Au collisions at RHIC - Brookhaven National Laboratory...in Au + Au collisions at RHIC Ning Yu Central China Normal University for the STAR Collaboration 2017/2/7 17:10-17:30 Outline

Beam energy dependence of 𝑑 and �� production in Au + Au collisions at RHIC

Ning YuCentral China Normal Universityfor the STAR Collaboration

2017/2/7 17:10-17:30

Outline

✯ Introduction

✯ STAR Experiment

✯ Results and Discussions

✯ Summary

Ning Yu, Quark Matter 2017@Chicago 1/20

2017/2/7 17:10-17:30

QCD Phase DiagramLHC,RHIC

Future FAIR Experiment

K. Fukushima and C. SasakiProg. Part. Nucl. Phys, 72, (2013) 99

✯ High temperature: QGP properties✯ High baryon density:

ü Critical point and phase boundaryü Possible new phase structure : quarkyonic matter

Phase transition

Correlations of nucleons

Light nuclei


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Light Nuclei Formation in HI Collisions✯ Light (anti)nuclei with small binding energy (𝜀), such as 𝑑 and �� with binding

energy 𝜀 = 2.2 MeV, are formed via final-state coalescence

𝐸(𝑑)𝑁(𝑑)𝑝(

= 𝐵( 𝐸-𝑑)𝑁-𝑑)𝑝-

.

𝐸/𝑑)𝑁/𝑑)𝑝/

(0.

≈ 𝐵( 𝐸-𝑑)𝑁-𝑑)𝑝-

(

, 𝑝(= 𝐴𝑝-

✯ In thermodynamics, 𝐵( is related to the nucleon freeze-out correlation volume 𝑉6or baryon density

𝐵( ∝ 𝑉680(, 𝐵9 =6𝜋)𝑅/-𝑚>

𝑚-9𝑉6

, 𝑅/- =𝑁/𝑁-

✯ Light nuclei may serve as probes of space-momentum density and correlation of nucleons at freeze-out. We will focus on 𝑑 (��) in this talk.

László P. Csernai, Joseph I. Kapusta Phys. Reps, 131,223(1986)B. Monreal, et. al. PRC60,031901(1999), PRC60,051902(1999)


2017/2/7 17:10-17:30

Energy Dependence of 𝑩𝑨Most Central

✯ The size of the fireball increase from low to high collision energy, 𝐵9 decrease with energy

✯ The behavior of 𝐵9 is different at high energy

✯ Is there any structure in the

energy dependence of 𝑩𝟐, from high energy to low energy ?

✯ Is there any centrality dependence of 𝑩𝟐?

✯ Is there any difference of 𝑩𝟐between deuteron and anti-

deuteron?PHENIX, PRL. 94, 122302 (2005).


1 10 100Collision Energy 𝒔𝑵𝑵� (GeV)

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RHIC Beam Energy Scan

𝒔𝐍𝐍� (GeV) 7.7 11.5 14.5 19.6 27 39 62.4 200Neve(M) 4 11 27 40 71 133 67 480𝝁𝑩(MeV) 420 315 260 205 155 115 72 20

✯ BES-I Au+Au collisions at 𝑠HH� = 7.7, 11.5, 14.5, 19.6, 27, 39 and 62.4 GeVü Search for conjectured QCD critical

point ü Search for the first order phase

transitionü Search for the onset of key QGP

signatures

STAR Collaboration, arXiv:1007.2613

J. Cleymans, H. Oeschler, K. Redlich, and S. WheatonPRC 73,034905 (2006)


2017/2/7 17:10-17:30

Solenoidal Tracker At RHICTime Projection Chamber（TPC）

ü Charged Particle Tracking

ü Momentum reconstruction

ü Particle identification from ionization

energy loss (dE/dx)

ü Pseudorapidity coverage |η| < 1.0

Time Of Flight (TOF)

ü Particle identification m2

ü Pseudorapidity coverage |η| < 0.9


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Particle Identification

Z (d) 0.4− 0.3− 0.2− 0.1− 0 0.1 0.2 0.3 0.4

Cou

nts

0

0.5

1

1.5

2

310×

DATASign.+Backgr.Sign.Backgr.

deuteron 39 GeV 0-5% < 0.8 GeV/c

T0.6 < p

)4/c2 (GeV2m2.5 3 3.5 4 4.5

Cou

nts

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

310×

DATASign.+Backgr.Sign.Backgr.

deuteron 39 GeV 0-5% < 2.8 GeV/c

T2.4 < p

𝑧> = log𝑑𝐸 𝑑𝑥⁄𝑑𝐸 𝑑𝑥⁄ >

OO

𝑚9 = 𝑝9𝑐9𝑡9

𝐿9 − 1

BB : Bethe-BlochH. Bichsel, Nucl. Instrum. Meth. A 562, 154 (2006).


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Efficiency and Acceptance

𝜀UVW 𝑝X = 𝑎Zexp −𝑎8𝑝X

^_+ 𝑝𝑜𝑙(2)

𝜀Ude 𝑝X = 𝑎Zexp −𝑎8𝑝X

^_

𝜀Ude 𝑝X =ThenumberofTOFMatchedTracks

ThenumberofTPCTracks


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Corrections✯ Energy Loss

✯ Background in 𝑑 analysis

𝑓 𝑝X = 𝐴 + 𝐵 1 +𝐶𝑝X9

{

- No centrality dependence of energy loss- Energy loss of 𝑑 and �� are the same- The energy loss for all the collision energy are the

same except 14.5 GeV (different material budget)


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Deuteron Spectra✯ Mid-rapidity ( 𝑦 ≤ 0.3) transverse

momentum distribution of 𝑑 from

Au+Au Collision

✯ Dash line: blast-wave function fits1 2 3 4

5

4

3

2

1

111.5 GeV

1 2 3 4

5

4

3

2

1

114.5 GeV

1 2 3 4

6−10

5−10

4−10

3−10

2−10

1−10

1

19.6 GeV

1 2 3 4

6

5

4

3

2

1

1

27 GeV

1 2 3 4

6

5

4

3

2

1

1

39 GeV

1 2 3 4

6−

10

5−

10

4−10

3−

10

2−10

1−10 62.4 GeV

1 2 3 4

6

5

4

3

2

1 200 GeV

1 2 3 4

6

5

4

3

2

1−

4 2× 0-10%

3 2×10-20%

2 2×20-40%

1 2×40-60%

0 2×60-80%

(GeV/c)T

Transverse Momentum p

Deuteron from Au+Au Collision

)2

/Ge

V2

dy)

(c

TN

/(d

p2

)dT

pπ

1/(

2

1 2 3 4

5−

10

4−10

3−

10

2−10

1−10

17.7 GeV

STAR Preliminary

d9𝑁𝑚X𝑑𝑚X

∝ � 𝑟d𝑟𝑚X𝐼Z𝑝Xsinh𝜌

𝑇 𝐾8𝑚Xcosh𝜌

𝑇

�

Z


2017/2/7 17:10-17:30

Anti-Deuteron Spectra

1 2 3 4

6

5

4

3

11.5 GeV

1 2 3 4

6

5

4

3

14.5 GeV

1 2 3 46−10

5−10

4−10

3−10

2−10 19.6 GeV

1 2 3 46

5

4

3

2

27 GeV

1 2 3 46

5

4

3

2

39 GeV

1 2 3 4

6−

10

5−

10

4−10

3−

10

2−10

1−10

62.4 GeV

1 2 3 4

6

5

4

3

2

1

200 GeV

1 2 3 4

6

5

4

3

2

1−

4 2× 0-10%

3 2×10-20%

2 2×20-40%

1 2×40-60%

0 2×60-80%

(GeV/c)T

Transverse Momentum p

Anti-Deuteron from Au+Au Collision

)2

/Ge

V2

dy)

(c

TN

/(d

p2

)dT

pπ

1/(

2

1 2 3 4

6−

10

5−

10

4−10

3−

10

d9𝑁𝑚X𝑑𝑚X

∝ � 𝑟d𝑟𝑚X𝐼Z𝑝Xsinh𝜌

𝑇 𝐾8𝑚Xcosh𝜌

𝑇

�

Z

STAR Preliminary

✯ Mid-rapidity ( 𝑦 ≤ 0.3) transverse

momentum distribution of �� from

Au+Au Collision

✯ Dash line: blast-wave function fits


2017/2/7 17:10-17:30

𝒑𝑻 and 𝑻𝒌𝒊𝒏, 𝜷

⟩ Part

N⟨100 200 300

( G

eV/c

)⟩

T p⟨

1

1.5

219.6 GeV 27 GeV 39 GeV62.4 GeV 200 GeV

Au+Au Anti-Deuteron

⟩ Part

N⟨100 200 300

( G

eV/c

)⟩

T p⟨

1

1.5

27.7 GeV 11.5 GeV 14.5 GeV 19.6 GeV27 GeV 39 GeV 62.4 GeV 200 GeV

Au+Au Deuteron

STAR Preliminary STAR Preliminary

39 GeV 𝑑 �� 𝜋, 𝐾, 𝑝∗

Cent. 𝑻𝒌𝒊𝒏(MeV) 𝜷(c) 𝑝X (GeV/c) 𝑝X (GeV/c) 𝑻𝒌𝒊𝒏(MeV) 𝜷(c) 𝑝X (GeV/c)0-10% 99±12 0.45±0.02 1.35±0.09 1.39±0.09 118±11 0.48±0.04 0.85±0.0510-20% 110±14 0.43±0.02 1.32±0.09 1.35±0.05 120±11 0.46±0.03 0.83±0.0520-40% 135±23 0.39±0.02 1.23±0.08 1.23±0.08 126±11 0.41±0.03 0.79±0.05

✯ 𝒑𝑻 decrease fromcentral to peripheralcollision

✯ 𝒑𝑻 of 𝑑 and 𝑑 areconsistent within error

✯ B.W. can describe both𝑑 and 𝜋, 𝐾, 𝑝 withsimilar parameters

∗ STAR Collaboration, arXiv:1701.07065 (submitted to PRC)


2017/2/7 17:10-17:30

Integral Yield 𝒅𝑵 𝒅𝒚⁄

✯ 𝑑𝑁 𝑑 /𝑑𝑦 is smaller at higher energy: baryon stopping✯ 𝑑𝑁(𝑑)/𝑑𝑦 increases with increasing energy: baryon pair production✯ 𝑁�� scaled 𝑑𝑁/𝑑𝑦 for 𝑑 show weak centrality dependence, for 𝑑

increase slightly from peripheral to central collision

⟩ Part

N⟨100 200 300

]⟩ P

art

N⟨×

dN

/dy/[

0.5

6−10

5−10

4−10

3−10

11.5 GeV 14.5 GeV 19.6 GeV 27 GeV39 GeV 62.4 GeV 200 GeV

Au+Au Anti-Deuteron

⟩ Part

N⟨100 200 300

]⟩ P

art

N⟨×

dN

/dy/[

0.5

3−10

2−10

7.7 GeV 11.5 GeV 14.5 GeV 19.6 GeV

27 GeV 39 GeV 62.4 GeV 200 GeV

Au+Au Deuteron

STAR Preliminary STAR Preliminary


2017/2/7 17:10-17:30

Antiparticle to Particle Ratios

✯ 𝑁 �� /𝑁 𝑑 ratio decreases as a function of collision centrality✯ 𝑁 �� /𝑁 𝑑 ratio decreases with decreasing energy

⟩ Part N⟨100 200 300

)/N(d

)d

N(

0

0.2

0.4

0.6

0.8 200 GeV 2×39 GeV

4×19.6 GeV PHENIX 200 GeV

STAR Preliminary

PHENIX, PRL. 94, 122302 (2005).


2017/2/7 17:10-17:30

𝑵(𝒅)/𝑵(𝒑) Ratio vs. Energy

The lines are from thermal model predictionA. Andronic, P. Braun-Munzinger, J. Stachel, H. Stocker, PLB697 (2011)203

(GeV)NNs10 210 310

Parti

cle

Rat

io

4−10

3−10

2−10

1−10

1STAR 0-10% d/p

p/dSTAR 0-10% SIS d/pEOS802 d/pNA49 d/pPHENIX d/p

p/dPHENIX ALICE d/p

Thermal Prediction

5 MeV±T = 163

✯ The N(𝑑)/𝑁(𝑝) ratios by thermal model prediction are consistentwith the data from SIS energies up to LHC

✯ A temperature of 𝑇 = 163 ± 5 MeV can be extracted from 𝑁(𝑑)/𝑁(𝑝)and 𝑁(��)/𝑁(��)

𝑁(𝑑)𝑁(𝑝) ~

𝐾9 𝑚> 𝑇⁄𝐾9 𝑚- 𝑇⁄

𝑒��X

𝑁(��)𝑁(��) ~

𝐾9 𝑚> 𝑇⁄𝐾9 𝑚- 𝑇⁄

𝑒0��X

STAR Preliminary


2017/2/7 17:10-17:30

𝒅/𝒑𝟐 and 𝒅�/𝒑�𝟐 Ratios✯ In thermal model with GCE (grand canonical

ensemble), 𝑑 𝑝9⁄ and �� 9⁄ should be the same if iso-spin effect can be neglected

𝜇 𝑇 =

12 ln

�� 9⁄𝑑 𝑝9⁄

✯ The 𝜇 /𝑇 can also be obtained by 𝜇 𝑇 =

12 ln

𝜋¡

𝜋0

The results are close to zero implying smalliso-spin effect

10 210

2d/p

0.2

0.4

0.6

0.8

3−10×

2d/p2

p/d

p err.

err.p

Au+Au 0-10%

(GeV)NNs10 210

/ T

Qµ 0.5−

0

2BES d/p-

π/+πBES -

π/+πNA49 Initial Iso-spin

STAR Preliminary

NA49, PRC 94, 044906 (2016)


2017/2/7 17:10-17:30

𝑩𝟐 v.s. 𝒎𝑻 and Collision Centrality

✯ The values of 𝐵9 increase as a function of 𝑚Xand decrease with collision centrality : collective expansion

✯ 𝐵9 𝑑 are smaller than that of 𝐵9 𝑑 , anti−baryon freeze out at a larger source

𝐵9 = 𝑎 £ exp 𝑏 𝑚X − 𝑚

NA44, EPJ C. 23, 237 (2002)

)2 - m (GeV/cTm0.5 1 1.5

)3/c2

(GeV

2B

1

2

3

4

3−10×

(d) 0-10%2B(d) 10-20%2B(d) 20-40%2B(d) 40-60%2B

)2 - m (GeV/cTm0.5 1 1.5

)3/c2

(GeV

2B

) 0-10%d(2B) 10-20%d(2B) 20-40%d(2B) 40-60%d(2B

Au+Au 39 GeV

STAR Preliminary


(GeV)NNs4 5 6 7 8 10 20 30 40 100 200

)3/c2

(GeV

2B

3−10

E864(d) Au+PbE866(d) Au+AuE877(d) Au+AuNA49(d) Pb+PbPHENIX(d) Au+Au

) Au+AudSTAR() Au+AudPHENIX(

/ A = 0.65 GeV/cT

pSTAR 0-10%(d) Au+Au

) Au+AudSTAR 0-10%(

Average of p+p and p+A

Central CollisionSTAR Preliminary

2017/2/7 17:10-17:30

Coalescence Parameters v.s. Collision Energy

✯ 𝐵9 decrease with collision energy. A minimum around sHH� = 20 GeV :change of EOS?!

✯ 𝐵9 𝑑 values are systematically lower than that of 𝐵9(𝑑) implying emitted source of anti-baryons is larger than those of baryons

arXiv:1410.2559

∝ ∆𝝉 ∝ 𝒄𝒔


2017/2/7 17:10-17:30

Discussion✯ Is there any structure in energy

dependence of 𝐵9, from high

energy to low energy ? (BES: Yes)

✯ Is there any centrality dependence

of 𝐵9? (Yes)

✯ Is there any difference of 𝐵9between deuteron and anti-

deuteron? (Yes) (GeV)NNs4 5 6 7 8 10 20 30 40 100 200

)3/c2

(GeV

2B

3−10

E864(d) Au+PbE866(d) Au+AuE877(d) Au+AuNA49(d) Pb+PbPHENIX(d) Au+Au

) Au+AudSTAR() Au+AudPHENIX(

/ A = 0.65 GeV/cT

pSTAR 0-10%(d) Au+Au

) Au+AudSTAR 0-10%(

Average of p+p and p+A

Central CollisionSTAR Preliminary


2017/2/7 17:10-17:30

Summary✯ STAR systematic results of 𝑑(��) production (𝑑𝑁/𝑑𝑦, 𝑝𝑇 ) from Au + Au collisions

at 𝒔𝐍𝐍� = 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4 and 200 GeV

✯ Coalescence parameter𝐵9for𝑑 and �� are extracted. 𝐵9(𝑑) and 𝐵9(��) are found to

be different in the most central collisions

✯ Similar to the 𝜋 HBT and net-proton high moment, around sHH� = 20 GeV, 𝐵9reaches a minimum implying EOS changes around the energy

✯ High statistics data are needed for future studies, especially at the high net-baryon

density, i.e., low collision energy region


Thank you

2017/2/7 17:10-17:30 Ning Yu, Quark Matter 2017@Chicago 21/20

Documents

Au collisions at RHIC - Brookhaven National Laboratory...in Au + Au collisions at RHIC Ning Yu Central China Normal University for the STAR Collaboration 2017/2/7 17:10-17:30 Outline