Introduction

A series of runs were taken March 7 & 8 with various thresholds on the ZDC and BBC conditions.  I will analyze these in 3 groups, as described by Jim here.   Until now the threshold was 60 60 front and back with BBC coincidence required.

Group One: Runs 10066175-7

These runs have about 2M events.  These runs had higher thresholds on the ZDC front and back of 150.  I correct for ped and gain and require a coincidence above a threshold of corrected ADC >=10.  After this cut I have about 200K events in the east ZDC for each of the 4 spin states and 300K events in the west ZDC for each of the 4 spin states.  Slat by slat and phi distribuiton asymmetries for this group are posted as group_one.pdf in the attachments.

The beam polarizations for these runs are:

Yellow= 0.232+/-0.015,      Blue= 0.206+/-0.017

This implies an analyzing power of ~6% for the yellow beam and ~9% for the blue beam.

Group Two: Runs 10067001-002

These runs have about 1M events.  These runs had thresholds on front, back and sum of 60 60 120.  After cuts I have about 150K events on the east for each spin state and 200K events on the west for each spin state.

With the above beam polarizations this implies analyzing powers of about 8% for the yellow beam and about 9% for the blue beam.

Group Three: Runs 10067003-008

Conditions varied on these runs, to quote Jim:

"Then I tried the requested relaxed BBC conditions. Runs 10067003-8 used
various combinations of one ZDC (F B 60 60) with one BBC. That is EE EW
WE and WW. The first 4 runs I checked the rate for each pair
independently.
10067003 zdcEbbcW ran at 600 Hz
10067004 zdcWbbcE ran at 800 Hz
10067005 zdcWbbcW ran at 750 Hz
10067006 zdcEbbcE ran at 520 Hz
Then 007 and 008 were run with all 4 in at the same time."

Again have about 1M events.  After cuts I have about 150K events in the east for each spin state and about 200K events in the west for each spin state.

 With the above beam polarizations this implies analyzing powers of about 9% for the yellow beam and about 8% for the blue beam.

Group Three Separately

After further discussion, it may not be best to analyze all of these together.  So I have runs 3-6, with only one trigger each, analyzed separately, with results attached.  Note that anytime we trigger on zdcX I don't get get a lot of events in direction Y.