Quark-gluon densities in the nuclear fragmentation region in heavy ion collisions at LHC

At the LHC, the leading partons in the nuclei are expected to interact with the maximal possible strength - black disk limit - up to transverse momenta of the order of few GeV. We demonstrate that in this limit the densities of the quark - gluon systems produced in the central AA collisions in the nucleus fragmentation regions should exceed 300 GeV/fm^3 which is at least as high as the densities discussed for the central region. Experimental signatures of such a regime are also discussed.Comment: 3 pages. Uses aipproc.cls. Contributed to proceedings of PANIC05, Santa Fe, NM, Oct. 24-28, 200

EMC effect, short-range nuclear correlations, neutron stars

The recent x>1 (e,e') and correlation experiments at momentum transfer Q^2 \ge 2 GeV^2 confirm presence of short-range correlations (SRC) in nuclei mostly build of nucleons. Recently we evaluated in a model independent way the dominant photon contribution to the nuclear structure. Taking into account this effect and using definition of x consistent with the exact kinematics of eA scattering (with exact sum rules) results in the significant reduction of R_A(x,Q^2)=F_{2A}(x,Q^2)/F_{2N}(x,Q^2) ratio which explains \sim 50% of the EMC effect for x\le 0.55 where Fermi motion effects are small. The remaining part of the EMC effect at $x\ge 0.5$ is consistent with dominance of the contribution of SRCs. Implications for extraction of the F_{2n}/F_{2p} ratio are discussed. Smallness of the non-nucleonic degrees of freedom in nuclei matches well the recent observation of a two-solar mass neutron star, and while large pn SRCs lead to enhancement of the neutron star cooling rate for kT\le 0.01 MeV.Comment: To be published in proceedings of PANIC 1

Inclusive and Exclusive Scatterings from Tensor Polarized Deuteron

The possibility of using a tensor polarized deuteron target in electroproduction reactions creates new opportunities for studying different phenomena related to the short-range hadronic and nuclear physics. The use of tensor polarized deuteron allows to isolate smaller than average inter-nucleon distances for the bound two-nucleon system. In this report we consider several of high $Q^2$ reactions which are particularly sensitive to the short-range two-nucleon configurations in the deuteron. The one is the relativistic dynamics of electron-bound-nucleon scattering which can be studied in both inclusive and exclusive reactions, other is the strong final state interaction in close proximity of two nucleons that can be used as a sensitive probe for color-transparency phenomena.Comment: 8 pages and 6 figures, proceedings of the Tensor Polarized Solid Target Workshop March 10-12, 2014 (Jefferson Lab, Newport News, USA

High-energy hadron physics at future facilities

We outline several directions for future investigations of the three-dimensional structure of nucleon, including multiparton correlations, color transparency, and branching processes at hadron colliders and at hadron factories. We also find evidence that pQCD regime for non-vacuum Regge trajectories sets in for $-t\ge 1 {GeV}^2$ leading to nearly t-independent trajectories.Comment: 8 pages, 1 figure, Invited talk at INPC07, Tokyo, June 3-8, 200

Transverse nucleon structure and multiparton interactions

The transverse structure of the nucleon as probed in hard exclusive processes plays critical role in the understanding of the structure of the underlying event in hard collisions at the LHC, and multiparton interactions. We summarize results of our recent studies of manifestation of transverse nucleon structure in the hard collisions at the LHC, new generalized parton distributions involved in multiparton interactions, presence of parton fluctuations. The kinematic range where interaction of fast partons of the projectile with the target reach black disk regime (BDR) strength is estimated. We demonstrate that in the BDR postselection effect leads to effective fractional energy losses. This effect explains regularities of the single and double forward pion production in $dAu$ collisions at RHIC and impacts on the forward physics in $pp$ collisions at the LHC.Comment: 21 page, 10 figures, to be published in proceedings of the LI Cracow School of Theoretical Physics "Soft side of the LHC", Zakopane, Poland, June 11-19, 201