[Rivet-svn] r3670 - trunk/src/Analyses

[blackhole at projects.hepforge.org]

Author: richardn
Date: Tue Apr 10 12:33:07 2012
New Revision: 3670

Log:
fix for symmetric beam energies

Modified:
   trunk/src/Analyses/CLEO_2004_S5809304.cc

Modified: trunk/src/Analyses/CLEO_2004_S5809304.cc
==============================================================================
--- trunk/src/Analyses/CLEO_2004_S5809304.cc	Tue Apr 10 08:57:17 2012	(r3669)
+++ trunk/src/Analyses/CLEO_2004_S5809304.cc	Tue Apr 10 12:33:07 2012	(r3670)
@@ -28,7 +28,9 @@
       const Beam beamproj = applyProjection<Beam>(e, "Beams");
       const ParticlePair& beams = beamproj.beams();
       FourMomentum mom_tot = beams.first.momentum() + beams.second.momentum();
-      LorentzTransform cms_boost(-mom_tot.boostVector());
+      LorentzTransform cms_boost;
+      if(mom_tot.vector3().mod()>0.001)
+	cms_boost = LorentzTransform(-mom_tot.boostVector());
       const double s = sqr(beamproj.sqrtS());
 
       // Particle masses from PDGlive (accessed online 16. Nov. 2009).