p 0 dn/d q distribution for selected runs been used for cross section calculations
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I.Larin 08/11 2006 1
0 dN/d distribution for selected runsbeen used for cross section calculations
Following cuts were applied• cluster energy greater than 0.5GeV• Energy sum of two s greater than 3.5GeV• Crystal part of Hycal was used for this analysis• Hycal timing: tdif within 4ns or 8ns (optional)• Best “in tdif” (closest to 0ns) candidate
Overview of 0 dN/d distribution
then two invariant mass distribution (with energy constraint) has been produced for
each bin of (0 production angle)
I.Larin 08/11 2006 2
0 dN/d distribution for selected runs, PWO-onlyEach bin of the distribution is a result of mass distribution fit
I.Larin 08/11 2006 3
Two invariant mass plots with the double gaussian fit; dN/dfor bins for = 0…0.16 degrees
I.Larin 08/11 2006 4
Two invariant mass plots with the double gaussian fit; dN/d for bins for = 1.12…1.28 degrees
I.Larin 08/11 2006 5
Two invariant mass plots with the double gaussian fit; dN/d for bins for = 2.4…2.56 degrees
I.Larin 08/11 2006 6
Two invariant mass plot with the double gaussian fit; dN/d for all bins
I.Larin 08/11 2006 7
No systematic shift between number of signal events in the total distribution and sum of partial (dN/d) mass distributions within statistical error of ~1%
I.Larin 08/11 2006 8
0 invariant mass spectrum without and with energy constraint
Contribution of selected bands
I.Larin 08/11 2006 9
Elasticity distribution with 0 mass constraint for events with no Hycal trigger bit-9 presented and
for all events
I.Larin 08/11 2006 10
No artificial structure under the elasticity peak resulting from mass constraint method is seen
I.Larin 08/11 2006 11
0 tdif distributionEach bin of the distribution is a result of mass distribution fit
I.Larin 08/11 2006 12
Two g invariant mass plot with the double gaussian fit; dN/d for all bins
| tdif | < 8ns cut
Difference betweendistributions with| tdif | < 8ns and| tdif | < 4ns cuts
I.Larin 08/11 2006 13
Two plots for| tdif | < 8ns and | tdif | < 4ns cutsPrimakoff region is selected
0 dN/d distribution, comparing timing cuts
I.Larin 08/11 2006 14
Difference between two results obtained with 4ns and 8ns timing cut is 0.8%
which is also within statistical error level
I.Larin 08/11 2006 15
Studying tagging ratio fluctuations during the first snake scan
• First, events with Tagger hit in one of 11 production T-counters were selected
• Hycal scan periods close to edges or central hole were excluded from the analysis as well as beam trips
• Then Hycal energy deposition was required to distinguish “false” and “real” Tagger candidates
• Three sets of “enough energy” in Hycal were selected: 20%, 40% and 60% of nominal beam energy (given by Tagger)
I.Larin 08/11 2006 16
Hycal energy response: ratio of Hycal energy to Beam energy defined by Tagger
I.Larin 08/11 2006 17
Tagging ratio (integrated over all 11 T-counters) defined with 3 values of Hycal energy cut VS snake scan time
I.Larin 08/11 2006 18
Tagging ratio (integrated over all 11 T-counters) fluctuations during the first snake
One entry per one time interval
I.Larin 08/11 2006 19
Tagging ratio for 1 and 2 T-counters, fluctuations during the first snake
I.Larin 08/11 2006 20
Tagging ratio for all E-channels, defined with Hycal, integrated over all first snake time
I.Larin 08/11 2006 21
Tagging ratio fluctuations during the first snake scan period were within 0.9%
Since Hycal was used in this study some fluctuations may come from Hycal response function difference for different Hycal parts
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