Initial Condition Fluctuations for Heavy Ion Collisions

Transcription

1 Initial Condition Fluctuations for Heavy Ion Collisions Philipe de Almeida Mota Takeshi Kodama (Ph.D. Advisor) Instituto de Física UFRJ, Rio de Janeiro, Brasil Max Planck Institut Frankfurt, Germany February 22, 2011 Ph. Mota, (UFRJ) February 22, / 25

2 motivation Two particle correlation observed at RHIC. Ph. Mota, (UFRJ) February 22, / 25

3 shadow effect smooth initial condition plus gaussian tube Ph. Mota, (UFRJ) February 22, / 25

4 shadow effect single particle distribution two particle correlation dip at the tube position and shoulders around it features dip at away side Ph. Mota, (UFRJ) February 22, / 25

5 smooth + 1 tube single particle distribution perfil de temperatura em t = 7 fm medium blocked by tube expansion which is much more explosive Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

6 smooth + 1 tubo 3 particle correlation 2 particle correlation dn 123 = d φ 12 φ 13 dφ dn 1 dφ (φ)dn 2 dφ (φ + φ 12) dn 3 dφ (φ + φ 13) Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

7 smooth + fluctuation 3 tubes, average over different events average of correlation correlation of averages C( φ) = dφ f 1 (φ)f 2 (φ + φ) f 1 (φ) f 2 (φ + φ) Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

8 smooth + fluctuation 3 particle correlation 3 particle cumulant Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

9 distance dependency 2 particle cumulant particle spectra strongly affects the cumulant but does not changes the spectrum Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

10 peripheral collisions temperature profile temperature profile Ph. Mota, (UFRJ) February 22, / 25

11 peripheral collisions medium + shadow shadow Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

12 initial conditions with fluctuations event-by-event hydro (non-homogenous IC) systematic study of observables focus in the 2 particle correlations (2+1)D with HG+lQCD EoS Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

13 random tubes model energy density profile ε(x ; b) = N(b) spatial probablity i ε tube (x R i ) P(R ; b) ε WN (R ; b) tube energy density ε tube i (x ) = ε tube 0 exp number of tubes ( (x R i ) )2 2(σ tube ) 2 N(b) = EWN (b) E WN (0) N(0) model parameters σ e N Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

14 random tubes σ = 0.7 fm, N = 200 σ = 0.35 fm, N = 200 same tube positions (b = 0.4) MC Glauber: 0 20% (b < 6.6 fm) Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

15 azimuthal distribution ( ) 2-Particle Correlation 0 20% GeV 2-Particle Correlation 0 20% GeV 1 1 C 0.5 C φ φ σ = 0.7 fm, N = 200 σ = 0.7 fm, N = 1000 σ = 0.35 fm, N = 200 σ = 0.35 fm, N = 1000 dip appearence favors smaller N no dip for higher N σ plays smaller role Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

16 azimuthal distribution ( ) Ratio shoulder/head trend shows ratio depends strongly on N no dip for N 800 Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

17 spectrum Spectrum (pi+) 0 10% Spectrum (pi+) 0 10% dn ptdptdy [c2 /GeV 2 ] dn ptdptdy [c2 /GeV 2 ] π π p T [GeV/c] p T [GeV/c] Optical Glauber σ = 0.7 fm, N = 200 σ = 0.7 fm, N = 1000 Optical Glauber σ = 0.35 fm, N = 200 σ = 0.35 fm, N = 1000 small differences for low p T granularity enhances high p T Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

18 spectrum 1 2π dn ptdptdy [GeV2 /c 2 ] pt [GeV/c] σ = 0.35 fm σ = 0.5 fm N σ = 0.7 fm OpGlauber sensitive to both N and σ p T trend increases with granularity OpGlauber σ = 0.35 fm N σ = 0.5 fm σ = 0.7 fm Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

19 elliptic flow Elliptic (pi+) 0 20% Elliptic (pi+) 0 20% v2 0.1 v p T [GeV/c] Optical Glauber σ = 0.7 fm, N = 200 σ = 0.7 fm, N = 1000 v 2 for high p T is strongly affected by σ possible saturation of v 2 for σ 0.35 fm p T [GeV/c] Optical Glauber σ = 0.35 fm, N = 200 σ = 0.35 fm, N = 1000 Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

20 elliptic flow p T = 1 GeV p T = 5 GeV v2 v N v 2 slowly converging N N affects v 2 stronger for low p T σ affects v 2 stronger for high p T Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

21 tube fluctuation 0.5 Elliptic (pi+) 0 20% tube positions and particle distribution 0.25 v average high pt [GeV/c] low flat neg 20.4 < < p p T T < < < p T < 5 same b 1PD reflects IC v ebe 2 is highly sensitive to IC event: high Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

22 tube fluctuation 0.5 Elliptic (pi+) 0 20% tube positions and particle distribution 0.25 v average high pt [GeV/c] low flat neg 0.4 < p T < < p T < 5 same b 1PD reflects IC v ebe 2 is highly sensitive to IC event: flat Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

23 tube fluctuation 0.5 Elliptic (pi+) 0 20% tube positions and particle distribution 0.25 v same b average high pt [GeV/c] 1PD reflects IC low flat neg v ebe 2 is highly sensitive to IC event: low 4 < p T < < p T < 1 2 < p T < 3 Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

24 tube fluctuation 0.5 Elliptic (pi+) 0 20% tube positions and particle distribution 0.25 v < p T < same b average high pt [GeV/c] 1PD reflects IC low flat neg v ebe 2 is highly sensitive to IC event: neg 4 < p T < 5 2 < p T < 3 Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25

25 summary and perspectives summary systematic study on the effects of granularity on the observables shadow effect survives throuth 2-particle correlations non-trivial results come from event-by-event study tubes lead to double peak structure and reduce v 2 for high p T v 2 depends more on tube width correlation depends more on number of tubes perspectives particle decays use microscopic models of IC apply to high multiplicity pp collisions Ph. Mota, philipe@if.ufrj.br (UFRJ) February 22, / 25