A mesonic decay in nuclei and the occupation number

Focusing on systems of many identical particles, Chapter 2 introduces appropriate operators to describe their properties in terms of Schwinger’s “measurement symbols.” The latter are then factorized into “creation” and “annihilation” operators, whose fundamental properties and commutation/anticommutation relations are derived in conjunction with the Pauli exclusion principle. This leads to “second quantization” with the Hamiltonian, number, linear and angular momentum operators expressed in terms of the annihilation and creation operators, as well as the occupation number representation. Finally, the concept of coherent states, as eigenstates of the annihilation operator, having minimum uncertainty, is introduced and discussed in detail.

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Predictors of contraceptive method discontinuation among adolescent and young women in three West African countries (Burkina Faso, Mali, and Niger)

BMC Women s Health ◽

10.1186/s12905-021-01326-0 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Adja Mariam Ouédraogo ◽

Adama Baguiya ◽

Rachidatou Compaoré ◽

Kadari Cissé ◽

Désiré Lucien Dahourou ◽

...

Keyword(s):

Marital Status ◽

Burkina Faso ◽

Young Women ◽

Contraceptive Method ◽

Occupation Number ◽

Education Level ◽

Demographic And Health Surveys ◽

Contraceptive Methods ◽

Unintended Pregnancies ◽

Contraceptive Discontinuation

Abstract Background The effective use of contraception among adolescents and young women can reduce the risk of unintended pregnancies. However, the prevalence of contraceptive use remains low in this age group. The objective of this study was to estimate the rate of contraceptive method discontinuation among adolescents and young women and to identify its associated factors in Burkina Faso, Mali, and Niger. Method This was a secondary analysis of data from Demographic and Health Surveys of Burkina Faso (2010), Mali (2012–2013), and Niger (2012). The dependent variable was the time to discontinuation of contraceptive methods. Independent variables were represented by sociodemographic, socioeconomic, and cultural characteristics. Mixed-effects survival analysis with proportional hazards was used to identify the predictors. Results A total of 2,264 adolescents and young women aged 15 to 24 years were included in this analysis, comprising 1,100 in Burkina Faso, 491 in Mali, and 673 in Niger. Over the last five years, the overall contraceptive discontinuation rate was 68.7% (50.1% in Burkina Faso, 59.6% in Mali, and 96.8% in Niger). At the individual level, in Burkina Faso, occupation (aHR = 0.33), number of living children (aHR = 2.17), marital status (aHR = 2.93), and region (aHR = 0.54) were associated with contraceptive discontinuation. Except for education and marital status, we found the same factors in Mali. In Niger, a women's education level (aHR = 1.47) and her partner (aHR = 0.52) were associated with discontinuation. At the community level, the region of origin was associated with discontinuation of contraceptive methods. Conclusion Most adolescents and young women experienced at least one episode of discontinuation. Discontinuation of contraceptive methods is associated with the level of education, occupation, number of children, marital status, and desire for children with the spouse. Promotion of contraceptive interventions should target adolescents, young women, and their partners, as well as those with a low education level or in a union.

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np-Pair Correlations in the Isovector Pairing Model

Symmetry ◽

10.3390/sym13081405 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1405

Author(s):

Feng Pan ◽

Yingwen He ◽

Lianrong Dai ◽

Chong Qi ◽

Jerry P. Draayer

Keyword(s):

Binding Energy ◽

Occupation Number ◽

Mean Field ◽

Energy Difference ◽

Binding Energies ◽

Pair Correlations ◽

Isospin Symmetry Breaking ◽

Pairing Model ◽

Proton Pairing ◽

Spin Basis

A diagonalization scheme for the shell model mean-field plus isovector pairing Hamiltonian in the O(5) tensor product basis of the quasi-spin SUΛ(2) ⊗ SUI(2) chain is proposed. The advantage of the diagonalization scheme lies in the fact that not only can the isospin-conserved, charge-independent isovector pairing interaction be analyzed, but also the isospin symmetry breaking cases. More importantly, the number operator of the np-pairs can be realized in this neutron and proton quasi-spin basis, with which the np-pair occupation number and its fluctuation at the J = 0+ ground state of the model can be evaluated. As examples of the application, binding energies and low-lying J = 0+ excited states of the even–even and odd–odd N∼Z ds-shell nuclei are fit in the model with the charge-independent approximation, from which the neutron–proton pairing contribution to the binding energy in the ds-shell nuclei is estimated. It is observed that the decrease in the double binding-energy difference for the odd–odd nuclei is mainly due to the symmetry energy and Wigner energy contribution to the binding energy that alter the pairing staggering patten. The np-pair amplitudes in the np-pair stripping or picking-up process of these N = Z nuclei are also calculated.

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Statistical physics as an approximate method in quantum mechanics of many particle systems in the occupation number representation

Soviet Physics Journal ◽

10.1007/bf00898323 ◽

1989 ◽

Vol 32 (10) ◽

pp. 860-865

Author(s):

A. N. Kushnirenko

Keyword(s):

Quantum Mechanics ◽

Approximate Method ◽

Statistical Physics ◽

Occupation Number ◽

Particle Systems ◽

Number Representation

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Mesonic Decay of aH14Nucleus

Physical Review ◽

10.1103/physrev.99.1046 ◽

1955 ◽

Vol 99 (3) ◽

pp. 1046-1047 ◽

Cited By ~ 8

Author(s):

Ö Haugerud ◽

S. O. Sörensen

Keyword(s):

Mesonic Decay

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π-mesonic decay of the hypertriton

Physical Review C ◽

10.1103/physrevc.57.1595 ◽

1998 ◽

Vol 57 (4) ◽

pp. 1595-1603 ◽

Cited By ~ 65

Author(s):

H. Kamada ◽

J. Golak ◽

K. Miyagawa ◽

H. Witała ◽

W. Glöckle

Keyword(s):

Mesonic Decay

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A LINEAR CORRELATION OF PROTON CHEMICAL SHIFTS IN SOME ALKYL CHLORIDES AND HYDROCARBONS WITH THE OCCUPATION NUMBER OF THE HYDROGEN ORBITALS

Canadian Journal of Chemistry ◽

10.1139/v65-444 ◽

1965 ◽

Vol 43 (12) ◽

pp. 3188-3192 ◽

Cited By ~ 11

Author(s):

F. Hruska ◽

G. Kotowycz ◽

T. Schaefer

Keyword(s):

Linear Correlation ◽

Occupation Number ◽

Chemical Shifts ◽

The Self ◽

Starting Values ◽

Occupation Numbers ◽

Self Consistent ◽

Consistent Group ◽

Proton Chemical Shifts ◽

Group Orbital

A linear correlation exists between the proton shifts of some alkyl chlorides and some hydrocarbons and the occupation numbers of the hydrogen 1s orbitals in the C—H bonds. The occupation numbers are those given by the self-consistent group orbital and bond electronegativity method. The application of this correlation to the prediction of starting values for occupation numbers, to the derivation of bond anisotropies in ethylene and acetylene, and to the prediction of hydrogen-bonded shifts of C—H protons is discussed.

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