# 2009.10.02 Jason vs. CVS EEMC geometry: sampling fraction and shower shapes

### Tests with Jason geometry file (ecalgeo.g23)

Monte-Carlo setup:

• One photon per event
• EEMC only geometry with LOW_EM option
• Throw particles flat in eta (1.08, 2.0), phi (0, 2pi), and pt (6-10 GeV)
• Using A2Emaker to get reconstructed Tower/SMD energy
(no EEMC SlowSimulator in chain)
• Vertex z=0
• ~50K/per particle type
• Non-zero energy: 3 sigma above pedestal

Color coding:

• Photon with Jason geometry (single particle MC)
• Photon with CVS (cAir fix) geometry (single particle MC)
• Eta-meson [pp2006 data] (single photons from eta-meson decay)

### Sampling fraction

Figure 1: Sampling fraction vs. thrown energy (upper plot)
and vs. azimuthal angle (lower left) and rapidity (lower right)

### Shower shapes

Single particle kinematic cuts: pt=7-8GeV, eta=1.2-1.4
Eta-meson shower shapes (blue) taken from Fig. 1 from here of this post
All shapes are normalized to 1 at peak (central strip)

Figure 2: Shower shapes

### Shower shapes sorted by pre-shower energy

Pre-shower bins:

1. Ep1 = 0, Ep2 = 0 (no energy in both EEMC pre-shower layers)
2. Ep1 = 0, Ep2 > 0
3. 0 < Ep1 < 4 MeV
4. 4 < Ep1 < 10 MeV
5. Ep1 > 10 MeV
6. All pre-shower bins combined

Ep1/Ep2 is the energy deposited in the 1st/2nd EEMC pre-shower layer.
For a single particle MC it is a sum over
all pre-shower tiles in the EEMC with energy of 3 sigma above pedestal.
For eta-meson from pp2006 data the sum is over 3x3 tower patch

Figure 3: Shower shapes (left) and their ratio (right)

Figure 4: Shower shape ratios

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