EEmc embedding embeds EEmc hits of a MC event from geant.root to EEmc hits of a data event of StEvent. Its implementation is based on the scheme of BEmc embedding. A README gives a full details of the implementation. Below is a picture of its flow chart.

The macro that runs the embedding can be found at /star/u/wzhang/wrkdir/embed/doEEmcEmbedEvent.C. The basic chain of the macro includes

1. StIOMaker (1) - To open event.root files

2. StIOMaker (2) - To open geant.root files

3. St_db_Maker - STAR database

4. StEEmcDbMaker - EEmc database of MuDst level

5. StEEmcPreMixerMaker - This simple maker makes sure that the chain timestamp is set with the real data time.

6. StMcEventMaker - To build a StMcEvent object in the memory. StMcEvent, StMcTrack, and StMcEventMaker have to be updated for EEmc. A local updated version is availabe to be committed to CVS.

7. StEEmcSimulatorMaker - This maker gets the StMcEvent in the memory with simulated EEmc hits and does a slow simulation of the detector, generating ADC values with the correct calibration tables in EEmc database.

   After this step, we have two StEmcCollections in the memory.

   • A real one from StEvent->emcCollection()
   • A simulated one created in step 7, which could be obtained with StEEmcSimulatorMaker->getEmcCollection()

8. StEEmcMixerMaker - This maker gets the two described StEmcCollections and adds the simulated one to the real data by simply adding ADC values for each subdetector. Only simulated hits of good channels identified by the database are added.

   Special attention should be paid to the pedestal of MC events. StEEmcSimulationMaker in step 7 has a flag mAddPed. If it is turned on in simulation, pedestal will be added to ADC of MC Hits. Then, there will be a double-pedestal in the embedded ADC. To eliminated the double-pedestal, we could turn on a flag mMinusPed of this maker.

9. StEEmcA2EMaker - To recalculate energy from ADC after embedding and reconstruct EEmc

10. StEEmcClusterMaker - EEmc cluster builder

11. StAssociationMaker - TPC association

12. StEEmcAssociationMaker - EEmc association

13. StEEmcEffAnalysisMaker - User's efficiency analysis maker