Relativistic Hartree-Bogoliubov theory with finite range pairing forces in coordinate space: Neutron halo in light nuclei

The Relativistic Hartree Bogoliubov (RHB) model is applied in the self-consistent mean-field approximation to the description of the neutron halo in the mass region above the s-d shell. Pairing correlations and the coupling to particle continuum states are described by finite range two-body forces. Finite element methods are used in the coordinate space discretization of the coupled system of Dirac-Hartree-Bogoliubov integro-differential eigenvalue equations, and Klein-Gordon equations for the meson fields. Calculations are performed for the isotopic chains of Ne and C nuclei. We find evidence for the occurrence of neutron halo in heavier Ne isotopes. The properties of the 1f-2p orbitals near the Fermi level and the neutron pairing interaction play a crucial role in the formation of the halo. Our calculations display no evidence for the neutron halo phenomenon in C isotopes.Comment: 7 pages, Latex, 5 P.S. Figures, To appear in Phys. Rev. Let

Molecular corridors and kinetic regimes in the multiphase chemical evolution of secondary organic aerosol

The dominant component of atmospheric, organic aerosol is that derived from the oxidation of volatile organic compounds (VOCs), so-called secondary organic aerosol (SOA). SOA consists of a multitude of organic compounds, only a small fraction of which has historically been identified. Formation and evolution of SOA is a complex process involving coupled chemical reaction and mass transport in the gas and particle phases. Current SOA models do not embody the full spectrum of reaction and transport processes, nor do they identify the dominant rate-limiting steps in SOA formation. Based on molecular identification of SOA oxidation products, we show here that the chemical evolution of SOA from a variety of VOC precursors adheres to characteristic "molecular corridors" with a tight inverse correlation between volatility and molar mass. The slope of these corridors corresponds to the increase in molar mass required to decrease volatility by one order of magnitude (-dM / dlogC_0). It varies in the range of 10–30 g mol^(−1), depending on the molecular size of the SOA precursor and the O : C ratio of the reaction products. Sequential and parallel reaction pathways of oxidation and dimerization or oligomerization progressing along these corridors pass through characteristic regimes of reaction-, diffusion-, or accommodation-limited multiphase chemical kinetics that can be classified according to reaction location, degree of saturation, and extent of heterogeneity of gas and particle phases. The molecular corridors and kinetic regimes help to constrain and describe the properties of the products, pathways, and rates of SOA evolution, thereby facilitating the further development of aerosol models for air quality and climate

Relativistic Hartree-Bogoliubov description of ground-state properties of Ni and Sn isotopes

The Relativistic Hartree Bogoliubov (RHB) theory is applied in the description of ground-state properties of Ni and Sn isotopes. The NL3 parameter set is used for the effective mean-field Lagrangian, and pairing correlations are described by the pairing part of the finite range Gogny interaction D1S. Fully self-consistent RHB solutions are calculated for the Ni ($28\leq N\leq 50$) and Sn ($50\leq N\leq 82$) isotopes. Binding energies, neutron separation energies, and proton and neutron $rms$ radii are compared with experimental data. The model predicts a reduction of the spin-orbit potential with the increase of the number of neutrons. The resulting energy splittings between spin-orbit partners are discussed, as well as pairing properties calculated with the finite range effective interaction in the $pp$ channel.Comment: 11 pages, RevTex, 12 p.s figures, submitted to Phys. Rev.

Relativistic Hartree-Bogoliubov description of sizes and shapes of A=20 isobars

Ground-state properties of A = 20 nuclei ($^{20}$N, $^{20}$O, $^{20}$F, $^{20}$Ne, $^{20}$Na, $^{20}$Mg) are described in the framework of Relativistic Hartree-Bogoliubov (RHB) theory. The model uses the NL3 effective interaction in the mean-field Lagrangian, and describes pairing correlations by the pairing part of the finite range Gogny interaction D1S. Binding energies, quadrupole deformations, nuclear matter radii, and differences in radii of proton and neutron distributions are compared with recent experimental data.Comment: LaTeX 11 pages, 6 eps figs, submitted to Nucl. Phys.

Color Molecular-Dynamics for High Density Matter

We propose a microscopic simulation for quark many-body system based on molecular dynamics. Using color confinement and one-gluon exchange potentials together with the meson exchange potentials between quarks, we construct nucleons and nuclear/quark matter. Statistical feature and the dynamical change between confinement and deconfinement phases are studied with this molecular dynamics simulation.Comment: 4 pages, 3 figure

Rural continental aerosol properties and processes observed during the Hohenpeissenberg Aerosol Characterization Experiment (HAZE2002)

International audienceDetailed investigations of the chemical and microphysical properties of rural continental aerosols were performed during the HAZE2002 experiment, which was conducted in May 2002 at the Meteorological Observatory Hohenpeissenberg (DWD) in Southern Germany. Online measurements included: Size-resolved chemical composition of submicron particles; total particle number concentrations and size distributions over the diameter range of 3 nm to 9 ?m; gas-phase concentration of monoterpenes, CO, O3, OH, and H2SO4. Filter sampling and offline analytical techniques were used to determine: Fine particle mass (PM2.5), organic, elemental and total carbon in PM2.5 (OC2.5, EC2.5, TC2.5), and selected organic compounds (dicarboxylic acids, polycyclic aromatic hydrocarbons, proteins). Overall, the non-refractory components of submicron particles detected by aerosol mass spectrometry (PM1, 6.6±5.4 ?g m?3, arithmetic mean and standard deviation) accounted for ~62% of PM2.5 determined by filter gravimetry (10.6±4.7 ?g m?3). The relative proportions of non-refractory submicron particle components were: (23±39)% ammonium nitrate, (27±23)% ammonium sulfate, and (50±40)% organics (OM1). OM1 was closely correlated with PM1 (r2=0.9) indicating a near-constant ratio of non-refractory organics and inorganics. The average ratio of OM1 to OC2.5 was 2.1±1.4, indicating a high proportion of heteroelements in the organic fraction of the sampled rural aerosol. This is consistent with the high ratio of oxygenated organic aerosol (OOA) over hydrocarbon-like organic aerosol (HOA) inferred from the AMS results (4:1), and also with the high abundance of proteins (~3%) indicating a high proportion of primary biological material (~30%) in PM2.5. This finding was confirmed by low abundance of PAHs (?3) and EC (?3) in PM2.5 and detection of several secondary organic aerosol compounds (dicarboxylic acids) and their precursors (monoterpenes). New particle formation was observed almost every day with particle number concentrations exceeding 104 cm?3 (nighttime background level 1000?2000 cm?3). Closer inspection of two major events indicated that the observed nucleation agrees with ternary H2SO4/H2O/NH3 nucleation and that condensation of both organic and inorganic species contributed to particle growth

Proton drip-line nuclei in Relativistic Hartree-Bogoliubov theory

Ground-state properties of spherical even-even nuclei $14\leq Z \leq 28$ and $N=18,20,22$ are described in the framework of Relativistic Hartree Bogoliubov (RHB) theory. The model uses the NL3 effective interaction in the mean-field Lagrangian, and describes pairing correlations by the pairing part of the finite range Gogny interaction D1S. Binding energies, two-proton separation energies, and proton $rms$ radii that result from fully self-consistent RHB solutions are compared with experimental data. The model predicts the location of the proton drip-line. The isospin dependence of the effective spin-orbit potential is discussed, as well as pairing properties that result from the finite range interaction in the $pp$ channel.Comment: 12 pages, RevTex, 10 p.s figures, submitted to Phys. Rev.

Exact, E=0, Solutions for General Power-Law Potentials. I. Classical Orbits

For zero energy, $E=0$, we derive exact, classical solutions for {\em all} power-law potentials, $V(r)=-\gamma/r^\nu$, with $\gamma>0$ and $-\infty <\nu<\infty$. When the angular momentum is non-zero, these solutions lead to the orbits $\r(t)= [\cos \mu (\th(t)-\th_0(t))]^{1/\mu}$, for all $\mu \equiv \nu/2-1 \ne 0$. When $\nu>2$, the orbits are bound and go through the origin. This leads to discrete discontinuities in the functional dependence of $\th(t)$ and $\th_0(t)$, as functions of $t$, as the orbits pass through the origin. We describe a procedure to connect different analytic solutions for successive orbits at the origin. We calculate the periods and precessions of these bound orbits, and graph a number of specific examples. Also, we explain why they all must violate the virial theorem. The unbound orbits are also discussed in detail. This includes the unusual orbits which have finite travel times to infinity and also the special $\nu = 2$ case.Comment: LaTeX, 27 pages with 12 figures available from the authors or can be generated from Mathematica instructions at end of the fil

Quantification of nitrotyrosine in nitrated proteins

For kinetic studies of protein nitration reactions, we have developed a method for the quantification of nitrotyrosine residues in protein molecules by liquid chromatography coupled to a diode array detector of ultraviolet-visible absorption. Nitrated bovine serum albumin (BSA) and nitrated ovalbumin (OVA) were synthesized and used as standards for the determination of the protein nitration degree (ND), which is defined as the average number of nitrotyrosine residues divided by the total number of tyrosine residues in a protein molecule. The obtained calibration curves of the ratio of chromatographic peak areas of absorbance at 357 and at 280 nm vs. nitration degree are nearly the same for BSA and OVA (relative deviations <5%). They are near-linear at low ND (< 0.1) and can be described by a second-order polynomial fit up to \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\hbox{ND}} = 0.5\left( {{R^2} > 0.99} \right)$$\end{document}. A change of chromatographic column led to changes in absolute peak areas but not in the peak area ratios and related calibration functions, which confirms the robustness of the analytical method. First results of laboratory experiments confirm that the method is applicable for the investigation of the reaction kinetics of protein nitration. The main advantage over alternative methods is that nitration degrees can be efficiently determined without hydrolysis or digestion of the investigated protein molecules

Relativistic Hartree-Bogoliubov description of the deformed ground-state proton emitters

Ground-state properties of deformed proton-rich odd-Z nuclei in the region $59 \leq Z \leq 69$ are described in the framework of Relativistic Hartree Bogoliubov (RHB) theory. One-proton separation energies and ground-state quadrupole deformations that result from fully self-consistent microscopic calculations are compared with available experimental data. The model predicts the location of the proton drip-line, the properties of proton emitters beyond the drip-line, and provides information about the deformed single-particle orbitals occupied by the odd valence proton.Comment: 9 pages, RevTeX, 3 PS figures, submitted Phys. Rev. Letter