On physical programme at FAIR

A. Sorin

5th Workshop on the scientific cooperation between German research centres and JINR Dubna, 17-19 January 2005

Plan

1. The Scientific Programme at Facility for Antiproton and Ion Research (FAIR)

1.1 Nuclear Structure Physics (NUSTAR)1.2 Physics with Antiprotons (PANDA)1.3 Nuclear Matter Physics (CBM)1.4 Antiproton-Proton Scattering Experiments with Polarization (PAX)

2. Scientific activity of BLTP

3. BLTP potential participation in the program at FAIR (SELECTED TOPICS)

3.1 Hadrons in dense medium3.2 QCD phase diagram3.3 Simulations of HIC

3.4 Nuclear structures and astrophysics3.5 Spin physics3.6 Manifestation of nonperturbative QCD vacuum in N-barN annihilation.

4. Conclusions

The Scientific Programme at Facility for Antiproton and Ion Research (FAIR)

Nuclear structure physics (NUSTAR)

Physics with antiprotons(PANDA, antiprotons of 1 – 15 GeV/c)

Nuclear Matter Physics (CBM, 10 – 40 GeV/nucl.)

1. Hadrons in dense medium (light vector mesons and charmonium )2. QCD phase diagram (critical point, phases of strongly interacting matter)

Antiproton-Proton Scattering Experiments with Polarization (PAX)

Fields and Particles

Development of the quantum field theory approach in the framework of the Standard Model of fundamental interactions and its extensions.

Lattice simulations for obtaining nonperturbative results in gauge theories.

Elaboration of the multiloop calculations in QCD, Electroweak theory and Minimal Supersymmetric Standard Model.

Theoretical predictions concerning the experimental observation of supersymmetry, the Higgs boson, investigation of the spin structure of the nucleon, T-odd spin effects, jet handedness, heavy flavor physics, vacuum structure in QCD, hadron properties in dense and hot media.

Elaboration of new phenomenological models to describe the hadron dynamics in the framework of general principles of quantum field theory incorporating basic experimental patterns.

JINR-GERMAN COLLABORATION:

Berlin FUB HUB; Aachen RWTH; Bielefeld Univ.; Bochum – RUB; Bonn Univ.; Dortmund Univ. ; Erlangen FAU; Hamburg DESY; Heidelberg Univ.; Jena FSU; Kaiserslautern TU; Regensburg Univ.; Rostock Univ.; Mainz JGU; Munich LMU; Tubingen Univ.; Wuppertal Univ.; Zeuthen DESY; Darmstadt GSI TUD

Nuclear Theory

Properties of atomic nuclei at the limits of their stability.

Dynamics of nuclear reactions and mechanisms of production of exotic nuclides.

Fundamental properties of exotic few-body nuclear, atomic and molecular systems.

Nuclear matter and its phase transitions at high temperature and density.

Relativistic nuclear physics.

Subnuclear and spin effects in few-nucleon systems.

JINR-GERMAN COLLABORATION:

Bonn Univ.; Erlangen FAU; Cologne Univ.; Leipzig Univ.; Regensburg Univ.; Rostock Univ.; Siegen Univ.; Stuttgart Univ.; Frankfurt/Main GU; Giessen JLU; Mainz JGU; Julich FZJ; Rossendorf FZR; Darmstadt GSI, TUD; Dresden MPI-PkS

Condensed Matter

Multiparticle models of solids, electron-lattice and spin interactions, phase transitions and kinetic phenomena in solids.

Equilibrium and nonequilibrium media with strong correlations (liquids and nuclear matter), the processes of multifragmentation, clusterization in phase transitions and the influence of surface effects on properties of clusters.

The theory of superconductivity, the influence of strong electric fields and temperature gradients on elastic, magnetic, and thermal properties of granular superconductors.

Nonlinear problems in multiparticle theory.

Equilibrium systems of the statistical mechanics and dissipative systems far from the thermodynamic equilibrium.

Mesoscopic systems and the Bose-Einstein condensation in atomic traps.

JINR-GERMAN COLLABORATION:

Bremen Univ.; Brunswick TU; Dortmund Univ.; Dresden TUD IFW; Duisburg Univ.; Hamburg Univ.; Leipzig Univ.; Magdeburg OvGU; Rostock Univ.; Stuttgart MPI-FKF

Modern Mathematical Physics

Quantum gravity, cosmology and strings

Nonperturbative regimes of supersymmetric gauge theories.

Quantum groups and integrable systems

JINR-GERMAN COLLABORATION:

Berlin FUB, HUB; Aachen RWTH; Bielefeld Univ.; Bonn UniBonn; Dortmund Univ.; Hannover Univ.; Jena FSU; Leipzig Univ.; Munich MPI-P; Potsdam AEI

SELECTED TOPICS:

D-meson properties.

J/ breakup.

-meson in medium.

QCD phase diagram

Simulations of HIC.

Search for the mixed phase.

Spin physics and new parton distributions.

Nonperturbative QCD vacuum in N-barN annihilation.

BLTP potential participation in the program at FAIR

Unified approach for exploring the nonperturbative behaviour of the low-energy QCD based on Dyson-Scwinger equations (DSE). Broad range of observables (hadron masses, -scattering, electromagnetic form factors, heavy quark physics (leptonic, semileptonic, radiative and strong decays of D and B mesons ) ) is described.

Calculated values of observables not included in fitting the model parameters.

The quantities (GeV) used in fitting the parameters. The weighting error is the experimental error.M.A.Ivanov, Yu.L.Kalinovsky, C.D.Roberts, PR D60 (1999)

034018.Input: gluon Green function in the infrared region, solution of the DS and BS equations in the impulse apptoximation quark propagators (no-pole functions = quark confinement) + BS amplitudes. Output: hadron masses, decay widths, form factors, cross sections, etc.Tasks for PANDA: masses and decay widths of the charmonium orbital excitations, glueballs and charmed hybrids. Leptonic and hadronic decays of the D-meson, search for CP-violation in the nonleptonic D-decays. Tasks for CBM: the study of the D-meson behaviour in dense matter.

Task for the theory: update.

J/ dissociation in dense hadronic matter

Box and D-exchange diagrams.

Ivanov, Korner, Santorelli, PRD70 (2004) 014005

Different approaches give very different results for the cross sections, 2 orders of magnitude(!) : nonrelativistic quark models (K.Martins, D.Blaschke, E.Quack PR C51 (1995) 2723, chiral Lagrangian (S.G.Matinyan, B.Mueller, PR C58 (1998) 2994 ).Unified approach: relativistic quark model, effective relativistic Lagrangian describing the nonlocal interaction of hadrons with their constituent quarks.

Medium effects at chiral/deconfinement transition may explain anomalous J/ suppression (NA50, CERN)(G.Burau, D.B.Blaschke, Y.L.Kalinovsky PLB 506 (2001) 297).

Input parameters: constituent quark masses and scale hadron size parameters.Output quantities: form factors, decay widths, cross sections, etc.

Task to PANDA and CBM: measure the spectral functions of J/ and D-mesons.

Task for theory: inclusion of light vector mesons.

Problems of SPS and RHIC: huge background from neutral pion decays

complicates identification of this signal.Privilege of FAIR: higher densities entail lower critical temperatures lower background!

Proposal for FAIR:

to consider the anomalous peak in the two-photon spectrum as a signal of the mixed phase formation and, therefore, a tool to identify the critical point in the QCD phase diagram (D.B. Blaschke, A.N. Sissakian, A.S. Sorin, M.K. Suleymanov).

A task for the theory: to check the robustness of the suggested signal by evaluating the sigma2 gamma transition within nonperturbative QCD approaches (lattice simulations, Dyson-Schwinger equations, Instanton calculus etc.)

The number of anomalous two-photon events in the narrow invariant mass region M_2gamma ~ M_sigma(mu_c, T_c) can be considered as a “clock” for the duration of the mixed phase.

Relativistic 3-fluid hydrodynamic model for the energy range: a few to 200 A GeV .

New: time-delayed evolution of a third baryon-free fluid, kinetic treatment of interflow friction depending on scalar density and in-medium cross sections nuclear stopping power.

Different equations of state can be used, e.g. with a deconfinement phase transition. Obtained results: for pure hadronic equation of state (ideal gas of hadrons and their resonances interacting via a density-dependent mean-field).

Simulations of Heavy-Ion Collisions (V.D.Toneev et al.)

Evolution of central Pb-Pb collisions in the phase diagram

Dynamical trajectories in the phase diagram show:

E_0 > 10 A GeV: system enters the new phase; E_0 > 30 – 40 A GeV: system passes the

critical point. Future: to include the phase transition in the simulation via the EoS;to describe suggested signals for the phase transition: strangeness production n_s/n_pi; dilepton and photon production.

Experimental results give an evidence of existence of sharp regime changes in event characteristics as a function of the collision centrality.

<Pt> of J/ and inverse slope ( T) of J/ transverse mass distributions in Pb-Pb interactions at 158 GeV/nucl. as a function of centrality (ET ) (NA38, NA50).

The experimental information on conditions of MP formation is important to fix the onset stage of the quark deconfiment for its future identification.

Search for the mixed phase of strongly interacting matter

Possible explanation: the regime changes is a manifestation of the Mixed Phase (MP) formation (A.N. Sissakian, A.S. Sorin, M.K. Suleymanov, G.M. Zinovjev).

Search for MP: anomalous peak in the angular distribution of protons and anomalous angular correlation of secondary particles production and anomaly in the small energy 0- or (+, -)-meson (lepton) pairs production, simultaneously, as a function of the centrality.

The cross section of J/ production in Pb-Pb interactions at 158 GeV/nucl. as a function of centrality (ET ) (NA38, NA50) normalaized to the cross section of Drell-Yan pairs.

The behaviour changes atET 40-50 GeV

Drell-Yan process: production of lepton pair with large mass Q and rapidity y h + h --> l+ + l- + X via annihilation q + barq l+ + l-.

Study of the missing ingredient of nucleon structure –TRANSVERSITY

PAX: Drell-Yan process with VALENCE antiquarks(!) Advantage is clearly seen:

Chiral soliton model (used for the prediction of pentaquark): Efremov, Goeke, Schweitzer (Q2 =5 (solid), 9(dashed),16 (dotted) GeV2)

Probabilistic model for Q2 =5GeV2: interference effects at quark level only (solid) and also at the level of quark-hadron transition (dashed) (Efremov, Teryaev, Zavada)

Model approaches to transversity:

For proton-proton collisions - small cross section d (the number of sea antiquarks is small) and small asymmetry ATT proportional to the product of the transversities of colliding hadrons (transversity of antiquarks is small): it makes difficult to study the transversity in the polarized pp collisions at RHIC.

Hadrons have to enter in PAIRS because the transversity is the chiral-odd distribution (unlike the spin-averaged quark distribution and longitudinal spin-dependent quark distribution) .

The transversity is the number of transverse polarized quarks in transverse polarized nucleon.

Difference with the perturbative QCD vacuum calculations: an enhancement of flavour and spin dependence.

Manifestation of nonperturbative QCD vacuum in N-barN annihilation.

Prediction in the framework of the nonperturbative (one-instanton) QCD vacuum calculation: N.I.Kochelev, A.E.Dorokhov, Yu.A.Zubov, Z.Phys. C65 (1995) 667.

The problem of mesons spectroscopy:are a0(980) and f0(980) excited q-barq or exotic four quarks qq-barq-barq states?

For proton-proton collisions - small cross section of four-quark mesons production (no valence anti-quarks(!)): makes difficult to study in pp collisions at RHIC.

PANDA: the enhancement of four-quark mesons production because of VALENCE antiquarks(!)

Tasks for the theory: 1. calculations of perturbative QCD contributions in the framework of both exotic and non-exotic quark models of a0(980) and f0(980) mesons;2. to update the nonperturbative QCD calculations within the exotic and non-exotic quark models of a0(980) and f0(980) mesons.

or ?a0(980) =

Conclusions

Contributions of BLTP to FAIR:

1. Science in the different projects (PANDA, CBM, PAX and NUSTAR) (BLTP is the member of CBM, PAX and NUSTAR collaborations).

2. Conferences and collaboration meetings, scientific exchange programmes(e.g. Heisenberg-Landau programme) .

3. Educational programmes for young scientists (summer and Winter schools programmes (DIAS-TH and Helmholtz International summer Schools, University center).