2009.12.07 Low EM study: LOW_EM option, 100KeV cuts, and DCUTE=100KeV

Updated on Wed, 2009-12-09 13:45. Originally created by seluzhen on 2009-12-07 08:49.

physics

Conclusions/dicsussion at the emc2 hypernew
http://www.star.bnl.gov/HyperNews-star/get/emc2/3369.html
http://www.star.bnl.gov/HyperNews-star/get/emc2/3375.html

Monte-Carlo setup:

Throwing one photon per event
Full STAR y2006h (latest EEMC, v6.1 and TPC, v04 geometries)
Throw particles flat in eta (1.08, 2.0), phi (0, 2pi), and energy (5-35 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

GEANT EM cuts list (default values in GeV)

CUTGAM - cut for gammas (GEANT default = 0.001)
CUTELE - cut for electrons (GEANT default = 0.001)
CUTHAD - cut for charged hadrons (GEANT default = 0.01)
CUTNEU - cut for neutral hadrons (GEANT default = 0.01)
CUTMUO - cut for muons (GEANT default = 0.01)
BCUTE - cut for electron brems (GEANT default = CUTGAM)
BCUTM - cut for muon brems (GEANT default = CUTGAM)
DCUTE - cut for electron delta-rays (GEANT default = 10^4)
DCUTM - cut for muon delta-rays (GEANT default = 10^4)
LOSS - energy loss
STRA - energy fluctuation model
Birks law parameters (Tracking Parameters)
MODEL BIRK1; RKB BIRK2; C BIRK3

Low EM cut configurations (values in GeV)

NoCuts: Default STAR geometry EM cuts

Endcap EMC setup is quite non-uniform
(all cuts are set via "Call GSTPAR (ag_imed,'CutName', Value)":
- Block EMGT: 30 degree megatile
  CUTGAM = 0.00001
  CUTELE = 0.00001
- Block ESCI: active scintillator (polystyrene) layer
  CUTGAM = 0.00008
  CUTELE = 0.001
  BCUTE = 0.0001
  CUTNEU = 0.001
  CUTHAD = 0.001
  CUTMUO = 0.001
  c-- Define Birks law parameters
  BIRK1 = 1.
  BIRK2 = 0.013
  BIRK3 = 9.6E-6
- Block ELED : lead absorber plate
  CUTGAM = 0.00008
  CUTELE = 0.001
  BCUTE = 0.0001
  CUTNEU = 0.001
  CUTHAD = 0.001
  CUTMUO = 0.001
- Block EALP: thin aluminium plate in calorimeter cell
  CUTGAM = 0.00001
  CUTELE = 0.00001
  LOSS = 1.
  STRA = 1.
- Block EHMS: defines the triangular SMD strips
  CUTGAM = 0.00008
  CUTELE = 0.001
  BCUTE = 0.0001
  c-- Define Birks law parameters
  BIRK1 = 1.
  BIRK2 = 0.0130
  BIRK3 = 9.6E-6
100KeV: All cuts are set to 100KeV
CUTGAM = 0.0001
CUTELE = 0.0001
BCUTE = 0.0001
BCUTM = 0.0001
DCUTE = 0.0001
DCUTM = 0.0001
DCUTE: All cuts are set to 10KeV, except electron delta-rays (DCUTE = 100KeV)
CUTGAM = 0.00001
CUTELE = 0.00001
BCUTE = 0.00001
BCUTM = 0.00001
DCUTE = 0.0001
DCUTM = 0.00001
LOW_EM: All cuts are set to 10KeV
CUTGAM = 0.00001
CUTELE = 0.00001
BCUTE = 0.00001
BCUTM = 0.00001
DCUTE = 0.00001
DCUTM = 0.00001

Figure 1: Endcap EMC sampling fraction for different cluster sizes:
1x1, 2x1, 3x3, and total energy in the EEMC
Lower right plot shows total s.f. vs. photon thrown energy