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1.
Two-neutrino double-beta decay of 150Nd to the first 0+ excited state in 150Sm is investigated with the 400-cm3 low-background HPGe detector. Preliminary data analysis for 6843 h shows an excess of events at 333.9 and 406.5 keV. If this excess is assigned to the investigated transition, then its half-life can be estimated at [1.2 ?0.3 +0.5 ±0.4(syst.)]×1020 yr. 相似文献
2.
Two-neutrino-double-beta decay of 150Nd to the first 0+ excited state in 150Sm is investigated with a 400-cm3 low-background HPGe detector. Data analysis for 11320.5 h shows an excess of events at 333.9 and 406.5 keV. This allows us to estimate the half-life of the investigated process as [1.4 ?0.2 +0.4 ±0.3(syst.)]×1020 yr. 相似文献
3.
A. S. Barabash 《Physics of Atomic Nuclei》2003,66(3):458-461
A brief review on the 2νββ decay of 100Mo to the 0+ excited state in 100Ru is performed. A weighted-average half-life value for the decay has been obtained, T1/2 = (6.8 ± 1.2) × 1020 yr. The corresponding average value for the nuclear matrix element was extracted, 0.095 ± 0.009. 相似文献
4.
Careful review of all the evidence makes it clear that at least three states are important at 12.4-MeV excitation in 20Ne (four, if the broad (2+) at 12.5 MeV is included). The three states are 3 - , 0 + , and 1 + (0+). The latter, which is quite strong in 19F (3He, d) singles, is probably the state observed in coincidence with 6.13-MeV γ-rays in 19F(3He, dγ).
Received: 19 August 2002 / Accepted: 28 October 2002 / Published online: 17 January 2003
RID="a"
ID="a"e-mail: fortune@physics.upenn.edu
Communicated by D. Guerreau 相似文献
5.
A.E. Dorokhov E.A. Kuraev Yu.M. Bystritskiy M. Sečanský 《The European Physical Journal C - Particles and Fields》2008,55(2):193-198
We reconsider QED radiative corrections (RC) to the π0→e+e- decay width. One kind of RC investigated earlier has a renormalization group origin and can be associated with the final
state interaction of electron and positron. It determines the distribution of lepton pair invariant masses in the whole kinematic
region. The other type of RC has a double-logarithmic character and is related to almost on-mass-shell behavior of the lepton
form factors. The total effect of RC for π0→e+e- decay is estimated to be 3.2%, and for η→e+e- decay it is 4.3%.
PACS 13.25.Cq; 12.38.Lg; 12.38.-t 相似文献
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8.
M. A. Cardona B. Roussière J. Libert J. Genevey J. Sauvage the ISOCELE ISOLDE Collaborations 《The European Physical Journal A - Hadrons and Nuclei》2007,31(2):141-154
Excited states in 182Os were populated by the β+/EC decay of 182Ir following mass separation. Gamma-ray and conversion electron spectroscopy techniques were employed. Monopole (E0) contributions were determined in transitions populating the ground-state band. A systematic study of the low-spin structures
in the Os isotopes is presented and a detailed analysis in the framework of a microscopic configuration mixing approach is
performed. 相似文献
9.
D.?R.?Zinatulina Ch.?Brian?on V.?B.?Brudanin R.?V.?Vasilyev K.?Ya.?Gromov V.?G.?Egorov C.?Petitjean V.?I.?Fominykh V.?G.?Chumin M.?V.?Shirchenko I.?A.?Yutlandov 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(6):825-828
The energy and time spectra of γ rays emitted during negative-muon capture in 150Sm were studied. The total muon lifetime in 150Sm was measured. The yields of several radioactive isotopes in this reaction were determined. The partial γ-ray yield upon muon capture by a 150Sm nucleus were measured. 相似文献
10.
J. Adam D. D. Bogachenko V. P. Garistov O. K. Egorov T. A. Islamov V. V. Kolesnikov V. I. Silaev A. A. Solnyshkin 《Bulletin of the Russian Academy of Sciences: Physics》2009,73(6):737-740
A possibility that the 0+ state with the energy of 681.3 keV exists in the 160Dy nucleus is discussed. Calculations based on the interacting vector boson model show that in addition to the known 0+ states with the number of bosons n = 2, 5, 6, and 7 there should exist other states with the number of bosons n = 1, 3, 4, and 8 in 160Dy. It is shown that the peak at the energy 681.3 keV, which we experimentally observed in the 160Dy internal conversion electron spectrum, can be ascribed to the 0+ state with the number of bosons n = 1 or n = 8. 相似文献
11.
Gao Xiangdong Chong Sheng Li Zhao Li Hao Zhang 《The European Physical Journal C - Particles and Fields》2008,55(2):317-324
The observation of three events for the decay Σ+→pμ+μ- with a dimuon invariant mass of 214.3 ± 0.5 MeV by the HyperCP Collaboration implies that a new particle X may be needed
to explain the observed dimuon invariant mass distribution. We show that there are regions in the SUSY-FCNC parameter space
where the A0
1 in the NMSSM can be used to explain the HyperCP events without contradicting all the existing constraints from the measurements
of the kaon decays, and the constraints from K0–K̄0 mixing are automatically satisfied once the constraints from kaon decays are satisfied.
PACS 14.80.Cp; 12.60.Jv; 14.20.Jn 相似文献
12.
T.M. Aliev S. Rai Choudhury A.S. Cornell Naveen Gaur 《The European Physical Journal C - Particles and Fields》2007,49(3):657-664
Standard model (SM) CP asymmetries in B→Kℓ+ℓ- are expected to be very small. This feature could help in the understanding of new physics scenarios which predict the existence
of CP odd phases in various Wilson coefficients. In this paper we have analyzed the B→Kℓ+ℓ- decay in scenarios beyond the SM where the Wilson coefficients have new CP odd phases. The sensitivity of the CP asymmetries
on these new weak phases is discussed.
PACS 13.20.He; 12.60.-i; 13.88.+e 相似文献
13.
Experimental limits on the half-lives with respect to the (0ν+2ν) double-beta decay of 130Te to excited states in 130Xe are obtained by using low-background HPGe detectors. At a 90% C.L., they are 1.6×1021, 2.7×1021, and 2.3×1021 yr for transitions to the 2 1 + , 2 2 + , and 0 1 + levels, respectively. 相似文献
14.
A. D. Pogrebnyak S. N. Bratushka L. V. Malikov N. Levintant N. K. Erdybaeva S. V. Plotnikov B. P. Gritsenko 《Technical Physics》2009,54(5):667-673
The surface layer of an equiatomic TiNi alloy, which exhibits the shape memory effect in the martensitic state, is modified
with high-dose implantation of 65-keV N+ ions (the implantation dose is varied from 1017 to 1018 ions/cm2). TiNi samples are implanted by N+, Ni+-N+, and Mo+-W+ ions at a dose of 1017–1018 cm−2 and studied by Rutherford backscattering, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction
(glancing geometry), and by measuring the nanohardness and the elastic modulus. A Ni+ concentration peak is detected between two maxima in the depth profile of the N+ ion concentration. X-ray diffraction (glancing geometry) of TiNi samples implanted by Ni+ and N+ ions shows the formation of the TiNi (B2), TiN, and Ni3N phases. In the initial state, the elastic modulus of the samples is E = 56 GPa at a hardness of H = 2.13 ± 0.30 GPa (at a depth of 150 nm). After double implantation by Ni+-N+ and W+-Mo+ ions, the hardness of the TiNi samples is ∼2.78 ± 0.95 GPa at a depth of 150 nm and 4.95 ± 2.25 GPa at a depth of 50 nm;
the elastic modulus is 59 GPa. Annealing of the samples at 550°C leads to an increase in the hardness to 4.44 ± 1.45 GPa and
a sharp increase in the elastic modulus to 236 ± 39 GPa. A correlation between the elemental composition, microstructure,
shape memory effect, and mechanical properties of the near-surface layer in TiNi is found. 相似文献
15.
16.
M. Gerçeklioglu 《The European Physical Journal A - Hadrons and Nuclei》2005,24(2):185-191
In this work, the effect of spin-quadrupole forces on the 0+ sates in 158Gd has been investigated. For this purpose, the model Hamiltonian including monopole pairing, quadrupole-quadrupole and spin-quadrupole forces has been diagonalized in one phonon basis. In conclusion, for the distribution of energies of the states and their collective properties, fairly good results have been obtained. 相似文献
17.
S. Singh R. Chandra P. K. Rath P. K. Raina J. G. Hirsch 《The European Physical Journal A - Hadrons and Nuclei》2007,33(4):375-388
The two-neutrino double-beta decay of 124, 126Xe , 128, 130Te , 130, 132Ba and 150Nd isotopes is studied in the Projected Hartree-Fock-Bogoliubov (PHFB) model. Theoretical 2ν β-β- half-lives of 128, 130Te , and 150Nd isotopes, and 2ν β+β+ , 2ν β+
EC and 2ν ECEC for 124, 126Xe and 130, 132Ba nuclei are presented. Calculated quadrupolar transition probabilities B(E2 : 0+ → 2+) , static quadrupole moments and g -factors in the parent and daughter nuclei reproduce the experimental information, validating the reliability of the model
wave functions. The anticorrelation between nuclear deformation and the nuclear transition matrix element M
2ν is confirmed. 相似文献
18.
19.
The ground-state band in 110Mo has been observed for the first time. The band, comprising six levels, has been populated in the spontaneous fission of 248Cm and studied by means of prompt
-ray spectroscopy using the EUROGAM2 array. The ratio
suggests that the deformation of 110Mo is smaller than that in 108Mo but may stabilize at higher neutron number, where an oblate shape is expected. The new data suggests that the deformation of Sr and Zr isotopes decreases above neutron number N = 64.Received: 23 February 2004, Published online: 2 June 2004PACS:
23.20.Lv
transitions and level energies - 21.60.Cs Shell model - 25.85.Ca Spontaneous fission - 27.60. + j
相似文献
20.
S. Kumari L. K. Jha B. N. Roy 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,55(1):93-97
Electron impact double ionization cross-sections of Sc+ions have been
calculated in the binary encounter approximation (BEA). Accurate expression
of σΔE(cross-section for energy transfer ΔE) and
Hartree-Fock velocity distributions for the target electrons have been used
throughout the calculations. Direct double ionization from ejection of 3d
and 4s electrons has been investigated in the modified double binary
encounter model incorporating the focusing action of the target ion on the
incident electron. The identification of the 3p shell whose ionization
provides a major contribution to double ionization through
ionization-autoionization is an interesting aspect of the present
investigation. The theoretical results show satisfactory agreement with the
experimental observations. 相似文献