After the Run 12 pp510 BeamLine was re-calibrated this month, I did some checks.

Question: would more restrictive cuts significantly alter the distributions of BeamLine parameters?

Answer: I compared the following sets of cuts:

1. Red triangles: BEMC matches >= 7, mult > 20 (used in the calibration)
2. Green crosses: BEMC matches >= 7, mult > 20, EEMC matches > 5
3. Blue circles: BEMC matches >= 7, mult > 40

Here are the distributions of parameters versus day and ZDC coincidence rate (which was unfortunately altered for days 85-86, thus giving a few points with very low ZDC values):

...vs. day:

...and vs. ZDC:

Differences appear to be at the sub-100 micron level in intercepts, and ~1-2e-4 (which corresponds to 100-200 microns at ±100 cm) level in slopes. This gives an idea of the systematic errors of the calibration, which are about at the level we try to achieve.

-Gene