1 / 25

Hot results from cold weather in a cool presentation

Hot results from cold weather in a cool presentation. kaons are the lightest strange particles  the most abundant  important piece in deciphering the final state puzzles. Studying nuclear matter created in pp, dA and AA collisions using charged kaons. Camelia Mironov

marshall-giles
Download Presentation

Hot results from cold weather in a cool presentation

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. Hot results from cold weather in a cool presentation

  2. kaons are the lightest strange particles  the most abundant  important piece in deciphering the final state puzzles Studying nuclear matter created in pp, dA and AA collisionsusing charged kaons Camelia Mironov Kent State University … or the story about the importance of identified-particle studies in heavy-ion collisions  kaons alone (truth for _any_ particle probably ) does not permit to draw too many conclusions

  3. Identification … Kμν (63%) Kππ0 (21%) Charged  charged + neutral V0charged daugthers V0 parent V0 K parent K parent V0 decay vertices Ks p + + p - L  p + p - L  p + p + or uses the V0s X-  L + p - X+L + p + W  L + K - K charged daughter K charged daughter KINK KINK Do all these particles show anything plus to what unidentified charged hadrons show?

  4. For outlook … RELAX !!!!!! (and this is not for me  ) Contrary to what my abstract might’ve let the impression, my talk won’t last 3 hours !!! Though interesting systems by themselves, I will refer to pp and dA collisions only by means of better understanding the AA data  nuclear modification factors • identified particle correlations

  5. RAB/RCP: h± <Nbin>/inelp+p describes the Nuclear Geometry Npart: number of nucleons in overlap region Nbin: number of inelastic nucleon-nucleon collisions (# binary collisions) participants Quantify the deviation from p+p collisions: • Charged Hadrons: • Au + Au : RCP and RAA ~ suppression • d + Au : RCP and RdA ~ enhancement (Cronin effect – experimental observation and not the explanation)

  6. AuAu: identified hadrons <Nbin>/inelp+p describes the nuclear geometry Baryons suppressed Mesonssuppressed BUT Mesons ~ 1.5GeV/c Baryons~ 2.5GeV/c • Mesons suppressed • Baryons enhanced maxRAAp(uud)<maxRAAΛ(uds)<maxRAAΞ(dss)

  7. Au + Au: RCP Experiment & Theory Fries et al nucl-th/0306027 Recombination describes fairly well the baryon – mesons differences Reco for K0s and Λ+Λbar Central(b=3fm) / Peripheral (b=12fm) Topor-Pop et al (nucl-th/0407095) … same Hijing/BBbar v2.0 Hijing/BBbar v2 0-10% / 60-90% For K- + K+ and Λ+Λbar

  8. R_AA: Experiment & Theory … Topor-Pop (private comunication) Hirano, Nara nucl-th/0307015 Hydro + jet quenching -hydrodinamics combined with minijets which go through jet quenching in the hot medium  nucl-th/0307015 • Hijing/BBv2.0 -Hijing + baryon junction + jet quenching + shadowing + Strong Color Field effects nucl-th/0407095

  9. dAu: identified hadrons <Nbin>/inelp+p describes the nuclear geometry  in d+Au also a difference between mesons and baryons (smaller though)

  10. RdA/RCP(dA): theory and experiment 1.Hwa, Yangnucl-th/0404066 Recombination (Oregon)  final state effect Kopeliovich, Nemchik, Schafer, Tarasov – Phys. Rev. Lett. 88(2002) 232303  Initial state elastic scatterings reproduce the general trend of the R_dA but NOT the particle species dependence

  11. So far … RAB/RCP HAS TO BE TREATED SEPARATELLY (at least until an explanation/scaling for the RAA strangeness ordering will be find out – an attempt: canonical suppression picture – more in talk by M Lamont) AuAu: the difference between mesons and baryons in the intermediate pT region is reproduced in several models: recombination, hydro+jet quenching etc = need more/different probes/measurements to test the models dAu: apart from the enhancement (as opposed to the suppression in AA) dA shows similar features as AA (like the differences between mesons and baryons) So .. toward different measurements …

  12. Hadronization ReCo(Oregon)… Mesons (qq) : Quark-antiQuark distribution Fqq(p1,p2) = T T + T S + S2 + S S Baryons (q1q2q3) Fq1q2q3(p1,p2) = T TT+ TT S + TS2 + S3+ TSS +SS2+SSS Recombination function known from recombination model Hwa, Phys. Rev. D (1980).

  13. Two particle correlations:Hwa, Yangnucl-th/0407081 Trigger Particle Associated Particles Jet structure by two-particle correlation within the jet: must consider 4/5 partons to recombine  Trigger on pions and calculate the distribution of the associated particles (AuAu collisions)

  14. Azimuthal correlations language Trigger Particle Back side Associated Particles Same side

  15. -h correlations in AA 5-10% 10-30% 0-5% 30-50% 50-70%

  16. Strange-charged hadrons correlations …  NO significant particle species dependency  NO strong centrality dependency (need systematics studies) BORING? Trigger Particle Back side Y. Guo (STAR) hep-ph/0403018 Associated Particles Same side NOT YET  0-5%: same side yield vs trigger pT  Lambda acts different There seem to be signs of particle specific phenomena in strange-charged hadrons correlations

  17. Strange-Strange correlations … hadrons hadrons Hadron production at SLD  short-range, local correlations short-range compensation of quantum numbers  long-range correlations between opposite chargeleading particle production: ssbar events different from uubar or ddbar events Rapidity difference between identified hadron pairs

  18. Strange-Strange hadrons correlations … __ Trigger Particle _____ __ - Back side L Û ( ) ( ) uds s u K • DONE – even so, ‘lack of statistics’  Associated Particles __ + L Û uds ) ( s u ) ( K Same side • NOT DONE (YET) - used to be ‘really lack of statistics’ - truth now: ‘lack of time’

  19. Not much… Λ trigger: 2<pT<6 (GeV/c) K assoc: 1.5< pT < pTtrigger (GeV/c)  Not much, but an interesting analysis to continue with

  20. Over all … ANSWER: Particle identification do offer plenty of surprises and do rises lots of new questions (to which we don’t know yet the whole answer) and more important High pT PID is essential in gaining more insight into hadronization mechanisms and medium properties knowledge.

  21. Thank you!

  22. Bonus

  23. Flow z Reaction plane M. Kaneta y x Reaction plane = (collision impact parameter, beam direction)

  24. Data Analysis Methods: • Nicolas Borghini et al. Phys. Rev. C 62, 034902(2000). Same Side Back Side Background pp: Au + Au: Gaussian Fit of back side: Cosine Fit of back side (momentum balance): Parameters are compared for different fits for two different pT cuts as the function of centralities

More Related