Equation of state of zero-temperature quark matter

We outline the key elements of a recent calculation aimed at determining the equation of state of deconfined (but unpaired) quark matter at zero temperature and high density, using finite quark masses. The computation is performed in perturbation theory up to three loops, and necessitates the development and application of some novel computational tools. In this talk, we introduce the basic features of these new techniques and review the main sources of motivation for considering finite mass effects in perturbation theory.     

On the nuclear modification factor at RHIC and LHC

We show that pQCD factorization incorporated with pre-hadronization energy-loss effect naturally leads to flatness of the nuclear modification factor RAA$R_{\mathit{AA}}$ for produced hadrons at high transverse momentum pT$p_T$. We consider two possible scenarios for the pre-hadronization: In scenario 1, the produced gluon propagates through dense QCD medium and loses energy. In scenario 2, all gluons first decay to quark–antiquark pairs and then each pair loses energy as propagating through the medium. We show that the estimates of the energy-loss in these two different models lead to very close values and is able to explain the suppression of high-pT$p_T$ hadrons in nucleus–nucleus collisions at RHIC. We show that the onset of the flatness of RAA$R_{\mathit{AA}}$ for the produced hadron in central collisions at midrapidity is about pT≈15$p_T\approx 15$ and 25 GeV at RHIC and the LHC energies, respectively. We show that the smallness (RAA<0.5$R_{\mathit{AA}}<0.5$ ) and the high-pT$p_T$ flatness of RAA$R_{\mathit{AA}}$ obtained from the kT$k_T$ factorization supplemented with the Balitsky–Kovchegov (BK) equation is rather generic and it does not strongly depend on the details of the BK solutions. We show that energy-loss effect reduces the nuclear modification factor obtained from the kT$k_T$ factorization about 30–50% at moderate pT$p_T$.     

On the ground state of Yang–Mills theory

We investigate the overlap of the ground state meson potential with sets of mesonic-trial wave functions corresponding to different gluonic distributions. We probe the transverse structure of the flux tube through the creation of non-uniform smearing profiles for the string of glue connecting two color sources in Wilson loop operator. The non-uniformly UV-regulated flux-tube operators are found to optimize the overlap with the ground state and display interesting features in the ground state overlap.     

Heavy flavour capabilities of the ALICE transition radiation detector

The ALICE Transition Radiation Detector (TRD) enhances the detection sensitivity of heavy-flavour production of the ALICE experiment at the LHC by providing electron identification above and fast trigger capabilities above . The combined particle identification from the Inner Tracking System (ITS), the Time Projection Chamber (TPC) and the Transition Radiation Detector enables measurements of D-mesons and B-mesons and, potentially, the Λ_b, assuming the reconstruction of the .     

Strongly correlated Fermi systems as a new state of matter

The aim of this review paper is to expose a new state of matter exhibited by strongly correlated Fermi systems represented by various heavy-fermion (HF) metals, two-dimensional liquids like ³He, compounds with quantum spin liquids, quasicrystals, and systems with one-dimensional quantum spin liquid. We name these various systems HF compounds, since they exhibit the behavior typical of HF metals. In HF compounds at zero temperature the unique phase transition, dubbed throughout as the fermion condensation quantum phase transition (FCQPT) can occur; this FCQPT creates flat bands which in turn lead to the specific state, known as the fermion condensate. Unlimited increase of the effective mass of quasiparticles signifies FCQPT; these quasiparticles determine the thermodynamic, transport and relaxation properties of HF compounds. Our discussion of numerous salient experimental data within the framework of FCQPT resolves the mystery of the new state of matter. Thus, FCQPT and the fermion condensation can be considered as the universal reason for the non-Fermi liquid behavior observed in various HF compounds. We show analytically and using arguments based completely on the experimental grounds that these systems exhibit universal scaling behavior of their thermodynamic, transport and relaxation properties. Therefore, the quantum physics of different HF compounds is universal, and emerges regardless of the microscopic structure of the compounds. This uniform behavior allows us to view it as the main characteristic of a new state of matter exhibited by HF compounds.     

Observability of a projected new state of matter: a metallic superfluid

Dissipationless quantum states, such as superconductivity and superfluidity, have attracted interest for almost a century. A variety of systems exhibit these macroscopic quantum phenomena, ranging from superconducting electrons in metals to superfluid liquids, atomic vapors, and even large nuclei. It was recently suggested that liquid metallic hydrogen could form two new and unusual dissipationless quantum states, namely, the metallic superfluid and the superconducting superfluid. Liquid metallic hydrogen is projected to occur only at an extremely high pressure of about 400 GPa, with pressures on hydrogen of 320 GPa having already been reported. The issue to be addressed is whether this state could be experimentally observable in principle. We propose four experimental probes for detecting it.     

Production and study of new heavy elements

The last results of search for spontaneously fissioning nuclei in the Allende meteorite, investigations of the mechanisms and productions of light Cf isotopes and 110 element using different dielectric detector types and methods of their development have presented.     

On a possible “crystallized” state of exciton matter

If no evidence for a Bose-Einstein condensation of excitons (ex) and biexcitons (ex₂) is found, the possibility of a condensation of exciton matter in the ordinary sense could be expected. On ground of an analogy of excitons with hydrogen atoms in the case of σ = m¹_e/m¹_h ? 1 a binding energy in a FCC phase is evaluated for a hypothetical para ex₂ lattice. It is shown that the binding energy, though small, is likely to be larger than the zero point energy. This result is however dependent of the value of m¹_h. The behaviour of orthobiexcitons is also briefly discussed. Though no evidence for such a condensation has been reported so far these considerations are instructive and may suggest new experiments. Some of them are examined.     

On the phase state of the core matter in a high-power discharge through a wire

Experimental facts attesting to a two-phase (liquid-metal-vapor) state of the matter in the core produced in a high-power discharge through thin wires are presented. The modern technique of multiframe x-ray shadow photography has made it possible to observe vapor bubbles in the core and their interaction with the shock wave penetrating from the corona. Pis’ma Zh. éksp. Teor. Fiz. 69, No. 5, 349–354 (10 March 1999)     

Towards a new Gogny force parameterization: Impact of the neutron matter equation of state

A new parameterization of the effective nucleon–nucleon Gogny interaction is proposed. It reproduces the neutron matter equation of state much better than the commonly used D1S Gogny interaction and furthermore reduces the binding energies' drift for the major part of the isotopic chains. Other important nuclear properties related both to nuclear matter and finite nuclei are studied and shown to be of similar quality as with D1S.     

On the phase structure of QCD in a finite volume

The chiral phase transition in QCD at finite chemical potential and temperature can be characterized for small chemical potential by its curvature and the transition temperature. The curvature is accessible to QCD lattice simulations, which are always performed at finite pion masses and in finite simulation volumes. We investigate the effect of a finite volume on the curvature of the chiral phase transition line. We use functional renormalization group methods with a two flavor quark-meson model to obtain the effective action in a finite volume, including both quark and meson fluctuation effects. Depending on the chosen boundary conditions and the pion mass, we find pronounced finite-volume effects. For periodic quark boundary conditions in spatial directions, we observe a decrease in the curvature in intermediate volume sizes, which we interpret in terms of finite-volume quark effects. Our results have implications for the phase structure of QCD in a finite volume, where the location of a possible critical endpoint might be shifted compared to the infinite-volume case.     

关于软玻密子的结构

本文修改了Landshoff-Nachtmann的软玻密子(Pomeron P)场论模型.从强子组分夸克具有结构的观点出发,根据高能强作用软过程中的最大非微扰强作用反应假定,提出了有关软P新的结构图像.对撞强子中的一对组分夸克被分解为裸夸克和一系列非微扰胶子(和夸克对).与此相应,软P的结构是由胶子形成的一系列切割梯形图之和所代表.在系统能量s很大而动量转移|t|很小的多重雷吉(Regge)运动学区间,并在保留lns的领头阶近似下,计算了这组切割梯形图之和所对应的散射振幅和总截面.它们的表达式出现了对s的Regge型幂次因子,得出了软P轨迹的简洁表达式.简单说明了按本文提出的方案可以讨论那些相关的强作用过程.     

Exploring the phase diagram of strongly interacting matter; news from SPS and RHIC

Two experimental programs are aiming to study nuclear collisions in the energy regime in order to explore an essential part of the phase diagram of strongly interacting matter. The programs are motivated by observations that indicate a phase transition to take place in this energy domain: the onset of deconfinement. The STAR collaboration proposes an energy scan in the Relativistic Heavy Ion Collider (RHIC) at BNL. The ongoing program of the NA61/SHINE experiment consists of a two-dimensional energy-system size scan in nuclear and elementary collisions. The goal of both programs is to study the properties of the onset of deconfinement and to eventually discover the conjectured critical point of strongly interacting matter. A comparison of the strengths and limitations reveals the complementarity of the two programs.     

Graft polymerization into the latent tracks of some perfluoropolymers films irradiated by heavy ions

The results of the graft polymerization of methacrylic acid into perfluoropolymers (the copolymer of tetrafluoroethylene with hexafluoropropylene, copolymer of tetrafluoroethylene with perfluoroallylether) irradiated with heavy ions (Kr, 430 MeV) are presented. It has been found that the graft polymer quantity depends upon the polymer nature and the ion fluence. The graft polymer amount and its penetration depth were measured by the weighting methods, the dye sorption and electron microscopy methods. The graft polymerization results in significant changes in the polymer volume and structure.     

Discovery of the Higgs boson by the ATLAS and CMS experiments at the LHC

The Standard Model (SM) Higgs boson was predicted by theorists in the 1960s during the development of the electroweak theory. Prior to the startup of the CERN Large Hadron Collider (LHC), experimental searches found no evidence of the Higgs boson. In July 2012, the ATLAS and CMS experiments at the LHC reported the discovery of a new boson in their searches for the SM Higgs boson. Subsequent experimental studies have revealed the spin-0 nature of this new boson and found its couplings to SM particles consistent to those of a Higgs boson. These measurements confirmed the newly discovered boson is indeed a Higgs boson. More measurements will be performed to compare the properties of the Higgs boson with the SM predictions.     

Study of the reaction step preceding sequential fission in the nuclear interaction (16.7 MeV/u) U+Au

The kinematical analysis of nuclear reactions between (16.7 MeV/u) ²³⁸U and ^nat.Au ions has been performed by using mica solid-state track detectors (SSNTD). The reaction products emanating from each isolated collision vertex were registered in the forward hemisphere with almost 2π angular coverage. It has been demonstrated previously that these tracks represent the second stage of a sequential fission process. In this paper the results of analysis pertaining to the first reaction step have been presented. Using a computer code based on the procedure of internal calibration it was possible to derive quantities like mass transfer, total kinetic energy loss, and scattering angles. It is shown that the mass flow and kinetic energy distribution between reacting partners interacting at different impact parameters during the first phase of the interaction decides the multiplicity of the final reaction products.