file is: 
 
Decay pbarpSystem 
  1.0  e+ e-     PHSP; 
Enddecay 
 
End 
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