[ABSTRAK
Fenomena halo neutron dalam nuklir digambarkan adanya kemunculan 'ekor' danadanya 'ruang kosong' antara core dan ekor pada distribusi neutron akibat energiikat yang lemah. Metode analisa halo yang dikembangkan oleh V. Rotival dkk [Phys.Rev. C79, 054308 (2009)] untuk menghitung besaran-besaran halo berdasarkan mo-del Hartree-Fock-Bogoulibov (HFB) pada isotop Cr dan isotop Sn menjadi salah sa-tu alternatif untuk mempelajari fenomena halo. Berbeda dengan Rotival dkk, kamimenggunakan model Relativistic Mean Field (RMF) pada penelitian ini. Berbedadengan hasil perhitungan berdasarkan model HFB, kami fokus mengamati perilakuspektrum single particle energy level 1g9~2 terhadap kemunculan halo pada isotopCr. Selain itu, pada penelitian ini kami juga memperlajari dampak dari suku crosscoupling meson ! − , suku-suku tensor dan suku pertukaran elektromagnetik padamodel RMF terhadap kemunculan halo pada isotop Cr dan isotop Sn. Hasil perhi-tungan prediksi kemunculan halo berdasarkan model RMF lebih besar dibandingkandengan hasil perhitungan berdasarkan model HFB (`NhaloeRMF > `NhaloeHFB):

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ABSTRACT
In neutron halo phenomenon, the neutron density displays an unusually extended'tail' and 'empty space' between the core and the tail due to weak binding energy.New analysis method of the halo was developed by V. Rotival, et al.[Phys. Rev. C79,054308 (2009)] in Cr-isotopes and Sn-isotopes, its usually applied with Hartree-Fock-Bogoliubov (HFB) model. Unlike them, we use the model of the Relativistic MeanField (RMF) in this research. We observed dierent behavior at the level 1g9~2 in linewith appearance of halo in Cr-isotopes. Moreover, in this research we also studiedthe eects of cross coupling meson ! − , tensor, and electromagnetic exchange inRMF model appearance of halo in Cr-isotopes and Sn-isotopes. The prediction ofthe existence of halo based on RMF model is greater than the prediction based onHFB model (`NhaloeRMF > `NhaloeHFB):, In neutron halo phenomenon, the neutron density displays an unusually extended'tail' and 'empty space' between the core and the tail due to weak binding energy.New analysis method of the halo was developed by V. Rotival, et al.[Phys. Rev. C79,054308 (2009)] in Cr-isotopes and Sn-isotopes, its usually applied with Hartree-Fock-Bogoliubov (HFB) model. Unlike them, we use the model of the Relativistic MeanField (RMF) in this research. We observed dierent behavior at the level 1g9~2 in linewith appearance of halo in Cr-isotopes. Moreover, in this research we also studiedthe eects of cross coupling meson ! − , tensor, and electromagnetic exchange inRMF model appearance of halo in Cr-isotopes and Sn-isotopes. The prediction ofthe existence of halo based on RMF model is greater than the prediction based onHFB model (`NhaloeRMF > `NhaloeHFB):]