Sample events

• top left: preshowerE vs. showerE, cut in 800<spec_r.gas.adc_sum_t<10000;
  - This is the definition of sample electron events from gas cerenkov detector, which will be used for shower/preshower efficiency analysis. Solid curve shows additional 2D cut in showerE and preshowerE to eliminate the pion contamination in electron samples due to gas cherenkov inefficiency;
• top right: preshowerE vs. showerE, cut in spec_r.gas.adc_sum_t>10000;
  - This defines sample pion events from gas cerenkov detector, which will be used for shower/preshower efficiency analysis, which will be used for gas cherenkov efficiency analysis;
• middle left: preshowerE vs. showerE, no cut, lines show the cuts in preshowerE and showerE to select sample electron events, which will be used for gas cherenkov efficiency analysis;
• middle right: preshowerE vs. showerE, no cut, lines show the rectangular region in preshowerE and showerE to select sample pion events;
• bottom left: preshowerE vs. showerE, no cut, lines show the rectangular region in preshowerE and showerE to select sample pion events (same as middle right, in larger scale);
• bottom right:preshowerE vs. showerE, cut in spec_r.gas.adc_sum_t>10000, lines show the rectangular region in preshowerE and showerE to select sample pion events.

Figure: sample events for a high electron run