عنوان البحث(Papers / Research Title)
LargeScale Shell Model Calculations of 134,136Sn, 134,136Te around doublymagic 132Sn
الناشر \ المحرر \ الكاتب (Author / Editor / Publisher)
فؤاد عطية مجيد
Citation Information
فؤاد,عطية,مجيد ,LargeScale Shell Model Calculations of 134,136Sn, 134,136Te around doublymagic 132Sn , Time 10/08/2016 09:11:35 : كلية التربية للعلوم الصرفة
وصف الابستركت (Abstract)
دارسة أنموذج القشرة لبعض النوى القريبة من القلب 132Sn
الوصف الكامل (Full Abstract)
1 INTRODUCTION The nuclei around double closures 132Sn becomes recently important for both experimental and theoretical study, nuclei around doubly closed shells play a special role. In fact, they yield direct information on the two basic ingredients of the model: single particle (SP) energies and matrix elements of the effective interaction [1] . This makes them the best testing ground for realistic shellmodel calculations where the effective interaction is derived from the free nucleonnucleon (NN) potential, as well as to test theoretical shell model description of nuclear structure in this region. Structure properties of some of these nuclei are important inputs for astrophysical r process model calculations [2]. Some of the structure issues recently studied are the decrease in the spinorbit interaction at N ? Z = 32 above the Z = 50,N = 82 double shell closure [3]. Shell model calculations were performed by F.A. Majeed to study neutron rich eveneven 132136Te using a realistic interaction derived from CDBonn nucleonnucleon potential for the positive and negative parity states and the transition rates B(E2;0g.s+?21+) the calculated results were compared with recently available experimental data[4]. Shell model calculation were performed by Brown et al. to study magnetic moments for 130132Sn and 132134Te isotopes due to the development of neutronrich radioactive beams at the Holifield Radioactive Ion Beam Facility which stimulated experimental and theoretical activity in heavy Sn and Te isotopes[5]. The binding energies, excitation energies, transition probabilities and magnetic moments were studied by M. Saha. Sarkar for neutronrich isotones N=8284 nuclei near 132Sn the results theoretical calculations are compared with experimental data [6]. Recently we have performed large
scale shell model calculations to study energy levels and reduced transition probabilities B(E2) for eveneven 5466Fe neutron rich isotopes by employing GXPF1, GXPF1A, KB3G and FPD6 effective interactions [7] and very recently we had performed a restricted nocore shell model calculations to study the lowlying energy levels for some selected light halo nuclei lies in the pshell using spsdpf model space with wbt effective interaction [8]. The aim of the present work is to study the level energies including the high J?values, binding energy and reduced transition probabilities B(E2;01+?21+) for 134Sn, 134,136Te and B(E2;41+?61+) for 136Sn by means of largescale shell model calculations without any restrictions by employing jj56pna, jj56pnb, kh5082, cw5082, jj56cdb and khhe effective interactions using the recent shell model code Nushellx@MSU [9] and compare the theoretical results with the most recent experimental data.
2 Shell Model Calculations
The independentparticle Hamiltonian of an Aparticle system can be written in terms twoparticle interactions as [10]. H=?_(k=1)^A?T_k + ?_(k=1)^A??_(l=k+1)^A??W((r_k ) ? ,(r_l ) ? ) (1)?
where W((r_k ) ? ,( r_l ) ? ) is the twobody interaction between the kth and lth nucleons. Choosing an average potential U(rk), the Hamiltonian becomes [10] .
H=?_(k=1)^A??[T_k ?+U(r_k)]+ ?_(k=1)^A??_(l=k+1)^A??W((r_k ) ? ,(r_l ) ? )?_(k=1)^A?U(r_k ) (2)?
3 Results and Discussions
3.1 Excitation Energies
In order to perform large scale shell model calculation in this mass region the core 132Sn for all nuclei under study with 2,4 particles outside the core for 134Sn, 136Sn, 134Te and 136Te respectively. Figure 1 present comparison between our theoretical work and experimental for 134 Sn isotope. Our theoretical work predicts the differences between 0+ and 2+ at 0.846 MeV, 0.846 MeV, 1.245 MeV, 1.245 MeV, 0.778 MeV and 1.636 MeV. By employing the effective interactions jj56pna ,jj56pnb, kh5082, cw5082, jj56cdb and khhe respectively .By comparing them with the experimental differences values is 0.726 MeV. We obtained the best agreement at jj56cdb interaction.
3.2 Reduced Transition Probabilities The electromagnetic transition probability B(E2;01+?21+) and B(E2;41+?61+) values are calculated for model space and for each interaction are compared with experimental data for 134Sn and 134,136 Te and 136Sn respectively. By taking the average value of the effective charge for proton and neutron. Table 1 presents the comparison between the calculated reduced transition probabilities for all interactions and compared it with the experimental data .for 134Sn taking average value of the effective charge for proton and e?eff =1.6 ,e?eff =0.6. We obtained the best agreement at jj56cdb interaction. This interaction is successful in describing the energy levels and Reduced Transition Probabilities for 134Sn. For 136Sn nucleus taking average value of the effective charge for proton and e?eff =0.2 ,e?eff =1.6 for each interactions for each interactions and compared it with the experimental the effective interactions jj56pna and jj56pnbto the are the nearest to the experimental value .for 134Te nucleus taking average value of the effective charge e?eff =0.8, e?eff =0.2. The best agreement with the experimental value at kh5082 interaction.
The 136Te isotope taking average value of the effective charge for proton and e?eff =0.4, e?eff =0.4 for each interactions. We obtained the best agreement at cw5082 interaction.
Conclusions
Unrestricted largescale shell model calculations were performed for to study the energy levels, reduced electric transition probabilities and binding energy for 134,136 Sn, 134,136 Te isotopes by employing the model space jj56pn with jj56pna, jj56pnb, kh5082, cw5082, jj56cdb and khhe effective interactions by using the shell model code Nushellx@MSU. The comparison of the calculated lowlying energy levels with the most recent experimental data and transition strengths B(E2) for these nuclei are in sophisticated agreement with the
تحميل الملف المرفق Download Attached File

