Niseem Magdy - drupal.star.bnl.gov dependence of... · Niseem Magdy Stony Brook University...

Niseem MagdyStony Brook University

[email protected]

CPOD2017

For the STAR Collaboration

2

QCD Phase Diagram

Ø Strong interest in the theoretical calculations which span a broad

(𝜇", T)domain.

3

QCD Phase Diagram

Ø The . /⁄ values are tuned in model calculations to describe the

experimental flow data at different collision energies

Ø Strong interest in the theoretical calculations which span a broad

(𝜇", T)domain.

Iu.A. Karpenko , et al.PRC 91, 064901 (2015)

4

STARPRL 112, 162 301 (2014)

v Investigate signatures for the first-order phase transition

ØStrong interest in the experimental measurements which span a broad (𝜇", T)domain.

QCD Phase Diagram

5

STARPRL 112, 162 301 (2014)

v Investigate signatures for the first-order phase transition

v Search for critical fluctuations

STAR PRL 112, 032 302 (2014)

ØStrong interest in the experimental measurements which span a broad (𝜇", T)domain.

QCD Phase Diagram

6

Azimuthal anisotropic flow

6

Ø Comprehensive set of flow measurements are important to study;ü Differentiate between initial-state models

q Initial-state eccentricity & its fluctuations

7


7



ü Transport coefficients (. /⁄ , etc)q Pin down the temperature dependence of the transport

coefficients

8


8



ü Transport coefficients (. /⁄ , etc)q Pin down the temperature dependence of the transport

coefficients

ü Detailed flow measurements could aid ongoing efforts

to search for the critical end point(CEP)

9


9

Dipole asymmetry

Asymmetry in initial geometry → Final state momentum anisotropy (flow)

𝑑𝑁𝑑𝜑4 = 1 + 29𝑣;

<

;

cos(𝜑 − Ψ;)

10


10

Dipole asymmetry

Asymmetry in initial geometry → Final state momentum anisotropy (flow)

𝑑𝑁𝑑𝜑4 = 1 + 29𝑣;

<

;

cos(𝜑 − Ψ;)

Ø The flow harmonic coefficients 𝑣; are influenced by eccentricities(𝜀;)[and their fluctuations], the speed of sound cC(µ", 𝑇), and transport

coefficients FC, GC, …

6

STAR Detector at RHICØ TPC detector mainly get

used in the current analysis

Ø Collected data for Au+Au at different 𝑠JJ� by STAR detector at RHIC

will be presented

Two-particle correlation function 𝐶r Δ𝜑 = 𝜑O − 𝜑P ,

𝐶𝑟 Δ𝜑 = 𝑑𝑁/𝑑Δ𝜑 and 𝑣;SP = ∑ UV WX YZC(;WX)�[\

∑ UV WX�[\

Azimuthal anisotropy measurements

Correlation function

12

Flow



∑ UV WX�[\

Non-flow



13

Flow

𝑯𝑩𝑻

𝑫𝒆𝒄𝒂𝒚



∑ UV WX�[\

𝑺𝒉𝒐𝒓𝒕 − 𝒓𝒂𝒏𝒈𝒆

𝑛 > 1𝑣;SP = 𝑣;S𝑣;P +𝛿/opVq

Non-flow



14ChargeNon-flow suppression is needed

Flow

𝑯𝑩𝑻


𝑴𝒐𝒎𝒆𝒏𝒕𝒖𝒎𝑪𝒐𝒏𝒔𝒆𝒓𝒗𝒂𝒕𝒊𝒐𝒏

Di−jets



∑ UV WX�[\

𝑺𝒉𝒐𝒓𝒕 − 𝒓𝒂𝒏𝒈𝒆𝑳𝒐𝒏𝒈 − 𝒓𝒂𝒏𝒈𝒆

𝑛 > 1𝑣;SP = 𝑣;S𝑣;P +𝛿/opVq

𝑛 = 1𝑣~SP = 𝑣~S𝑣~P +𝛿�p;�

Non-flow



15ChargeNon-flow suppression is needed

16

Ø Short-range non-flow effect get reduced using |Δη| > 0.7 cut

The 𝑣�vs centrality at 𝑠JJ� = 200using different 𝛥𝜂 cuts

Short-range non-flow suppression𝑺𝒉𝒐𝒓𝒕 − 𝒓𝒂𝒏𝒈𝒆Non−flow𝑯

𝑩𝑻


0

0.02

0.04

0.06

0.08

0.1

20 40 60 80

v2

Au+Au200 GeV|∆η| > 0.3

LSUS

0

0.02

0.04

0.06

0.08

0.1

20 40 60 80

|∆η| > 0.7

0

0.02

0.04

0.06

0.08

0.1

20 40 60 80

|∆η| > 0.9

0.8

0.9

1

1.1

1.2

20 40 60 80

LS/US

0.8

0.9

1

1.1

1.2

20 40 60 80Centrality%

LS/US

0.8

0.9

1

1.1

1.2

20 40 60 80

LS/US

STAR Preliminary

𝑣~SP = 𝑣~S𝑣~P +𝛿�p;�𝑛 = 1

𝑣~~ 𝑝�S, 𝑝�P = 𝑣~��; 𝑝�

S 𝑣~��; 𝑝�

P − 𝐶𝑝�S𝑝�

P

17

arXiv:1203.0931arXiv:1203.3410arXiv:1208.1874arXiv:1208.1887arXiv:1211.7162

1

Long-range non-flow suppression

𝑣~~ in Eq(1) represents NxM matrix which we fit with N+1 parameters

𝑴𝒐𝒎

𝒆𝒏𝒕𝒖𝒎𝑪𝒐𝒏𝒔𝒆𝒓𝒗𝒂𝒕𝒊𝒐𝒏

𝑳𝒐𝒏𝒈 − 𝒓𝒂𝒏𝒈𝒆

𝑪 ∝ < 𝒑𝑻𝟐 >< 𝑴𝒖𝒍𝒕 > �𝟏


ØGood simultaneous fit ( ��

;��~1.1) obtained with Eq. 1

18


1



𝑴𝒐𝒎



𝑪 ∝ < 𝒑𝑻𝟐 >< 𝑴𝒖𝒍𝒕 > �𝟏

-1

0

1

2

1 2 3

v 11

x10-3

Au+Au0-5%

200 GeV

(a)

0.2 < paT < 0.6 (GeV/c)

-1

0

1

2

1 2 3

v 11

1.0 < paT < 1.4 (GeV/c)

(b)

-1

0

1

2

1 2 3

v 11

pbT (GeV/c)

1.4 < paT < 1.8 (GeV/c)

(c)

-1

0

1

2

1 2 3

v 11

1.8 < paT < 2.6 (GeV/c)

(d)

STAR Preliminary

𝑣~~ 𝑝�S, 𝑝�P = 𝑣~��; 𝑝�

S 𝑣~��; 𝑝�


P


ØGood simultaneous fit ( ��

;��~1.1) obtained with Eq. 1

Øv~~characteristic behavior gives a good constraint for 𝒗𝟏𝒆𝒗𝒆𝒏 𝐩𝐓 extraction19


1



𝑴𝒐𝒎



𝑪 ∝ < 𝒑𝑻𝟐 >< 𝑴𝒖𝒍𝒕 > �𝟏

-1

0

1

2

1 2 3

v 11

x10-3

Au+Au0-5%

200 GeV

(a)

0.2 < paT < 0.6 (GeV/c)

-1

0

1

2

1 2 3

v 11

1.0 < paT < 1.4 (GeV/c)

(b)

-1

0

1

2

1 2 3

v 11

pbT (GeV/c)

1.4 < paT < 1.8 (GeV/c)

(c)

-1

0

1

2

1 2 3

v 11

1.8 < paT < 2.6 (GeV/c)

(d)

STAR Preliminary

𝑣~~ 𝑝�S, 𝑝�P = 𝑣~��; 𝑝�

S 𝑣~��; 𝑝�


P

ØThe characteristic behavior of 𝑣~��; 𝑝� shows a weak centrality dependence

The extracted 𝒗𝟏𝒆𝒗𝒆𝒏 𝒑𝑻 and the momentum conservation parameter 𝐶 at 𝑠JJ� = 200

20

𝜂 < 1and|Δ𝜂| > 0.7Long-range non-flow suppression

𝑴𝒐𝒎



STAR Preliminary

0

0.04

0.08

0.12

0 1 2 3

veven

1

pT(GeV/c)

Au+Au200 GeV

0%-10%10%-20%20%-30%30%-40%

Ø Fit to 𝑣~��; 𝑝� data shows 𝑣~��; 𝑝� centrality dependent

𝐯𝟏𝟏 𝒑𝑻𝒂, 𝒑𝑻𝒃 = 𝒗𝟏𝒆𝒗𝒆𝒏 𝒑𝑻

𝒂 𝒗𝟏𝒆𝒗𝒆𝒏 𝒑𝑻

𝒃 − 𝑪𝒑𝑻𝒂𝒑𝑻

𝒃

ØThe characteristic behavior of 𝑣~��; 𝑝� shows a weak centrality dependence

The extracted 𝒗𝟏𝒆𝒗𝒆𝒏 𝒑𝑻 and the momentum conservation parameter 𝐶 at 𝑠JJ� = 200

21

𝐯𝟏𝟏 𝒑𝑻𝒂, 𝒑𝑻𝒃 = 𝒗𝟏𝒆𝒗𝒆𝒏 𝒑𝑻


𝒃 − 𝑪𝒑𝑻𝒂𝒑𝑻

𝒃

𝜂 < 1and|Δ𝜂| > 0.7Long-range non-flow suppression

𝑴𝒐𝒎



STAR Preliminary

0

0 0.01 0.02

0

0.004

0.008

C

1/<Mult>

Au+Au200 GeV

Ø The momentum conservation parameter 𝐶 scales as < 𝑴𝒖𝒍𝒕 >�𝟏

0

0.04

0.08

0.12

0 1 2 3

veven

1

pT(GeV/c)

Au+Au200 GeV

0%-10%10%-20%20%-30%30%-40%

Ø Fit to 𝑣~��; 𝑝� data shows 𝑣~��; 𝑝� centrality dependent

STAR Preliminary

𝑪 ∝ < 𝒑𝑻𝟐 >< 𝑴𝒖𝒍𝒕 > �𝟏

22

Flow harmonics

𝒗; 𝐶𝑒𝑛𝑡𝒗; 𝜂, 𝑝�

23

Flow harmonics

𝒗; 𝐶𝑒𝑛𝑡

𝒗; 𝑠JJ�

𝒗; 𝜂, 𝑝�

ØSimilar characteristic behavior of 𝑣~��; 𝑝� at all energies

Ø𝑣~��; 𝑝� agrees with hydrodynamic calculations at 200 GeV

ØMomentum conservation parameter 𝐶 scales as 𝑀𝑢𝑙𝑡 �~

The extracted 𝑣~��; 𝑝� at all BES energies

24

Transverse momentum dependence of 𝑣~��;

STAR Preliminary

𝐯𝟏𝟏 𝒑𝑻𝒂, 𝒑𝑻𝒕 = 𝒗𝟏𝒆𝒗𝒆𝒏 𝒑𝑻


𝒕 − 𝑪𝒑𝑻𝒂𝒑𝑻

𝒕

HydroE.Retinskaya , et al.

PRL 108, 252302 (2012)

0

0.1

0 1 2

veven

1(a) Au+Au

200 GeV0-10%

Hydro(η/s = 0.16)

0

0.1

0 1 2

veven

1

62.4 GeV(b)

0

0.1

0 1 2

veven

1

(c)39 GeV

0

0.1

0 1 2

veven

1

(d)27 GeV

0

0.1

0 1 2

19.6 GeV

(e)

0

0.1

0 1 2

pT (GeV/c)

(f)14.5 GeV

0

0.1

0 1 2

11.5 GeV(g)

0

0.1

0 1 2

7.7 GeV(h)

0

1

2

0 0.02 0.04 0 1 2

C

⟨ Mult ⟩-1

×102

Ø𝑣~��; increases weakly as collisions

become more peripheral

The extracted 𝒗𝟏𝒆𝒗𝒆𝒏 𝐶𝑒𝑛𝑡 and the momentum conservation parameter at different beam energies

25




𝒕

Centrality dependence dependence of 𝑣~��;

STAR Preliminary

0

0.01

0.02

10 20 30 40 50 60 70

|v1ev

en|

Centrality%

(a) Au+Au0.4 < pT < 0.7(GeV/c)

200 GeV39 GeV

19.6 GeV

For different beam energies;

Ø𝑣~��; increases weakly as collisions

become more peripheral

The extracted 𝒗𝟏𝒆𝒗𝒆𝒏 𝐶𝑒𝑛𝑡 and the momentum conservation parameter at different beam energies

26




𝒕

Centrality dependence dependence of 𝑣~��;

STAR Preliminary

0

0.01

0 0.01 0.02

0

0.01

C(√

s NN

)

⟨ Mult ⟩-1

(b)

0

0.01

0.02

10 20 30 40 50 60 70

|v1ev

en|

Centrality%

(a) Au+Au0.4 < pT < 0.7(GeV/c)

200 GeV39 GeV

19.6 GeV

STAR Preliminary

𝑪 ∝ < 𝒑𝑻𝟐 >< 𝑴𝒖𝒍𝒕 > �𝟏

Ø Momentum conservation parameter 𝐶 scales as 𝑀𝑢𝑙𝑡 �~

For different beam energies;

27

The extracted 𝑣;¦~ 𝜼 at all BES energies

𝜂 < 1and|Δ𝜂| > 0.7Pseudorapidity dependence of𝑣;¦~

Ø 𝑣; 𝜼 has similar trends for different beam energies.

Ø 𝑣; 𝜼 decreases with harmonic order n.

0

0.02

0.04

0 0.4 0.8

v nAu+Au

200 GeV0-40%

(a)

0

0.02

0.04

0 0.4 0.8

v n

62.4 GeV(b)

0

0.02

0.04

0 0.4 0.8

v n

39 GeV(c) v2/2

v3v4

0

0.02

0.04

0 0.4 0.8

v n

27 GeV(d)

0

0.02

0.04

0 0.4 0.8

19.6 GeV(e)

0

0.02

0.04

0 0.4 0.8

|η|

14.5 GeV(f)

0

0.02

0.04

0 0.4 0.8

11.5 GeV(g)

0

0.02

0.04

0 0.4 0.8

7.7 GeV(h)

STAR Preliminary

28

0

0.1

0.2

0 1 2 3

v nAu+Au200 GeV0-40%

(a)

0

0.1

0.2

0 1 2 3

v n

62.4 GeV(b)

0

0.1

0.2

0 1 2 3

v n

39 GeV(c)v2v3v4v5

0

0.1

0.2

0 1 2 3

v n

27 GeV(d)

0

0.1

0.2

0 1 2 3

19.6 GeV(e)

0

0.1

0.2

0 1 2 3

pT(GeV/c)

14.5 GeV(f)

0

0.1

0.2

0 1 2 3

11.5 GeV(g)

0

0.1

0.2

0 1 2 3

7.7 GeV(h)

The extracted 𝑣;¦~ 𝑝� at all BES energies

𝜂 < 1and|Δ𝜂| > 0.7Transverse momentum dependence of𝑣;¦~

Ø 𝑣; 𝑝� has similar trends for different beam energies.

Ø 𝑣; 𝑝� decreases with harmonic order n.

STAR Preliminary

0

0.04

0 20 40 60

v nAu+Au

200 GeV(a)

0

0.04

0 20 40 60

v n

62.4 GeV(b)

0

0.04

0 20 40 60

v n

39 GeV(c)v2/2

v3v4v5

0

0.04

0 20 40 60

v n

27 GeV(d)

0

0.04

0 20 40 60

19.6 GeV(e)

0

0.04

0 20 40 60

Centrality%

(f) 14.5 GeV

0

0.04

0 20 40 60

11.5 GeV(g)

0

0.04

0 20 40 60

7.7 GeV(h)

The extracted𝑣;¦~ Centrality at all BES energiesCentrality dependence of𝑣;¦~

Ø 𝑣; Centrality has similar trends for different beam energies.

Ø 𝑣; Centrality decreases with harmonic order n.

STAR Preliminary

16

Ø|𝑣~��;| shows similar values to 𝑣¨ at 0.4 < 𝑝� < 0.7(𝐺𝑒𝑉/𝑐)

The extracted 𝒗𝟏𝒆𝒗𝒆𝒏 vs 𝑠JJ� at 0%-10% centrality

30




𝒕

𝜂 < 1and|Δ𝜂| > 0.7Beam-energy dependence of 𝑣~��;

-0.02

-0.01

0

0.01

0.02

10 100

√sNN(GeV)

vn

Au+Au0-10%

0.4< pT < 0.7(GeV/c)veven

1v3

STAR Preliminary

Reflection

Ø|𝑣~��;| shows similar values to 𝑣¨ at 0.4 < 𝑝� < 0.7(𝐺𝑒𝑉/𝑐)

The extracted 𝒗𝟏𝒆𝒗𝒆𝒏 vs 𝑠JJ� at 0%-10% centrality

31




𝒕

𝜂 < 1and|Δ𝜂| > 0.7Beam-energy dependence of 𝑣~��;

P.BożekPLB 717, 287-290 (2012)

0 50 100 150 2000

0.2

0.4

0.6

0-5%

5-10%

10-20%

20-30%

ε

2ε

3ε

1ε

partN

Øε¨ > ε~

ü 𝑣¨ has larger viscous damping effect than 𝑣~��;

-0.02

-0.01

0

0.01

0.02

10 100

√sNN(GeV)

vn

Au+Au0-10%

0.4< pT < 0.7(GeV/c)veven

1v3

STAR Preliminary

Reflection

The extracted 𝑣;¦~vs 𝑠JJ� at 0-40% centrality

Beam-energy dependence of𝑣;¦~

Ø 𝑣; 𝑠JJ� shows a monotonic increase with beam-energy.

Ø 𝑣; 𝑠JJ� decreases with harmonic order n (viscous effects).

STAR Preliminary

18

0

0.01

0.02

0.03

0.04

10 100

√sNN(GeV)

(a)

vn

Au+Au0-40%

v2/2v3v4

33

Summary-I Comprehensive set of flow measurements were studied for Au+Au collision system at all BES energies with one set of

cuts.ØFor n > 1;

ü 𝑣; decreases with harmonic order n.

ØFor n = 1;

34


cuts.ØFor n > 1;


ü 𝑣; 𝑝�, 𝜂, Centrality indicates a similar trend for different beam energies.

ØFor n = 1;

35


cuts.ØFor n > 1;



ü 𝑣; 𝑠JJ� shows a monotonic increase with beam-energy.

ØFor n = 1;

36


cuts.ØFor n > 1;




ØFor n = 1;ü Similar characteristic behavior of 𝑣~��; 𝑝� at all energies.

37


cuts.ØFor n > 1;





ü Momentum conservation parameter 𝐶 scales as 𝑀𝑢𝑙𝑡 �~

38


cuts.ØFor n > 1;






ü |𝑣~��;| shows similar values to 𝑣¨ (larger viscous effect for 𝑣¨)

39


cuts.ØFor n > 1;







ØMore information could be extracted from 𝑣; measurements via the acoustic ansatz

Ø 𝑣; measurements are sensitive to system shape (𝜀;), size(𝑅𝑇) and transport coefficients F

C, GC, … .

40

arXiv:1305.3341Roy A. Lacey, et al.


PRC 84, 034908 (2011)P. Staig and E. Shuryak.

PRC 88, 044915 (2013)E. Shuryak and I. Zahed

Acoustic ansatz


C, GC, … .

41





Acoustic ansatz

Ø Acoustic ansatz

ü Sound attenuation in the viscous matter reduces the magnitude of 𝑣;.


C, GC, … .

42

𝑆~ 𝑅𝑇 ¨~ 𝑁Uo then 𝑅𝑇~ 𝑁Uo²³





Acoustic ansatz

Ø Acoustic ansatz

ü Sound attenuation in the viscous matter reduces the magnitude of 𝑣;.Ø Anisotropic flow attenuation,

�´µ´∝ 𝑒�¶;� ,𝛽 ∝ F

/ ~¸�

Ø From macroscopic entropy considerations


C, GC, … .

𝒍𝒏 𝒗𝒏𝜺𝒏

∝ −𝒏𝟐 𝜷» 𝑵𝑪𝒉�𝟏𝟑 where 𝜷» ∝ 𝜼

𝒔

43






Acoustic ansatz

Ø Acoustic ansatz


�´µ´∝ 𝑒�¶;� ,𝛽 ∝ F

/ ~¸�


Ø We can rewrite Eq(i)

Ø At the same centrality we have

𝒍𝒏 𝒗𝒏𝟏/𝒏

𝒗𝟐𝟏/𝟐 ∝ − 𝒏 − 𝟐 𝜷» 𝑵𝑪𝒉

�𝟏𝟑 where 𝜷» = 𝑨 𝜼𝒔 1.7

1.8

1.9

10 100⟨ N

ch ⟩1/

3

√sNN(GeV)

Au-Au0-40%

where A is constant


C, GC, … .

𝒍𝒏 𝒗𝒏𝜺𝒏

∝ −𝒏𝟐 𝜷» 𝑵𝑪𝒉�𝟏𝟑 where 𝜷» ∝ 𝜼

𝒔

44






Acoustic ansatz

Ø Acoustic ansatz


�´µ´∝ 𝑒�¶;� ,𝛽 ∝ F

/ ~¸�


Ø We can rewrite Eq(i)

Ø At the same centrality we have


𝒗𝟐𝟏/𝟐 ∝ − 𝒏 − 𝟐 𝜷» 𝑵𝑪𝒉

�𝟏𝟑 where 𝜷» = 𝑨 𝜼𝒔


𝒗𝟐𝟏/𝟐 𝑵𝑪𝒉

𝟏𝟑(𝒏−𝟐)�𝟏= 𝜷»»

1.7

1.8

1.9

10 100⟨ N

ch ⟩1/

3

√sNN(GeV)

Au-Au0-40%

where A is constant

45

Viscous coefficient

ØThe viscous coefficient shows a non-monotonic behavior with beam-energy

𝜷»» = 𝒍𝒏 𝒗𝒏𝟏/𝒏

𝒗𝟐𝟏/𝟐 𝑵𝑪𝒉

𝟏𝟑 𝒏 − 𝟐 �𝟏 = 𝑨𝜼𝒔

STAR PreliminarySTAR Preliminary

0.4

0.8

1.2

10 100

0.4

0.8

1.2

√sNN(GeV)

(b)

β′ ′

n = 3n = 4

0

0.01

0.02

0.03

0.04

10 100

√sNN(GeV)

(a)

vn

Au+Au0-40%

v2/2v3v4

ConclusionComprehensive set of STAR measurements presented for

𝑣;(𝑝�, 𝜂, Centrality𝑎𝑛𝑑 𝑠JJ� ) for Au+Au collisions.

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ØFor 𝑣;:ü 𝑣; 𝑝�, 𝜂, Centrality indicates a similar trend for different beam energies.



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The viscous coefficient (𝑨 𝜼𝒔), is non-monotonic versus

the collision-energy with an apparent minimum near ~15 GeV.

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