02 Feb

February 2009 posts

 

2009.02.02 No pre-shower cuts, Normalization fudge factor 1.24

Ilya Selyuzhenkov February 02, 2009

Data sets

  • pp2006 - STAR 2006 pp longitudinal data (~ 3.164 pb^1)
    Trigger: eemc-http-mb-L2gamma [id:137641]
  • gamma-jet[gamma-filtered] - data-driven Prompt Photon [p6410EemcGammaFilter] events.
    Partonic pt range 2-25 GeV.
  • QCD jets[gamma-filtered] - data-driven QCD [p6410EemcGammaFilter] events.
    Partonic pt range 2-25 GeV.

Cuts applied

  • Di-jet events
  • Require to reconstruct photon momentum (no gamma-jet isolation cuts)
  • Gamma pt > 7GeV
  • L2gamma emulation in Monte-Carlo
  • L2gamma triggered pp2006 events
  • cos (phi_jet - phi_gamma) < -0.8
  • detector |eta_jet|< 0.8
  • |v_z| < 100

Figures

All figures:

  • All pre-shower conditions combined, No pre-shower cuts
  • Thick blue line shows MC sum: QCD + gamma-jet
  • Black solid circles: pp2006 data
  • Monte-Carlo results first scaled to 3.164 pb^-1 according to Pythia luminosity
    and then an additional fudge factor of 1.24 has been applied.
    Fudge factor is defined as the yields ratio from data to scaled with Pythia luminosity Monte-Carlo
    for pt_jet>7GeV and pt_gamma>7 candidates

Figure 1: Vertex z distribution with pt_jet>7 cut (left) and without pt_jet cut (rigth)

Figure 2: Photon (left) and away side jet (right) pt

Figure 3: Photon detector eta (left) and corrected for vertex eta (right)

Figure 4: Away side jet detector eta (left) and corrected for vertex eta (right)

Figure 5: Preshower 1 (left) and Pre-shower2 (right) energy

2009.02.03 No pre-shower cuts, pt_jet >7 vs. No pt_jet cuts

Ilya Selyuzhenkov February 03, 2009

Data sets

  • pp2006 - STAR 2006 pp longitudinal data (~ 3.164 pb^1)
    Trigger: eemc-http-mb-L2gamma [id:137641]
  • gamma-jet[gamma-filtered] - data-driven Prompt Photon [p6410EemcGammaFilter] events.
    Partonic pt range 2-25 GeV.
  • QCD jets[gamma-filtered] - data-driven QCD [p6410EemcGammaFilter] events.
    Partonic pt range 2-25 GeV.

Cuts applied

  • Di-jet events
  • Require to reconstruct photon momentum (no gamma-jet isolation cuts)
  • Gamma pt > 7GeV
  • L2gamma emulation in Monte-Carlo
  • L2gamma triggered pp2006 events
  • cos (phi_jet - phi_gamma) < -0.8
  • detector |eta_jet|< 0.8
  • |v_z| < 100

Figures

Each figure has:

  • All pre-shower conditions combined, No pre-shower cuts
  • Thick blue line shows MC sum: QCD + gamma-jet
  • Black solid circles shows pp2006 data
  • Left plots: pt_jet>7GeV
    Right plots: no cuts on pt_jet
  • Monte-Carlo results for QCD and gamma-jet samples are first
    scaled to 3.164 pb^-1 according to Pythia luminosity,
    added together, and then an additional fudge factor of 1.24 applied.
    Fudge factor is defined as pp2006 to Monte-Carlo sum ratio
    for pt_jet>7GeV and pt_gamma>7 candidates

Figure 1: Vertex z distribution

Figure 2: Photon detector eta

Figure 3: Corrected for vetrex photon eta

Figure 4: Away side jet detector eta

Figure 5: Corrected for vetrex away side jet eta

Figure 6:Photon pt

Figure 7: Away side jet pt

Figure 8: Pre-shower 1 energy

Figure 9: Pre-shower 2 energy

2009.02.06 Pre-shower energy distribution Run6 vs. Run8 geometry

Ilya Selyuzhenkov February 06, 2009

Data sets

  • pp2006 - STAR 2006 pp longitudinal data (~ 3.164 pb^1)
    Trigger: eemc-http-mb-L2gamma [id:137641]
  • mc2006: gamma-jet+QCD jets [p6410EemcGammaFilter] events.

    • Partonic pt range 2-25 GeV.

  • pp2008 - STAR 2008 pp data
    Trigger: etot-mb-l2 [id:7]

Cuts applied

  • Di-jet events
  • Require to reconstruct photon momentum (no gamma-jet isolation cuts)
  • Gamma pt > 7GeV, jet pt > 7GeV
  • L2gamma emulation in Monte-Carlo
  • L2gamma triggered for pp2006 and pp2008 events
  • cos (phi_jet - phi_gamma) < -0.8
  • detector |eta_jet|< 0.8
  • |v_z| < 100

Figures

Each figure has:

  • All pre-shower conditions combined, No pre-shower cuts
  • Red circles show pp2006 data
  • Black triangles show pp2008 data
    Data scaled to match the integraled yield from pp2006 data
  • Green line shows MC sum: QCD + gamma-jet
    Monte-Carlo results for QCD and gamma-jet samples are first
    scaled to 3.164 pb^-1 according to Pythia luminosity,
    added together, and then an additional fudge factor of 1.24 applied.
    Fudge factor is defined as pp2006 to Monte-Carlo sum ratio
    for pt_jet>7GeV and pt_gamma>7 candidates

Observations

  • Pre-shower energy distributions from pp2008 data set
    are narrower than that for pp2006 data.
    This corresponds to smaller amount of material budget in y2008 STAR geometry.
  • Pre-shower energy distribution from Monte-Carlo with y2006 geometry
    closer follows the distribution from pp2008 data set, rather than that from pp2006 data.
    This indicates the lack of material budget in y2006 Monte-Carlo.

Note: There is a "pre-shower sector 10 problem" for pp2008 data,
which results in migration of small fraction of events with pre-shower>0 into
pre-shower=0 bin (first zero bins in Fig.1 and 2. below).
For pre-shower>0 case this only affects overall normalization of pp2008 data,
but not the shape of pre-shower energy distributions.
I'm running jet-finder+my software to get more statistics from pp2008 data set,
and after more QA will produce list of runs with "pre-shower sector 10 problem",
so to exclude them in the next iteration of my plots.

Figure 1: Pre-shower1 energy distribution

Figure 2: Pre-shower2 energy distribution

2009.02.09 pp2006, pp2008, amd mc2006 comparison

Ilya Selyuzhenkov February 06, 2009

Data sets

  • pp2006 - STAR 2006 pp longitudinal data (~ 3.164 pb^1)
    Trigger: eemc-http-mb-L2gamma [id:137641]
  • mc2006: gamma-jet+QCD jets [p6410EemcGammaFilter] events.

    • Partonic pt range 2-25 GeV.

  • pp2008 - STAR 2008 pp data
    Trigger: etot-mb-l2 [id:7]

Cuts applied

  • Di-jet events
  • Require to reconstruct photon momentum (no gamma-jet isolation cuts)
  • Gamma pt > 7GeV, jet pt > 7GeV
  • L2gamma emulation in Monte-Carlo
  • L2gamma triggered for pp2006 and pp2008 events
  • cos (phi_jet - phi_gamma) < -0.8
  • detector |eta_jet|< 0.8
  • |v_z| < 100

Figures

Each figure has:

  • All pre-shower conditions combined, No pre-shower cuts
  • Red circles show pp2006 data
  • Black triangles show pp2008 data
    Data scaled to match the integraled yield from pp2006 data
  • Green line shows MC sum: QCD + gamma-jet
    Monte-Carlo results for QCD and gamma-jet samples are first
    scaled to 3.164 pb^-1 according to Pythia luminosity,
    added together, and then an additional fudge factor of 1.24 applied.
    Fudge factor is defined as pp2006 to Monte-Carlo sum ratio
    for pt_jet>7GeV and pt_gamma>7 candidates

Kinematics

Figure 1: vertex z

Figure 2: photon detector eta

Figure 3: jet detector eta

Figure 4: photon pt

Figure 5: jet pt

Figure 6: gamma-jet pt balance

Figure 7: Photon neutral energy fraction

Figure 8: Jet neutral energy fraction

Figure 9: cos(phi_gamma-phi_jet)

Photon candidate's 2x1, 2x2, and 3x3 tower cluser energy

Figure 10: 3x3 cluster energy

Figure 11: 2x1 cluster energy

Figure 12: 2x2 cluster energy

Number of charge tracks, Barrel and Endcap towers within r=0.7 for photon and gamma

Figure 13: Number of charged track associated with photon candidate

Figure 14: Number of Barrel towers associated with photon candidate

Figure 15: Number of Endcap towers associated with photon candidate

Jet energy composition

Figure 16: Jet energy part from Barrel towers

Figure 17: Jet energy part from charge tracks

2009.02.16 pt_jet>5GeV: pre-shower sorting with new normalization

Ilya Selyuzhenkov February 16, 2009

Data sets

  • pp2006 - STAR 2006 pp longitudinal data (~ 3.164 pb^1)
    Trigger: eemc-http-mb-L2gamma [id:137641]
  • mc2006: gamma-jet+QCD jets [p6410EemcGammaFilter] events.

    • Partonic pt range 2-25 GeV.

  • pp2008 - STAR 2008 pp data
    Trigger: etot-mb-l2 [id:7]

Cuts applied

  • Di-jet events
  • Require to reconstruct photon momentum (no gamma-jet isolation cuts)
  • Gamma pt > 7GeV, jet pt > 7GeV
  • L2gamma emulation in Monte-Carlo
  • L2gamma triggered for pp2006 and pp2008 events
  • cos (phi_jet - phi_gamma) < -0.8
  • detector |eta_jet|< 0.8
  • |v_z| < 100

Figures

Each figure has:

  • pp2008 data scaled to match the integraled yield from pp2006 data
  • mc2006 stand for MC sum: QCD + gamma-jet
    Monte-Carlo results for QCD and gamma-jet samples are first
    scaled to 3.164 pb^-1 according to Pythia luminosity,
    added together, and then an additional fudge factor of 1.24 applied.
    Fudge factor is defined as pp2006 to Monte-Carlo sum ratio
    for pt_jet>7GeV and pt_gamma>7 candidates

plots for pt_gamma>7GeV, pt_jet > 5GeV

  1. All pre-shower combined: 1D distributions
  2. All pre-shower combined: 2D correlations
  3. Pre-shower sorting 1D distributions

 

2009.02.19 Photon-jet analysis status update for Spin PWG

Photon-jet analysis status update for Spin PWG (February 19, 2009)

Slides: download pdf

Previous versions: v1, v2

Link for CIPANP abstract

 

 

CIPANP 2009 abstract on photon-jet measurement

CIPANP 2009 abstract on photon-jet study

Title:
"Photon-jet coincidence measurements
in polarized pp collisions at sqrt{s}=200GeV
with the STAR Endcap Calorimeter"

Abstract: download pdf

Previous versions: v1, v2, v3, v4

Conference link: CIPANP 2009