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1.
The hyperfine structure (hfs) of the metastable atomic states 3d64s6 D 1/2, 3/2, 5/2, 7/2, 9/2 of55Mn was measured using theABMR- LIRF method (atomicbeammagneticresonance, detected bylaserinducedresonancefluorescence). The hfs constantsA andB, corrected for second order hfs perturbations, could be derived from these measurements. The theoretical interpretation of these correctedA- andB-factors was performed in the intermediate coupling scheme taking into account the configurations 3d 54s 2, 3d 64s and 3d 7. Examining the influence of the composition of the eigenvectors on the hfs parameters \(\left\langle {r^{ - 3} } \right\rangle ^{k_s k_l } \) it was found, that for the configuration 3d 64s the two-body magnetic interaction should be considered in the calculation of the eigenvectors. Investigating second order electrostatic configuration interactions and relativistic effects and using calculated relativistic correction factors we obtained for the nuclear quadrupole moment of the nucleus55Mn a value ofQ=0.33(1) barn, which is not perturbed by a shielding or antishielding Sternheimer factor. The following hfs constants have been obtained: $$\begin{gathered} A\left( {{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}} \right) = 882.056\left( {12} \right)MHz \hfill \\ A\left( {{3 \mathord{\left/ {\vphantom {3 2}} \right. \kern-\nulldelimiterspace} 2}} \right) = 469.391\left( 7 \right)MHzB\left( {{3 \mathord{\left/ {\vphantom {3 2}} \right. \kern-\nulldelimiterspace} 2}} \right) = - 65.091\left( {50} \right)MHz \hfill \\ A\left( {{5 \mathord{\left/ {\vphantom {5 2}} \right. \kern-\nulldelimiterspace} 2}} \right) = 436.715\left( 3 \right)MHzB\left( {{5 \mathord{\left/ {\vphantom {5 2}} \right. \kern-\nulldelimiterspace} 2}} \right) = - 46.769\left( {30} \right)MHz \hfill \\ A\left( {{7 \mathord{\left/ {\vphantom {7 2}} \right. \kern-\nulldelimiterspace} 2}} \right) = 458.930\left( 3 \right)MHzB\left( {{7 \mathord{\left/ {\vphantom {7 2}} \right. \kern-\nulldelimiterspace} 2}} \right) = 21.701\left( {40} \right)MHz \hfill \\ A\left( {{9 \mathord{\left/ {\vphantom {9 2}} \right. \kern-\nulldelimiterspace} 2}} \right) = 510.308\left( 8 \right)MHzB\left( {{9 \mathord{\left/ {\vphantom {9 2}} \right. \kern-\nulldelimiterspace} 2}} \right) = 132.200\left( {120} \right)MHz \hfill \\ \end{gathered} $$   相似文献   

2.
Lifetimes and hfs coupling constants of some excited states of the 4d 9 5p configuration of Pd I have been determined in a level crossing experiment by observing the field dependence of the polarization of the fluorescence radiation in a magnetic field. From the halfwidths of the measured zero field level crossing signals one obtains the mean lifetimes of the following fine structure states:τ(3P 1 0 )=(7.46±0.32)nsec;τ(3 P 2 0 )=(6.9±0.76)nsecτ(3P 1 0 )=(4.99±0.35)nsec;τ(3 D 1 0 )=(4.89±0.40)nsecτ((3D 3 0 )=(6.99±0.49)nsec;τ(3 F 4 0 )=(7.09±0.46)nsec.Δm=2 crossing signals were detected in the3 P 1 0 ,3D 3 0 and3F 4 0 -states of the odd isotope105Pd. A detailed analysis of the experimental curves yields the hfs coupling constantsA andB of these states:A(3P 1 0 )=?(133±2) Mc/sec;B(3 P 1 0 )=(140±30) Mc/secA(3D 3 0 )=?(120±10) Mc/sec;B(3 D 3 0 )=?(660±100) Mc/secA(3F 4 0 )=?(87±2) Mc/sec;B(3 F 4 0 )=?(330±30) Mc/sec. A theoretical calculation of the hfs constants is given on the basis of reduced matrix elements. Within the limit of the errors these values agree with the experimental ones. The nuclear electric quadrupole moment deduced from the measuredB values isQ (105Pd)=(0.8±0.3)·10?24 cm2 (without corrections).  相似文献   

3.
Using the reaction138Ba(α,2n)140Ce the magnetic moment of the 10 1 + isomer atE x =3714.7 keV in theN=82 nucleus140Ce has been determined by means of the TDPAD method toμ=+10.3(4)μ N . Measuredg-factors in140Ce are compared to calculations within the shell model with configuration mixing. For the 10 1 + isomer in140Ce the four proton configuration π(1g 7 2/2 ,2d 5 2/2 ) has been found to be dominant. From theg-factor measurement strong contributions of multiparticle excitations to thegp2d 3/2,π3s 1 2 or π1h 11 2 shells and admixtures of neutron excitations to the wave function of the 10 1 + state could be excluded. The strongE1γ-branch of the deexcitation of the 10 1 + isomer in140Ce can be explained by means of small admixtures of configurations which contain the outer subshell excitationsπ2f 7/2 andπ1h 9/2. On this basisE1 transitions experimentally observed in theN=82 nuclei140Ce,141Pr and145Eu may be understood.  相似文献   

4.
The contributions of the superposition of configurations ns 25d 76s+ns5d 76sn′s+ns5d 76s 2 (n=1–5, n′=7–10) to the parameters of the hyperfine structure a 5d 01 , a 5d 12 , a 5d 10 , a 6s 10 in the spectrum of the osmium atom Os I are calculated. Nonzero contributions are shown to be made only to the parameters a 5d 10 and a 6s 10 . This fact justifies the inclusion of the parameter a 5d 10 in the semiempirical analysis of experimental values of magnetic dipole constants of the hyperfine structure of the 5d 7 s configuration in the spectrum of the osmium atom. The effect of nucleus volume on the parameters of the hyperfine structure in the spectra of osmium isotopes 187Os and 189Os is estimated.  相似文献   

5.
High-spin states in 114In were populated using the reaction 110Pd(7Li, 3n)114In at a beam energy of 26MeV. The level scheme of 114In consisting of six bands is established up to excitation energy ~ 5MeV and spin ~ 17 ? with the addition of 58 new transitions and their configurations are discussed. The intense positive-parity dipole cascade may be interpreted as shears band based on $ \pi$ [(g 9/2)-1] ? $ \nu$ [(g 7/2/d 5/2)(h 11/2)2] configuration. The $ \Delta$ I = 2 bands based on proton excitation have been observed in 114In for the first time.  相似文献   

6.
The ratios of the radiative transition probabilities for the lines of the P, Q, and R branches of the (4d)r 3Π g ? , (4d)s 3Δ g ? → (2p) c 3Π u ± band systems of the H2 molecule have been measured for the first time. Significant (to two orders of magnitudes) differences are found between the experimental values and the adiabatic theory predictions. It is established that the results of the nonadiabatic calculation performed by us in the pure-precession approximation taking into account the electronic-rotational interaction of the 4d 3Πg and 4d 3Δg states are in agreement with the experimental data. The optimal energies of rovibronic levels of the r 3Π g ? , s 3Δ g ? , c 3Π u ? , and c 3Π u + states have been found and reidentification of 11 from 54 spectral lines, assigned previously to the (0-0) and (1-1) bands, was performed.  相似文献   

7.
Using the204Hg(α, pn)-reaction andα-particles of energies 39–55 MeV, we have found an isomeric 3.6 min 12? state in206Tl at 2,642.9 keV which has the two-hole configurationπh 11 2/?1 vi 13 2/?1 The 12? state decays mainly by anE5 transition of energy 1,021.4 keV to a 7+ state at 1,621.5 keV whose main configuration isπs 1 2/?1 vi 13 2/?1 There is, in addition, evidence for a weak 565 keVM 4 branch to an 8+ state at 2,078 keV whose main configuration should beπh 11 2/?1 vf 5 2/?1 . The 7+ state decays by a stretched cascade ofγ-rays to states of the following values ofJ π and excitation energy: 5 ? + , 1,405.4 keV; 4?, 952.1 keV; 2?, 265.8 keV and 0?, 0 keV. The main configurations of these states areπh 11 2/?1 vp 1 2/?1 ,πd 3 2/?1 vf 5 2/?1 ,πd 3 2/?1 vp 1 2/?1 andπs 1 2/?1 vp 1 2/?1 respectively. From the nuclear masses of208Pb,207Pb,207Tl, and206Tl and the experimental excitation energies it is possible to obtain the proton hole-neutron hole interaction in206Tl. This interaction is compared with the calculations of Kuo and Herling and the discrepancies are discussed. The 12?→8+ M4 transition rate is reduced because of destructive interference between the protonh 11/2d 3/2 and the neutroni 13/2f 5/2 contributions. The magnitude of the reduction is accurately reproduced by the wave functions of Kuo and Herling. The 12?→7+ E5 transition rate is about twice as large as the single-holeπh 11 2/?1 πs 1 2/?1 transition rate. This deviation is fully explained by the configuration admixtures in the 7+ state, given by Kuo and Herling.  相似文献   

8.
It is shown how several discrepancies in the optical hfs of the Eu can be understood as consequences of the exchange polarization of the inner and outers-electrons by the spin of the half filled (4f 7)-subshell, an effect which should produce additional magnetic fields at the nucleus. Thus from the two different values of the electronic splitting constanta 6s in the two Eu-II ground states the polarization field from the 6s-shell (Δ H 6s ) is determined to be ca. +260 KG, and the formal splitting constantσ (??3 mK) of the (4f 7)-subshell yields ca. ?350 KG for the fieldΔ H (1?5) from the five innern s-shells (n=1?5) in good agreement with the strength of the inner field obtained from recent Mössbauer effect studies.Δ H (1?5) is deduced to be approximately equal in all sufficiently analysed ground and excited configurations of the neutral and ionised Eu atom ((4f 7) 6s, 6p, 5d, 6s 2 and 6s 6p). Other elements with half filled subshells (Am, Mn) show similar features in their optical hfs. For Am+ ((5f 7) 7s) ca. ?2200 KG are found for the inner field (Δ H (1?6)). For several 3d-elements it was found that the agreement between the calculated polarization fields and those following from experimental results is better than assumed so far.  相似文献   

9.
By optical means (i.e. hollow cathode, Fabry-Perot-interferometer and spectrograph) the hyperfine structure of 15 transitions in the Re-I spectrum was investigated. This permits to state the hfs coupling constantsA, B for 15 levels belonging to the configurations (5d 5) 6s 2, (5d 5) 6s 6p, (5d 5) 6s 7s, (5d 6) 6s, (5d 6) 6p and (5d 4) 6s 2 6p. It was found that the (5d 5) 6s 2 6 S 5/2 ground state, too, shows a small hfs. Of its magnetic splitting both size and sign could be determined (A 0,185,187=?2,2±0,4 mK); for a possible quadrupole splitting upper limits were obtained. Estimates of the quadrupole moments resulted inQ 185,187?2,9b. — In the case of two levels (x 6 P 7/2 andy 6 F 11/2) the hfs analysis raises doubts as to their classification.  相似文献   

10.
Starting from an isospin invariant shell-model hamiltonian, we describe a method for deriving microscopically the IBM-hamiltonian appropriate to lights d-shell nuclei. The key ingredients of our approach are:a) the Belyaev-Zelevinsky-Marshalek (BZM) bosonization procedure;b) two successive unitary transformations that extract the “maximally decoupled” collective bosons with angular momentaJ=0(s ππ + ,s νν + ,s πν + ) andJ =2(d ππ + ,d νν + ,d πν + (T=0),d πν + (T=1)). The method is applied to obtain the low-energy spectra and the electron scattering form factors for the 0 1 + →2 1 + transitions in20Ne and24Mg. Good agreement with the exact shell-model results is achieved. The inclusion of proton-neutron bosons (s πν + ,d πν + (T=1),d πν + (T=0)), as well as the renormalization of boson parameters due to the non-collective degrees of freedom, are shown to play a crucial role.  相似文献   

11.
The high relative abundance ofs \(\bar s\) quarks in the quark-gluon plasma will result in peculiar hadronization ratios whereby the Ξ/Λ ratio should be much higher than in usual processes. As a result the Λ( \(\bar \Lambda\) ) should exhibit a sizeable longitudinal polarization due to their importantΞ( \(\bar \Xi\) ) filiation. Discussing such spin effect, the report starts with the determination of theW spin, a recent and successful application of the helicity formalism.  相似文献   

12.
The hyperfine structure and the Stark effect shift of the 4d5s5p z 2 F 5/2 states in the Y I spectrum were investigated by level-crossing technique. Between the Zeeman effect region and the Paschen-Back region of hyperfine structure states some of the levels cross. The resonance radiation of these coherently excited levels show an interference effect of the scattering amplitudes in the crossing region. The level-crossing signals give information about hfs splitting and lifetime of the excited states under investigation. The magnetic hfs splitting factorsA of the 4d5s5p z 2 F 5/2, 7/2 states and their lifetimes were deduced. $$\begin{gathered} |A (z^2 F_{5/2} )| = (23.8 \pm 0.04) MHz \frac{{g_J }}{{0.854}} \hfill \\ |A (z^2 F_{7/2} )| = (84.08 \pm 0.01) MHz \frac{{g_J }}{{1.148}} \hfill \\ \tau (z^2 F_{5/2} ) = (46 \pm 3) 10^{ - 9} s \frac{{0.854}}{{g_J }} \hfill \\ \tau (z^2 F_{7/2} ) = (44 \pm 4) 10^{ - 9} s \frac{{1.148}}{{g_J }}. \hfill \\ \end{gathered} $$ With an electric field parallel to the magnetic field a shift of the level-crossing signals of the 4d5s5p z 2 F 5/2, 7/2 states was observed, and the Stark constants β were deduced. $$\begin{gathered} |\beta (z^2 F_{5/2} )| = (0.0020 \pm 0.0002) MHz/(kV/cm)^2 \hfill \\ |\beta (z^2 F_{7/2} )| = (0.0025 \pm 0.0015) MHz/(kV/cm)^2 . \hfill \\ \end{gathered} $$   相似文献   

13.
We fit the scattering lengths in the triplets-,p- andd- waves for the two channels \(\bar pp \to \bar \Lambda \Lambda\) and \(\bar \Lambda \Lambda \to \bar \Lambda \Lambda\) near theΛ production threshold to the differential cross section \(\frac{{d\sigma }}{{d\Omega }}(\bar pp \to \bar \Lambda \Lambda )\) and to the polarization P.  相似文献   

14.
The g factors of rovibrational levels of the (4d)r 3Π g ? and (4d)s 3Δ g ? states of the H2 and D2 molecules have been obtained for the first time. These values were found within the nonadiabatic model taking into account the interaction of the 4dπ3Πg and 4dδ3Δg states in the pure precession approximation using semiempirical values of the expansion coefficients of the wave function in an adiabatic basis, which was obtained for the first time for the states of the triplet 4d complex of terms of the hydrogen molecules, and the results of numerical calculation of the overlap integrals of the vibrational wave functions of these states. It is established that the interference effects of the interaction between the 4dπ3Π g ? and 4dδ3Δ g ? states lead to significant (up to 7 times for the r 3Π g ? state of the H2 and D2 molecules and 70 and 8 times for the s 3Δ g ? state of the H2 and D2 molecules, respectively) differences between the nonadiabatic values of the g factors and the corresponding adiabatic values. It is found that the perturbed values of the g factors are much closer to the values corresponding to the case of Hund’s d coupling of angular momenta than to the values corresponding to the b coupling. It is established that the perturbations of the g factors of rovibrational levels of the states of the 4d complex of terms are much greater (up to 2 times for the 3Π g ? states and 350 times for the 3Δ g ? states) than the perturbations of the same characteristics for the 3d complex of terms of the hydrogen molecule with the same vibrational and rotational quantum numbers.  相似文献   

15.
The odd-odd 88 37Rb51 and 86 35Br51 nuclei have been produced as fission fragments in the fusion reaction 18O$ + $208Pb at 85MeV bombarding energy and studied with the Euroball IV array. Their high-spin level schemes have been built from the triple $ \gamma$ -ray coincidence data and $ \gamma$ - $ \gamma$ angular correlations have been analyzed in order to assign spin and parity values to many observed states. The proposed configurations involve proton excitations from three sub-shells located close to the Fermi levels, $ \pi$ p 3/2 , $ \pi$ f 5/2 , and $ \pi$ g 9/2 , the $ \nu$ d 5/2 neutron acting as a spectator. The residual $ \pi$ $ \nu$ interactions are extracted from the multiplets of states resulting from the $ \pi$ p 3/2 $ \nu$ d 5/2 and $ \pi$ f 5/2 $ \nu$ d 5/2 configurations. The empirical values of the latter are discussed and compared to those known in two similar configurations having j p = j n with l p = l n + 1 , where the role of the tensor force had been highlighted.  相似文献   

16.
The followingg-factors have been derived from time integral measurements of γ-γ angular correlations in the static magnetic hyperfine field of magnetized gadolinium metal probes:156Gd:g(4 1 + )=+0.310(19)g(6 1 + )=+0.25(21)g(4 3 + , 1511 keV)=+0.809(27)158Gd:g(4 1 + )=+0.409(15). The 5.35d 156Tb sources were produced by the reaction156Gd(d, 2n)156Tb in our cyclotron. A carrier-free 150y 158Tb source was obtained from ISOLDE/CERN. In comparison with the precisely knowng-factors of the 2 1 + states,g(2 1 su+ ,156Gd) =+0.386(4) andg(2 1 + ,158Gd)=0.381(4), we observe a large reduction for the156Gd 4 1 + state whereasg increases slightly for158Gd. The half-life of the 4 1 + state of158Gd was remeasured as158Gd:T 1/2(4 1 + )=148(2) ps. A measurement of the rotation in the 4 3 + state of156Gd in external magnetic fields of various strengths up toB ext=9.5 T did not confirm the anomalous dependence of the magnetic hyperfine field in gadolinium metal on the external field, which has been reported by Persson et al. [29].  相似文献   

17.
In the framework of the GBAR (Gravitational Behaviour of Antihydrogen at Rest) experiment, cross sections for antihydrogen ion ( \(\bar {\mathrm {H}}^{+}\) ) production in collisions between antiprotons ( \(\bar {\mathrm {p}}\) ) and excited positronium atoms (Ps), with intermediate production of antihydrogen ( \(\bar {\mathrm {H}}\) ), have been computed using a perturbative theory, namely Continuum Distorted Wave - Final State (CDW-FS). The results suggest to use antiprotons at 1, 2 or 6 keV with, respectively, Ps(3p,3d), Ps(2p) or no Ps excitation. A simulation using these cross sections is under development to investigate the reaction chamber geometry and the parameters of the different beams (positrons, antiprotons and laser). This simulation, focusing on Ps(3d), predicts at least one \(\bar {\mathrm {H}}^{+}\) ion per pulse of 3·106 \(\bar {\mathrm {p}}\) at 1 and 6 keV, and highlights both the interest of positronium excitation and the need for short pulses of particles.  相似文献   

18.
In the presence of an electric dipole coupling of $\overline {tt} $ to a photon, and an analogous ‘weak’ dipole coupling to the Z, CP violation in the process e+e? $\overline {tt} $ results in modified polarization of the top and the anti-top. This polarization can be analyzed by studying the angular distributions of decay charged leptons when the top or anti-top decays leptonically. Analytic expressions are presented for these distributions when eithert or $\overline t $ decays leptonically, including $\mathcal{O}$ s) QCD corrections in the soft-gluon approximation. The angular distributions are insensitive to anomalous interactions in top decay. Two types of simple CP-violating polar-angle asymmetries and two azimuthal asymmetries, which do not need the full reconstruction of thet or $\overline t $ , are studied. Independent 90% CL limits that may be obtained on the real and imaginary parts of the electric and weak dipole couplings at a linear collider operating at √ s = 500 GeV with integrated luminosity 500 fb? and also at √s = 1000 GeV with integrated luminosity 1000 fb? have been evaluated. The effect of longitudinal electron and/or positron beam polarizations has been included.  相似文献   

19.
A chiral-motivated \({\bar{K}N - \pi\Sigma - \pi\Lambda}\) potential was constructed and used in Faddeev calculations of different characteristics of \({\bar{K}NN - \pi\Sigma N}\) system. First of all, binding energy and width of the K ? pp quasi-bound state were newly obtained. The low-energy K ? d scattering amplitudes, including scattering length, together with the 1s level shift and width of kaonic deuterium were calculated. Comparison with the results obtained with the phenomenological \({\bar{K}N - \pi\Sigma}\) potential demonstrates that the chiral-motivated potential gives more shallow K ? pp state, while the characteristics of K ? d system are less sensitive to the form of \({\bar{K}N}\) interaction.  相似文献   

20.
The hfs in the 72 P 3/2-state of133Cs has been investigated by optical double resonance in a strong magnetic field. From the positions of the magnetic dipole transitions Δm j =± 1, Δm i =0 the magnetic hfs coupling con slanta (72 P 3/2)=16.591(25) MHz and theg j -factorg j (72 P 3/2)=1.33410(15) could be derived. Contrarily to recent measurements,g j agrees well with the value calculated from the Lande formula.  相似文献   

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