1 / 11

Jet hadrochemistry with ALICE. An idea.

Jet hadrochemistry with ALICE. An idea. Sergey Kiselev, ITEP Moscow for the TOF group Medium modifications of jet hadrochemistry ALICE PID performance Methods, variables, … Jet hadrochemistry in p+p at LHC Next steps Conclusions. Medium modifications of jet hadrochemistry.

dahlia
Download Presentation

Jet hadrochemistry with ALICE. An idea.

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Jet hadrochemistry with ALICE. An idea. • Sergey Kiselev, ITEP Moscow for the TOF group • Medium modifications of jet hadrochemistry • ALICE PID performance • Methods, variables, … • Jet hadrochemistry in p+p at LHC • Next steps • Conclusions Task-Force meeting, CERN S.Kiselev

  2. Medium modifications of jet hadrochemistry S.Sapeta, U.A.Wiedemann EPJ, C55, 293 (2008) A unique prescription of how to model the medium modification of jet fragmentation does not exist. Medium modification of jets depends on the exchange of - momentum - color - flavor - baryon number between the partonic projectile and the medium A simple model of a parton shower with enhanced medium induced branching but unmodified hadronization is used. Parton splitting functions Pq→qg , … are enhanced by one common model-independent factor (1+fmed). Since the model does not implement other effects, it may be expected to underestimate the medium modifications of jet hadrochemistry. Task-Force meeting, CERN S.Kiselev

  3. No medium modificationMLLA (modified leading logarithmic approximation) + LPHD (local parton–hadron duality) formalism Fig.2. Two examples for the comparison of the MLLA+LPHD formalism with data on single inclusive spectra inside a jet as a function of the logarithm of the hadron momentum fraction ξ. (a) The distribution (4) of charged pions (π+ + π−), kaons (K+ + K−) and (anti-) protons (p + pbar) in a jet of energy Ejet = 14.5 GeV, compared to TPC data on e+e− collisions. The MLLA parameters are Λ = 155 MeV and KLPHD = 1.22. (b) The MLLA+LPHD distribution of all charged hadrons in a jet of energy Ejet = 108 GeV for various opening angles Θc, compared to CDF data from p pbar collisions. The MLLA parameters are Λ = Q0 = 235 MeV, KLPHD = 0.555 Task-Force meeting, CERN S.Kiselev

  4. Particle ratios vs pT Cone opening angle Θc = 0.28 ~50 – 100% medium effect Task-Force meeting, CERN S.Kiselev

  5. Jet modification factor JAA dNh/dpT (med) JAA = ---------------- dNh/dpT (vac) A significantly modified jet hadrochemistry can be expected Increases with mh and Ejet Maximum effect at pT ~ 5 GeV/c Task-Force meeting, CERN S.Kiselev

  6. TOF PID performance • One can study jet hadrochemistry with TOF at 0.5 < pT < ~3-5 GeV/c Task-Force meeting, CERN S.Kiselev

  7. ALICE PID performance … with ALICE at pT < ~30 GeV/c Task-Force meeting, CERN S.Kiselev

  8. Methods, variables, … Methods: - jet reconstruction - a la RHIC triggered particle azimuthal correlations Variables for each of species (π± , K± , p± ): - multiplicity - longitudinal distributions - transverse distributions - ratios K±/π± , … Systems: - pp, PYTHIA, HERWIG, … - pA , HIJING, … - AA, HIJING, PYQUEN, … Task-Force meeting, CERN S.Kiselev

  9. Jet hadrochemistry in p+p at LHC There are theoretical speculations that at LHC energies “medium”/”collective state” can be created even in p+p (due to multiple scattering) If so, jet hadrochemistry and other characteristics of jet quenching can be used to “feel” the medium as deviations from vacuum values Task-Force meeting, CERN S.Kiselev

  10. Next steps at generator level: - comparison generator predictions with data (single inclusive spectra, … for π± , K± , p±) inside a jet - sensitivity to a generator … In the AliRoot package: - a task/macro to start analysis for pp on CAF … Task-Force meeting, CERN S.Kiselev

  11. Conclusions “The analysis of the hadrochemical composition of jets in heavy ion collisions is a terra incognita, for which data are not available yet. It is in experimental reach of the LHC.” (S.Sapeta, U.A.Wiedemann EPJ, C55, 293 (2008)) ALICE PID performance let us study medium modifications of jet hadrochemistry Task-Force meeting, CERN S.Kiselev

More Related