2.76 TeV and 4 TeV Hydjet sample comparison


Purpose of this study is to find out different characteristics of muon, J/psi and Upilon in the 4 TeV and 2.76 TeV Hydjet samples.

Data samples are located under MIT T2 servers. In the DBS, dataset name is :

  • 2.76 TeV (~ 1M events) : /Hydjet_Quenched_MinBias_2760GeV_MC_3XY_V24_GEN-SIM-RAW/davidlw-Hydjet_Quenched_MinBias_2760GeV_MC_3XY_V24_GEN-SIM-RAW-51550601a6965131c06787129d40c7a9/USER
  • 4 TeV (~ 35000 events) : /Hydjet_MinBias_4TeV/Summer09-MC_31X_V9-v1/GEN-SIM-RAW

Used program :

Issue on 2.8 TeV :

  • Number of muon per event is larger at 4 TeV and 2.76 TeV (~1/event) than at 2.8 TeV (~0.3/event).
  • Related material is on the indico : slide
  • pt hat hydjet cut in the samples (cut at 6 GeV/c for 2.8 TeV vs. 7 GeV/c in 4 TeV)

To do lists from HI di-lepton meeting:

  • Check what cross section is used for Pythia input in HYDJET and compare with NLO expectations (integrated numbers should be enough). The theoretical calculations should give a pt, eta distribution. One needs to compare the spectra from hydjet to the one from theory and see how well they match, in what region. Does the change in pt hat cut modify the muon pt specta (and those measurable) ?
  • Compare with HIJING (from Alice people) if the information is easy to access (but probably only at forward rapidity).

Mother particle comparison

Comparison :
  • Transverse momentum (pt) trends are similar between 2.76 TeV and 4 TeV for same mom ID



List of all mother particle ID of muon

  • % is calculated by this formula




Because 4 TeV sample doesn't have enough J/psi, here is another plot from other 4 TeV sample. Original twiki site of this plot is here.


List of all mother particle ID of J/psi




Muon's rapidity, phi, pt distribution

  • Because number of total event for each sample is different, normalization is done by this formula


J/psi's rapidity, phi, pt distribution


Upsilon's rapidity, phi, pt distribution


-- MiheeJo - 21 Mar 2010

Topic attachments
I Attachment History Action Size Date Who Comment
PNGpng Jpsi_From_mother_dongho.png r2 r1 manage 59.2 K 2010-03-23 - 02:29 UnknownUser  
PNGpng formula1.png r2 r1 manage 8.6 K 2010-03-21 - 15:18 UnknownUser  
PNGpng formula2.png r2 r1 manage 11.0 K 2010-03-21 - 15:19 UnknownUser  
PNGpng jpsi_momid.png r1 manage 14.3 K 2010-03-21 - 10:14 UnknownUser  
PNGpng muon_momid.png r1 manage 32.0 K 2010-03-21 - 10:14 UnknownUser  
PNGpng pt_momid_jpsi_tot.png r3 r2 r1 manage 127.0 K 2010-03-21 - 10:10 UnknownUser  
PNGpng pt_momid_mu_tot.png r4 r3 r2 r1 manage 142.3 K 2010-03-21 - 10:10 UnknownUser  
PNGpng pt_momid_upsi_tot.png r3 r2 r1 manage 33.7 K 2010-03-21 - 10:10 UnknownUser  
PNGpng y_phi_pt_jpsi.png r2 r1 manage 56.9 K 2010-03-21 - 15:44 UnknownUser  
PNGpng y_phi_pt_muon.png r2 r1 manage 52.4 K 2010-03-21 - 15:48 UnknownUser  
PNGpng y_phi_pt_upsi.png r2 r1 manage 31.0 K 2010-03-21 - 15:48 UnknownUser  
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Topic revision: r6 - 2010-03-25 - MiheeJo
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