01 Jan

January 2009 posts

 

2009.01.08 Away side jet pt vs. photon pt

Ilya Selyuzhenkov January 08, 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

Comments

(concentrated on pre-shower1>0 case
which has better statistics for QCD Monte-Carlo):

  • Fig.1, lower plots
    Vertex z distributions from QCD MC and pp2006 data are different in the negative region
  • Fig.2, lower plots
    For the away side jet pt < 8GeV region
    QCD Monte-Carlo underestimates the data.
  • Fig.4, lower plots
    gamma-jet pt asymmetry plot shows
    that in QCD MC photon and jet pt's are better correlated than in the data
  • Fig.5, lower plots
    Most of the differences between QCD MC and pp2006 data for pre-shower1>0 case
    are probably from the lower gamma and jet pt region

Figures

Figure 1: Vertex z distribution

Figure 2: Away side jet pt

Figure 3: Photon pt

Figure 4: gamma-jet pt asymmetry: (pt_gamma - pt_jet)/pt_gamma

Figure 5: gamma pt vs. away side jet pt
1st column: triggered pp2006 data
2nd column: gamma-jet MC (l2gamma trigger on)
3rd column: QCD background MC (l2gamma trigger on)

2009.01.20 Away side jet pt vs. photon pt: more stats for QCD pt_parton 9-15GeV

Ilya Selyuzhenkov January 20, 2009

Note:
this is an update with 10x more statitstics for QCD 9-15GeV parton pt bin.
See this post for old results.

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

Comments

  • Vertex z distributions from QCD MC and pp2006 data
    are different in the negative region (see Fig.1)
  • pp2006 data to Monte-Carlo ratio
    does not depends on reconstructed photon pt,
    but it has some vertex z dependence
    (see data to MC ratio in Fig.6 for pre-shower1 > 4MeV case)

Figures

Figure 1: Vertex z distribution

Figure 2: Away side jet pt

Figure 3: Photon pt

Figure 4: gamma-jet pt asymmetry: (pt_gamma - pt_jet)/pt_gamma

Figure 5: gamma pt vs. away side jet pt
1st column: triggered pp2006 data
2nd column: gamma-jet MC (l2gamma trigger on)
3rd column: QCD background MC (l2gamma trigger on)

Data to Monte_Carlo normalization

Figure 6: pp2006 data to Monte -Carlo sum [QCD + gamma-jet] ratio
for pre-shower1>4MeV (most of statistics)
Left: data to MC ratio vs. reconstructed gamma pt.
Solid line shows constant line fit (p0 ~ 1.3)
Right: data to MC ratio vs. reconstructed vertex position

2009.01.27 gamma and jet pt plots with detector |eta|_jet < 0.8, pt_jet > 7

Ilya Selyuzhenkov January 27, 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)
  • jet pt > 7GeV
  • Gamma pt > 7GeV or no pt cuts
  • 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, pre1<10MeV
  • Left plots: no gamma pt cut
    Right plots: pt_gamma >7GeV
  • Thick blue line shows MC sum: QCD + gamma-jet
  • Thin solid color lines shows distributions from various partonic pt bins for QCD MC
    See figures legend for color coding

Figure 1: Vertex z distribution

Figure 2: Photon eta

Figure 3: Away side jet eta

Figure 4:Photon pt

Figure 5: Away side jet pt

Figure 6: Away side jet detector eta

2009.01.27 gamma and jet pt plots with |eta|_jet < 0.7

Ilya Selyuzhenkov January 27, 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 or no pt cuts
  • L2gamma emulation in Monte-Carlo
  • L2gamma triggered pp2006 events
  • cos (phi_jet - phi_gamma) < -0.8
  • |eta_jet|< 0.7
  • |v_z| < 100

Figures

All figures:

  • All pre-shower conditions combined, pre1<10MeV
  • Left plots: no gamma pt cut
    Right plots: pt_gamma >7GeV
  • Thick blue line shows MC sum: QCD + gamma-jet
  • Thin solid color lines shows distributions from various partonic pt bins for QCD MC
    See figures legend for color coding

Figure 1: Vertex z distribution

Figure 2: Photon eta

Figure 3: Away side jet eta

Figure 4:Photon pt

Same as in Fig.4 on a log scale: no gamma pt cut and pt>7GeV

Figure 5: Away side jet pt

Same as in Fig.5 on a log scale: no gamma pt cut and pt>7GeV