Magnetic moments of Jπ = 192− mirror states in 43Ti and 43Sc

The time-differential perturbed angular distribution method was used to determine the g-factors of the $\text{(}\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}\text{)}{}^3\text{19}\text{2}{}^{\mathrm{?}}$ states in ⁴³Ti and ⁴³Sc. The results for the mass 43 mirror pair are: ${}^{43}\text{Ti}\text{: g = 0.760 ± 0.001, T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{, = 560 ± 6}\text{ns}$, ${}^{43}\text{Sc}\text{: g = 0.3286± 0.0007, T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{= 473 ± 5}\text{ns}$. Considering in addition the magnetic moments in A = 41 and 42, it is suggested that the deformed states considered by Johnstone and Castel and by Erikson are responsible for the observed large deviations from the Schmidt values.     

Recoil-distance lifetime measurements in 51Cr, 53Cr, 53Mn and 53Fe

Levels in ⁵¹Cr, ⁵³Cr, ⁵³Mn and ⁵³Fe were excited via (α, n) or (α, p) reactions. Using the recoil-distance method, mean-lives (in ps) have been obtained for excited states (keV) in the residual nuclei: ${}^{51}\text{Cr}\text{(2256) = 66±2,}{}^{53}\text{Cr}\text{(1536) = 21.5±3.5,}{}^{53}\text{Cr}\text{(2173) = 6.7±3.1,}{}^{53}\text{Mn}\text{(2564) = 20}{}^{\mathrm{+8}}{}_{\mathrm{?6}}\text{and}{}^{53}\text{Fe}\text{(1424) = 4.0±1.0}$. Reduced transition probabilities calculated from these values are compared with the available theoretical values.     

Homogeneously broadened far-infrared absorption line due to the E → 2A transition of excited chromium ions in ruby

By use of far-infrared laser spectroscopy, we have found that for a high-quality ruby crystal at low temperature, the absorption line due to the electronic transition between the excited states $\text{E}\text{(}{}^2\text{E)}$ and $\text{2}\text{A}\text{(}{}^2\text{E) of Cr}{}^{\mathrm{3+}}$ ions is homogeneously broadened. From the linewidth (0.011 cm^-1) the lifetime of the 2ā level against emission of 29 cm^-1 phonons is obtained.     

Stereoelectronic properties of photosynthetic and related systems: Ab initio configuration interaction calculations on the ground and lower excited singlet and triplet states of magnesium chlorin and chlorin

Ab initio configuration interaction wavefunctions and energies are reported for the ground state and many low-lying singlet and triplet states of magnesium chlorin and chlorin, and are employed in an analysis of the electronic absorption spectra of these systems.In chlorin, the calculated visible spectrum consists of two ${}^1\text{(π, π}{}^1\text{)}$ states, the lower energy, y-polarized state exhibiting moderate absorption intensity in contrast to the very weak absorption of the higher energy x-polarized state. The configurational composition of both states is well described by the four-orbital model. Five ${}^1\text{(π, π}{}^1\text{)}$ states are responsible for the Soret band envelope. A moderately intense y-state lies under the low energy edge of the band envelope, while two x-polarized states of moderate and strong intensity, respectively, are responsible for the band maximum. The final two ${}^1\text{(π, π}{}^1\text{)}$ states lie at the high energy edge of the Soret band and introduce a measure of asymmetry into the band envelope. Two ${}^1\text{(n, π}{}^1\text{)}$ states of very weak oscillator strength are also found in this region of the spectrum. All the Soret states are of complex configurational composition, and several of the higher lying states contain contributions from doubly excited configurations.The calculated visible spectrum of magnesium chlorin also consists of two ${}^1\text{(π, π}{}^1\text{)}$ states, with the weakly absorbing x-polarized state lying approximately 200 cm^?1 lower in energy than the moderately intense y-polarized state. The configurational composition of both states is well described by the four-orbital model. Four ${}^1\text{(π, π}{}^1\text{)}$ states constitute the bulk of the intensity in the Soret band envelope. In distinction to chlorin, the moderately intense ${}^1\text{(π, π}{}^1\text{)}$ state at the low energy edge of the band envelope is x-polarized. Two intense ${}^1\text{(π, π}{}^1\text{)}$ states of y- and x-polarization, respectively, constitute the band maximum region, and a single x-polarized state of moderately strong intensity can be assigned to the high energy shoulder of the band envelope. Two other weakly absorbing ${}^1\text{(π, π}{}^1\text{)}$ states are also found in this region, along with another weakly absorbing state of mixed in-plane and out-of-plane polarization. No clearly defined ${}^1\text{(n, π}{}^1\text{)}$ states are observed. As was the case for chlorin, all the Soret states are of complex configurational composition, and some of the higher energy states contain significant contributions from doubly excited configurations.Chlorin and magnesium chlorin both possess three ${}^3\text{(π, π}{}^1\text{)}$ states which lie below S₁ and a single ${}^3\text{(π, π}{}^1\text{)}$ which lies slightly above S₂. All four of the low-lying ${}^3\text{(π, π}{}^1\text{)}$ states in each molecule are well described by the four-orbital model, with T₁ being essentially a single configuration in each case. The remainder of the ${}^3\text{(π, π}{}^1\text{)}$ states are clustered in the same energetic region as the comparable ${}^1\text{(π, π}{}^1\text{)}$ Soret states, with comparably complex configurational compositions.Dipole moments and charge distributions for low-lying singlet and triplet states are also reported, and are used to rationalize chemical reactivity characteristics.     

Dye laser site selection spectroscopy on U6+ luminescent molecular centers in LiF-U3O8 crystals

The polarized excitation and emission spectra of the U⁶⁺ molecular centers giving the most intense emission lines at 18 940 cm^?1 and 19 285 cm^?1 are presented and analyzed in detáil. From the polarization experiments, it is shown that the symmetry of the centers is C_4v and that the symmetries of the observed electronic states are Γ₂, Γ₁ and Γ₅. Finally, an electronic model is proposed which associates the emission and excitation lines of the U⁶⁺ centers in the visible region to transitions between the fundamental state $\text{Γ}{}_1\text{(6p}{}^6\text{,}{}^1\text{S)}$ and the states of the excited configuration $\text{6p}{}^5\text{(}{}^2\text{P}\text{3}\text{2}\text{) 7s}$.     

Reaction mechanism and spin information in the sequential breakup of 18O at 82 MeV

The α-decays of states in ¹⁸O have been studied in the sequential breakup reaction ${}^{12}\text{C}\text{(}{}^{18}\text{O}\text{,}{}^{18}\text{O}{}^1\text{→}{}^{14}\text{C}\text{α)}$ at 82MeV. Double-differential cross sections have been obtained for the states excited in ¹⁸O. A conventional analysis of the decay correlations does not yield unambiguous information on the spins of the states excited. However a systematic dependence of the correlations on the angle of the ¹⁸O¹ in the c.m. frame is observed, allowing the determination of the transferred angular momentum. The double-differential cross sections have been analysed with the DWBA and a strong absorption model. The latter allows the extraction of quantitative information on spins and reaction mechanism from the data.     

The electronic spectrum of gaseous SnS

Observations of the spectrum of SnS excited in chemiluminescence have led to the characterization of two low-lying excited states of SnS, $\text{a}\text{Ω}\text{1(}{}^3\text{Σ}{}^{\mathrm{+}}\text{)}$, with T_e = 18 143.9 cm^?1, and $\text{A0}{}^{\mathrm{+}}\text{(}{}^3\text{Π}\text{)}$, with T_e = 22 021.3 cm^?1. Extended rotational analyses of the perturbed bands observed in the absorption spectrum enable assignments to be suggested for the components $\text{Ω}\text{0}{}^{\mathrm{+}}$ and 1 of ³Σ^? and $\text{Ω}\text{1}$ of ³Π.     

The quasihole aspect of hole strength distributions in odd potassium and calcium isotopes

The ${}^{\mathrm{40,42,44,48}}\text{Ca}\text{(}\text{d}\text{, ρ)}{}^{\mathrm{39,41,43,47}}\text{K and}{}^{\mathrm{40,44}}\text{Ca(d, t)}{}^{\mathrm{39,43}}$ reactions have been studied at 52 MeV. Angular distributions have been taken and spectroscopic factors have been extracted by means of a DWBA analysis for states with excitation energies up to typically 10 MeV. Analog relations are proposed for mass-39 and mass-43 nuclei. A discussion of proton occupation numbers for various shells above and below the Fermi surface shows a substantial and about equal core excitation for ⁴²Ca and ⁴⁴Ca. Typically 70 % of the $\text{1}\text{d}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}$ hole strengths have been located. The corresponding energy averaged strength distributions show quasihole structures whose widths are dominated by phonon-hole coupling to the first 2⁺ state in the target nucleus.     

Experimental and theoretical studies of positive pion production on 10B and 40Ca by 163–186 MeV protons

The reactions ${}^{10}\text{B(p}\text{,π}{}^{\mathrm{+}}\text{)}{}^{11}\text{B}$ and ${}^{40}\text{Ca(p}\text{,π}{}^{\mathrm{+}}\text{)}{}^{41}\text{Ca}$ have been studied for proton energies between 163 and 186 MeV. Angular distributions for the ground states and the excited state at 2.13 MeV in ¹¹B are presented. Cross sections calculated in the one-nucleon model, under different assumptions about the interaction Hamiltonian as well as the pion and proton optical potentials, are compared with the experimental distribution from the $\text{1}\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}$ state in ⁴¹Ca.     

Nucleon-exchange type charge-exchange process and the spin-forbidden (6Li, 6He) transitions

The second order DWBA formalism for the nucleon pick-up and stripping type two-step process is presented for the cases of exact finite-range interaction, no-recoil approximation and zero-range approximation. The several first-order “spin-forbidden” charge-exchange (⁶Li, ⁶He) transitions are investigated by such direct nucleon-exchange mechanisms. They are the analog transitions: ${}^{26}\text{Mg}\text{(0}{}^{\mathrm{+}}\text{) →}{}^{26}\text{Al}\text{(0.226}\text{MeV}\text{0}{}^{\mathrm{+}}\text{)}$ and ${}^{42}\text{Ca}\text{(0}{}^{\mathrm{+}}\text{→}{}^{42}\text{Sc}\text{(}\text{g.s.}\text{0}{}^{\mathrm{+}}\text{)}$, and the natural parity state excitations: ${}^{48}\text{Ca}\text{(0}{}^{\mathrm{+}}\text{) →}{}^{48}\text{Sc(g.s.}\text{6}{}^{\mathrm{+}}$ and 0.253 MeV 4⁺). The spin-flip mechanisms using a spin-independent force through the direct nucleon-exchange process are discussed. This type of two-step approach can provide a satisfactory interpretation for these transitions. It may also indicate a strong nucleon-exchange type charge-exchange mechanism for allowed transitions.     

Search for highly excited states in 8Be

Excitation functions and angular distributions of the reactions ${}^7\text{Li}\text{(}\text{p}\text{, α)α}{}^1$ and ${}^6\text{(}\text{Li}\text{(}\text{d}\text{, α)α}{}^1$ have b investigated for the excitation-energy region E_X = 21?28 MeV in ⁸Be ($\text{α}{}^1$ denotes the first excited state of the α-particle). pronounced resonant structure has been observed in both channels around E_X = 24 MeV. It is excited simultaneously by odd and even angular momenta. The experimental results are discussed in the light of two models, the αα¹ cluster model and the symplectic model which take into account the configuration interaction (core excitation) in different manners.     

Gyromagnetic ratios of excited states in 123, 125Te

The results of integral precession measurements are reported for $\text{3}\text{2}{}^{\mathrm{+}}$ and $\text{5}\text{2}{}^{\mathrm{+}}$ excited states in ^123,125Te. The measurements were made using the ion implantation perturbed angular correlation technique by recoiling the excited nuclei into polarized iron. The measured mean lifetimes and g-factors are: ${}^{123}\text{Te (440 keV,}\text{3}\text{2}{}^{\mathrm{+}}\text{) τ = 39±4 ps, g = 0.34 ± 0.06}$; $\text{(505 keV,}\text{5}\text{2}{}^{\mathrm{+}}\text{) τ = 26±3 ps, g = 0.04±0.025}$; and ${}^{125}\text{Te(443 keV,}\text{3}\text{2}{}^{\mathrm{+}}\text{) ρ = 27±3.3 ps, g = 0.39±0.06}$; $\text{(464 keV,}\text{5}\text{2}{}^{\mathrm{+}}\text{) g = 0.12±0.04}$. The results are compared with theoretical predictions.     

α-Vibrations

The existence of states which change the number of particles in four and wich are specifically excited in α-transfer reactions like (¹⁶O, ¹²C), (⁶Li, d), etc. is predicted, as a consequence of the existence of proton and neutron pairing vibrations which are strongly excited in two-particle transfer reactions. In particular a J^π = 0⁺ two-phonon σ-vibration (4p?4h) state is expected at ≈ 7 MeV of excitation in ²⁰⁸Pb and with a relative cross section $\text{σ(}{}^{204}\text{Hg}\text{→ 7}\text{MeV}\text{(}{}^{208}\text{Pb}\text{))/σ(}{}^{208}\text{Pb}\text{→}\text{gs}\text{(}{}^{212}\text{Po}\text{)) ≈ 1}$. Similar states are expected in neighbouring nuclei.     

The five-nucleon system above the three-particle threshold

Compound nucleus states in ${}^5\text{Li}$ and ${}^5\text{He}$ have been investigated with the ${}^3\text{He(d,p)pt}$ and ${}^3\text{H(d,n)pt}$ three-particle reactions. The observed $\text{J}{}^{\mathrm{\pi }}\text{=}\text{3}\text{2}{}^{\mathrm{?}}$ states (E_X≈20 MeV) can be understood, in analogy to the ground states of the A=5 system, by coupling a $\text{p}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$ nucleon to the first 0⁺ excited state of ${}^4\text{He}$.     

Infrared laser spectra of HF and DF

The six lowest states, dissociating into the $\text{(}{}^2\text{P)}\text{Al}\text{(}{}^4\text{S)}\text{N}$ and $\text{(}{}^2\text{P)}\text{Al}\text{(}{}^2\text{D)}\text{N}$ atomic states, are calculated using a nonempirical pseudopotential for the representation of the atomic cores and an extensive CI. The ground state is assigned as ³Π, but the ¹Σ⁺ and ³Σ^? minima are less than 0.5 eV higher. The results are compared with the few experimental data.     

Rydberg states of SiBr

New uv absorption spectra have been observed for SiBr. Five Rydberg states are identified to the states $\text{(4sσ)}{}^2\text{Σ}{}^{\mathrm{+}}$, $\text{(5sσ)}{}^2\text{Σ}{}^{\mathrm{+}}$, $\text{(4pπ)}{}^2\text{Π}$, $\text{(3dπ)}{}^2\text{Π}$, and $\text{(3dδ)}{}^2\text{Δ}$ by comparison with SiF and SiCl. The ionization potentials of SiCl and SiBr have been determined for the first time, and were 6.82 and 6.67 eV, respectively.     

Hyperfine structure of the 53P1 state of 115Cdm

The magnetic fields at which Zeeman sublevels cross in the excited 5³P₁ state of the 43-day isomer ¹¹⁵Cd^m have been determined for three pairs of levels. The crossing fields are used to determine the magnetic dipole hyperfine structure constant $\text{A(}{}^3\text{P}{}_1\text{) = ?656.491 (4)}\text{MHz}$ and the quadrupole constant $\text{B(}{}^3\text{P}{}_1\text{) = 129.39 (6)}\text{MHz}$.