Resolve "B0Tracker acceptance tests"

Closes #50

benchmarks/b0_tracker/scripts/b0_tracker_hits.cxx

@@ -40,21 +40,21 @@ void b0_tracker_hits(const char* fname = "./sim_output/sim_forward_protons.root"
     std::vector<double> result;
     for (const auto& h : hits) {
       ROOT::Math::XYZVector vec(h.position.x,h.position.y,h.position.z);
-      result.push_back(vec.eta());
-      std::cout << vec.eta() << "\n";
+      result.push_back(1000*vec.theta());
+      std::cout << 1000*vec.theta() << "\n";
     }
     return result;
   };
 
-  auto d1 = d0.Define("hits_eta", hits_eta, {"B0TrackerHits"});
+  auto d1 = d0.Define("hits_theta", hits_theta, {"B0TrackerHits"});
 
-  auto h1 = d1.Histo1D({"h1", "hits_eta", 100, 0,20}, "hits_eta");
+  auto h1 = d1.Histo1D({"h1", "hits_theta", 100, 0,20}, "hits_theta");
   TCanvas* c = new TCanvas();
   h1->DrawCopy();
-  c->SaveAs("results/b0_tracker_hits_eta.png");
-  c->SaveAs("results/b0_tracker_hits_eta.pdf");
+  c->SaveAs("results/b0_tracker_hits_theta.png");
+  c->SaveAs("results/b0_tracker_hits_theta.pdf");
   auto n1 = h1->GetMean();
-  std::cout << "Pseudorapidity of hits: " << n1 << std::endl;
+  std::cout << "Polar angle of hits: " << n1 << std::endl;
 
   //if (n1 < 5) {
   //        std::quick_exit(1);