Change definition of underlying event in jetHadronsPid.cxx

Instead of using randomly chosen orthogonal axis and drawing cones, rotate cones by 90 degrees in phi both ways while keeping eta the same , creating two underlying event cones

Author: llorenc-11

PWGJE/Tasks/jetHadronsPid.cxx

@@ -400,14 +400,20 @@ struct JetHadronsPid {
 
   void getPerpendicularDirections(const TVector3& p, TVector3& u1, TVector3& u2)
   {
-    double const treshold = 1e-9;
-    if (p.Mag2() < treshold) {
+    double const threshold = 1e-9;
+
+    if (p.Pt() < threshold) {
       u1.SetXYZ(0, 0, 0);
       u2.SetXYZ(0, 0, 0);
       return;
     }
-    u1 = p.Orthogonal();
-    u2 = p.Cross(u1);
+
+    double pt = p.Pt();
+    double eta = p.Eta();
+    double phi = p.Phi();
+
+    u1.SetPtEtaPhi(pt, eta, phi + PIHalf);
+    u2.SetPtEtaPhi(pt, eta, phi - PIHalf);
   }
 
   template <typename TrackIts>