04 Apr

April 2009 posts

2009.04.17 WSU nuclear seminar

The STAR spin program with longitudinally polarized proton beams

2009.04.21 Adding SMD info to the LDA

Cut optimization with Fisher's LDA classifier

ROOT implementation for LDA:

Application for cuts optimization in the gamma-jet analysis

LDA configuration: default

LDA input parameters:

  1. Energy fraction in 3x3 cluster within a r=0.7 radius: r3x3
  2. Photon-jet pt balance: [pt_gamma-pt_jet]/pt_gamma
  3. Number of charge tracks within r=0.7 around gamma candidate
  4. Number of Endcap towers fired within r=0.7 around gamma candidate
  5. Number of Barrel towers fired within r=0.7 around gamma candidate

Figure 1: LDA discriminant (no SMD involved in training)

Figure 2: LDA (no SMD): Efficiency, rejection, purity vs. discriminant

Figure 3: SMD energy in 25 central strips (LDA-dsicriminant>0, no pre-shower1 cut)

Figure 4: SMD energy in 25 central strips (LDA-dsicriminant>0, pre-shower1 < 10MeV)

Figure 5: Maximum residual (LDA-dsicriminant>0, no pre-shower1 cut)

Figure 6: Maximum residual (LDA-dsicriminant>0, pre-shower1 < 10MeV)

LDA+ SMD analysis

SMD info added:
a) energy in 5 central srtips
b) maximum sided residual

Figure 7:LDA with SMD: Efficiency, rejection, purity vs. LDA discriminant

Figure 8: LDA discriminant with SMD

Figure 9: Maximum residual (SMD LDA-dsicriminant>0, pre-shower1 < 10MeV)

LDA with and without SMD comparison

Figure 10:LDA (no SMD): Efficiency, rejection, purity plots

Figure 11: LDA with SMD: Efficiency, rejection, purity plots

2009.04.28 LDA plus SMD analysis with pre-shower sorting

Cut optimization with Fisher's LDA classifier

ROOT implementation for LDA:

Application for cuts optimization in the gamma-jet analysis

LDA configuration: default

LDA input parameters (includes SMD inromation of the distance from max sided residual plot):

  1. Energy fraction in 3x3 cluster within a r=0.7 radius: r3x3
  2. Photon-jet pt balance: [pt_gamma-pt_jet]/pt_gamma
  3. Number of charge tracks within r=0.7 around gamma candidate
  4. Number of Endcap towers fired within r=0.7 around gamma candidate
  5. Number of Barrel towers fired within r=0.7 around gamma candidate
  6. Distance to 80% cut line (see this link for more details)

The number of strips in SMD u or v planes is required to be greater than 3

Figure 1: SMD energy in 25 central strips sorted by pre-shower energy

  1. Upper left: pre1=0, pre2=0
  2. Upper right: pre1=0, pre2>0
  3. Lower left: 0<4MeV
  4. Lower right: 4<10MeV

Right plot for each pre-shower condition shows the ratio of pp2006 data to sum of the Monte-Carlo samples
Colour coding:
black pp2006 data, red gamma-jet MC, green QCD MC, blue gamma-jet+QCD
(combined plot for all pre-shoer bins can be found here)

 

Figure 2: SMD energy in 5 central strips sorted by pre-shower energy
(combined plot can be found here)

Figure 3: Maximum residual sorted by pre-shower energy
(combined plot can be found here)

Figure 4: LDA discriminant. Note: LDA algo trained for each pre-shower condition independently

Figure 5: LDA: Efficiency, rejection, purity vs. discriminant, sorted by pre-shower energy

Figure 6: LDA: Efficiency, rejection, purity plots sorted by pre-shower energy
For each pre-shower condition each plot has 4 figures:

  1. u-left: rejection vs. efficiency
  2. u-right: purity vs. efficiency
  3. l-left: purity vs. rejection
  4. l-right: significance (signal/sqrt{signal+background}) vs. efficiency