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HFE analysis at √sNN = 54.4 GeV at STAR

Updated on Thu, 2024-05-09 23:13. Originally created by agafover on 2023-05-25 03:30.

                                                                                                  SELECTION CUTS


BAD RUN LIST: 18153035-18153046, 18153057, 18154037-18154039, 18156031, 18156052, 18157003, 18157016,
                         18157065, 18158012, 18158013, 18158020, 18158021, 18160015, 18161021, 18165036, 18165039,
                         18166017, 18166019, 18168013, 18168015, 18168029, 18169009, 18169036, 18171009, 18172014.

INCLUSIVE ELECTRON CUTS:

  • Trigger: 
Trigger
RunId range, minbias
580001 18153049-18156032
580021 18156046-18172014

  •  Event level:

|Vx| > 1.0e-5
|Vy| > 1.0e-5
|Vz| > 1.0e-5
Vr = √(Vx2+Vy2) > 2.0
|Vz| < 35.0
|Vz - vzVpd| < 3

  • Centrality selection: 0-20 %, 20-40%, 40-60%, 0-60%
  • Track cuts:

primary track
pT > 0.2 GeV/c
|nHitsFit| >= 20
|η| < 0.8
|nHitsDedx| >= 15
nHitsRatio >= 0.52
|DCA| < 1.5 cm
|φ| < 1.25 || |φ| > 1.95

 



  • Track has a hit in the first three TPC layers

  • TPC electron selection:

            pT > 1.25 GeV/c : -1.2 < nσe < 2

            pT <= 1.25 GeV/c :

p > 0.8 GeV/c -1.2 < nσe < 2
p <= 0.8 GeV/c 2.25p - 3 < nσe < 2
  • TOF hybrid electron selection:

pT < 1.5 GeV/c : |1 - 1/β| < 0.025

pT >= 1.5 GeV/c : |1 - 1/β| < 0.025 only for tracks with TOF info

  • BEMC electron selection:

  1. pT > 1.25 GeV/c
  2. 0.6 < E0/p < 1.5
  3. cluster energy > 0.1 GeV
  4. tower energy > 0.1 GeV
=======================================================================================================                                                                                                   PHOTONIC ELECTRON SELECTION

For every inclusive electron we pair the track with the following cuts:

 

global track
pT > 0.2 GeV/c
|nHitsFit| >= 15
|η| < 1
nHitsRatio >= 0.52
|nσe| < 3

Pair cuts:

  1. |DCApair| < 1 cm
  2. Mee < 0.1 GeV/c2

=======================================================================================================

                                                                                                  p, K and merged π selection (pure samples)
  • Common cuts:
  1. Good run selection
  2. Trigger selection
  3. Event selection
  4. Track selection
  5. Hit in the first three layers
  • p selection cuts:
p mass |m2 - 0.879|< 0.02 GeV/c2
p nσ |nσp| < 4
  • K selection cuts:
K mass |m2 - 0.243| > 0.005 GeV/c2
K nσ |nσK| < 4
  • merged π selection cuts:
merged π mass |m2 - 0.019| > 0.003 GeV/c2
merged π nσ |nσmerged π| > 5

=======================================================================================================
=======================================================================================================


                                                                                                                        ANALYSIS STEPS:

nSigmaE fits:

  • Pure samples of p, K, merged pions, photonic electrons 
  • Total nSigmaE fits for 0-20%, 20-40%, 40-60%, 0-60% centralities
  • Purity for different centralities                                             

  • nSigmaE efficiency

       

Ratios:

More plots can be found here: drupal.star.bnl.gov/STAR/system/files/nSigmaEfits.pdf (OLD)

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1/beta cut efficiency:

Comparison of efficiencies calculated as an arithmetic mean from the histogram and fit. Errors from the efficiency from the fit are included in the systematic error.

       

Ratios:

 

More plots can be found here: drupal.star.bnl.gov/STAR/system/files/invBetaPE.pdf (NEW)

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BEMC matching + E/p cut efficiency:


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TOF matching efficiency:

For inclusive electrons after trigger, event, track, TPC (flat |nSigE| < 0.5), BEMC and TOF(hybrid) cut we pair a track with PE selection cuts (|nSigE| < 0.6). Mee < 0.004
LS is not subtracted

Ratios:

Technical plots for TOF matching efficiency:
drupal.star.bnl.gov/STAR/system/files/TOFmatching_oldTOF_flatnSigTag05Partn06_noLS.pdf (NEW)
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TPC tracking efficiency: (became lower after adding a φ cut)
 
   

Ratios:

Technical plots : https://drupal.star.bnl.gov/STAR/system/files/ElPosEff_newDedx.pdf (OLD)

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Total inclusive electron efficiency:
 

  • pT < 1.25 GeV:            εTPC * εnσe * ε1/β * εTOF
  • 1.25 < pT < 1.5 GeV:   εTPC * εnσe * ε1/β * εTOF * εBEMC+E/p
  • pT > 1.5 GeV:              εTPC * εnσe * εBEMC+E/p (1 - εTOF + εTOF * ε1/β)

Ratios:

More plots could be found here: drupal.star.bnl.gov/STAR/system/files/TotalInclElEff_0.pdf (NEW)
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Photonic electron efficiency:

Ratios:

More plots could be found here: drupal.star.bnl.gov/STAR/system/files/TotalEff_0.pdf (OLD)
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Photonic electron yield:


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Inclusive electron yield:


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Non-photonic electron yield:

More plots can be found here: drupal.star.bnl.gov/STAR/system/files/NPEyield_new.pdf
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Rcp:

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