C o l o r G l a s s C o n d e n s a t e a n d - - PowerPoint PPT Presentation

SLIDE 1

C

• l
• r

G l a s s C

• n

d e n s a t e a n d p a r t

• n

s a t u r a t i

• n

:

• v

e r v i e w

• f

r e c e n t d e v e l

• p

m e n t s

A d r i a n D u m i t r u R I K E N B N L a n d B a r u c h C

• l

l e g e , C U N Y

Q u a r k M a t t e r 2 1 2 , A u g u s t 1 3 – 1 8 , Wa s h i n g t

• n

D . C .

SLIDE 2

O u t l i n e O u t l i n e

• I

n t r

• d

u c t i

• n

& M

• t

i v a t i

• n
• M

u l t i p l i c i t y f l u c t u a t i

• n

s a n d K N O s c a l i n g

• F

r

• m

P r

• t
• n

s t

• n
• n
• l

i n e a r c

• l
• r

f i e l d s i n n u c l e i : t e s t i n g q u a n t u m e v

• l

u t i

• n

a n d i n i t i a l c

• n

d i t i

• n

s d N / d y , d N / d p

T

, R

p A

i n p + P b a t L H C

• F

r

• m

d i p

• l

e s t

• q

u a d r u p

• l

e s : h

• h

a n g u l a r c

• r

r e l a t i

• n

s

• γ
• h

a n g u l a r c

• r

r e l a t i

• n

s

• S

u m m a r y & O u t l

• k

SLIDE 3

(p)QCD very (p)QCD very successful for successful for short-distance short-distance phenomena involving phenomena involving few few particles / quanta particles / quanta

• Q

Q q u a r k

• n

i u m s p e c t r u m , M

Q

/ Λ

Q C D

≫ 1

• H

i g h

• E

T

j e t s i n h a d r

• n

i c c

• l

l i s i

• n

s a n d e

+

e

• →

q q g E

T

/ Λ

Q C D

≫ 1

• D

I S w i t h h i g h l y v i r t u a l p h

• t
• n

√ Q

2

/ Λ

Q C D

≫ 1

• .

. .

SLIDE 4

Because: Because:

• α

s

( Q

2

) ≪ 1

• E

x p a n d a b

• u

t f r e e q u a n t a , a d d i n i n t e r a c t i

• n

s

• n

e b y

• n

e

SLIDE 5

But fails for: But fails for:

• D

i s t a n c e s ~ 1 f m ;

• k

, l e t ' s l e a v e c

• n

f i n e m e n t f

• r

a n

• t

h e r d a y . . .

• H
• t

Q C D , e v e n w h e n T / Λ

Q C D

≫ 1 ( P i s a r s k i : n e c e s s a r y t

• e

x p a n d a b

• u

t D e b y e s c r e e n e d E f i e l d ! )

• H

i g h

• e

n e r g y p r

• c

e s s e s a t f i x e d v i r t u a l i t y : e f f e c t i v e c h a r g e

2

α

s

( Q

2

) ≪ 1 b u t t h e r e a r e m a n y O ( 1 / α

s

) p a r t n e r s t

• i

n t e r a c t w i t h : g l u

• n

s i n t e r a c t a l

• t

! → ( s e m i

• h

a r d ) Q C D b e c

• m

e s n

• n
• l

i n e a r

SLIDE 6

G l u

• n

d e n s i t y p e r u n i t t r a n s v e r s e a r e a a t s m a l l x : i n t r i n s i c s e m i

• h

a r d s c a l e ! l a r g e p h a s e

• s

p a c e d e n s i t y ,

• c

c u p a t i

• n

n u m b e r O ( 1 / α

s

)

M c L e r r a n & V e n u g

• p

a l a n ( 1 9 9 4 + ) :

SLIDE 7

N

• n
• l

i n e a r f i e l d s a r e a g r e a t i n t e l l e c t u a l c h a l l e n g e i n m

• d

e r n p h y s i c s :

• G

r a v i t y : f

• r

m a t i

• n
• f

b l a c k h

• l

e s , . . .

• Q

E D p a i r c r e a t i

• n

i n e x t r e m e l a s e r f i e l d s

• Q

C D : n

• n
• l

i n e a r c

• l
• r

f i e l d s i n h a d r

• n

s / n u c l e i b

• s

t e d t

• r

a p i d i t y y ≫ 1

SLIDE 8

• M

V : t r y c l i m b i n g t h e c a m e l f r

• m

b a c k !

• I

f

• c

c u p a t i

• n

n u m b e r i s h i g h , e x p a n d a b

• u

t c l a s s i c a l s

• l

u t i

• n

r a t h e r t h a n a b

• u

t “ n

• t

h i n g ”



c l a s s i c a l f i e l d b e h i n d “ p a n c a k e ”

• f

v a l e n c e c h a r g e s



q u a n t u m f l u c t u a t i

• n

s ( s m a l l

• x

e v

• l

u t i

• n

)

SLIDE 9

e&m fields of boosted charge (v→1):

2d Coulomb potential

J.D. Jackson: classical E&M

valence charge density “ “shock wave” shock wave”

SLIDE 10

+ s

• f

t Y M f i e l d s + c

• u

p l i n g

• f

s

• f

t

↔ hard

In a hadron / nucleus the local valence color charge density is random

μ2 ~ g2A1/3; κ3 ~ g3A2/3; κ4 ~ g4A

Averages:

SLIDE 11

M u l t i p l i c i t y d i s t r i b u t i

• n

: N e g a t i v e B i n

• m

i a l f r

• m

M V m

• d

e l

Gelis, Lappi, McLerran: NPA (2009) Schenke, Tribedy, Venugopalan: 2012

N B D

t w

• p

a r a m e t e r d i s t r i b u t i

• n

: m e a n n , w i d t h

SLIDE 12

Multiplicity distributions in pp pp collisions

T r i b e d y & V e n u g

• p

a l a n : P L B 2 1 2 P ( n ) : n e g a t i v e b i n

• m

i a l d i s t r i b u t i

• n

SLIDE 13

K N O s c a l i n g ( e v e n p + P b a p p r

• x

. ) K N O s c a l i n g ( e v e n p + P b a p p r

• x

. )

f

• r

A + B :

z = z =

Ψ ( Ψ ( z ) = z ) =

D u m i t r u & N a r a : P R C 2 1 2

p A @ L H C , m b d + A u @ R H I C

SLIDE 14

KNO from Neg. Binomial Distribution ? KNO from Neg. Binomial Distribution ?

In the limit 1 1 « « n n / k / k, NBD can be written as

n P ( n ) ≡ ψ ( z ) i s u n i v e r s a l u n i v e r s a l ( i n d e p e n d e n t

• f

e n e r g y )

K

• b

a , N i e l s e n , O l e s e n , N P B ( 1 9 7 2 )

which is independent of n n ! !

SLIDE 15

i ) a p p r

• x

. G a u s s i a n a c t i

• n

i i ) h i g h

• c

c u p a t i

• n

n u m b e r KNO in terms of small-x gluons (p KNO in terms of small-x gluons (pT

T~Q

~Qs

s):

): F

• r

a c t i

• n

w i t h ~ ρ

4

• p

e r a t

• r

:

G a u s s / M V ρ

4

Poster by Elena Petreska ! Poster by Elena Petreska !

SLIDE 16

S u b n u c l e

• n

s c a l e f

• r

K N O f l u c t u a t i

• n

s ?

Q

s

• 1
• →

“ s p i k i e r ” i n i t i a l d e n s i t y d i s t r i b u t i

• n

f

• r

h y d r

• ?

( s e e w

• r

k b y G a v i n & M

• s

c h e l l i , H . P e t e r s e n , T . K

• d

a m a e t a l , . . . )

Talk by S. Moreland at QM12 ! Talk by S. Moreland at QM12 !

s e e L a p p i & M c L e r r a n , M ü l l e r & S c h ä f e r , S c h e n k e , T r i b e d y , V e n u g

• p

a l a n , . . .

SLIDE 17

R i d g e i n v e r y h i g h

• m

u l t i p l i c i t y p p @ 7 T e V R i d g e i n v e r y h i g h

• m

u l t i p l i c i t y p p @ 7 T e V

( We i L i f

• r

C M S , Q u a r k M a t t e r 2 1 1 , A n n e c y )

p e a k s a t ~ 3 . 5 G e V ! p e a k s a t ~ 3 . 5 G e V !

D u s l i n g & V e n u g

• p

a l a n : a r X i v : 1 2 1 . 2 6 5 8

SLIDE 18

Eccentricity Eccentricity ε ε3

3 in Au+Au

in Au+Au

G l a u b e r f l u c

• n

l y G l a u b e r + N B D k ~ m i n ( T

A

, T

B

)

D u m i t r u & N a r a : P R C 2 1 2

SLIDE 19

Evolution with energy: quantum fluctuations Evolution with energy: quantum fluctuations

• A

t r a p i d i t y f a r f r

• m

v a l e n c e c h a r g e s , r e s u m m a t i

• n

t

• a

l l

• r

d e r s i n ( α

s

Y )

n

r e q u i r e d

SLIDE 20

r c B K ( g e n e r a l i z e d ) u n i n t e g r . g l u

• n

d e n s i t y r c B K ( g e n e r a l i z e d ) u n i n t e g r . g l u

• n

d e n s i t y

proton center of A~200 nucleus ~1/k ~1/k2

2

~1/k ~1/k2

2γ γ

J . A l b a c e t e 2 1 + J . A l b a c e t e 2 1 +

f

• r

w . R H I C L H C

SLIDE 21

Energy and centrality dependence of multiplicities

i ) K h a r z e e v , L e v i n , N a r d i m

• d

e l i ) K h a r z e e v , L e v i n , N a r d i m

• d

e l

( u p d a t e d p r e d i c t i

• n

s f r

• m

a r X i v : 1 1 1 1 . 3 3 1 ) w i t h

SLIDE 22

d + A u @ R H I C d + A u @ R H I C A A @ R H I C & L H C A A @ R H I C & L H C

SLIDE 23

p + p @ 9 p + p @ 9 p + p @ 2 3 6 p + p @ 2 3 6 p + p @ 7 p + p @ 7 p + P b @ 4 4 p + P b @ 4 4 p r e d i c t i

• n

p r e d i c t i

• n

SLIDE 24

i i ) k i i ) k

┴ ┴ factorization with rcBK UGDs

factorization with rcBK UGDs

BK equation (incl. non-linear terms → saturation of scattering amplitude!) running-coupling kernel (Balitsky prescription) dipole scattering amplitude in adj. rep. (dipole) unintegrated gluon distribution:

SLIDE 25

Centrality and energy dependence of multiplicities Centrality and energy dependence of multiplicities from rcBK: from rcBK:

A l b a c e t e & D u m i t r u : a r X i v : 1 1 1 . 5 1 6 1 A l b a c e t e & D u m i t r u : a r X i v : 1 1 1 . 5 1 6 1

• assumes Nhadr ~ Nglue

WS “core” WS “core” ~ 1/ ~ 1/α

α

s s(k)

(k)

in UGD in UGD

( c

• m

p a r i s

• n

t

• d

a t a f r

• m

P H O B O S / A L I C E )

• D

i f f e r e n t U G D s g i v e d i f f e r e n t E

T

!

• Wh

i c h w

• r

k s b e s t w i t h ( v i s c

• u

s ) h y d r

• ?

A l b a c e t e , D u m i t r u , F u j i i , N a r a : i n p r e p a r a t i

• n

SLIDE 26

p + p @ 2 3 6 , 7 G e V p + p @ 2 3 6 , 7 G e V p + P b @ 5 p + P b @ 5 p r e d i c t i

• n

p r e d i c t i

• n

SLIDE 27

T r i b e d y & V e n u g

• p

a l a n : P L B 2 1 2

I P

• S

a t m

• d

e l a n d a n i n d e p e n d e n t r c B K s t u d y :

SLIDE 28

• C

G C b a s e d a p p r

• a

c h e s ( c

• n

s t r a i n e d b y R H I C , L H C

• p

p & r e a s

• n

a b l e m

• d

e l f

• r

A ) p r e d i c t s i m i l a r d N / d η a r

• u

n d η ~ f

• r

u p c

• m

i n g p + P b a t L H C !

• i

f

• k

, w e h a v e a v e r y e c

• n
• m

i c a l d e s c r i p t i

• n
• f

m u l t i p l i c i t i e s i n t e r m s

• f

s i n g l e s i n g l e s c a l e Q

s

( A , √ s ) !

( η ~ , m i n b i a s )

SLIDE 29

B a s e l i n e : p

T

s p e c t r a i n p p a t h i g h e n e r g i e s

U s i n g A A M Q S ( A l b a c e t e e t a l . ) u n i n t e g r a t e d g l u

• n

d i s t r i b u t i

• n

f i t t e d t

• H

E R A

• D

I S ! I n i t i a l c

• n

d i t i

• n

f

• r

r c B K e v

• l

( γ = 1 . 1 ! ) :

A l b a c e t e , D u m i t r u , F u j i i , N a r a : i n p r e p a r a t i

• n

SLIDE 30

R

p A

f

• r

p + P b a t 5 T e V :

• R

p A

< 1 a t p

T ( h a d r

• n

)

~ 1

• 2

G e V

• R

p A

d e c r e a s e s ( s l i g h t l y ) w i t h r a p i d i t y

• g

e n e r i c a l l y R

p A

( c e n t r a l ) < R

p A

( m b )

• C

r

• n

i n p e a k w a s h e d

• u

t b y e v

• l

u t i

• n

A l b a c e t e , D u m i t r u , F u j i i , N a r a : i n p r e p a r a t i

• n

SLIDE 31

Hadron spectra modification in pA

X .

• N

. Wa n g : p A @ L H C w k s h p , X .

• N

. Wa n g : p A @ L H C w k s h p , C E R N , j u n e 4 – 8 , 2 1 2 C E R N , j u n e 4 – 8 , 2 1 2 s u r v i v i n g C r

• n

i n p e a k ? s u r v i v i n g C r

• n

i n p e a k ?

SLIDE 32

T r i b e d y & V e n u g

• p

a l a n : P L B 2 1 2

• t

h e r C G C b a s e d p r e d i c t i

• n

s f

• r

R

p A

@ L H C , m i n b i a s m i n b i a s

J a l i l i a n

• M

a r i a n & R e z a e i a n : P R D 8 5 ( 2 1 2 )

( n

• t

e : i m p l i c i t a v e r a g e

• v

e r WS a s s u m e d N

c

• l

l

= 6 . 5 ; ( Q

s A

/ Q

s p

)

2

= 2

• 4

) ( w i t h e x p l i c i t WS g e

• m

e t r y )

N L O c

• r

r e c t i

• n

s i n c r e a s e R

p A

s l i g h t l y

SLIDE 33

D i h a d r

• n

a n g u l a r c

• r

r e l a t i

• n

s i n p A D i h a d r

• n

a n g u l a r c

• r

r e l a t i

• n

s i n p A

i n v

• l

v e s n e w

• b

j e c t s ( h i g h e r n

• p
• i

n t f u n c t i

• n

s ) s u c h a s q u a d r u p

• l

e :

J a l i l i a n

• M

a r i a n & K

• v

c h e g

• v

: P R D ( 2 4 ) F . D

• m

i n g u e z e t a l . : P R D ( 2 1 1 )

Talk by T. Lappi at QM12 ! Talk by T. Lappi at QM12 !

SLIDE 34

A n g u l a r d e c

• r

r e l a t i

• n

f

• r

d e n s e t a r g e t A n g u l a r d e c

• r

r e l a t i

• n

f

• r

d e n s e t a r g e t

S t a s t

• ,

X i a

• ,

Y u a n : a r X i v : 1 1 9 . 1 8 1 7

y

1

~ y

2

~ 3 . 2

c e n t r a l d + A u c e n t r a l d + A u p e r i p h e r a l d + A u p e r i p h e r a l d + A u

Talk by B. Xiao at QM12 ! Talk by B. Xiao at QM12 !

SLIDE 35

γ

• h

a d r

• n

a n g u l a r c

• r

r e l a t i

• n

s i n p A γ

• h

a d r

• n

a n g u l a r c

• r

r e l a t i

• n

s i n p A

J a l i l i a n

• M

a r i a n a n d R e z a e i a n : a r X i v : 1 2 4 . 1 3 1 9

Talk by J. Jalilian-Marian at QM12 ! Talk by J. Jalilian-Marian at QM12 !

i n v

• l

v e s

• n

l y u G D / 2

• p
• i

n t f u n c t i

• n

( r c B K ) :

SLIDE 36

b a c k

• t
• b

a c k p e a k d i s a p p e a r s b a c k

• t
• b

a c k p e a k d i s a p p e a r s w i t h w i t h

• l
• w

e r k

T

• h

i g h e r e n e r g y

SLIDE 37

S u m m a r y / O u t l

• k

C u r r e n t l y , a l l C G C e y e s a r e

• n

p + P b @ L H C ! O b s e r v a b l e s : O b s e r v a b l e s :

• m

u l t i p l i c i t y d N

c h

/ d η

• m

u l t i p l i c i t y d i s t r i b u t i

• n

P ( n )

• n

u c l e a r m

• d

i f i c a t i

• n

f a c t

• r

R

p P b

( p

T

, y )

• h
• h

a n d γ

• h

a n g u l a r c

• r

r e l a t i

• n

s

P h y s i c s : P h y s i c s :

• R

H I C → L H C :

• p

e n u p p h a s e s p a c e f

• r

v i r t u a l g l u

• n

f l u c t u a t i

• n

s !

• L

H C c a n p r

• b

e k

T

t a i l s a t s m a l l x ≤ 1

• 2
• e

f f e c t i v e M V

• t

y p e a c t i

• n

f

• r

h a r d “ v a l e n c e ” c h a r g e s S = ∫ d

2

r d y ( ρ

2

+ ρ

4

)

• r

c B K r e s u m m a t i

• n
• f

a v e r a g e ( d i p

• l

e ) d e n s i t y ; f u l l N L O n e e d e d ?

• f

l u c t u a t i

• n

s : K N O & h y d r

• i

n i t i a l c

• n

d i t i

• n
• h

i g h e r n

• p
• i

n t c

• r

r e l a t i

• n

f u n c t i

• n

s ( Q u a d r u p

• l

e )

Talk by C. Marquet at QM12 ! Talk by C. Marquet at QM12 !

M

• r

e

• n

e A , p A a n d f u t u r e

• f

C G C :

SLIDE 38

B a c k u p S l i d e s

SLIDE 39

Single-inclusive production (at LO in ρ): amplitude |amplitude|2

SLIDE 40

D i p

• l

e e v

• l

u t i

• n

w i t h f l u c t u a t i

• n

s & s a t u r a t i

• n

D i p

• l

e e v

• l

u t i

• n

w i t h f l u c t u a t i

• n

s & s a t u r a t i

• n

( I a n c u , K

• v

n e r , L u b l i n s k y , M u e l l e r , M u n i e r , S h

• s

h i , T r i a n t a f y l l

• p
• u

l

• s

, . . . ) r u n n i n g c

• u

p l i n g v e r s i

• n

: A . D u m i t r u e t a l . , J H E P ( 2 7 )

d i s t r i b u t i

• n
• f

d i p

• l

e n u m b e r i n t a r g e t , r ≤ 1 / Q

s

r . c . e v

• l

u t i

• n

r . c . e v

• l

u t i

• n

f . c . e v

• l

u t i

• n

f . c . e v

• l

u t i

• n
• r

. c . e v

• l

u t i

• n

s a t i s f i e s K N O ! r . c . e v

• l

u t i

• n

s a t i s f i e s K N O !

• f

. c . e v

• l

u t i

• n

t

• s

t r

• n

g d i f f u s i

• n

f . c . e v

• l

u t i

• n

t

• s

t r

• n

g d i f f u s i

• n

SLIDE 41

Phenix Collab., PRL 2011 Phenix Collab., PRL 2011

• MC-KLN initial condition (kT factorization with Glauber fluct. only

Glauber fluct. only) underestimates v3 !

SLIDE 42

Classical YM solutions w/ fluctuating initial Classical YM solutions w/ fluctuating initial conditions (incl. NBD !) conditions (incl. NBD !)

S c h e n k e , T r i b e d y , V e n u g

• p

a l a n , S c h e n k e , T r i b e d y , V e n u g

• p

a l a n , a r X i v : 1 2 2 . 6 6 4 6 a r X i v : 1 2 2 . 6 6 4 6

• l
• w

e r ε2 than MC-KLN

• higher ε3

SLIDE 43

DIPSY MC (Lund) w. fluctuations in BFKL ladders DIPSY MC (Lund) w. fluctuations in BFKL ladders

C . F l e n s b u r g : I S M D 2 1 1 , C . F l e n s b u r g : I S M D 2 1 1 , H i r

• s

h i m a H i r

• s

h i m a

c

• m

p a r e D I P S Y <

• >

M C

• K

L N : c

• m

p a r e D I P S Y <

• >

M C

• K

L N : ε ε2

2 similar,

similar, ε ε3

3 larger

larger

• d
• e

s D I P S Y r e p r

• d

u c e K N O i n p p , p A ? d

• e

s D I P S Y r e p r

• d

u c e K N O i n p p , p A ?

D I P S Y D I P S Y K L N K L N

ε ε2

2

ε ε3

3