May 10, 2019 - PrimEx-Eta Meeting
Time and Place
- Time: Friday, May 10, 2019 2:00 pm EST.
- Room: CEBAF Center, Room F227
- If joining via web browser, go to  https://jlab.bluejeans.com/7572695553/
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- eta -> 2gamma Plots
- Drew showed some plots (see slides) showing the motivations for the cuts and vetos used in selecting eta -> 2gamma events, as well as highlighting some issues that will need to be studied in detail at a later point.
- These plots were all made using the default calibration constants with a time stamp from the middle of April, so they don't have any updates to the timing or energy calibrations applied.
- It would good to ask Sean to attend one of the meetings in the future to give a detailed explanation as to how the fcal and rf timing is calculated.
- Ilya pointed out that we will likely need to study each channel of the hadronic background individually with simulations.
- For some reason, subtracting accidentals reduced the eta yields consistently over all angular bins. This likely indicates an issue with the fitting that needs to be corrected.
- CCAL LED stability
- Sasha showed some plots of the LED signal amplitude as a function of the run number.
- His plots showed the signals were pretty consistent (2-3% fluctuations), however some channels close to the center saw a clear trend in the signal amplitude over the course of the run
- Reference PMT signals also look pretty stable, with even less fluctuation.
- Overview of Ilya's physics talk at the collaboration meeting:
- what is primexd, statistics
- mention compton on different targets
- dNdTheta, constrained mass, elasticity
- Future Plans:
- analyze data
- ask for second run