1 / 34

Status of PPR Chapter 6.5 Charm and Beauty

Status of PPR Chapter 6.5 Charm and Beauty. Editors: F. Antinori 2 and A. Dainese 1,2 1 University and 2 INFN – Padova. Before moving to ~editorial matters… …The Latest News: “The charm of non-central collisions”.

marja
Télécharger la présentation

Status of PPR Chapter 6.5 Charm and Beauty

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. Status of PPR Chapter 6.5Charm and Beauty Editors: F. Antinori2 and A. Dainese1,2 1University and 2INFN – Padova ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  2. Before moving to ~editorial matters… …The Latest News: “The charm of non-central collisions” • This item is missing in 6.5, although important (need to know requested number of events for RCP & v2 studies… see physics motivations later on) • First steps: • Calculated heavy-quark yields as a function of centrality (using centrality classes as defined in PPR 6.1) • Estimated D0Kp performance in semi-periph. collisions (preliminary) • Goal: have something on D0 in the PPR, maybe something on B  e+X ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  3. Heavy quarks and dNch/dy vs centrality(PPR 6.1 classes) b-dependence of shadowing from Emel’yanov, Khodinov, Klein, Vogt, PRC61 (2000) 044904 ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  4. Heavy quarks and dNch/dy vs centrality (2) for v2 for RCP b-dependence of shadowing from Emel’yanov, Khodinov, Klein, Vogt, PRC61 (2000) 044904 ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  5. D0 Kp in 33-58% Pb-Pb (2.5x106 evts) • Used signal and background samples for Pb-Pb 0-5% • Rescaled signal by 0.11 (decrease of Ncc/event) • assumed same shadowing as in central collisions… • Rescaled backgr. by [(dNch/dy)33-58%/(dNch/dy)0-5%]2 ~ 0.01 • Assumed same tracking & PID efficiencies & resolutions as in central collisions • Issue: primary vertex reconstruction may be worse • xy: same resolution as in central, given by beam size • z: worse resolution sz(dNch/dy=600) = 15 mm (from Catania’s vertex reconstruction results) [sz(dNch/dy=6000) = 5 mm] • not a problem: z used only for pointing angle, where resolution dominated by secondary vertex z-res. ~ 80 mm • (roughly) Retuned cuts for new normalization ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  6. Rel. statistical error for 33-58% 33-58% Larger bins than for 0-5% have to be used 0-5% ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  7. pT distribution for 33-58% (0-5%) same systematic errors (band) as for 0-5% assumed ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  8. RCP for 0-5%/33-58% • only stat. errors (dominated by 33-58% errors, if RCP=1) • errors estimation for more likely RCP~0.4 in progress • systematic error should mainly come from <Ncoll> ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  9. pT bin (GeV/c) pT bin (GeV/c) Signal Signal sv2 (statistical) sv2 (statistical) 5-7 5-7 3x74 74 0.05 0.08 33-58% 2.5x106 evts 20-60% 4x106 evts 7-10 7-10 3x34 34 0.12 0.07 10-14 10-14 12 3x12 0.12 0.20 5-14 5-14 3x120 120 0.04 0.06 First look at v2(quick&dirty) • For pT < 5 GeV/c, candidate are signal + background need to study bkg v2 (e.g. using sidebands or ev. mixing) and subtract it requires dedicated study • For pT > 5 GeV/c, background is negligible just get v2 from all D0 candidates (only signal) • First trial, for pT > 5 GeV/c: assumed v2 ~ 0.10-0.20 Need more “non-central” events? ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  10. Back to editorial matters…Contents of chapter 6.5 • 6.5.1 Physics motivations • 6.5.2 Available measurements of heavy-flavour hadroproduction • 6.5.3 Charm and beauty production at LHC • 6.5.4 Exclusive charm reconstruction with D0 Kp • 6.5.5 Perspectives for the study of charm quenching • 6.5.6 Beauty detection in the semi-electronic decay channels ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  11. New sections to be added • 6.5.7 Beauty in the muon channels • Single and di- muons in Pb-Pb (by R. Guernane) • Presented as work in progress: • 3- and 4-muons in pp and pA (prel. study by A. Morsch) • e-m correlations (prel. study by P. Crochet) • 6.5.8pp-specific section: detection possibilities for nonlinear effects in gluon evolution via charm ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  12. 6.5.1 Physics Motivations • Heavy quarks: produced in early stage, hard scale, calculable in pQCD • Added pp and pA specific motivations: • test pQCD and factorization in pp/pA • look for break down of factorization: shadowing, gluon saturation, Color Glass Condensate • look for multiparton scattering in pA • Revised AA motivations. Heavy quarks can probe: • density of medium, via energy loss and its dependences (mass, colour charge) • degree of thermalization, via v2 ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  13. 6.5.1 Physics Motivations • Probing high-density initial state with heavy quarks • nonlinear gluon evolutions in pp • shadowing in pA (AA) • CGC in pA (AA) • Multiple parton scattering in pA ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  14. 6.5.1 Physics Motivations • Probing high-density initial state with heavy quarks • nonlinear gluon evolutions in pp • shadowing in pA (AA) • CGC in pA (AA) • Multiple parton scattering in pA • Saturation scale Qs2(x) ~ xg(x)A/RA2 ~ xg(x)A1/3 • At LHC for x~10-4, Qs~1-5-2 GeV > mc • For mT,c~Qs, charm prod. CGC-dominated: • scales with Npart in pA (not Ncoll) • harder pT spectra, since typical kT~Qs~1.5 GeV, while • in standard factorization kT~LQCD~0.2 GeV ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  15. predicted rate: cccc/cc ~ 10% (Treleani et al.) signature: events with “tagged” DD (can use D0+e+ or e+e+) and ch. conj. NB: there is a “background” from normal bb events, but is can be estimated from measured single inclusive b cross section 6.5.1 Physics Motivations • Probing high-density initial state with heavy quarks • nonlinear gluon evolutions in pp • shadowing in pA (AA) • CGC in pA (AA) • Multiple parton scattering in pA probe “many-body” PDFs normal and anomalous: different A dep. ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  16. mass effect 6.5.1 Physics Motivations • Medium effects in AA: • heavy-quark energy loss • azimuthal asymmetry / v2 / coalescence RD/h enhancement probes color-charge dep. of E loss RB/h enhancement probes mass dep. of E loss Armesto, Dainese, Salgado, Wiedemann, PRD71 (2005) 054027. ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  17. f = p/2 f = 0 6.5.1 Physics Motivations • Medium effects in AA: • heavy-quark energy loss • azimuthal asymmetry / v2 / coalescence RHIC 200 GeV • The azimuthal asymmetry (v2) of D and B • mesons in non-central collisions tests: • at low/moderate pT: coalescence scenario, v2 of c/b quarks, hence degree of thermalization of medium • at higher pT: path-length dependence of E loss (almond-shaped medium => v2~5-10%) Greco, Ko, Rapp, nucl-th/0312100 ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  18. 6.5.2 Available measurements • Not only pA and AA, included also ppbar (Tevatron) • pA: • Charm production in pA fixed target up to sqrt{s} ~ 40 GeV: understood and well described by binary scaling • AA: • The NA50 di-muons enhancement puzzle • Single electrons from PHENIX (RAA and v2) • Additions: • Charm and beauty in ppbar at 1.96 TeV (compared to FONLL calc.) • Charm in d-Au at 200 GeV: STAR D meaurement compared to FONLL calc. ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  19. 6.5.3 Production at LHC • Total cross sections at NLO in nucleon-nucleon collisions from MNR code with CTEQ5M and MRST2001 • Extrapolation to p-Pb and Pb-Pb collisions • Spectral shapes and tuning of event generators (PYTHIA) • Hadronization and decays • Being added: • figures with theoretical uncertainty bands from MNR and, optionally, FONLL • theoretical uncertainty for extrapolation of pp measurement from 14 TeV to 5.5 TeV ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  20. 6.5.3 Production at LHC 0.5 mt < mF,mR < 2 mt, 1.3 < mc < 1.7 GeV, 4.5 < mb < 5.0 GeV ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  21. 6.5.3 Production at LHC Extrapolation of the pp data from 14 to 5.5 TeV beauty 14/5.5 charm 14/5.5 +10/-15% syst. error +5/-10% syst. error 0.5 mt < mF,mR < 2 mt, 1.3 < mc < 1.7 GeV, 4.5 < mb < 5.0 GeV ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  22. 6.5.4 D0 Kp • D0 K-p+ analysis in central Pb-Pb (0-5%) • done for B = 0.4 T and dNch/dy = 6000 • extrapolation to lower multiplicity (3000) • extrapolation to lower field (0.2 T) • Same analysis in pp: focus on pp-specific problems, namely primary vertex uncertainty due to necessity to reduce luminosity at ALICE I.P. to ~1030 cm-2s-1 • Being included: p-Pb study by R. Grosso • Physics performance: • uncertainties in charm cross section measurement • energy loss studies: sensitivity to RAA and ratio D/hadrons ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  23. mc PDFs scales down to pt ~ 0 ! The Physics plots (1) • D0 cross section measurement ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  24. The Physics plots (2) • Charm quenching: sensitivity to D-meson suppression updated predictions Armesto, Dainese, Salgado, Wiedemann, PRD71 (2005) 054027 ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  25. Study shadowing in p-Pb at 8.8 TeV? (to be included) R.Grosso, PhD thesis (2004) ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  26. 6.5.6 B  e+X in Pb-Pb (complete study presented at ALICE Week in March) Using electrons in 2 < pt < 20 GeV/c obtain B meson 2 < ptmin < 30 GeV/c inner bars: stat. errors outer bars: stat.  pt-dep. syst. errors not shown: 11% normalization error Note: quenching curves mainly for illustration. Pb-Pb vs. pp comparison needed to study E loss Study of Be+X in pp is in progress in Padova ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  27. 6.5.7 Beauty with muons in Pb-Pb (still to be included, but ~ copy-paste from ALICE note) (Guernane et al.) ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  28. Summary • Ch 6.5 text in good shape: ~70 pages! • Received comments by Jurgen, Yiota, Luciano (thanks!) • We plan to still include: • D0 in p-Pb results • D0 performance in semi-peripheral Pb-Pb • D quenching studies • B m • possible non-linear effects in pp • a paragraph on future developments (other channels / physics observables) ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  29. EXTRAS ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  30. Results for 33-58% Not divided by bin width Larger bins than for 0-5% have to be used ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  31. S/B and Significance for 33-58% 33-58% 0-5% ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  32. 6.5.2 Available measurements CDF D-meson data at 1.96 TeV hep-ex/0307080 FONLL predictions by Cacciari and Nason ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  33. 6.5.2 Available measurements CDF B  J/ + X data at 1.96 TeV FONLL and MC@NLO predictions by Cacciari, Frixione, Mangano, Nason and Ridolfi, hep-ph/0312132 ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

  34. FONLL, hep-ph/0502203 6.5.2 Available measurements STAR D-meson data in d-Au at 200 GeV nucl-ex/0407006 nucl-ex/0404029 (high pt prelim.) ALICE Physics Forum - Utrecht, June 14, 2005 Andrea Dainese

More Related