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1.
The weak fragments of the 3p1/2, 3p3/2, 2f5/2, 2f7/2 and 1i13/2 proton states of209Bi as seen in the208Pb (3He,d) reaction can be explained with the coupling of the renormalised proton states and the vibrational states of208Pb. The energies of the zerothorder proton shell-model states as well as the collective admixtures of the weak fragmented proton states of209Bi have been deduced from the core-particle coupling model.  相似文献   

2.
The distribution of the discrete 1h 9/2, 2f 7/2, 1i 13/2 and 2f 5/2 proton states of209Bi and 2g 9/2, 1i 11/2, 1j 15/2 and 2g7/2 neutron states of209Pb have been obtained within the particle-vibration coupling model calculation and compared with the experimental datas baising on the most recent high resolution stripping reaction on208Pb using 480 MeV12C projectile. The optimised shell model energies arising from the core-polarisation effect have profound influence for both the study of the structures of the high spin continuum shell model states of208Pb and stability of superheavy nuclei.  相似文献   

3.
States in207Pb are observed in the proton decay of the lowest 5? and 4? analog resonances in208Bi. Evidence is given that one group of these states corresponds to the206Pb(2ü, 0.8)?g 9/2 and208Pb(3?, 2.6)?p 3 2/?1 multiplets.  相似文献   

4.
The quadrupole as well as the octopole vibrational states of206Pb are coupled to the 2g 9/2, 1i 11/2 and 1j 15/2 neutron states to explain the fragmentation of 1j 15/2 state in207Pb as observed in the206Pb(d,p) reaction. The structures of weak fragmented 1j 15/2 states are deduced through the particle-core coupling scheme.  相似文献   

5.
The decay properties of theJ π=1/2+,E exc=1,098 keV state in203Bi were studied. The state was populated via the204Pb(p, 2n) reaction and the activity was studied with the ion guide isotope separator on-line system IGISOL. The half-life of the 1/2+ state was measured to beT 1/2=303 ±5 ms. From this value the partial half-lives of the three depopulating branches 1/2+ →7/2? (E3), 1/2+→5/2? (E3 +M2) and 1/2+→9/2 g.s. ? (M4) were deduced. Since all the transitions are configuration forbidden in first order, a detailed study of second-order shell-model configuration mixing could be performed.  相似文献   

6.
Theγ-decay of levels in21Ne up to 10 MeV excitation energy has been investigated byn — γ coincidence measurements initiated with the18O(α, nγ) reaction at 12, 13, 14.5 and 15.4 MeV bombarding energies. Spin(-parity) assignments of excited states are obtained by combining then — γ angular correlation measurements performed atE α=11, 11.82 and 13.6 MeV with a consideration of lifetimes, neutron penetrabilities of the unbound states, and information from the mirror nucleus21Na. The resulting values of Ex[keV]?J π are as follows: 4525-5+, 4686-3+, 5431-7+, 5549-3+, 5819-7?, 6175-7+, 6268-9+, 6550-9, 6639-9, 7006-7+, 7041-9, 7356-7 or 9, 7422-11(?), 7648-7+, 7981-11 or (7+), 8154-9, 8240-11, 8664-9? or 11 or 13?, 9401-13?, 9867-13? or 15+, 9941-13? or 15 or 17+. The assignment of mirror levels in21Ne —21Na has been extended to the 6175 keV level of21Ne. Excitation energies, electromagnetic properties, Gamow?Teller matrix elements and spectroscopic factors of positive parity states are compared with the results of shell-model calculations which employ a unifieds—d shell Hamiltonian and the unrestricted configuration space of the 0d 5/2 —1s 1/2—0d3/2 shell. Collective properties contained in shell model wave functions are explored up to the termination of bands atJ=17/2 or 19/2. The spectrum of intruder states in21Ne is observed to begin with a 5628 keV,J π=7/2+ state. The 7422, 8664 and 9401 keV levels are assigned as members of previously established negative-parity rotational bands.  相似文献   

7.
The energies and spectroscopic factors ofJ π=5/2+ states of nucleus91Nb excited via a reaction transferring a proton to the 2d 5/2 orbit of90Zr target state have been calculated. Effective two-body interaction used has been extracted from the experimentally observed two-body energies of (1g 9 2/?1 (n) 2d 5/2(n)), (1g 9 2/?1 (n) 1g 9/2(p)) and (1g 9/2(p)-2d 9/2(n)) multiplets in90Zr,90Nb and92Nb nuclei respectively. Most of the calculated energies and the strengths ofJ π=5/2+ levels have reasonably good counterparts in the experimental spectrum, however the calculation shows about 17% strength lying at 6.8 MeV, without having a confirmed counterpart in the observed level scheme. The reduced transition strengthsB(M1) forM l transitions from 5/2? T>(11/2) state to the various components of 5/2+ T<(=9/2) state have also been reported; but the corresponding experimental values are not available. The main feature of the reduced transition strengths is that theM1 transition to the state at 3.69 MeV is inhibited whereas that to the state at 6.79 MeV is enhanced, the relevant core-configuration, interfering destructively in the former case and constructively in the latter.  相似文献   

8.
Tritons from the reaction139La(d, t)138La atE d=16 MeV were analyzed at eleven reaction angles from 22 ° to 90 ° with a broad-range magnetic spectrograph. TheQ-value of the reaction is ?2522±5 keV. The nine lowest-lying states in138La are interpreted in terms of the shell model configurations (πg 7/2)?1 (vd 3/2)?1, (πg 7/2)?1 (vs 1/2)?1 and (πg 7/2)?2 (πd 5/2)?1(vd 3/2)?1. Seven levels in the energy range of 700–1300 keV are populated byl=5 transitions and are interpreted as coming from the (πg 7/2)?1(vh 11/2)?1 configuration. The ground state of138La is shown to haveJ π=5+. Therefore, beta decay by unique second-forbidden transitions to the 2+ one-phonon states of138Ce and138Ba must be inferred in spite of unusually high logft values of 19.2 and 18.5, respectively.  相似文献   

9.
From 208Pb (p, p’) via isobaric analog resonances in 209Bi , at E x = 6420 keV in the doubly magic nucleus 208Pb , a new state with spin 2- with half the s 1/2 p 3/2 strength and major g 7/2 f 5/2 , d 3/2 f 5/2 fractions is identified. Ten more 2- states up to E x = 7.0 MeV are identified and their structure discussed, among them six states with new spin assignments. The known 6314 1- state is shown to contain almost the entire s 1/2 p 3/2 strength.  相似文献   

10.
All the multipole transition densities between the seven T = 0 states in 12C are calculated with the use of the microscopic 3α resonating-group wave functions which are obtained by dynamically solving the 3α relative motion with the total antisymmetrization taken into account exactly. The observed elastic and inelastic electron scattering form factors for the transition to the 21+, 41+, 02+, 11?and 31? states are well reproduced with no additional effective charge. The existence of a deformed intrinsic state for the 01+, 21+and 41+states is deduced by the analysis of the transition densities between them which are derived by the weak-coupling-type 3α wave functions; the intrinsic density distribution is illustrated. The monopole density distribution of the 02+, 22+ and 11?, states is found to be much longer ranged than that of the 01+, 21+ and 41+ states; the 31? state case is intermediate. On the basis of the transition densities between the 01+, 21+, 02+ and 22+ states, analysis is made of the transition between the shell-like states and the molecule-like states with a large spatial-structure change. Specific, effective nucleon-nucleon interactions are folded into the transition densities here obtained. The evident dependence of the radial shape of the folded nucleon-12C form factors on the choice of the interactions and the multi-step form factors for the excitation of the 02+, 11? and 31? states are discussed.  相似文献   

11.
The fragmentations of the 3s 1/2, 2d 3/2, 2d 5/2 and 1.h 11/2 proton states were deduced using the hole-core coupling model calculation and compared with recent206Pb ( \(\vec d\) ,3He) reaction data. The energies of the proton fragments carrying the main shell-model strengths were used to deduce the radial wave functions of205T1 and207Tl that give rise to charge distributions of these nuclei. From their respective charge distributions, root mean square radii of206Pb and208Pb were extracted.  相似文献   

12.
The magnetic moments of the 5/2 1 + state in117Te at 274.4 keV and of the 7/2 1 + state in121Te at 443.1 keV have been determined asμ exp(5/2+)=?0.75(5)n.m. andμ exp(7/2+)=+0.63(7) n.m., respectively, using the TDPAD method and the reactions115,119Sn(α,2n)117,121Te. An evaluation method is described which provides, in case of the normalized time differential patternR(t) exhibits less than half of an oscillation period, a unique value of the Larmor frequency. The comparison of the measured magnetic moments with Nilsson-, soft rotor Coriolis- as well as core-particle coupling calculations gives valuable hints on the shape dependence of magnetic moments and, consequently, on the deformation of different states in the odd transitional nuclei117–125Te. In the light of the core-particle coupling model the positive parity states of117Te and121Te are interpreted as the members ofΔJ=1 andΔJ=2 bands built on thes 1/2,d 3/2,d 5/2 and g7/2 single-particle states, respectively.  相似文献   

13.
A. WÜEST  P. RUPPER  F. MERKT 《Molecular physics》2013,111(23):1941-1958
The I(3/2u) and I(3/2g) states of Kr+ 2 have been investigated by pulsed-field-ionization zero-kinetic-energy (PFI-ZEKE) photoelectron spectroscopy following (2 + 1′) resonance-enhanced multiphoton excitation via the 0+ g Rydberg state located below the Kr?([4p]55p[1/2]0) + Kr(1S0) dissociation limit of Kr2. From the positions of a large number of vibrational bands in the spectra of the 84Kr2 and 84Kr-86Kr isotopomers, the adiabatic ionization potentials (IP(I(3/2u)) = 112672.4 ± 0.8cm?1, IP(I(3/2g)) = 111 395.0 ± 1.4cm?1), the dissociation energies (D + 0(I(3/2u)) = 368.8 ± 2.0cm?1, D + 0(I(3/2g)) = 1646.2 ± 2.3cm?1) and vibrational constants for both ionic states have been determined. Potential energy curves have been extracted which perfectly reproduce all experimental observations and are accurate over a wide range of energies and internuclear distances. The equilibrium internuclear distances (R + e(I(3/2u)) = 4.11 ± 0.04 Å, R + e(I(3/2g)) = 3.35 ± 0.10 Å) have been derived by comparing the intensity distribution in the PFI-ZEKE photoelectron spectra to calculated Franck-Condon factors. The dissociation energy of the I(3/2g) state and the equilibrium internuclear distance of the I(3/2u) state differ markedly from previously reported values.  相似文献   

14.
An 8+ state has been identified at 4390 keV in the doubly semi-magic nucleus96Zr through the study of angular correlations among the γ radiation which is emitted in the β? decay of the 10 s isomer of96Y. This state probably has the configuration πg 9 2/2 and is populated through a GT decay from the 8+ member of the [πg9/2?νg7/2] multiplet in96Y. The deexcitation indicates that it belongs to a band based on the 0+ state in96Zr.  相似文献   

15.
Matrix elements of the residual interaction in 208Pb are derived from the wavefunctions and the energies of states and configurations in 208Pb. From the experimentally determined wavefunctions of 20 low-lying states in 208Pb with spins Iπ = 2?, 3?, 4?, 5?, 6?, 7? one obtains matrix elements of the effective residual interaction among particlehole configurations defined with respect to the physical ground state of 208Pb. The average value of these matrix elements is about 100 keV. No significant difference in the average value of the off-diagonal matrix elements is found for the different spin values. Also many nondiagonal matrix elements have values approaching the diagonal matrix elements.  相似文献   

16.
Excited states in85Rb have been studied via the82Se(7Li, 4n) reaction by using in-beamγ-ray spectroscopy. On the basis of new experimental data on coincidence relations, angular distributions and linear polarizations of theγ-rays the yrast sequence has been extended up to a 33/2+ level at 7.1 MeV excitation energy. Using the DSA method mean lifetimes have been determined for 9 levels. Above the 21/2+ yrast state 5 fast M1 transitions withB (M 1) ≧0.3 W.u. have been identified. They are interpreted as transitions between recoupled states of the configuration πg9/2ν(g9/2) 8+ ?2 or πg9/2(f 5 2 /?1p 3 2?1 )4+ν(g9/2) 8+ ?2 .  相似文献   

17.
The (2 + 1) photoionization mass spectra of Xe2 molecules are studied in a supersonic jet upon excitation by laser radiation in the energy range 80321.3–77821 cm?1, corresponding to the dissociation of the Xe2 molecule into atoms Xe(1 S 0) + Xe*(6p, 5d). Several vibrational progressions are observed, which are attributed to two-photon transitions of Xe2 from the ground state to the excited states of the O + g, 1g, and 2g symmetries. Based on the analysis of these progressions, the molecular constants of a number of excited states of Xe2 are estimated.  相似文献   

18.
A new optogalvanic technique with an rf discharge was applied to a high-resolution study of the Rydberg states of N2. The Ledbetter band, c4(0)1Πua″(0)1Σg+, and a new visible band, c5(0)1Σu+a″(0)1Σg+, were studied at a Doppler-limited resolution of 0.05 cm?1. A Doppler-free method was also applied to resolve overlapped lines. Precise wavenumbers were determined for the rotational transitions of the two Rydberg bands. The rotational and the centrifugal constants for the lowest Rydberg state, a″(0)1Σg+, were determined to be B0 = 1.913748(42) cm?1 and D0 = 6.088(99) × 10?6 cm?1, where the numbers in parentheses are the standard deviation and apply to the last digits.  相似文献   

19.
Inelastic proton scattering on 206Pb, 207Pb and 208Pb through isobaric analog resonances has been used to study neutron particle-hole excitations with large ground-state γ-branches in these Pb isotopes. Relative (p, p′) cross sections at 90° are extracted for structures selectively excited on the d52, s12and d32?g72 resonances. Interpretation of excitations is 206Pb and 207 Pb in terms of coupling to states in 208Pb is discussed. Branching ratios for 1?states in 208Pb at 4.84, 5.29, 5.94 and 6.31 MeV and the 12+ state in 207Pb at 4.63 MeV are deduced.  相似文献   

20.
Excited states of the doubly-odd nucleus80Br have been studied via the reactions80Se(p, n),80Se(d,2n) and78Se(α, pn) using in-beamγ-ray spectroscopy. A positiveparity level sequence built on aI π=5+ state at 331.04 keV has been found up to spin (10). For this 5+ level de-exciting to the known 5? isomeric state and for the 6+ level at 357.22 keV half-lives of 0.7 and 0.4 ns, respectively, have been determined. Negativeparity states have been observed up to spin (6). For the positive-parity level sequence the configuration (πg 9/2,vg 9/2) and collective excitations are proposed. Some of the negative-parity states are tentatively interpreted as arising from the configurations (πp 3/2,vg 9/2) and (πp 3/2, (vg 9/2) 7 2/3 ).  相似文献   

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