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"Sebuah model fenomenologis sederhana untuk reaksi fotoproduksi kaon yang bekerja dari energi ambang hingga energi tinggi dipelajari dan dikembangkan dalam penelitian ini. Model ini merupakan kombinasi antara model isobarik; yang bekerja pada energi menengah, dan model Regge; yang bekerja pada energi tinggi. Kombinasi dicapai dengan menggunakan formalisme Regge pada amplitudo kanal resonansi t dengan partikel pertukaran K* dan K1. Pada daerah energi menengah, diperoleh efek redaman amplitudo yang lebih baik dibandingkan penggunaan faktor bentuk hadronik. Pada daerah energi tinggi, diperoleh deskripsi yang baik untuk sudut hamburan kecil namun belum diperoleh hasil yang baik untuk sudut sangat kecil, 0.9 ≤ Cos θ ≤ 1.0. Penggunaan model ini untuk integrasi GDH sum rule memberikan kontribusi yang konvergen pada kanal reaksi fotoproduksi kaon.

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Kaon Photo production in the High-Energy RegionA simple phenomenological model for kaon photo production which works from thresh-old up to the high energy region is studied and developed in this work. The model is a combination of isobaric model; which works in the intermediate energy region, and Regge model; which works in the high energy model. The combination is achieved by using Regge formalism for the t-channel resonance amplitude with exchange particles K* and K1. In the intermediate energy region, we obtain better cut-off effect compared to the use of hadronic form factors. In he high energy region, we obtain good results for small scattering angle, but the model still unable to describe the experimental data at very forward angles, 0.9 ≤ Cos θ ≤ 1.0. Integration of the GDH sum rule with this model gives a convergent result for the contributions of kaon photo production to the GDH sum rule."

"Dalam tesis ini telah dipelajari kinematika dan penampang lintang hamburan en→eΣ0. Penampang lintang total tersebut dibagi ke dalam dua bagian yaitu bagian pertukaran foton untuk verteks nγΣ0 dan bagian pertukaran Z0 untuk verteks nZ0Σ0. Kedua bagian tersebut dinyatakan dalam faktor-faktor bentuk kompleks yang dipilih agar dapat dilakukan parametrisasi proses fisika di kedua verteks. Dengan menggunakan data eksperimental untuk peluruhan radiatif Σ0→nγ kedua bagian penampang lintang tersebut, dalam bentuk, 􀜴􀰊 dan 􀜴􀯓, dapat ditentukan di mana, 􀜴􀰊 dan 􀜴􀯓 adalah perbandingan kedua penampang lintang terhadap penampang lintang hamburan elastik en→en. Dengan memperhatikan pendekatan orde pertama, perhitungan dilakukan untuk berbagai energi elektron datang dari 0.3 GeV sampai dengan 1.7 GeV dan berbagai sudut hambur dari 5° sampai dengan 90°. Untuk −q2 kecil 􀜴􀰊 dan 􀜴􀯓 dapat dipandang sebagai fungsi dari q2 saja. Untuk −q2 ≈ 0.3 (GeV)2 didapatkan hasil 􀜴􀰊~10􀬿􀬵􀬸 dan 􀜴􀯓~5􀵈10􀬿􀬶􀬸. Hasil perhitungan ini menunjukkan adanya penindasan yang luar biasa pada proses en→eΣ0 relatif terhadap hamburan elastik en→en dan juga menunjukkan bahwa proses ini didominasi oleh bagian pertukaran photon. Dapat disimpulkan bahwa proses en→eΣ0 dapat terjadi meskipun dengan peluang yang sangat kecil sehingga sangat sulit untuk dapat diamati dalam pengukuran yang dilakukan dewasa ini.

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In this thesis the kinematics and the cross section of the scattering process en→eΣ0 have been studied. The total cross section is divided into two parts, the photon exchange part for nγΣ0 vertex and the Z0 exchange part for nZ0Σ0 vertex. These two parts are expressed in terms of complex form factors which are chosen to parameterize the physics at both vertices. Using the experimental data for the radiative decay Σ0→nγ these cross sections, in term of 􀜴􀰊 and 􀜴􀯓, can be determined, whereas 􀜴􀰊 and 􀜴􀯓 are the ratio of these cross sections to cross section of the elastic scattering en→en. With regard to the first order approximation, the calculations have been performed for different incident electron energies from 0.3 GeV to 1.7 GeV, and different scattering angles from 5° to 90°. For small −q2, 􀜴􀰊 and 􀜴􀯓, can be considered as a function of only q2. For −q2 ≈ 0.3 (GeV)2 the calculation results in 􀜴􀰊~10􀬿􀬵􀬸 and 􀜴􀯓~5􀵈10􀬿􀬶􀬸. These calculations show that there exists a very large suppression in the en→eΣ0 proccess, as compared to the elastic scattering en→en, as well as that this proccess is dominated by the photon exchange part. As a conclusion, the hyperon production process en→eΣ0 may occur but with a very small probability. Therefore the measurement of this process is very difficult at present."

"The National Nuclear Energy Agency of Indonesia (BATAN) has one dedicated spectrometer for inelastic neutron scattering experiments. The instrument is a thermal neutron triple-axis spectrometer known as SN1. SN1 was installed in 1992 in the experimental hall of G. A. Siwabessy Research Reactor, Serpong, Banten. Malfunctions of the hardware and software have prevented the instrument from performing inelastic scattering measurements since 1996. The 2011-2015 five years project has been initiated to revitalize and optimize the SN1. The project serves as a preparation for the utilization of SN1 for the investigation of lattice dynamics, spin wave and magnetic excitations in condensed matters that will be started in 2016. In 2013, SN1 has successfully been repaired and was able to measure phonon dispersion relation of available single crystals, i.e., Cu, pyrolytic graphite (PG), Ge, and Al. In 2015, the first experiment on magnetic excitation to investigate magnon dispersion relation of a known Fe single crystal has been carried out. Standard methods of inelastic scattering measurements, i.e., a constant-energy transfer hω with either fixed final neutron energy Ef = 14.7 meV or fixed incoming neutron energy Ei = 30.59 meV, and a constant momentum transfer Q with fixed incoming neutron energy Ei = 30.59 meV, were applied to measure the low-energy magnetic excitations. For fixed Ef measurement, a 5-cm thick PG filter was set between the sample and the analyzer to eliminate λ/n harmonics. To limit the energy and momentum spreads of the beam, collimations of 40 minutes were applied before and after the sample. The spin waves were measured along the three principal symmetry directions of [00ζ], [ζζ0], and [ζζζ]. The measured magnons were compared to values in reference and were found to be in a good agreement with them. With such accomplishments, we are convinced that SN1 is now ready for its inelastic scattering application and will become one of BATAN’s neutron instrument which is routinely utilized for materials characterization on lattice dynamics and magnetic excitations by local and foreign scientists. Besides reporting the SN1 first measured magnon, the current status of SN1 instrument development will also be presented briefly."

"Hamburan K+p dihitung dengan menggunakan kinematika relativik. Model potensial yang digunakan digambarkan sebagai model pertukaran meson dan hiperon. Penampang lintang differensial dan besaran-besaran spin dihitung. Perhitungan dibandingkan dengan yang menggunakan kinematika nonrelativistik untuk melihat efek relativistik pada energi bervariasi.

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Scattering of K+p is calculated using relativistic kinematics. The Model used is described as a potential model for meson and hiperon. Differential cross section and spin observables calculated. The calculations are compared with using non relativistics to see relativistic effects on energy range."

"Perhitungan hamburan K⁺p dikerjakan dengan menyelesaikan persamaan Lipp- mann-Schwinger untuk matriks-T dalam basis partial wave dalam ruang momentum. Sebagai input diambil model potensial pertukaran hadron orde dua untuk interaksi K⁺p. Model ini melibatkan pertukaran skalar meson σ, vektor meson ρ dan ω, serta hiperon A dan Σ. Hasil yang diperoleh dibandingkan dengan hasil perhitungan yang menggunakan teknik tiga dimensi pada energi yang bervariasi.

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K+p scattering is formulated in partial wave technique in momentum space. The second order contribution of hadron exchange model potential for K+p interaction is being considered to produce the elements of T-matrix as the solutions of Lippmann-Schwinger equation. The interaction contents of me- son scalar-σ, vector-ρ, vector-ω, hyperon-A and hyperon-Σ exchange. The result will be compared with the data of similar reaction produced in three-dimensional technique at several energies."

"Deskripsi hamburan pion nukleon sampai dengan energi kinetik laboratorium pion 660 MeV diperoleh dengan memperluas model yang telah dikembangkan oleh Gross dan Surya. Amplitudo hamburan πΝ di dalam model ini diperoleh dengan menggunakan persamaan Bethe-Salpeter yang direduksi menjadi persamaan integral 3 dimensi dengan mengambil pion on-shebt pada semua keadaan intermediatenya. Kernel persamaan relativistik terdiri dari nukleon. Roper, S11, σ, dan ρ. Suku crossed nukleon, Roper, dan Sit dan suku pertukaran σ dan ρ didekati dengan pendekatan kontak. Dinamika internal eta meson, yang berasal dari peluruhan resonan 811 ikut diperhitungkan di dalam model ini untuk menjelaskan data eksperimen pada energi kinetik laboratorium pion di atas 600 MeV. Eta meson ini juga dipertahankan on-shell pada semua keadaan intermediatenya. Model ini mernberikan hasil pencocokan ke pergeseran fase gelombang S dan P yang cukup balk sampai energi kinetik laboratorium pion 660 MeV.

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The Role of S11 in Pion Nucleon ScatteringDescription of pion nucleon scattering up to 660 MeV pion laboratory kinetic energy obtained by extending pion nucleon scattering model developed previously by Gross and Surya is given in this paper. The πΝ scattering amplitude is obtained by using :3-dimensional reduction of the Bethe-Salpeter equation in which the pion is restricted to its mass shell. The kernel of the equation includes nucleon. Roper. and Su. with their corresponding crossed terms approximated by contact interaction. and contact σ and ρ like exchange terms. The dynamics of eta, which is restricted to its mass shell in all intermediate states, is included in this model to give a good description of experimental data above 600 MeV pion laboratory kinetic energy. Good fits to the S and P wave πΝ phase shifts up to 660 MeV pion laboratory kinetic energy are obtained."