2008.06.18 Photon-jet reconstruction with the EEMC detector (talk at the STAR Collaboration meeting)

Ilya Selyuzhenkov June 18, 2008

Slides

Photon-jet reconstruction with the EEMC detector - Part 1: pdf or odp

Talk outline (preliminary)

1. Introduction and motivation

2. Data samples (pp2006, MC gJet, MC QCD bg)
   and gamma-jet reconstruction algorithm:

   • di-jets, isolation cuts, EEMC 3x3 cluster
   • Data sets used and sample EEMC response to a photon candidate

3. Comparing pp2006 with Monte-Carlo simulations scaled to the same luminosity
   (EEMC pre-shower sorting):

   • Gamma pt distribution
   • gamma and jet pt, eta, phi, gamma-jet delta_pt, eta, phi distributions
   • Energy distributions in various EEMC layers

4. EEMC SMD shower shapes from different data samples
   (pp2006 and data-driven Monte-Carlo):

   • Shower shapes sorted by energy in pre-shower 1 and 2 layers
   • pp2006 shower shapes sorted by vertex z, detector eta, phi, pt

5. Sided residual plots: pp2006 vs data-driven Monte-Carlo
   (gammas from eta meson: 3 gaussian fits)

   • Sided residual: 2D correlations
   • Sided residual: 1D projections

6. Various cuts study:

   • R_cluster cut of 0.99 and 0.9 comparison
     (Cluster energy distribution vs number of EEMC towers fired: Fig.4)
   • Charge particle veto and TPC tracking
   • Away side jet pt matching

7. Some QA plots:

   • Gamma candidate u- vs. v- plane high strip distribution; x:y position
   • Vertex z distribution

8. A_LL reconstruction technique:

   • Method and gamma-jet candidates raw asymmetry

9. Work in progress... To do list:

   • Understading MC background and pp2006 data shower shapes discrepancy
   • Implementing sided residual technique with shapes sorted by pre1&2 (eta, sector, etc?)
   • Tuning analysis cuts
   • Quantifying signal to background ratio
   • Background subtraction for A_LL, ...
   • What else?
10. Talk summary