4,256 research outputs found
Radiative proton-antiproton annihilation and isospin mixing in protonium
A detailed analysis of the radiative annihilation is made in the
framework of a two-step formalism, the annihilates into meson
channels containing a vector meson with a subsequent conversion into a photon
via the vector dominance model (VDM). Both steps are derived from the
underlying quark model. First, branching ratios for radiative protonium
annihilation are calculated and compared with data. Then, details of the
isospin interference are studied for different models of the initial protonium
state and also for different kinematical form factors. The isospin interference
is shown to be uniquely connected to the mixing in the
protonium state. Values of the interference terms directly deduced from data
are consistent with theoretical expectations, indicating a dominant
component for the and a sizable component for the
protonium state. The analysis is extended to the
transition, where the large observed branching ratio remains unexplained in the
VDM approach.Comment: 34 pages, RevTeX, 2 figures, to appear in Phys. Rev. C; typos
correcte
Li spectrum from Li fragmentation
A recently developed time dependent model for the excitation of a nucleon
from a bound state to a continuum resonant state in the system n+core is
applied to the study of the population of the low energy continuum of the
unbound Li system obtained from Li fragmentation. Comparison of
the model results to new data from the GSI laboratory suggests that the
reaction mechanism is dominated by final state effects rather than by the
sudden process, but for the population of the l=0 virtual state, in which case
the two mechanisms give almost identical results. There is also, for the first
time, a clear evidence for the population of a d resonance in
Li.Comment: 15 pages, 4 figures, 3 tables. Accepted for publication in
Nucl.Phys.
Reaction and break-up cross sections of 11Li at 0.8 and 0.28 GeV/u
In this paper we calculate reaction and breakup cross sections for the two- neutron halo nucleus of Li using the optical limit of Glauber theory. Calculations are presented and compared to experimental data at 0.8 and 0.28 GeV/u on a series of targets. The Li nucleus is described as a three-body system, a core plus two neutrons, with a phenomenological neutron-core potential and a density dependent neutron-neutron interaction of zero range. Three different wave functions are constructed which have different and two-neutron components but correspond to the same binding energy close to the experimental value. We show that the agreement with all the experimental observables is achieved only if the 11Li wave function contains about 30% of configuration
Identitas Lokal Vs Sentralisasi Udara Radio Berjaringan di Kota Makassar
The purpose of the research are to know the comparison between the local identity and national identity of radio network in Makassar: to know the efforts by the radio network in representing local identity. The research is in Makassar, which is in Radio Delta FM, Smart FM, Prambors FM and I-Radio. The methods that used in this research is descriptive qualitative. Informants in this study were selected through purposive sampling technique based on certain criteria. The data collection methods in this research are interview, observation, documentation, and referencing to some previous studies and literatures on this subject. The collected data are analyzed through Milles and Huberman's interactive model. The results of this study shows the comparison between the local identity and national identity of the radio network in Makassar has already suitable to the standard of SSJ regulation only in the duration of airing. Whereas in terms of programs, most of the radio network tends to play more songs with an interludes of common topics without any local content. This research also shows that there are differences in the efforts to represent the local identity of each radio network. Delta FM Makassar and Prambors FM Makassar represented their locality through duration of airing, while Smart FM Makassar and I-Radio Makassar also representing them through local content. Tujuan studi ini adalah untuk mengetahui perbandingan antara identitas lokal dan identitas nasional radio berjaringan di Kota Makassar; untuk mengetahui upaya yang dilakukan radio berjaringan dalam merepresentasikan identitas lokalnya. Studi ini dilaksanakan di Kota Makassar, yaitu di Radio Delta FM, Smart FM, Prambors FM dan I-Radio. Metode yang digunakan dalam studi ini adalah deskriptif kualitatif. Informan dalam studi ini dipilih melalui teknik purposive sampling berdasarkan kriteria-kriteria tertentu. Metode pengumpulan data yang dilakukan dalam studi ini adalah wawancara, observasi, dokumentasi, dan studi kepustakaan dengan mengkaji buku-buku, hasil studi, dan literatur-literatur lain yang berhubungan dengan studi tersebut. Data yang dikumpulkan kemudian dianalisis dengan menggunakan Model Analisis Interaktif Miles dan Huberman. Hasil studi ini menunjukkan bahwa perbandingan antara identitas lokal dan identitas nasional radio berjaringan di Kota Makassar sudah sesuai dengan standar regulasi SSJ dalam hal durasi siaran saja. Sedangkan dari segi program siaran, sebagian besar radio berjaringan tersebut cenderung lebih banyak memutarkan lagu dengan selingan topik ringan tanpa adanya muatan lokal. Studi ini juga menunjukkan bahwa terdapat perbedaan upaya yang dilakukan dalam merepresentasikan identitas lokal masing-masing radio berjaringan. Delta FM Makassar dan Prambors FM Makassar merepresentasikan lokalitasnya melalui total jam siaran lokal, sedangkan Smart FM Makassar dan I-Radio Makassar merepresentasikannya melalui jam siaran dan muatan konten lokal
Particle-particle random phase approximation applied to Beryllium isotopes
This work is dedicated to the study of even-even 8-14 Be isotopes using the
particle-particle Random Phase Approximation that accounts for two-body
correlations in the core nucleus. A better description of energies and
two-particle amplitudes is obtained in comparison with models assuming a
neutron closed-shell (or subshell) core. A Wood-Saxon potential corrected by a
phenomenological particle-vibration coupling term has been used for the
neutron-core interaction and the D1S Gogny force for the neutron-neutron
interaction. Calculated ground state properties as well as excited state ones
are discussed and compared to experimental data. In particular, results suggest
the same 2s_1/2-1p_1/2 shell inversion in 13Be as in 11Be.Comment: to appear in Phys. Rev.
Effects of Biochar Amendment and Arbuscular Mycorrhizal Fungi Inoculation on Availability of Soil Phosphorus and Growth of Maize
A glasshouse experiment was conducted to study the interactive effects of biochar amendment and arbuscular mycorrhizal fungi (AMF) inoculation on phosphorus uptake by maize (Zea mayze L.) grown on a calcareous soil of Kupang, East Nusa Tenggara. The biochar was made of cow dung. Twelve treatment combinations (three biochars levels of 0, 5 and 7.5 g/kg of soil, and four AMF inoculation levels of 0, 5, 10 and 15 spores / kg of soil) were arranged in a completely randomized block design with three replicates. Results of the study showed that at 8 weeks after transplanting, the biochar and mycorrhizal treatments increased the availability soil phosphorus and phosphorus uptake by maize. Application 4.5 and 7.5 g biochar/kg of soil combined with inoculation of 10-15 AMF spores / kg of soil provided to high value of phosphorus uptake by maize. Application of biochar alone, however, did not significantly improve maize growth and phosphorus uptake by maize
Non-minimal Einstein-Yang-Mills-Higgs theory: Associated, color and color-acoustic metrics for the Wu-Yang monopole model
We discuss a non-minimal Einstein-Yang-Mills-Higgs model with uniaxial
anisotropy in the group space associated with the Higgs field. We apply this
theory to the problem of propagation of color and color-acoustic waves in the
gravitational background related to the non-minimal regular Wu-Yang monopole.Comment: 14 pages, no figure
Gaming the no-choice system? School choice and persistent educational inequality in China
The admission policy for public compulsory schools in China is neighbourhood enrolment which entitles children to attend their assigned local school free of charge, and this policy has been rigorously implemented in recent years to prevent school choice. However, driven by disparities in education provision, parents still find ways to make choices in an officially no-choice public educational system. Inspired by a Bourdieusian framework, this study uses the China Family Panel Studies (CFPS) to explore the relationships between family capital, school choice, and the quality of the school pupils attend. We seek to offer a lens to explore the prevalence and patterns of school choice, and its impact on constructing educational stratification. Findings suggest persistent inequality in the no-choice policy context and that children from more privileged families are more likely to study in higher performing schools
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