Regular Series


Vol. 47 (2016), No. 8, pp. 1999 – 2119


Superheavy Nuclei and Beyond: A Possible Upper Bound of the Periodic Table

abstract

Systematic calculations of superheavy region from \(Z=100\) to \(Z=150\) and \(N/Z\) ratio ranging from 1.19 to 2.70 have been carried out within the framework of the Relativistic Hartree–Bogolyubov model. It has been shown that the possible upper limit on the periodic table could be \(Z=146\), which is at variance with predictions of sophisticated atomic many-body calculations.


all authors

N. Burtebayev, A. Duisebayev, B.A. Duisebayev, M. Nassurlla, S.K. Sakhiev, B.M. Sadykov, S.B. Sakuta, T.K. Zholdybayev, S. Kliczewski, R. Siudak, M. Wolińska-Cichocka

Refraction Effects in the \(\alpha \) and \(^3\)He Scattering on \(^{14}\)N Nuclei at Energies About 50 MeV

abstract

The elastic and inelastic scattering of \(\alpha \)-particles at 48.2 MeV and \(^3\)He at 50 and 60 MeV energies on \(^{14}\)N nuclei with excitation of the 3.95 MeV (1\(^+\)) and 7.03 MeV (2\(^+\)) states was studied. The analysis of angular distributions was performed using the coupled channels and distorted waves methods. A good description of the experimental data in the full angular range with potentials having volume integrals of the real part near 400–500 MeV fm\(^3\) was obtained. The rainbow effects caused by refractive properties of the real nuclear potential were clearly seen in the measured angular distributions of the elastic scattering.


Estimate of Cold Nuclear Matter Effects on Bottom Production in \(d\)+Au Collisions at \(\sqrt {s_{_{NN}}} = 200\) GeV

abstract

Measurement of bottom-quark production in relativistic heavy-ion collision can shed light on transport properties of the hot nuclear matter created in these collisions. For interpretation of these results, it is important to have an estimate of so-called cold nuclear matter (CNM) effects for \(b\) quarks i.e. modification of production not related to the formation of the “hot” matter. In this paper, we estimate the modification of the bottom-quark production due to cold nuclear matter effects at mid-rapidity in \(d\)+Au collisions at \(\sqrt {s_{_{NN}}} = 200\) GeV at RHIC. First, we simulated semi-leptonic decays of charmed hadrons in \(d+\)Au collisions at \(\sqrt {s_{_{NN}}} = 200\) GeV at RHIC to calculate the yield of electrons from charmed hadrons. Then, we subtracted this yield from experimental data on production of electrons from heavy-flavor hadrons decays to obtain electrons from bottom-hadron decays. We found out that bottom production is not suppressed due to CNM effects in \(d+\)Au collisions at RHIC. Moreover, shadowing and initial \(k_{\mathrm {T}}\) broadening for charm quarks explain at low \(p_{\mathrm {T}}\) (\(p_{\mathrm {T}} \lt 2.5\) GeV/\(c\)) the enhancement of heavy-flavor decay electron yield observed in \(d+\)Au collisions compared to binary-scaled \(p+p\) baseline.


Temperature Dependence of Upsilon Suppression in Quark–Gluon Plasma and Study of Its Critical Parameters

abstract

The critical values of screening parameters for \({\mit \Upsilon }_{1S}\) and \({\mit \Upsilon }_{2S}\) in Quark–Gluon Plasma (QGP) have been estimated, where the screened potential is represented by an optical potential of type \(V(r,\lambda ) = - [\frac {V_{0}+iW_{0}}{1+\exp ((r-R)\lambda )}]\). It has been observed that the critical screening length possesses smaller value indicating a larger suppression compared to the value obtained when the screened potential is represented by real potential. The variation of two-particle energies of \({\mit \Upsilon }_{1S}\) and \({\mit \Upsilon }_{2S}\) with temperature has also been studied. It has been observed that below \(T=0.8\,T_{\rm c}\), the two-particle energy remains almost invariant before approaching to deconfinement phase at \(T=T_{\rm c}\). The results obtained are compared with other existing estimates.


Fluctuations in the Statistical Model of the Early Stage of Nucleus–Nucleus Collisions

abstract

Predictions on fluctuations of hadron production properties in central heavy-ion collisions are presented. They are based on the Statistical Model of the Early Stage and extend previously published results by considering the strongly intensive measures of fluctuations. In several of the considered cases, a significant change in collision-energy dependence of calculated quantities as a result of the phase transition is predicted. This provides an opportunity to observe new signals of the onset of deconfinement in heavy-ion collisions experiments.


Effects of the Minimal Length on the Thermal Properties of a Two-dimensional Dirac Oscillator

abstract

The effect of the minimal length on the thermal properties of a Dirac oscillator is considered. The canonical partition function is well-determined by using the method based on the Epstein zeta function. Through this function, all thermodynamics properties, such as the free energy, the total energy, the entropy, and the specific heat, have been determined. Moreover, this study leads to a minimal length in the interval of \(10^{-16}\lt \Delta x\lt 10^{-14}\) m with the following physically acceptable condition \(\beta \gt \beta _{0}=\frac {1}{m_{0}^{2}c^{2}}\). We show that this condition is obtained directly through the properties of the Epstein zeta function, and the minimal length \(\Delta x\) coincide with the reduced Compton wavelength \(\bar {\lambda }=\frac {\hbar }{m_{0}c}\).


New Solution to the Two-dimensional Lenz–Ising–Onsager Problem

abstract

In this work, a new analytical solution to the two-dimensional Lenz–Ising–Onsager (2D LIO) problem in zeroth external magnetic field is presented. The developed approach is based on using twice the transfer-matrix method and generalized Jordan–Wigner transform. This allows to reduce the initial problem to the problem of the many-particle (fermions) interaction.


Stress-energy Tensor of the Quantized Massive Fields in Spatially-flat \(D\)-dimensional Friedmann–Robertson–Walker Spacetimes

abstract

We construct and investigate the general stress-energy tensor, \(T_{a}^{b}\), of the quantized massive field in the \(D\)-dimensional spatially-flat Friedmann–Robertson–Walker spacetime within the framework of the adiabatic approximation. The behavior of \(T_{a}^{b}\) for \(4\leq D \leq 12\) is examined for the exponential (in the conformal time) and power-law cosmological models with the special emphasis put on the conformal and minimal curvature coupling. It is shown that time component of the stress-energy tensor is proportional to the spatial component and that the proportionality constant can be calculated without the detailed knowledge of the tensor. In the exponential expansion in even dimensions, the energy density of the quantized field identically vanishes for the conformally coupled fields and is positive for the minimal coupling. The analogous formulas for the odd-dimensional spacetimes do not exhibit this simple behavior and the energy density is positive for physical values of the coupling. The relations of the adiabatic method to the Schwinger–DeWitt approach is briefly discussed.


ERRATUM for Acta Phys. Pol. B 47, 1909 (2016)

Hadron Correlations at Energies from GeV to TeV


ERRATUM for Acta Phys. Pol. B 47, 1867 (2016)

Fluctuations and the QCD Phase Diagram


ERRATUM for Acta Phys. Pol. B 47, 1781 (2016)

Forward Physics at the LHC: from the Structure of the Pomeron to the Search for \(\gamma \)-induced Resonances


ERRATUM for Acta Phys. Pol. B 47, 1293 (2016)

Photoelectric Effect for Twist-deformed Space-time


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