1. Hycal response function study

2. Observed elasticity during snake scan when beam was centered on W2016
Shape of experimentally observed response function:
*) resp. function itself
*) accidentals (with false tagger hits)
*) + electronics noise ??
*) + “leakage” ??
response function tail
“pile up”
threshold ?
Which part of experimentally observed response function should be compared with the function reproduced by MC ?

3. Response function was split into elasticity regions
X = min – 0.2
X = 0.2 – 0.5
X = 0.5 – 0.8
X = 0.8 – 0.9
These regions probably are lost in data analysis

4. Fraction of events in these elasticity regions were estimated for runs with different beam current: 20, 30, 50, 60, 95 pA
Hycal resp. function itself
is assumed independent from beam current.
Fit was applied.
Fitting function:
Y = c1/x + c0
Values of c0 were
Used as asymptotic
values.

5. What does MC reproduce for response function
snake
centered
Tails in MC are due to wrapping. “Zero” bin vanishes at beam slope > few mrad and looks not significant for p0 and compton.
“Zero” bin can be confirmed or rejected during the next run. It can be used as a measure of wrapping “effective thickness”.

6. Compare data with MC Difference between data and MC ~ 0.5 – 0.9%
1.3GeV
4.4GeV
X range MC
Data asympt.
Min – 0.2
0.02 ± 0.00
0.15 ± 0.03
0.2 – 0.5
0.23 ± 0.04
0.5 – 0.8
0.07 ± 0.01
0.40 ± 0.05
0.8 – 0.9
0.38 ± 0.02
0.61 ± 0.05
X range MC
Data asympt.
Min – 0.2
0.03 ± 0.01
0.06 ± 0.02
0.2 – 0.5
0.02 ± 0.00
0.14 ± 0.04
0.5 – 0.8
0.08 ± 0.01
0.26 ± 0.03
0.8 – 0.9
0.40 ± 0.02
0.57 ± 0.04

7. Observed tagging ratio (using Hycal) for different E-channels within one (isolated) T-channel
Tagging ratio looks have -1% jump when “entering production region”.
False hits
real hits
False hits
real hits