test: impact on M_X from boost patch

draw_mx.C

@@ -0,0 +1,19 @@
+// ninja && clas-stringspinner --seed 29877 --trig 10000 --cut-inclusive 11,211,-211|grep M_X| awk '{print $2}' > output.dat
+void draw_mx(TString file_name = "output.dat", TString title = "m_x") {
+  auto tr = new TTree();
+  tr->ReadFile(file_name, "mx/D");
+  // new TCanvas();
+  // tr->Draw("mx");
+  auto c = new TCanvas("c", "c", 800, 600);
+  auto mx_dist = new TH1D("mx_dist",title,100,0.9,1.5);
+  tr->Project("mx_dist", "mx");
+  mx_dist->Draw();
+  auto peak = mx_dist->GetBinCenter(mx_dist->GetMaximumBin());
+  auto dev = 0.03;
+  // mx_dist->Fit("gaus","","",peak-dev,peak+dev);
+  auto delta = new TLine(1.232, 0, 1.232, mx_dist->GetMaximum());
+  delta->SetLineColor(kRed);
+  delta->SetLineWidth(3);
+  delta->Draw();
+  c->SaveAs(file_name+".png");
+}

draw_mx_2.C

@@ -0,0 +1,25 @@
+// ninja && clas-stringspinner --seed 29877 --trig 10000 --cut-inclusive 11,211,-211|grep M_X| awk '{print $2}' > output.dat
+void draw_mx_2(TString file_name = "output.both.dat") {
+  gStyle->SetOptStat(0);
+  auto tr = new TTree();
+  tr->ReadFile(file_name, "mx_before/D:mx_after/D");
+  // new TCanvas();
+  // tr->Draw("mx");
+  auto c = new TCanvas("c", "c", 800, 600);
+  auto mx_dist_before = new TH1D("mx_dist_before", "M_{X} distribution", 60, 1.0, 1.35);
+  auto mx_dist_after = new TH1D("mx_dist_after",   "M_{X} distribution", 60, 1.0, 1.35);
+  tr->Project("mx_dist_before", "mx_before");
+  tr->Project("mx_dist_after", "mx_after");
+  mx_dist_before->SetLineColor(kBlue);
+  mx_dist_after->SetLineColor(kRed);
+  mx_dist_after->SetLineStyle(kDashed);
+  mx_dist_after->SetLineWidth(2);
+  mx_dist_before->SetLineWidth(2);
+  mx_dist_before->Draw();
+  mx_dist_after->Draw("same");
+  auto delta = new TLine(1.232, 0, 1.232, mx_dist_before->GetMaximum());
+  delta->SetLineColor(kGreen+1);
+  delta->SetLineWidth(3);
+  delta->Draw();
+  c->SaveAs(file_name+".png");
+}

src/clas-stringspinner.cpp

@@ -694,6 +694,60 @@ int main(int argc, char** argv)
           lund_particle.vz
           );
 
+    // make sure we have a delta
+    bool delta_found = false;
+    for(auto const& par : *evt.particles()) {
+      if(par.id() == 2214) {
+        delta_found = true;
+        break;
+      }
+    }
+    if(!delta_found) continue;
+
+    // find the scattered electron
+    int ele_idx = -1;
+    double ele_p = -10000;
+    for(int idx = 0; idx < evt.size(); ++idx) {
+      auto const& par = evt[idx];
+      if(par.isFinal() && par.id() == 11) {
+        auto this_p = std::hypot(par.px(), par.py(), par.pz());
+        if(this_p > ele_p) {
+          ele_p = par.e();
+          ele_idx = idx;
+        }
+      }
+    }
+    // fmt::print("ele_idx = {}\n", ele_idx);
+    if(ele_idx < 0) continue;
+
+    // loop over pi+ pi- dihadrons
+    for(int idxA = 0; idxA < evt.size(); ++idxA) {
+      auto const& parA = evt[idxA];
+      if(parA.isFinal() && parA.id() == 211) {
+        for(int idxB = 0; idxB < evt.size(); ++idxB) {
+          auto const& parB = evt[idxB];
+          if(parB.isFinal() && parB.id() == -211) {
+
+            Pythia8::Vec4 p_beam(0.0, 0.0, 10.6040999877, 10.6041);
+            Pythia8::Vec4 p_target(0.0, 0.0, 0.0, 0.93827);
+
+            auto p_ele = evt[ele_idx].p();
+            auto p_pip = parA.p();
+            auto p_pim = parB.p();
+
+            // calculate missing mass
+            auto vecW = p_beam + p_target - p_ele;
+            auto vecPh = p_pip + p_pim;
+            auto M_X = (vecW - vecPh).mCalc();
+            fmt::print("M_X {}\n", M_X);
+          }
+        }
+      }
+    }
+
+    // if(evnum < 1000)
+    //   evt.list(false, false, 10);
+
     // finalize
     if(!enable_count_before_cuts) {
       if(++evnum >= num_events)

src/config/clas12.h

@@ -70,6 +70,6 @@ inline void config_clas12(Pythia8::Pythia& pyth) {
   // handle event printouts
   set_config(pyth, "Next:numberShowInfo = 0");
   set_config(pyth, "Next:numberShowProcess = 0");
-  set_config(pyth, "Next:numberShowEvent = 1");
+  set_config(pyth, "Next:numberShowEvent = 0");
 
 }