# 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:

- Ep1 = 0, Ep2 = 0 (no energy in both EEMC pre-shower layers)
- Ep1 = 0, Ep2 > 0
- 0 < Ep1 < 4 MeV
- 4 < Ep1 < 10 MeV
- Ep1 > 10 MeV
- 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