set SigmaX and SigmaY from LPC-like calculation in BetaFunc case

cms-sw · Nov 1, 2023 · a773608 · a773608
1 parent b9a4b4c
commit a773608
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Showing 4 changed files with 40 additions and 8 deletions.
diff --git a/CondFormats/BeamSpotObjects/interface/SimBeamSpotObjects.h b/CondFormats/BeamSpotObjects/interface/SimBeamSpotObjects.h
@@ -35,8 +35,8 @@ class SimBeamSpotObjects {
     fMeanX = 0.0;
     fMeanY = 0.0;
     fMeanZ = 0.0;
-    fSigmaX = 0.0;
-    fSigmaY = 0.0;
+    fSigmaX = -1.0;
+    fSigmaY = -1.0;
     fSigmaZ = 0.0;
     fbetastar = 0.0;
     femittance = 0.0;
@@ -56,8 +56,8 @@ class SimBeamSpotObjects {
   void setMeanY(double val) { fMeanY = val; }
   void setMeanZ(double val) { fMeanZ = val; }
   /// set sigmaX, sigmaY, sigmaZ
-  void setSigmaX(double val) { fSigmaX = val; }
-  void setSigmaY(double val) { fSigmaY = val; }
+  void setSigmaX(double val);
+  void setSigmaY(double val);
   void setSigmaZ(double val) { fSigmaZ = val; }
   /// set BetaStar and Emittance
   void setBetaStar(double val) { fbetastar = val; }

diff --git a/CondFormats/BeamSpotObjects/src/SimBeamSpotObjects.cc b/CondFormats/BeamSpotObjects/src/SimBeamSpotObjects.cc
@@ -1,7 +1,28 @@
 #include "CondFormats/BeamSpotObjects/interface/SimBeamSpotObjects.h"
 
+#include <cmath>
 #include <iostream>
 
+// Set SigmaX and SigmaY:
+// - from value in case of Gaussian Smearing
+// - from LPC-like calculation in case of BetaFunc Smearing
+void SimBeamSpotObjects::setSigmaX(double val) {
+  if (val >= 0.) {  // Gaussian smearing
+    fSigmaX = val;
+  } else {  // BetaFunc smearing
+    fSigmaX = (1 / std::sqrt(2)) * std::sqrt(femittance * fbetastar);
+  }
+}
+
+void SimBeamSpotObjects::setSigmaY(double val) {
+  if (val >= 0.) {  // Gaussian smearing
+    fSigmaY = val;
+  } else {  // BetaFunc smearing
+    fSigmaY = (1 / std::sqrt(2)) * std::sqrt(femittance * fbetastar);
+  }
+}
+
+// Printout SimBeamSpotObjects
 void SimBeamSpotObjects::print(std::stringstream& ss) const {
   ss << "-----------------------------------------------------\n"
      << "              Sim Beam Spot Data\n\n"

diff --git a/CondTools/BeamSpot/plugins/BeamProfile2DBWriter.cc b/CondTools/BeamSpot/plugins/BeamProfile2DBWriter.cc
@@ -63,14 +63,14 @@ BeamProfile2DBWriter::BeamProfile2DBWriter(const edm::ParameterSet& iConfig)
   beamSpot_.setMeanX(iConfig.getParameter<double>("MeanX"));
   beamSpot_.setMeanY(iConfig.getParameter<double>("MeanY"));
   beamSpot_.setMeanZ(iConfig.getParameter<double>("MeanZ"));
-  beamSpot_.setSigmaX(iConfig.getParameter<double>("SigmaX"));
-  beamSpot_.setSigmaY(iConfig.getParameter<double>("SigmaY"));
   beamSpot_.setSigmaZ(iConfig.getParameter<double>("SigmaZ"));
   beamSpot_.setAlpha(iConfig.getParameter<double>("Alpha"));
   beamSpot_.setPhi(iConfig.getParameter<double>("Phi"));
   beamSpot_.setBetaStar(iConfig.getParameter<double>("BetaStar"));
   beamSpot_.setEmittance(iConfig.getParameter<double>("Emittance"));
   beamSpot_.setTimeOffset(iConfig.getParameter<double>("TimeOffset"));
+  beamSpot_.setSigmaX(iConfig.getParameter<double>("SigmaX"));
+  beamSpot_.setSigmaY(iConfig.getParameter<double>("SigmaY"));
 }
 
 //
@@ -99,8 +99,8 @@ void BeamProfile2DBWriter::fillDescriptions(edm::ConfigurationDescriptions& desc
   desc.add<double>("MeanX", 0.0)->setComment("in cm");
   desc.add<double>("MeanY", 0.0)->setComment("in cm");
   desc.add<double>("MeanZ", 0.0)->setComment("in cm");
-  desc.add<double>("SigmaX", 0.0)->setComment("in cm");
-  desc.add<double>("SigmaY", 0.0)->setComment("in cm");
+  desc.add<double>("SigmaX", -1.0)->setComment("in cm");
+  desc.add<double>("SigmaY", -1.0)->setComment("in cm");
   desc.add<double>("SigmaZ", 0.0)->setComment("in cm");
   desc.add<double>("BetaStar", 0.0)->setComment("in cm");
   desc.add<double>("Emittance", 0.0)->setComment("in cm");

diff --git a/CondTools/BeamSpot/test/BeamProfile2DBWriter_cfg.py b/CondTools/BeamSpot/test/BeamProfile2DBWriter_cfg.py
@@ -42,11 +42,22 @@
 process.maxEvents = cms.untracked.PSet(input = cms.untracked.int32(1))
 
 from CondTools.BeamSpot.beamProfile2DBWriter_cfi import beamProfile2DBWriter
+# For the BetaFunc smearing (realistic Beamspot) set the following parameters:
+# - X0, Y0, Z0, SigmaZ, BetaStar, Emittance
 process.BeamProfile2DBWriter = beamProfile2DBWriter.clone(X0        = 0.0458532,
                                                           Y0        = -0.016966,
                                                           Z0        = -0.074992,
                                                           SigmaZ    = 3.6,
                                                           BetaStar  = 30.0,
                                                           Emittance = 3.931e-8,)
 
+# For the Gaussian smearing (ideal Beamspot) set the following parameters:
+# - MeanX, MeanY, MeanZ, SigmaX, SigmaY, SigmaZ
+#process.BeamProfile2DBWriter = beamProfile2DBWriter.clone(MeanX     = 0.0,
+#                                                          MeanY     = 0.0,
+#                                                          MeanZ     = 0.0,
+#                                                          SigmaX    = 0.0015,
+#                                                          SigmaY    = 0.0015,
+#                                                          SigmaZ    = 3.6,)
+
 process.p = cms.Path(process.BeamProfile2DBWriter)