Hot Topics in Heavy Ion Collisions Theory - BNL

Equation of State at finite µB Transport Coefficients Chiral Magnetic Effect Jets+hydro

Hot Topics in Heavy Ion Collisions Theory

Jacquelyn Noronha-HostlerUniversity of Houston

RHIC & AGS User’s Meeting 2017June 22th 2017


Sadly I won’t be able to cover

Electron Ion Collider/Spin(Matt Sievert, Ferdinand Willeke, Salvatore Fazio, BerndSurrow)sPHENIX(Rosi Reed, Anne Sickles, Sanghwa Park)Small Systems(Mark Mace, Shenglu Huang, Heikki Mantysaari)Heavy Flavor(Miguel Escobedo, Zhenyu Ye)


Equation of State


Equation of State- Lattice QCD

Equation of State agrees for stout (WB) and HISQ(HotQCD) actions

q

q

WB Phys.Lett. B730 (2014) 99-104HotQCD Phys.Rev. D90 (2014) 094503


Thermalized charm quarks?

Still questions at µB = 0. Sensitive Observables?

WB Collaboration Nature 539 (2016) no.7627, 69-71


Large baryon densities

NICER

NICER Neutron Star Satellite(2017)

Beam Energy Scan II RHIC (2017-2019)

Great Collider in China>10 years from now

China

BES

Baryon Density

~2024

until 2025

-2025


Reconstructing EOS at finite µB from Lattice QCD

Lattice QCD Equation of State+ variable CPSee also J. Noronha Tues and S. Sharma Weds

0

0.1

0.2

0.3

0.4

0.5

140 160 180 200 220 240 260 280

µB/T=2

µB/T=2.5

µB/T=1

HRG

nS=0, nQ/nB=0.4

n B(T

,µB)

/T3

T [MeV]

O(µB6)

O(µB4)

O(µB2)

HotQCD Phys.Rev. D95 (2017) no.5, 054504

0

0.1

0.2

0.3

0.4

0.5

0.6

140 160 180 200 220 240 260 280

µB/T=2

µB/T=2.5

µB/T=1

HRG

nS=0, nQ/nB=0.4

[P(T

,µB)

-P(T

,0)]/

T4T [MeV]

O(µB6)

O(µB4)

O(µB2)

HotQCD Phys.Rev. D95 (2017) no.5, 054504

Critical Point

No sign of criticality up to µB/T ≤ 2 and T ≥ 0.9Tc for O(µ6B)


Mapping the phase diagram- part 1

Tf (µB) = T0

(1− κf

2

(µBT0

)2)

130

135

140

145

150

155

160

165

170

0 50 100 150 200 250 300 350 400 450

STAR ALICE Becattini et al.

T f (µ

B) [M

eV]

constant Pεs

crossover lines130

135

140

145

150

155

160

165

170

0 50 100 150 200 250 300 350 400 450

µB [MeV]

See S. Sharma

Lattice QCD: relatively flatcurvature across µB

Thermal fits consistentlyabove the pseudo-critical T

Missing strange baryons?

π,p K,Λ,Ξ,Ω

Separate lights vs. strange freeze-out temperatures

References

Lattice QCD [HotQCD] PRD95 (2017) no.5, 054504, PRD 83, 014504 (2011); [WB] PLB 751, 559 (2015), JHEP1104, 001 (2011); [INFN] PRD 92, no. 5, 054503 , Thermal Fits [STAR] arXiv:1701.07065; [ALICE]J.Phys.Conf.Ser. 779 (2017) no.1, 012012; Missing Hadrons: PRL113 (2014) no.7, 072001; NPA931 (2014)1108-1113 ; arXiv:1702.01113 2 Temperatures: PRL111 (2013) 202302



M/σ2 = χ1/χ2

■■ ■

■ ■

■

■■

△△

Tc 2+1 Lattice QCD

TCE net-p,Q's HRG

TCE net-K's HRG

0 100 200 300 400120

130

140

150

160

170

μB [MeV]

T[M

eV]

net-K results including mostup-to-date strange resonances→ Tstr > Tlight

net-K comparisons to LatticeQCD (partial pressures)Tstr ≥ 148 MeV

Lattice

stat+sysstat

sNN =200 GeV

STAR

130 135 140 145 150 155 160 1650

10

20

30

40

50

60

T [MeV]

MK/σ

K2References

Lattice QCD [HotQCD] Phys.Rev. D95 (2017) no.5, 054504, Phys. Rev. D 83, 014504 (2011); [WB] Phys. Lett. B751, 559 (2015), JHEP 1104, 001 (2011); [INFN] Phys. Rev. D 92, no. 5, 054503 , net-p,Q HRG Phys.Lett. B738(2014) 305-310 net-K HRG HRG from [WB] arXiv:1702.01113; Partial Pressures arXiv:1607.02527



M/σ2 = χ1/χ2

■■ ■

■ ■

■

△△

△

△

△

■■

△△

Tc 2+1 Lattice QCD

TCE net-p,Q's HRG

TCE net-K's HRG

0 100 200 300 400120

130

140

150

160

170

μB [MeV]

T[M

eV]

net-K results including mostup-to-date strange resonances→ Tstr > Tlight

net-K comparisons to LatticeQCD (partial pressures)Tstr ≥ 148 MeV

Lattice

stat+sysstat

sNN =200 GeV

STAR

130 135 140 145 150 155 160 1650

10

20

30

40

50

60

T [MeV]

MK/σ

K2References

Lattice QCD [HotQCD] Phys.Rev. D95 (2017) no.5, 054504, Phys. Rev. D 83, 014504 (2011); [WB] Phys. Lett. B751, 559 (2015), JHEP 1104, 001 (2011); [INFN] Phys. Rev. D 92, no. 5, 054503 , net-p,Q HRG Phys.Lett. B738(2014) 305-310 net-K HRG HRG from [WB] arXiv:1702.01113; Partial Pressures arXiv:1607.02527


net-p Skewness vs. kurtosis

κσ2(√

sNN) =χ4χ2

(T , µB)CE =

rB,042︸︷︷︸

rB,031

+ rB,242︸︷︷︸

3rB,231

(µB/T ) +O(µ4B)

MP/σP2

STAR: 0.4 GeV<pt<0.8 GeV

PRL 112 (2014) 032302

SPσP fit

κPσP2 fit

κPσP2

SPσP3 / MP

HRG

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0 0.2 0.4 0.6 0.8 1

Many caveats:Volume variation vs. centralitybinning V. Skokov et al., PRC (2013)

Efficiencies A.Bzdak,V.Koch, PRC (2012)

Spallation protons

Kinematic/acceptance cutsV. Koch, S. Jeon, PRL (2000)

Protons vs. baryon fluctuationsM. Asakawa and M. Kitazawa, PRC(2012), M.Nahrgang et al., EPJ(2015)

Hadronic interactions J.Steinheimer etal., PRL (2013)

References

Lattice QCD J.Phys.Conf.Ser. 779 (2017) no.1, 012015;


Modern Critical Point Predictions

●

●

●

●

●

●

Black Hole Engineering

2+1 Lattice QCD (μB

6 )

HBT+FSS

Dyson-Schwinger+Baryons

2 Lattice QCD

2+1 NJLtruncated Dyson-Schwinger

σpT

< pT >+Finite-Size Scaling Exclusion

Unlikely due to transition line

curvature

Allowed Region

0 200 400 600 80050

100

150

200

μB [MeV]

T[M

eV]

References

Lattice QCD [HotQCD]PRD95(17)no.5,054504; Finite-Size ScalingPRC84,011903(11); R. LaceyPRL114(15)no.14,142301; Black Hole Engineering arXiv:1706.00455; 2+1 Polyakov LoopPLB732(14)273;Dyson-SwingerPRD93(16)no.3,034013 ; DGGPRD95(17)no.5,054512; 2+1 NJLIJMPA32(17)no.11,1750061; Oldersummary: Stephanov PoS LAT2006:024,2006


Modern Critical Point Predictions

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●

●

●

●

●

●

●●●●

●

●

● ● ● ● ●●

●

Black Hole Engineering

2+1 Lattice QCD (μB

6 )

Dyson-Swinger+Baryons

2+1 NJL

Thermal Fits

net-p,Q fluctuations

truncated Dyson-Swinger

σpT

< pT >+Finite-Size Scaling Exclusion

Unlikely due to transition line

curvature

Allowed Region

0 200 400 600 80050

100

150

200

μB [MeV]

T[M

eV]

References

Lattice QCD [HotQCD]PRD95(17)no.5,054504; Finite-Size ScalingPRC84,011903(11); R. LaceyPRL114(15)no.14,142301; Black Hole Engineering arXiv:1706.00455; 2+1 Polyakov LoopPLB732(14)273;Dyson-SwingerPRD93(16)no.3,034013 ; DGGPRD95(17)no.5,054512; 2+1 NJLIJMPA32(17)no.11,1750061; Oldersummary: Stephanov PoS LAT2006:024,2006


Transport Coefficients (η/s(T , µB), ζ/s(T , µB),DB(T , µB) ... )


Theoretical calculations of viscosity at µB = 0

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æ æ ææ æ æ

æ ææ

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à àààà

àà

àà à à à

UrQMDPHSD kubo kin.

AdS�CFT

HRG+HS+QGP

semiQGP

DS YangMills

BAMPS

monopoles

100 150 200 250 300 350 4000.0

0.5

1.0

1.5

T HMeVL

Η�s

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ì

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HRG+HS

PHSD

pQCD

nonconf. AdS

14 mom.

100 150 200 250 300 350 4000.00

0.05

0.10

0.15

0.20

0.25

0.30

T HMeVLΖ

�s

References

See references in JNH arXiv:1512.06315


Bayesian Analysis

Tminη/s = Tpeakζ/s = TSW

0.15 0.20 0.25 0.30Temperature [GeV]

0.0

0.2

0.4

η/s

KSS bound 1/4π

Prior rangePosterior median90% credible region

[DUKE ] arXiv:1704.04462

Small systems?Talks by R. Belmont, M. Mace, S. Huang

(η/s)RHIC ∼ 0.12(η/s)RHIC ∼ 0.06

[McGill] Gabriel Denicol Quark Matter 2017


Mixed Harmonic Correlations- a solution?

Cm,n,m+n = 〈cos(mφ1 + nφ2 − (m + n)φ3)〉

-120

-80

-40

0

40

× 10-3

(a)C112×Npart2

×10-3

STAR Data -400

0

400

800

× 10-3

Au+Au 200 GeV

(c)C224×Npart2

×10-3

EKRT η/s (T) -50

0

50

× 10-3

(e)C246×Npart2

×10-4

Glauber-Eccent

-80

-40

0

40

80

0 100 200 300

(b)

C123×Npart2

×10-3

Npart

Teany-Yan

-50

0

50

100

150

0 100 200 300

(d)

C235×Npart2

×10-4

Npart

EKRT η/s=0.2

-20

0

20

40

0 100 200 300

(f)

C336×Npart2

×10-4

Npart

IP-Glasma+MUSIC

[STAR] arXiv:1701.06497Need to understand v1, v5, v6 → εn’s or η/s(T ), ζ/s(T )?


BES: Viscosity vs. Dynamic Universality Class

No Critical Point

⇑ µB , ⇓ viscosityFrom HRG,Transport: Kadam,Mishra Nucl.Phys. A934(2014) 133-147See also Denicol, Jeon, Gale,Noronha Phys.Rev. C88(2013) no.6, 064901

Critical PointUniversality Class H

Divergence ⇑ inviscosity at CP

3D Ising Model-Mixing betweenchiral condensateand baryon densityPRD70 (2004) 056001

Critical PointUniversality Class B

Finite viscosity atCPPRL115(2015)no.20,202301

AdS/CFT:PRD78 (2008) 106007

AdS/non-CFT:PRD83(2011)086005

Dynamical CP phenomena Review

Rev. Mod. Phys. 49, 435


Hydrodynamic upgrades needed at the BES

from B. Schenke Tues.


Diffusion

In water, diffusion increases with temperature


Diffusion of Baryons

CFT limit

μB=0

μB=100MeV

μB=200MeV

μB=300MeV

μB=400MeV

150 200 250 3000.00

0.05

0.10

0.15

T [MeV]

TDB(T,μB)

non-conformal AdS

along freeze-out line

3 7.7 19.6 62.4 2000.0

0.2

0.4

0.6

0.8

1.0

1.2

s [GeV]

D˜B

Baryons get “stuck" at the critical point- implementation intohydro+new observables needed for BESIIPhys.Rev.Lett. 115 (2015) no.20, 202301 ; arXiv:1704.05558


Sensitivity to baryon diffusion in hydro

√sNN = 19.6 GeV

C. Shen, G. Denicol, C. Gale, S. Jeon, A. Monnai, B. Schenke, arXiv:1704.04109


Finding the Chiral Magnetic Effect

Chiral Magnetic Effect (CME)should follow B field

Isobar Run 18Hold v2 (background) constant,vary B field

Deng et al PRC94,041901 (2016)


Magnetohydrodynamics

Best estimates of B field/initialcharge density

See Talk by S. Shi Tues.

Lifetime of the B Field

See Talk by V. Skokov Tues.

Questions still remain about initial charge density, lifetime of Bfield, axial charge non-conservation. See S. Schlichting Weds


Question 1: Small Systems

B field no longer aligned with ψ2(arXiv:1610.07964), but signal still seen

Could the proton size growin high multiplicity events?R2

p(s;N) = R2p(s)

NN̄

D. Kharzeev QCD Chirality 2017

Could it be a backgroundeffect?Schlichting and Pratt PRC83,014913 (2011)

What new observables coulddistinguish these scenarios?


Question 2: Flow Background

Event-shape engineering

[ALICE] QM2017

How does it scale withother vn’s?What about RHIC/smallsystems?Need theoretical models toexplain all observables


Question 3: Central Collisions

ψ2 and ψB no longeraligned for centralcollisionsB-field consistent with dataWould Event shapeengineering be flat forcentral RHIC collisions?


Jets fully coupled to a realistic medium


Coupling jets+relativistic viscous hydrodynamics

Realistic event-by-eventfluctuating hydro backgroundsPRL 116(2016) no.25,252301; PRC 95(2017)no.4,044901

Coupled to advances from pQCDZ. Kang and T. Chien Tues.

Bayesian analysis[JETSCAPE] S. Cao Tues.

Exploration of jet substructure,jet grooming etc

"We call for an agreement between theorists and experimentalists on the appropriate treatment of the background,Monte Carlo generators that enable experimental algorithms to be applied to theoretical calculations, and a clearunderstanding of which observables are most sensitive to the properties of the medium, even in the presence ofbackground. " Connors, Nattrass, Reed, and Salur arxiv:1705.01974

References

Shown Tachibana et al, PRC95(2017)no.4,044909; Others Pang et al, PRC86(2012)024911; HYDJET++ (manypapers); LBT (many papers); Andrade et al, PRC90(2014)no.2,024914; Schule and TomasikPRC90(2014)no.6,064910


Outlook

Beam energy scan:Equation of State at finite µB. Almost there for BESCritical Point? Still need hydro updates, work in progress

Transport coefficients:Numerous effective models. Bayesian analysis helpfulBaryon Diffusion promising for CP searches.

Chiral Magnetic Effect:Significant progress made on MagnetohydrodynamicsIsobar run 18 to shed light on signal vs. background

Jets: Efforts underway for combining realisticevent-by-event hydrodynamics+reconstructed jets andBayesian analysis.

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Hot Topics in Heavy Ion Collisions Theory - BNL