1 / 14

3 p Correlation at RHIC

3 p Correlation at RHIC Reference : nucl-th/0310057 森田健司 ( 早大理工 ) 室谷心 ( 徳山女子短大 ) 中村博樹 ( 早大理工 ) Introduction Models Effect of long-lived resonances on the 2 p correlation Q 3 dependence of the 3 p correlation Results Summary ‘Measure’ : chaoticity l “HBT Puzzle” HBT Effect

Angelica
Download Presentation

3 p Correlation at RHIC

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. 3p Correlation at RHIC Reference : nucl-th/0310057 森田健司 (早大理工) 室谷心 (徳山女子短大) 中村博樹 (早大理工) • Introduction • Models • Effect of long-lived resonances on the 2p correlation • Q3 dependence of the 3p correlation • Results • Summary

  2. ‘Measure’ : chaoticity l “HBT Puzzle” HBT Effect Coherent Chaotic (=random relative phase) affected by other effects (Long-lived resonance, Coulomb int., etc...) Motivation – Chaotic or Coherent? (Local) equilibrium? / Exotic phenomena? Intensity Correlation as a ‘Measure’ • 2-body: Chaoticity of the source and Information on geometry (size)

  3. 3p Correlation : An Alternative Tool • 3-body: Chaoticity and asymmetry of the source ‘Measure’ : weight factor =1 for chaotic source in experiments Not affected by long-lived resonances

  4. but... l = 0.91-0.97 from the above e lexp = 0.5 @ Central Au+Au 130A GeV Consistency ? Analysis by STAR Col. STAR Coll., nucl-ex/0306028 Extraction of w from r3(Q3) Chaotic fraction e Central Mid-Central Using Partial Coherent Model e ~ 0.8 (80% of pions come from the chaotic source) quadratic/quartic fit to extract w

  5. In this work... • Check consistency of 2p and 3p correlations • 3 partial coherent source model -distinguish production mechanism ? • 2p correlation – Correction for long-lived resonance decays • Q3 dependence of r3

  6. Models Heinz and Zhang, PRC56, 426(’97), Nakamura and Seki, PRC61, 054905 (’00) Model I : Partial Coherent Parameter: chaotic fractionepc epc Note : 0 < epc < 1 1-epc Parameter: mean # of coh. sources am Model II : Multicoherent (Poisson Distribution) Each of the models contains single parameter only.

  7. Models (contd) Model III : Partial Multicoherent Parameter: two parameters e : Chaotic Fraction, a : Mean # of Coh. Sources (Poisson Dist.) Note : 0 < e < 1 l w Consistent determination of e and a from l and w

  8. Apparent reduction of l by long-lived resonances Gyulassy and Padula, PLB217,181 (’88), Heiselberg, PLB379,27 (’96), Csorgo et al., Z.Phys.C71, 491 (’96) x : p production point Semi-classical description: average on lifetime t Experimental resolution ofq : ~ 5 MeV Resonances with larger G cannot be resolved!

  9. Correction for long-lived resonances Need : Estimation of # of long-lived resonances Statistical model Ks0, h, h’, f, L, S, X (up to S*(1385) ) T=160-180 , mB = 40-50, mS = 9, mI3 = -1 [MeV] Cleymans and Redlich (1999), Broniowski and Florkowski (2001), Braun-Munziger et al., (2001)

  10. Results of ltrue lexp = 0.5 (STAR, PRL87,082301 (’01)) 0.817 < l < 0.896

  11. Extraction of w : Correlation functions r3(Q3)/2 : Constructed from C2(Qij) and C3(Q3) Need to establish functional form of C2 and C3 to obtain r3(0)/2 fit with

  12. Q3 dependence of r3 Experiment : decrease with Q32 Chaotic Source : ~1 at small Q32 increase at large Q32 due to projection Decrease with Q3 – coherent components must exist Value of w : 0.873 - 0.892

  13. Results • Model I and II • Model III 0 < e < 0.26 4.71 < a < 8.62 All models show partial coherent source

  14. Conclusion • 2- and 3- pion Correlation – Degree of Coherence. • 3-type of Source Models. • Correction for Long-Lived Resonance Decays. • @RHIC: Not fully chaotic but small coherence still exists. • All of models gives the consistent result. • Future Problem: • As a function of multiplicity • Distinction among models?

More Related