Directed ow of heavy avor dragged by a hot tilted reball ... · reball and pushed by electromagnetic eld Sandeep Chatterjee With: Piotr Bozek_ AGH-UST, Krakow based on: Phys. Rev

Directed flow:Electromagnetic origin

Directed flow:Geometric origin

Directed flow:electromagnetic +geometric

Summary

Backup

Directed flow of heavy flavor dragged by a hot tiltedfireball and pushed by electromagnetic field

Sandeep ChatterjeeWith: Piotr BozekAGH-UST, Krakow

based on:Phys. Rev. Lett. 120, 192301 (2018) (arXiv: 1712.01189);

arXiv: 1804.04893

WPCF, Krakow, 24 May, 2018

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Summary

Backup

EM field in the initial state

x(a) reaction plane

projectile spectators

participant zone

target spectators

projectile (η>0)target (η<0)

z

fig. from 1306.4145

• B = −B y , B decreases as the spectators recede. Fornon-zero conductivity σ of the medium, this gives rise to aclock-wise E in the above reaction plane

• A positive charge at η > 0 experiences B force along x whileE force along −x , the net force resulting in a directed flow v1

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Summary

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v1 split between positive and negative chargedparticles due to EM field

-3 -2 -1 1 2 3Y

-0.00004

-0.00002

0.00002

0.00004

v1

Gursoy, Kharzeev, Rajagopal 2014

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Summary

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1000 times stronger effect on HQ

-2 -1.5 -1 -0.5 0 0.5 1 1.5 2y

-0.04

-0.02

0

0.02

0.04

v1

(y

)

D[cq] , t=tf.o.

D [cq], t=tf.o.

D [cq], t=2 fm/c.

D [cq], t=5 fm/c

Das, Plumari, SC, Alam, Scardina, Greco 2016•

v avg1 =

1

2

(v1

(D0)

+ v1

(D0))

vdiff1 = v1

(D0)− v1

(D0)

v avg1 = 0, vdiff

1 6= 0;, 4/30




Summary

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Effect of bulk v1 on HQ ?

η-6 -4 -2 0 2 4 6

(%

)1

v

-3

-2

-1

0

1

2

3

PHOBOS: 6 - 40%

0 - 5%

: 0 - 5%⟩ t

p⟨ / ⟩ x

p⟨

5 - 40%40 - 80%

-1 -0.5 0 0.5 1

-0.4

-0.2

0

0.2

0.4

fig. from PRL 101 252301 (2008)

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Summary

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entropy deposition in non-central collision

r1r2

-6 -4 -2 0 2 4 6

-4

-2

0

2

4

x

y

r1 < r2 → ρ (r1) > ρ (r2)

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Summary

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entropy deposition in non-central collision

-4 -2 0 2 4

-6

-4

-2

0

2

4

6

Η

x

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Summary

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entropy deposition from participant sources

Tilted bulk: Brodsky et. al. 1977; Adil, Gyulassy 2005; Bialas,Czyz 2005

x(a) reaction plane


participant zone

target spectators


z

-3 -2 -1 0 1 2 3

-2

-1

0

1

2

Η

x

from 1306.4145 Bulk profile

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Summary

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Initial condition for a tilted fireball

s(τ0, x , y , η||

)= s0

[αNcoll + (1− α)

(N+

part f+(η||)

+

N−part f−(η||))]

f(η||)

f(η||)

= exp

−θ (|η||| − η0||

) (|η||| − η0||

)2

2σ2

f+(η||)

=

0, η|| < −ηTηT +η||

2ηT, −ηT ≤ η|| ≤ ηT

1, η|| > ηT

with f−(η||)

= f+(−η||

)(rapidity-odd component)

Bozek, Wyskiel 2010

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Summary

Backup

Tilted bulk → directed fluid velocity

-4 -2 0 2 4

-4

-2

0

2

4

Η

x

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Summary

Backup

Tilted bulk → directed fluid velocity

Tilted bulk: Brodsky et. al. 1977; Adil, Gyulassy 2005; Bialas,Czyz 2005

x(a) reaction plane


participant zone

target spectators


z

-3 -2 -1 0 1 2 3

-2

-1

0

1

2

Η

x

from 1306.4145 Bulk directed flow

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Summary

Backup

Tilted bulk → directed fluid velocity → chargedparticle v1

Bozek, Wyskiel 2010

• Tilted IC captures the charged particle v1

• small v1

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Summary

Backup

entropy depositing sources: participant vs binarycollision sources

HQ from hard processes → FB-symmetricRapidity-even HQ dragged by Rapidity-odd bulk

x(a) reaction plane


participant zone

target spectators


z

-4 -2 0 2 4

-2

-1

0

1

2

Η

x

from 1306.4145 Bulk vs heavy flavor

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Summary

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Heavy Quark Tomography

charm, anti-charm stronger probes of the tilt than the light flavor

-4 -2 0 2 4

-4

-2

0

2

4

Η

x

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Summary

Backup

entropy depositing sources: participant vs binarycollision sources

x(a) reaction plane


participant zone

target spectators


z

-4 -2 0 2 4

-2

-1

0

1

2

Η

x

from 1306.4145 v1(HQ) > v1(Bulk)

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Summary

Backup

to quantify the heavy flavor v1

need to calibrate

• the tilt of the bulk: constrained by charged particle v1, Bozek,Wyskiel 2010

• drag between the bulk and heavy flavor: constrained by heavyflavor RAA and v2 at mid-rapidity, we use an ansatzγ = γ0T

(Tm

)x

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Summary

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Calibrating the drag on HQs

0 1 2 3 40

0.5

1

1.5

2T/m = 0.2Tγ

= 0.2Tγ

STAR

(a)

(GeV)T

p

AA

R

0 1 2 3 40

0.05

0.1

0.15

0.2

0.25

T/m = 0.2Tγ = 0.2Tγ

STAR

(b)

(GeV)T

p

2v

1 1.5 2 2.55−

0

5

10

15

20 T/m = 0.2Tγ = 0.2Tγ

(c)

LQCD QPM Bayesian DpQCD

cT/T

T sDπ2

SC, Bozek PRL,120, 192301 (2017)

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Summary

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HQ v1 O(10) larger !

predicted to be 5 - 20 times larger than charged particle v1 slope !

0 2 4 60

2

4

6

8

charged particles STAR

DD, T∝γ 1.5

T∝γ

Tη

%=0η

ηd1

dv

-

TiltLarge Small

2− 0 210−

5−

0

5

10(a) :DD,

∝γ T 1.5TTiltlargesmall

Charged Particle: STAR Hydro

η

(%

)1v

SC, Bozek PRL,120, 192301 (2017)

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Summary

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fresh from QM 2018: largest measured directedflow

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Summary

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comparison to data

largest measured v1: order of magnitude larger than that ofcharged particle

0 2 4 60

5

10

15

charged particles

STAR QM2018

DD, T∝γ 1.5

T∝γ

Tη

%=0η

ηd1

dv

-TiltLarge Small

SC, Bozek PRL,120, 192301 (2017)

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Summary

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comparison to data

largest measured v1: order of magnitude larger than that ofcharged particle

0 2 4 60

5

10

15

charged particles

STAR QM2018

DD, T∝γ 1.5

T∝γ

Tη

%=0η

ηd1

dv

-

TiltLarge Small

0 1 26−

4−

2−

0

2

4

6(b)

DD,

charged particles STAR Hydro

(GeV)T

p)

(%)

T(p 1v

NOTE: data with pT > 1.5 GeV, similar cut in model will result inlarger v1

SC, Bozek PRL,120, 192301 (2017)

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Summary

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HQ acquires non-zero 〈pX 〉 - a clear signal of theinitial shift between HQ and bulk

0.95

0.65

0.35

hard processes

thermalized matter

ΗÈÈ = - 2

-6 -3 0 3 6

-6

-3

0

3

6

x HfmL

yHfmL

2− 0 2

6−

4−

2−

0

2

4 DD, %1v > %

T>/<p

x<p

charged particles

STAR Hydro

η

〈px〉 ∼ 40 MeV at η = 1

SC, Bozek PRL,120, 192301 (2017)

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Summary

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Beam energy dependence

210 310

1−10

1

(b)

charged particles

Data Hydro

DD, T∝ γ 1.5 T∝ γ

GeVNNs

%=0ηavg

ηd1

dv

-

SC, Bozek 1804.04893

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Summary

Backup

Ratio of HQ to bulk v1

210 310

5

10

15

T∝ γ 1.5 T∝ γ

(GeV)NNs

=0ηηd1Bu

lkd

v /

=0ηavg

ηd1H

Qd

v

SC, Bozek 1804.04893

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Summary

Backup

HQ v1 with Tilt+EM field

1− 0 13−

2−

1−

0

1

2

3 = 200 GeVNNsAu+Au,

1.5 T∝ γ = 0.4 fm0τ

-1 = 0.035 fmσ

D

D

η

(%

)1v

• v avg1 6= 0, vdiff

1 6= 0

SC, Bozek 1804.04893

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Summary

Backup

Dependence on conductivity and initializationtime

10 20 30

0

0.2

0.4

0.6

0.8 = 200 GeVNNsAu+Au,

(a)

(fm)0τ

0.2 0.6

)-1 (fmσ310

%=0ηdif

f

ηd1

dv

-

0.2 0.4 0.6

3

3.2

3.4

3.6

3.8

4

(b)

= 200 GeVNNsAu+Au,

)-1 (fmσ310 35 11

(fm)0τ%

=0ηavg

ηd1

dv

-

SC, Bozek 1804.04893

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Summary

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Beam energy dependence

210 3100

0.2

0.4

0.6

0.8

1

(a)

T∝ γ 1.5 T∝ γ

(GeV)NNs

%=0ηdif

f

ηd1

dv

-

SC, Bozek 1804.04893

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Summary

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fresh from QM 2018: hint of split in v1 of D0

and D0

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Summary

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Summarising

• Heavy flavor directed flow as a probe of 2 initial state physicswas discussed: longitudinal profile of matter distribution andthe electromagnetic field and medium conductivity

• Order of magnitude larger directed flow was predicted forheavy flavor compared to bulk. Split due to EM field issmaller compared to the average directed flow due to tiltedbulk, resulting in same sign flow of both D0 and D0

• Comparison to STAR QM2018 data suggests preference forlarge tilt (effect of pT cut is expected to allow for smaller tilt)

• Ratio of HQ to bulk v1 is predicted to be larger at LHC thanat RHIC- stronger drag due to higher temperature

• HQ v1 adds to the existing list of HQ RAA and v2 to provideinformation on the drag coefficient between the bulk matterand HQ

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Summary

Backup

BACKUP: what causes the large v1: T or uµ ?

2− 0 20.04−

0.02−

0

0.02

0.04

both none T µ u

η

1v

• FB asymmtery of which hydro field causes the large HQ v1 ?• By selectively choosing profiles with broken boost invarinace,

we find the HQ v1 is mainly caused by the FB asymmetricdrag by the flow field uµ

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Documents

Directed ow of heavy avor dragged by a hot tilted reball ... · reball and pushed by electromagnetic eld Sandeep Chatterjee With: Piotr Bozek_ AGH-UST, Krakow based on: Phys. Rev