Fix on magnetic field sign used in error calculation (F. Prino)

diff --git a/ITS/AliITSVertexer3D.cxx b/ITS/AliITSVertexer3D.cxx
index 270252cb8441a57d599d3b482d4f1c8d0f5964eb..a645099fa5b0d08b1f859b2a441d411464c47699 100644 (file)
--- a/ITS/AliITSVertexer3D.cxx
+++ b/ITS/AliITSVertexer3D.cxx
@@ -338,9 +338,9 @@ Int_t AliITSVertexer3D::FindTracklets(TTree *itsClusterTree, Int_t optCuts){
   Double_t a[3]={xbeam,ybeam,0.}; 
   Double_t b[3]={xbeam,ybeam,10.};
   AliStrLine zeta(a,b,kTRUE);
-  static Double_t bField=AliTracker::GetBz()/10.; //T
+  static Double_t bField=TMath::Abs(AliTracker::GetBz()/10.); //T
   SetMeanPPtSelTracks(bField);
-
+  
   Int_t nolines = 0;
   // Loop on modules of layer 1
   for(Int_t modul1= firstL1; modul1<=lastL1;modul1++){   // Loop on modules of layer 1