--- PamCut/CollectionActions/Histo2DActions/MassVsRigHistoAction/MassVsRigHistoAction.cpp	2010/04/07 10:31:43	1.3
+++ PamCut/CollectionActions/Histo2DActions/MassVsRigHistoAction/MassVsRigHistoAction.cpp	2010/04/20 10:26:25	1.4
@@ -8,6 +8,7 @@
 /*! @file MassVsRigHistoAction.cpp The MassVsRigHistoAction class implementation file. */
 
 #include "MassVsRigHistoAction.h"
+#include "TMath.h"
 
 MassVsRigHistoAction::MassVsRigHistoAction(const char *actionName, TString outFileBase, TString mode,
     bool outRoot, bool outText, TString title, Int_t Z, TString rigBinFile) :
@@ -17,9 +18,10 @@
 
 void MassVsRigHistoAction::OnGood(PamLevel2 *event) {
     Float_t betaev = event->GetTrack(0)->GetToFTrack()->beta[12];
-    if(betaev>1) betaev = 2-betaev;
     Float_t rigev = 1./event->GetTrack(0)->GetTrkTrack()->GetDeflection();
-    Float_t Mass = _Z*rigev*sqrt(pow(betaev,-2)-1);
+    Float_t Mass = 0;
+    if(TMath::Abs(betaev) <= 1.) Mass = _Z*rigev*sqrt(pow(betaev,-2)-1);
+    else Mass = -_Z*rigev*sqrt(1-pow(betaev,-2));
     Fill(rigev, Mass);
 }