Kirill Tuchin

Cronin effect and high p(T) suppression in pA collisions

We review the predictions of the theory of a color glass condensate for a gluon production cross section in

Inclusive gluon production in DIS at high parton density

p(d)A

Universal properties of bulk viscosity near the QCD phase transition

collisions. We demonstrate that, at moderate energies, when the gluon production cross section can be calculated in the framework of the McLerran-Venugopalan model, it has only a partonic level Cronin effect in it. At higher energies or rapidities corresponding to smaller values of the Bjorken x, quantum evolution becomes important. The effect of quantum evolution at higher energies or rapidities is to introduce the suppression of high-

Bulk viscosity of QCD matter near the critical temperature

{p}_{T}

Particle production in strong electromagnetic fields in relativistic heavy-ion collisions

gluons slightly decreasing the Cronin enhancement. At still higher energies or rapidities quantum evolution leads to the suppression of produced gluons at all values of

Time and space dependence of the electromagnetic field in relativistic heavy-ion collisions

{p}_{T}.

Elliptic flow from minijet production in heavy ion collisions

We calculate the cross section of a single inclusive gluon production in deep inelastic scattering at very high energies in the saturation regime, where the parton densities inside hadrons and nuclei are large and the evolution of structure functions with energy is nonlinear. The expression we obtain for the inclusive gluon production cross section is generated by this nonlinear evolution. We analyze the rapidity distribution of the produced gluons as well as their transverse momentum spectrum given by the derived expression for the inclusive cross section. We propose an ansatz for the multiplicity distribution of gluons produced in nuclear collisions which includes the effects of nonlinear evolution in both colliding nuclei.

Multiparticle production and thermalization in high-energy QCD

Abstract We extract the bulk viscosity of hot quark–gluon matter in the presence of light quarks from the recent lattice data on the QCD equation of state. For that purpose we extend the sum rule analysis by including the contribution of light quarks. We also discuss the universal properties of bulk viscosity in the vicinity of a second-order phase transition, as it might occur in the chiral limit of QCD at fixed strange quark mass and most likely does occur in two-flavor QCD. We point out that a chiral transition in the O ( 4 ) universality class at zero baryon density as well as the transition at the chiral critical point which belongs to the Z ( 2 ) universality class both lead to the critical behavior of bulk viscosity. In particular, the latter universality class implies the divergence of the bulk viscosity, which may be used as a signature of the critical point. We discuss the physical picture behind the dramatic increase of bulk viscosity seen in our analysis, and devise possible experimental tests of related phenomena.

Open charm production in heavy ion collisions and the color glass condensate

Kubos formula relates bulk viscosity to the retarded Greens function of the trace of the energy-momentum tensor. Using low energy theorems of QCD for the latter we derive the formula which relates the bulk viscosity to the energy density and pressure of hot matter. We then employ the available lattice QCD data to extract the bulk viscosity as a function of temperature. We find that close to the deconfinement temperature bulk viscosity becomes large, with viscosity-to-entropy ratio ζ/s ~ 1.