r3  04 Sep 2012  15:57  RobertoPerezBenito  r2  12 Sep 2011  13:52  RobertoPerezBenito  

Event Generators 
Event Generators 

twoPionGen 
Documentation for the event generators developed in our group... 

A Monte Carlo event generator for the process , when both the proton target and the antiproton beam are unpolarized, is described. The kinematic region covers the antiproton momentum range from 0.79GeV to 12.0GeV, in the LAB frame. For the low energy regime, the parametrization of the cross section is based on a Legendre polynomial fit to data from the (antiproton beam) CERN 28GeV proton synchroton. For the high energy regime, the recent predictions by J. van de Wiele and S. Ong based on a Regge Theory approach were used. The generator is a useful first tool to study pion production at PANDA. 


The generator is part of the current "trunk" version of PANDA ROOT. 

Full documentation for the event generator can be found here. 

The and cross section 

We describe the differential cross section for the processes , with or , and , when both the proton target and the antiproton beam and the antiproton beam are unpolarized. For lepton production, the cross section is a leading order calculation with a massive lepton in the final state. For pion production, the parametrization of the cross section in the low energy regime is based on a Legendre polynomial fit to data from the (antiproton beam) CERN 28GeV proton synchroton, whereas in the high energy regime the recent predictions by J. van de Wiele and S. Ong based on a Regge Theory approach were used. A computer code to perform integration of both the lepton and pion cross section in a userdefined kinematic region is also described. 

Full documentation can be found here. 

A tar (gziped) file with the computer code to perform numerical integration of both the lepton and pion cross section can be found here. 

r3  04 Sep 2012  15:57  RobertoPerezBenito  r2  12 Sep 2011  13:52  RobertoPerezBenito  