1. Test Pulse Neighbors #4 Carl Goodrich 10/2/07

2. Last Time In Phi Detectors –Every link can be classified as either C 0, C 1, or C 2, based on the arrangement of inner and outer strips –In all C 1 links, channels 6 and 21 were affected by the test pulse (injected into 4 and 23) Double gaussian- reflects large cross-talk

3. Cross-talk and Histograms Think of every histogram as two gaussians centered at x + and x -. In most cases, x + = x - ≈ 0, resulting in a single peek. We can think of x ± as a function of the test pulse: x ± = γ * TP ± γ is a (unitless) measure of the cross talk γ = 1 at channels 4 and 23 Note: γ can be negative γ << 1 γ ≈ 5 / 40 γ ≈ 0.125

4. Data Selection Polarity of TP(4) and TP(23) are always opposite –Consider only “+” data around ch. 4 and “-” data around ch. 23 Exclude every event (in the whole link) where the CMs signal is negative at ch. 4

5. TELL1 27, link 9 (C 0 )- select data Ch.4 Ch.23 TP + TP -

6. TELL1 27, link 10 (C 1 ) - select data Ch.4 Ch.23 TP + TP -

7. TELL1 27, link 11 (C 2 ) - select data Ch.4 Ch.23 TP + TP -

8. γ for each neighbor

9. TELL1 27, link 9 (C 0 ) Ch.4 Ch.23

10. TELL1 27, link 10 (C 1 ) Ch.4 Ch.23

11. TELL1 27, link 11 (C 2 ) Ch.4 Ch.23