STUDY OF PP AND HEAVY-IONCOLLISIONS AT ENERGIES UP TO

LHC

Larissa Bravina, University of OsloR. Kolevatov, L. Malinina, G. Eyyubova, M.S.Nilsson, E.Zabrodin

NuPECC town meeting in Bergen 11-12.06.2010

RELATIVISTIC HEAVY ION THEORY IN

UNIVERSITY OF OSLO

Prof. Larissa Bravina (UiO since 2003)

NFR project

• Dr. Rodion Kolevatov (80 % Post Doc, NFR) theory

• Dr. Ludmila Malinina (20% Post Doc, NFR) ALICE experiment (from JINR,Dubna)

• Dr. Evgeny Zabrodin (researcher, NFR) theory

• PhD Student Mads S. Nilsson (UiO,topforsk) ALICE experiment

• PhD Student Gyulnara Eyyubova (QUOTA, UiO) ALICE experiment

Konrad Tywoniuk (PhD in 2008, financed by UiO), theory + ALICE exp

Ionut Chr. Arsene (PhD in 2009, financed by QUOTA UiO), BRAHMS exp. / theory

Main activity – development of MC models for LHC, RHIC and FAIR

- simulations for LHC (UHKM-HYDJET++ is official

ALICE event generator)

- reconstruction methods for flow and HBT radii for ALICE

- flow-jets-correlations-ridge-resonances

- theoretical predictions for pp, pA and AA collisions

diffraction, soft, semihard, hard physics, shadowing , heavy quarkonia,

flow, flow in pp, Regge theory, HBT, jets and jet quenching, fluctuations, correlations,

microscopic (QGSM, URQMD) and macroscopic approaches (HYDJET++)

RELATIVISTIC HEAVY ION THEORY IN

UNIVERSITY OF OSLO

FIAS, Frankfurt M. Bleicher, G. Burau, H. Stoecker (GSI)MSU, Moscow I. Lokhtin, A. SnigirevJINR, Dubna B.V. Batyunya(*), A.S. Vodopianov (*)LPT, Orsay A. CapellaITEP, Moscow A. Kaidalov, K. Boreskov, O. KancheliITP, Tuebingen J. Bleibel, C. Fuchs, A. FaesslerBITP, Kiev Yu. Karpenko, Yu. SinyukovIGFAE, Santiago de Compostella E.G. Ferreiro, K. Tywoniuk (now in Lund U.)Tel Aviv U. and Penn State U. L. Frankfurt, M. Strikman(*) –working within ALICE experimental program

=============================================24–papers in international refereed journals12–published conference contributions32–oral and poster presentations (for 5 years)

External collaborators:

OSLO HEAVY-IONTHEORY GROUP

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. …

THE GLAUBER MODEL

heavy-ion collisions

in each rescattering there is a certain probability for particle production

COHERENT INTERACTION

the projectile becomes large compared to the

target

interacts simultaneously with the whole system

effectively less interaction - shadowing

dramatic change of space-time picture

1. SHADOWING:

COMPARISON WITH RHIC AU+AU @ 200 GEV

8

weaker recombination at forward

stronger initial state effects! weaker

comover suppression at forward

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

1. SHADOWING: PREDICTIONS FOR LHCK. Tywoniuk, L.B. et al., J. Phys. G 35 (2008) 104156

A. Capella, L.B. et al., Eur. Phys. J. C 58 (2008) 437

2. HYDJET++ = HYDJET + FASTMC

HYDJET

FASTMCI. Lokhtin et al., Comput. Phys. Commun. 180 (2009) 779

N. 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

3. ELLIPTIC FLOW IN HYDJET++

G. Eyyubova, L.B. et al.,

Phys. Rev. C80 (2009)

064907;

arxiv:1001.3602[hep-ph]

Hydro flowJet contribution

4. FREEZE-OUT AT RHIC: URQMDM.S. Nilsson (to be submitted)

FREEZE-OUT AT RHIC: QGSM

5. HANBURY-BROWN—TWISS CORRELATIONSM.S. Nilsson , L. Malinina, L.B. et al. (to be submitted)

Detector

NON-IDENTICAL HBT CORRELATIONSM.S. Nilsson , L. Malinina, L.B. et al. (to be submitted)

IDENTICAL HBT CORRELATIONSM.S. Nilsson , L. Malinina, L.B. et al. (to be submitted)

6. EQUILIBRATION IN THE CENTRAL CELL (FAIR)

Kinetic equilibrium:Isotropy of velocity distributions

Isotropy of pressure

Thermal equilibrium: Energy spectra of particles are

described by Boltzmann distribution

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

EOS IN THE CELL: OBSERVATION OF KNEEtemperature vs. chemical potentials

Although the “knee” is similar to that in 2-flavor lattice QCD, it is

related to inelastic (chemical) freeze-out in the system

S. Ejiri et al., PRD 73

(2006) 054506

L.B. et al.,

PRC 78 (2008) 014907;

E. Zabrodin, L.B. et al,

arXiv:0902.4601

7. QGSM PREDICTIONS FOR PP AT LHC

Gribov’s Reggeon Calculus + string phenomenology

A.B. Kaidalov, K.A.Ter-Martirosyan, PLB 117 (1982)

N.S.Amelin, L.B., Sov.J.Nucl.Phys. 51 (1990) 133

N.S.Amelin, E.F.Staubo, L.P.Csernai, PRD 46 (1992) 4873

At ultra-relativistic energies: multi-Pomeron scattering, single and double

diffraction, and jets (hard Pomeron exchange)

7. QGSM:

7. QGSM:

QGSM PREDICTIONS and RESULTS FOR LHC

Inelastic collisions NSD collisions

J.B

leib

el.

L.B

. et

al.

, (w

ork

in

pro

gre

ss)

QGSM PREDICTIONS and RESULTS FOR LHC

Transverse momentum distributions

J.B

leib

el,

L.B

. et

al.

(w

ork

in

pro

gre

ss)

PREDICTIONS FOR PP @ LHC

QGSM: extended longitudinal scaling in p+p collisions holds

High-multiplicity tail

is pushed up, whereas

maximum of the

distribution is shifted

towards small values

of z

At energies below 100

GeV different

contributions overlap

strongly, whereas at

higher energies –

more multi-string

processes

24

6

8

=> Enhancement of high multiplicities

VIOLATION OF KNO SCALING AT LHC

8. Anisotropic flow in pp

8. Anisotropic flow in pp

Fourie expansion of invariant cross section:

it depends on – energy, centrality,rapidity, pt, particle id:

8. Anisotropic flow in pp

8. ANISOTROPIC FLOW IN PP

And connected with EOS and final

state interactions.

8. ANISOTROPIC FLOW IN PP

In Regge theory it appears as initial state effect and inversely proportional to

the radius of the object: for pp it could be larger then for AA :

Anisotropic flows from initial state of a fast nucleus.

K.G. Boreskov, A.B. Kaidalov, O.V. Kancheli, Eur.Phys.J.C58:445-453,2008.

In Gauss approximation

8. Anisotropic flow in pp

8. Anisotropic flow in ppEstimates of hadron azimuthal anisotropy from multiparton interactions in proton-

proton collisions at sqrt(s) = 14 TeV. D. d'Enterria , G.Kh. Eyyubova, et al

Eur.Phys.J.C66:173,2010.

8. Anisotropic flow in pp

Summary and outlook

• LHC is a discovery machine for both hard and soft

physics in HI collisions

• Event generators are an indispensable tool for planing

the experiments and analysis of data

• => Further development of existing MC generators

• HI theory groups in Oslo utilizes it to study :

EOS, elliptic flow, particle freeze-out, HBT

correlations of unlike particles, particle-jet

correlations, heavy quark production in a large pT

range, scaling properties …

CONFERENCE ON NUCLEAR PHYSICS