Larissa Bravina (UiO)pp, flow, freeze-out, HBT, charm-beauty,HYDJET++, Shadowing, small x physics I. Arsene, K.Tywoniuk, Dr. E. Zabrodin

Flow in pp Dr. R. Kolevatov,

HBT, flow, jets (ALICE and BRAHMS) :I. Arsene, Dr. L. Malinina, PhD G. Eyyubova,

PhD M.S.Nilsson

Bergen town-meeting, 13.04.2010 Bergen town-meeting, 13.04.2010

1. Gluon shadowing

2. Elliptic flow

3. HYDJET++

4. Freeze-out

5. HBT correlations

6. Equation of State

7. Predictions for pp

8. Flow in pp 9. Di-hadron azimuthal correl. …

3

weaker comover suppression at forward weaker recombination at forward stronger initial state effects!

A. Capella, L.B., E. Ferreiro, A. Kaidalov, K. Tywoniuk, E. Zabrodin, Eur. Phys. J C58 (2008) 437

K. Tywoniuk, L.B. et al., J. Phys. G 35 (2008) 104156A. Capella, L.B. et al., Eur. Phys. J. C 58 (2008) 437

HYDJET

FASTMCI. Lokhtin et al., Comput. Phys. Commun. 180 (2009) 779N. Amelin, … L.B. … et al., Phys. Rev. C 77 (2008) 014903

K. Tywoniuk, L.B. et al., Phys. Lett. B 657 (2007) 170

HYDJET++

The model possesses crossing of baryon and meson branches.Hydrodynamics gives mass ordering of v2

G. Eyyubova, L.B. et al.,Phys. Rev. C80 (2009) 064907;arxiv:1001.3602[hep-ph]

Hydro flowJet contribution

3. ELLIPTIC FLOW: 3. ELLIPTIC FLOW: predictions for LHCpredictions for LHC

20%

44%

L. B., G. Eyyubova et al., arXiv:1001.3602; PRC 80 (2009) 064907

Hydro+jets = reduction of flow RHIC

LHC

Influence of resonance decays

Constituent Quark Scaling at LHCConstituent Quark Scaling at LHC

No scaling for Appearance of the approximate direct particles scaling for all particles

LHC: NCQ scaling will be only approximate

SQM’09, Buzios, Brasil, 27.09-02.10.2009

M.S. Nilsson, ”LHC and beyond” (Lund, Feb. 2009)

M.S. Nilsson , ”LHC and beyond” (Lund, Feb. 2009)

M.S. Nilsson , L.B. et al. (to be submitted)

DetectorDetector

M.S. Nilsson , L. Malinina, L.B. et al. (to be submitted)

M.S. Nilsson , L. Malinina, L.B. et al. (to be submitted)

6. EQUILIBRATION IN THE CENTRAL 6. EQUILIBRATION IN THE CENTRAL CELL (FAIR)CELL (FAIR)

Kinetic equilibrium:Kinetic equilibrium: Isotropy of velocity distributionsIsotropy of velocity distributions

Isotropy of pressureIsotropy of pressure

Thermal equilibrium: Thermal equilibrium: Energy spectra of particles are Energy spectra of particles are described by Boltzmann distributiondescribed by Boltzmann distribution

Chemical equlibrium:Chemical equlibrium: Particle yields are reproduced by SM with the same values of Particle yields are reproduced by SM with the same values of

EOS: HOW DENSE CAN BE THE EOS: HOW DENSE CAN BE THE MEDIUM? MEDIUM?

”” B

ig”

cell

(V

= 5

x5x5

fm

^3

Big

” ce

ll (

V =

5x5

x5 f

m^

3 ))

Dramatic differences at the non-equilibrium stage; after beginning of Dramatic differences at the non-equilibrium stage; after beginning of kinetic equilibrium the energy densities and the baryon densities are the kinetic equilibrium the energy densities and the baryon densities are the same for ”small” and ”big” cell same for ”small” and ”big” cell

““ Sm

all”

cel

l (V

=S

mal

l” c

ell (

V =

> 0

)>

0)

L. B

. et

al.,

Ph

ys. R

ev. C

78

(200

8)

0149

07

EOS IN THE CELL: OBSERVATION EOS IN THE CELL: OBSERVATION OF KNEEOF KNEE

temperature vs. chemical potentialstemperature vs. chemical potentials

Although the “knee” is similar to that in 2-flavor lattice QCD, it is Although the “knee” is similar to that in 2-flavor lattice QCD, it is related to inelastic (chemical) freeze-out in the system related to inelastic (chemical) freeze-out in the system

S. Ejiri et al., PRD 73 S. Ejiri et al., PRD 73 (2006) 054506(2006) 054506

L.B. et al., PRC 78 (2008) 014907;E. Zabrodin, L.B. et al,arXiv:0902.4601

7. QGSM PREDICTIONS FOR 7. QGSM PREDICTIONS FOR PP AT LHCPP AT LHC

Gribov’s Reggeon Calculus + string phenomenologyGribov’s Reggeon Calculus + string phenomenology

At ultra-relativistic energies: multi-Pomeron scattering, single and double diffraction, and jets (hard Pomeron exchange)

7. QGSM:

7. QGSM:

PREDICTIONS FOR LHC PREDICTIONS FOR LHC

Inelastic collisionsInelastic collisions

NSD collisionsNSD collisions

PREDICTIONS FOR PP PREDICTIONS FOR PP @ LHC@ LHC

QGSM: extended longitudinal scaling in p+p collisions holdsQGSM: extended longitudinal scaling in p+p collisions holds

High-multiplicity tail High-multiplicity tail isis pushed up, whereas pushed up, whereas maximum of the maximum of the distribution is shifted distribution is shifted towards small values towards small values of of zz

At energies below 100 At energies below 100 GeV different GeV different contributions overlap contributions overlap strongly, whereas at strongly, whereas at higher energies – higher energies – more multi-string more multi-string processesprocesses

24

68

=> Enhancement of high multiplicitiesEnhancement of high multiplicities

VIOLATION OF KNO SCALING VIOLATION OF KNO SCALING AT LHCAT LHC

8. Anisotropic flow in pp

8. Anisotropic flow in pp

8. Anisotropic flow in pp

9. Di-hadron correlations (J. Milosevic, O. Djordjic )

9. Di-hadron correlations

9. Di-hadron correlations

9. Di-hadron correlations

9. Di-hadron correlations

9. Di-hadron correlations

Summary and outlookSummary and outlook• LHC is a LHC is a discovery machine discovery machine for both hard and soft for both hard and soft

physics in HI collisionsphysics in HI collisions• Event generators are an indispensable tool for planing Event generators are an indispensable tool for planing

the experiments and analysis of datathe experiments and analysis of data• => Further development of existing MC generators=> Further development of existing MC generators• HI theory groups in Oslo utilizes it to study : HI theory groups in Oslo utilizes it to study :

EOS, elliptic flow, EOS, elliptic flow, particle freeze-out, HBT correlations of unlike particle freeze-out, HBT correlations of unlike particles, particle-jet correlations, heavy quark particles, particle-jet correlations, heavy quark production in a large pT range, scaling properties …production in a large pT range, scaling properties …

Back-up Slides

W. Busza, JPG 35 (2008) 044040 W. Busza, JPG 35 (2008) 044040

Example of extended longitudinal scaling in different reactions

e+e－

W. Busza, JPG 35 (2008) 044040 W. Busza, JPG 35 (2008) 044040 UA5 Collab., Phys. Rep. 154 (1987) 247UA5 Collab., Phys. Rep. 154 (1987) 247

Charged particle pseudorapidity density at as a function of √s

Violation of Feynman scaling,but ext. long. scaling holds?!

VIOLATION OF VIOLATION OF ELSELS IN A+A AT IN A+A AT LHC? LHC?

Statistical thermal model: ELS will be violated in A+A @ LHC. What about Statistical thermal model: ELS will be violated in A+A @ LHC. What about p+p ?p+p ?

J. Cleymans, J.Struempfer, L.Turko, PRC 78 (2008) 017901

WHY SCALING HOLDS IN THE WHY SCALING HOLDS IN THE MODEL? MODEL?

In string models both In string models both FSFS and and ELS ELS holds in the fragmentation regionsholds in the fragmentation regions

2 21 2

2

Correlation function

Particles are uncorrelated if

Particle inclusive cross section

In the fragmentation region of

( , ) exp{ ( )}

1

1 2

( , , )

p

i j i j

i j

i i iTi

i iT

Consider now inclusive process

C y y y y

y y y

i X

d y y y y pf

dy d p

1 2 1 2

21

article1

Inclusi

1 , 1

n

ve density

/ ( , )

i i

i i inel i iT

y y y y y y

f y y p

Shor

t ran

ge c

orre

latio

ns( )

1max

( ) 2

exp{ ( )

therefo e

)

r

}

( ,

iiF i

ii F iT

px y y

p

n x p

VIOLATION OF KNO SCALINGVIOLATION OF KNO SCALING

A.B.Kaidalov, K.A.Ter-Martirosyan, PLB 117 (1982) 247A.B.Kaidalov, K.A.Ter-Martirosyan, PLB 117 (1982) 247 UA5 Collaboration, Phys. Rep. 154 (1987) 247UA5 Collaboration, Phys. Rep. 154 (1987) 247 N.S.Amelin, L.V.Bravina, Sov.J.Nucl.Phys. 51 (1990) 133 N.S.Amelin, L.V.Bravina, Sov.J.Nucl.Phys. 51 (1990) 133

√√ss

Charged-particle Charged-particle multiplicity distributions multiplicity distributions in the KNO variables in in the KNO variables in nondiffractive nondiffractive antiproton-proton antiproton-proton collisions at collisions at √s = 546 GeV √s = 546 GeV andand

53 GeV 53 GeV