3P Multiplet Research Articles

Quark structure of the chi _{mathrm{c}}(3P) and X(4274) resonances and their strong and radiative decays

We calculate the masses of chi _{mathrm{c}}(3P) states with threshold corrections in a coupled-channel model. The model was recently applied to the description of the properties of chi _{mathrm{c}}(2P) and chi _{mathrm{b}}(3P) multiplets (Ferretti and Santopinto in Phys Lett B 789:550, 2019]. We also compute the open-charm strong decay widths of the chi _{mathrm{c}}(3P) states and their radiative transitions. According to our predictions, the chi _{mathrm{c}}(3P) states should be dominated by the charmonium core, but they may also show small meson-meson components. The X(4274) is interpreted as a c {{bar{c}}}chi _{mathrm{c1}}(3P) state. More information on the other members of the chi _{mathrm{c}}(3P) multiplet, as well as a more rigorous analysis of the X(4274)’s decay modes, are needed to provide further indications on the quark structure of the previous resonance.

Assessing the role of silicate polymerization on metal oxyhydroxide surfaces using X-ray photoelectron spectroscopy

The iron oxide phases that precipitate in weathered environments can contain large amounts of adsorbed silicic acid (H 4SiO 4). This adsorbed silicate can be present as monomeric or oligomeric silicate species and affects many properties of iron oxides such as morphology, phase stability and surface charge. Therefore understanding the chemistry of H 4SiO 4 at iron oxide interfaces is important to describe the geochemistry of iron oxides and the elements that are associated with iron oxides. In this study we have measured the Si 2s and Si 2p binding energies (BE) in the XPS spectra of silicate adsorbed onto preformed ferrihydrite under conditions where the silicate surface chemistry is well defined. The positions of both the Si 2s and Si 2p peaks are indicative of the degree of polymerization of adsorbed silicate, but the Si 2p peaks overlap with an Fe 3p multiplet splitting peak. For ferrihydrite-adsorbed H 4SiO 4 the Si 2s peak BE increased from 153.1 to 153.9 eV as the H 4SiO 4 surface concentrations (Γ Si in mol Si (mol Fe) − 1 ) increased from 0.03 to 0.2. The low Γ Si Si 2s BE value is slightly lower than the Si 2s BE of the orthosilicate almandine (153.3 eV), while the high Γ Si value lies midway between almandine and the tectosilicate quartz (154.6 eV). The positions of the Si 2s peaks correlate with the Si–O stretching bands (ν(Si–O)) in the FTIR spectra and are consistent with a model in which monomeric silicate species are present at low Γ Si and one dimensional oligomers are formed at higher Γ Si. The Si 2s BE and ν(Si–O) for synthetic and natural ferrihydrites co-precipitated with silicates are substantially lower than those for silicate adsorbed onto preformed ferrihydrite, clearly indicating a lower degree of silicate polymerization for silicate adsorbed onto the internal surfaces between ferrihydrite domains. The Si 2s and ν(Si–O) for co-precipitated ferrihydrites appear to be indicative of the age of the ferrihydrite and the rate of ferric precipitation.

Measurements of relative line strengths in N I multiplets for transition arrays 3s– np ( n=3, 4, 5)

Applying the emission method, intensities of 60 spectral lines of neutral nitrogen (N I) belonging to 15 multiplets originating from 3s– np ( n=3, 4, 5) transition arrays have been measured. A wall-stabilized arc, operated at atmospheric pressure in helium with some admixture of nitrogen was applied as the excitation source. From measured line intensities, relative line strengths within multiplets have been evaluated. For transitions with Δ n=1 and 2, significantly larger discrepancies from LS coupling results are found if compared to transitions 3s–3p (Δ n=0). The measured relative line strengths within 3s–3p multiplets are compared with older measurements, recent calculations and with the new data recommended by NIST.

Element-specific magnetometry with photoelectron dichroism: FeCo and FeNi

We have investigated fcc Fe x Co 1− x and Fe x Ni 1− x alloys grown on Cu(1 0 0) with X-ray magnetic linear dichroism angular distributions in photoemission (XMLDAD). To achieve this end, a simple model has been developed, which accurately describes the experimental spectra and supports our application of XMLDAD as a form of elementally specific magnetometry. This model combines the simplicity and physical insight of a single-electron picture with multielectronic effects, via the utilization of “Doniach–Sunjic” lineshapes for each component within the Fe 3p multiplet. We will also briefly discuss the observed fine structure in the emission of the Fe 3p core level, which was previously predicted but lacking experimental confirmation. We have found different behavior for the dichroism of the Fe 3p level at high and low Fe concentrations upon alloying with Co, compared to alloying with Ni. These contrasting observations can be explained in part by the different behavior of the atomic volume. Both systems show also a change of the in-plane easy axis upon increasing the Fe content. For small concentrations the easy axis is along the {0 1 1} direction, which changes to the {0 0 1} direction at a higher Fe content. Interestingly the actual transition occurs in both instances at roughly the same electron/atom count.

Experimental Study of LS Coupling Along Isoelectronic Sequences

In order to test the prediction of the LS coupling approximation for several light elements (B, C, N, O, F and Ne), the line intensity ratios of the 3s–3p multiplets along the isoelectronic sequences of lithium and beryllium and line intensity ratios of 3s–3p and 3p–3d multiplets along isoelectronic sequences of boron, carbon, nitrogen, oxygen and fluorine have been investigated experimentally. The light sources were two low-pressure pulsed arcs. The plasma electron densities were determined from the width of the He II Pα line.

Electron-pair densities of group 14, 15, and 16 atoms in their low-lying multiplet states

Electron-pair intracule (relative motion) h(u) and extracule (center-of-mass motion) d(R) densities are studied for the 3P, 1D, and 1S multiplet states of five group 14 atoms with p2 configurations, the 4S, 2D, and 2P multiplets of five group 15 atoms with p3 configurations, and the 3P, 1D, and 1S multiplets of five group 16 atoms with p4 configurations. For all 15 atoms, it is confirmed that a lower total energy E in a high angular momentum state is always accompanied with the decrease of the electron–nucleus attraction energy Ven which is greater than the increase in the electron–electron repulsion energy Vee, as discussed in the literature for a few light atoms. In all the cases, the difference in the radial intracule densities 4πu2h(u) clarifies that for a multiplet with a higher angular momentum, the probability of finding a pair of electrons separated by a short/long distance is larger/smaller, leading to a greater Vee and a smaller average interelectronic distance 〈u〉. The Fermi hole effect is not important for the relative stability of the multiplets examined. For the multiplets arising from the pn electronic configurations, the differences in the radial extracule densities 4πR2d(R) are found to be almost isomorphic with the corresponding intracule ones: In a multiplet with a high angular momentum, the average center-of-mass radius 〈R〉 of an electron pair is always smaller, and two electrons are more likely to be at opposite positions with respect to the nucleus. Accordingly, the valence p orbital in a more stable multiplet is more tight, resulting in a lower electron–nucleus attraction energy Ven for all the 15 atoms.

Wavelengths, Isotope Shifts, and Oscillator Strengths in B [CSC]ii[/CSC] at 1362 and 1624 Å

The wavelength and isotope shift of the B II resonance line at 1362 A, generally used for the determination of the boron abundance and the cosmic 10B/11B ratio, have been measured in the laboratory with high accuracy. The corresponding data for the B II 2s2p 3P-2p2 3P multiplet at 1624 A are also reported. The measurements are supported by calculations, which also provide oscillator strengths.

Magnetic asymmetry in photoemission from Fe(100) with linearly polarized synchrotron radiation.

We have measured partially angle-integrated photoemission with linearly polarized undulator radiation on the valence band and on the 3p and 3s core levels of iron in an Fe(100) single crystal. A large asymmetry is measured for 3p core levels when reversing the magnetization direction perpendicular to the photoemission plane. A smaller but clear asymmetry is also measured in the valence (3d) band spectrum, and no asymmetry is measured for the 3s core levels. The results are explained by the transverse spin polarization of the near-normal-emission photoelectrons which is induced by the light p polarization and by spin-orbit interaction in the initial state. From the line-shape change of the 3p core level as a function of magnetization reversal the fine structure of the 3p multiplet is derived. This effect provides a very efficient diagnostic of the surface magnetization direction allowing to measure magnetic ordering at surfaces similarly to the Kerr effect, but in a chemically specific and intrinsically surface sensitive way as shown by examples on ferromagnetically coupled and antiferromagnetically coupled Fe/Cr interfaces.

Energy dependence of the outer core-level multiplet structures in atomic Mn and Mn-containing compounds.

We consider the energy dependence of the Mn 3s and 3p multiplets from gas-phase atomic Mn and crystalline ${\mathrm{MnF}}_{2}$ and ${\mathrm{KMnF}}_{3}$ over the range from x-ray photoelectron spectroscopy (XPS) energies down to energies near threshold. First comparing atomic and solid-state spectra for these multiplets permits concluding that the splittings in the compounds ${\mathrm{MnF}}_{2}$, MnO, and ${\mathrm{Cd}}_{0.3}$${\mathrm{Mn}}_{0.7}$Te are highly atomic in character, with no significant effects due to extra-atomic screening. Measuring the energy dependence for atomic Mn, ${\mathrm{MnF}}_{2}$, and ${\mathrm{KMnF}}_{3}$ then shows for both the 3s and 3p multiplets that there is a decrease in the intensities of the higher-binding-energy quintet states relative to those of the corresponding septet states as the excitation energy is lowered. This effect on the quintet:septet branching ratios is also found to extend to rather high energies, with the ratios at the XPS limit of \ensuremath{\approxeq}1400 eV above threshold being approximately 25\char21{}30 % greater than those at \ensuremath{\approxeq}200 eV above threshold. We show that this energy-dependent final-state branching ratio is not due simply to spin-dependent dipole matrix elements as derived from single-configuration Hartree-Fock calculations. We suggest that this effect is caused by the sudden-to-adiabatic transition, which at lower energies favors the exchange-stabilized septet states that are the ground states of the ions formed. However, two prior theoretical models for such sudden-to-adiabatic intensity changes [Stohr, Jaeger, and Rehr, Phys. Rev. Lett. 51, 821 (1983) and Thomas, Phys. Rev. Lett. 54, 182 (1985)] were not found to describe our results well, particularly in the extension of the effect to higher energies. We consider qualitatively a configuration-interaction model with quintet-septet interchannel coupling that may better describe these effects and form the basis for more quantitative calculations.

Rydberg series in the arc spectrum of antimony

The absorption spectrum of antimony vapour produced by the flash discharge of SbF5 vapour was photographed in the region 1320–1700 Å (1 Å = 10−10 m) by means of a 10 m vacuum spectrograph. Of a total of 302 absorption lines observed, 203 were classified into 11 Rydberg series, two of which are autoionized. Four of the series have not been previously reported, and a total of 142 new lines are added to the previous analyses. The ionization limits for the 3P multiplet of Sb II were also refined.

Spin-polarized photoelectron diffraction and valence-band photoemission from MnO(001).

Spin-polarized photoelectron diffraction (SPPD) has previously been proposed as a technique for studying short-range magnetic order in magnetic materials, and the first experimental study of this kind was performed on the ionic antiferromagnetic ${\mathrm{KMnF}}_{3}$ [B. Sinkovic, B. Hermsmeier, and C. S. Fadley, Phys. Rev. Lett. 55, 1227 (1985)]. We present here a much more detailed study of SPPD for the antiferromagnetic transition-metal oxide MnO with a (001) surface orientation. The Mn 3s and Mn 3p multiplets have been studied using both low-energy (192.6 eV) and high-energy (1486.7 eV) x-ray excitation and the intensity ratios I${(}^{5}$S(\ensuremath{\uparrow}))/I${(}^{7}$S(\ensuremath{\downarrow})) and I${(}^{5}$P(\ensuremath{\uparrow}))/I${(}^{7}$P(\ensuremath{\downarrow})) have been measured as a function of both direction and temperature. Data obtained with the lower excitation energy and resulting in kinetic energies of 50--100 eV show an abrupt change or step in both the I${(}^{5}$S(\ensuremath{\uparrow}))/I${(}^{7}$S(\ensuremath{\downarrow})) and I${(}^{5}$P(\ensuremath{\uparrow}))/I${(}^{7}$P(\ensuremath{\downarrow})) intensity ratios at \ensuremath{\approxeq}530\ifmmode\pm\else\textpm\fi{}20 K or \ensuremath{\approxeq}4.5 times the N\'eel temperature ${\mathit{T}}_{\mathit{N}}$.This change is interpreted to be a new type of short-range-order transition occurring at what is denoted ${\mathit{T}}_{\mathrm{SR}}$. Also, these same quintet or septet intensity ratios show a weak peak at ${\mathit{T}}_{\mathit{N}}$, suggesting for the first time that SPPD has sensitivity to long-range magnetic order. Data obtained for the I${(}^{5}$S(\ensuremath{\uparrow}))/I${(}^{7}$S(\ensuremath{\downarrow})) intensity ratio with the higher excitation energy show no such effects, a result consistent with the much weaker exchange scattering expected at such energies. Additional x-ray photoelectron spectroscopy spectra and azimuthal scans of Mn and O core-level intensities are considered and these establish that (i) the sample surface had good stoichiometry and was very clean and well ordered, (ii) the SPPD effects observed at ${\mathit{T}}_{\mathrm{SR}}$ are not due to any surface structural change, and (iii) a single-scattering cluster (SSC) theoretical model is at least a qualitatively reasonable starting point for describing such effects. We also compare experimental results for the magnitudes of these steps with calculations based upon exchange scattering in the spin-polarized SSC model [B. Sinkovic and C. S. Fadley, Phys. Rev. B 31, 4665 (1985)], and conclude that there is at least qualitative agreement. A final aspect of our data concerns the temperature dependence of the Mn 3d--dominated valence-band spectra: These spectra are found to show no measurable change in crossing ${\mathit{T}}_{\mathrm{SR}}$, but by contrast exhibit a large 0.4-eV increase in width in going below ${\mathit{T}}_{\mathit{N}}$, which is in contradiction to recent theoretical predictions.

Photoionization cross-section calculations for atomic lithium

Calculations based upon relaxed Hartree-Fock functions for the 1s diagram and satellite photoionization cross sections for atomic lithium are presented and compared with current experimental results. Configuration interaction in the initial and final ionic-core states is included in the calculation. While the results for the 1S and 3S multiplets are promising the present theory is shown to be limited in providing accurate cross sections for the 1P and 3P multiplets related to conjugate processes. The existence of continuum configuration interaction is demonstrated to be likely, and the influence of the lithium optical final state is shown to be of importance.

Experimental fine-structure branching ratios for Na-rare-gas optical collisions.

Experimental ratios for branching into the fine-structure levels of the Na 3p multiplet, as a consequence of an optical collision with He, Ne, Ar, Kr, or Xe, are reported. The process studied is Na(3s $^{2}S_{1/2}$)+scrR+nh\ensuremath{\nu}\ensuremath{\rightarrow} Na(3p $^{2}P_{j}$)+scrR+(n-1)h\ensuremath{\nu} , where scrR represents a rare-gas atom and where the laser frequency \ensuremath{\nu} is tuned in the wings of the Na resonance transitions. The branching ratios are defined as I(D1)/I(D2) where I(D1) and I(D2) are measured intensities of the atomic Na D1 and D2 lines. The ratios are determined for detunings ranging from about 650 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ in the blue wing to 170 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ in the red wing of the Na 3p multiplet. The branching is found to be strongly detuning dependent in the vicinity of the NaAr, NaKr, and NaXe near-red-wing satellites. The blue-wing branching ratios show a detuning-dependent approach to a recoil, or sudden statistical, limit of 0.5, irrespective of the rare gas. Fine-structure changing cross sections have also been measured for resonant excitation of the Na 3p $^{2}P_{j}$ state; the results are consistent with cross sections obtained from wing excitation.

The direct measurement of the 3 3P0-3 3P1 fine-structure interval and the gJ-factor of atomic silicon by laser magnetic resonance

The J - 1 fine structure interval and the g-factor of the 3P1 state have been determined with high precision in the present laser magnetic resonance measurements of the ground 3p2 3P multiplet of atomic Si. Delta-E(3P1-3P0) = 2,311,755.6(7) MHz, and gJ(3P1) = 1.500830(70). Single-configuration calculations of gJ for 3P1 and 3P2 yield a value for the latter which, at 1.501095, is noted to differ by an unexpectedly large margin from the experimental value.

Absorption and Dispersion Studies of the 4s4p 3P-4p2 3P Multiplet of Zn. I

The 4 s 4 p 3 P levels of Zn have been populated by a DC discharge and three series of measurements have been applied to observe the 4 s 4 p 3 P -4 p 2 3 P multiplet at about λ2100 A. These are (1) precise measurement of the absorption profile for the 3 P 1 - 3 P 2 autoionizing transition, (2) total-absorption measurement for the same transition with simultaneous dispersion (hook) measurement for the 4 s 4 p 3 P 1 -4 s 5 s 3 S 1 transition at λ4722 A, and (3) simultaneous hook measurements for the 3 P - 3 P multiplet concerned and the 4 s 4 p 3 P -4 s 5 s 3 S visible multiplet. The autoionization rate of the 4 p 2 3 P 2 level is 4.72×10 12 s -1 from (1). From (2) and (3) the gf values are 0.76, 0.68, 0.68 and 0.97 for 3 P 1 - 3 P 2 , 3 P 0 - 3 P 1 , 3 P 1 - 3 P 0 and 3 P 2 - 3 P 1 , respectively, by reference to the absolute f values (∼0.14) for the visible multiplet.

Laser–microwave methods for precise determination of the fine and hyperfine structure of Li+ions

Three methods were developed for the determination of the fine and hyperfine structures of helium-like Li+ ions in a metastable state 1s2s 3S1 and in a short-lived multiplet 1s2p 3P: hyperfine structure (hfs) spectroscopy of the 2 3S1 state using laser optical pumping and microwave transition; hfs investigation of the 2 3P multiplet by laser excitation and microwave-induced optical pumping of the 2 3S1 state; rf controlled spectroscopy of large term splitting with the aid of two dye lasers. The first method was used to study the hfs splitting of the 2 3S1 state of the 6,7Li+ isotope and the magnetic hfs interaction constants were obtained. The hfs anomaly was in good agreement with the results obtained from the hfs splitting of the ground state of the atom. A small shift of the 2 3S1, F = 3/2 level of the 7Li+ ion, which was due to the hyperfine shift of the 1S and 3S levels, was measured. This was done using the second method and microwave measurements were made also of the 2 3P state 7Li+.

Semi-Empirical Calculations of Fine Structure Splittings and Ionisation Potentials in the MgI Isoelectronic Sequence

A semi-empirical parametrisation of the singlet-triplet and fine structure splittings for available measurements of the 3s3p 1,3P levels in the MgI isoelectronic sequence has revealed regularities which are useful for interpolation and extrapolation. By combining an extrapolation of the empirical gross energies, Slater integrals and spin-orbit splitting factors to highly ionised members of this sequence with available measurements for the 3s2 1S-3s3p 1P transitions, the positions of the members of the 3s3p 3P multiplets and the ionisation potentials can be predicted.

Direct measurement of fine structure in the ground state of atomic carbon by laser magnetic resonance

The fine-structure intervals in the ground 2 3P multiplet of lZC I have been measured with high accuracy by laser magnetic resonance. The results are: AR(3Y2-3P1) = 809.3446 (29) GHz and AE(3Y1-3Po) = 492.1623(7) GHz. These precise nieasurements have made possible the astronomical detection of far-infrared line emissions from I2C atoms in several interstellar sources, as reported in the accompanying Letter by Phillips et al. Subject headings: atomic processes - infrared : spectra I. INTRODUCTION

Ultraviolet pumping of N/+/ fine-structure levels

view Abstract Citations (12) References (12) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Ultraviolet pumping of N+ fine-structure levels. Flannery, B. P. ; Rybicki, G. B. ; Sarazin, C. L. Abstract The effects of radiative pumping, through the six-line UV 3D - 3P multiplet at 1085 A, on the population of the fine-structure levels of N(+) are investigated. Results are presented for both optically thin and optically thick media. For the more important case of an optically thick nebula, an efficient method is outlined for the numerical solution of the multiline multilevel radiative-transfer problem in a model H II region described by plane-parallel geometry, point source illumination, and homogeneous physical conditions. The method is applied to construct a grid of models for N(+) spanning a wide range of values for the electron density, the strength of the UV source, and the line optical depth of the nebula. In general it is found that radiative pumping and transfer effects can significantly alter the level populations, but the effect often mimics results obtained without radiative pumping with a different electron density. For Stroemgren spheres around early-type stars it is found as a result of transfer effects, the role of pumping is never likely to be important. Infrared emission from the fine-structure decays at 122 and 240 microns is also discussed. Publication: The Astrophysical Journal Pub Date: May 1979 DOI: 10.1086/157040 Bibcode: 1979ApJ...229.1057F Keywords: Fine Structure; Nebulae; Nitrogen Ions; Optical Pumping; Ultraviolet Astronomy; Atomic Excitations; Doppler Effect; Electron Density (Concentration); Energy Levels; H Ii Regions; Lyman Spectra; Radiative Transfer; Statistical Distributions; Stellar Evolution; Stellar Spectra; Astrophysics; H II Regions:Radiative Transfer; Line Formation full text sources ADS |

Dependence of K-shell fluorescence yields on multiplet states of neon

The K-shell fluorescence yields are calculated to be equal to 0.013 and 0.028 respectively for 3P and 1P multiplet states of 1s 1 2s 2 2p 5 configuration of neon. This observation can significantly effect analyses of ion-atom collision experiments where in X-ray production cross-sections are measured.