Curriculum Vitae Name: Momen Ahmad Orabi Nationality: Egyptian Date and Place of birth: 25/11/1978 Kingdom of Saudi Arabia Occupation: Lecturer in Physics Department, Faculty of Science, Cairo University, Egypt. Mailing Address: Physics Department, Faculty of Science, Cairo University, Giza, Egypt. E-mail: momen_ahmad_orabi@yahoo.com Mobile: 01096154275 Academic Information: BSc: General Physics, 1999 from Cairo University, Egypt. MSc: Theoretical Nuclear Physics, 2003 from Cairo University, Egypt. PhD: Theoretical Nuclear Physics, 2009 from Niigata University, Japan. Computer Skills: Operating Systems: Windows and Linux. Programming Languages: Fortran, Mathematica, C++ and Java. Language Skills: Arabic: Native English: Very good Teaching Experience: 1) Laboratory experiments all grades, including nuclear laboratory. 2) Computer Science (Basics of computer & C++), second grade. 3) Digital Systems Design (Verilog HDL), fourth grade. 4) Nuclear accelerators, Master course. 5) Waves and Modern physics, first grade.
6) Electricity, first grade. 7) Magnetism, first grade. 8) Nuclear scattering, Master course. Conferences, Schools and Visits: 1) CERN Summer School, Geneva, France and Switzerland 2003. 2)Training for CMS detector, Quaid-e-Azam University, Islamabad, Pakistan 2004. 3) Workshop at Yukawa Institute for Theoretical Physics, Kyoto, Japan 2006. 4) Clusters 07 Conference, England, UK 2007. 5) FM50 Symposium, Tokyo, Japan 2007. 6) JPS meeting, Osaka, Japan 2008. 7) CNS-EFES Summer School, RIKEN, Tokyo, Japan 2008. 8) CERN, Geneva, France and Switzerland 2009. 9) KEK, Tsukuba, Japan 2011. Summary of Past Research 1) Master Work: The main aim of the master work was to study and compare between approximate methods that are known or expected to improve the eikonal few-body Glauber model at low and medium energies. We were especially interested in comparing the semi-classical WKB approximation with the Continuation of Partial Waves (CPW) method. We applied this study on point particle projectiles n, p and 4 He incident on 12 C target at different low and medium energies, and then we considered the composite projectile 6 He incident on the same target 12 C at 41.6 MeV/nucleon, in which 6 He nucleus was considered as composed of three clusters; 4 He plus two halo neutrons. The results we had in brief were good agreements with the
experimental data for the CPW method which seemed to be in general more efficient than the WKB approximation. 2) Ph.D. Work: During the doctor course I have been basically studying the structure of some nuclei considered as a few-body (few-cluster) systems. We calculate the energy spectrum and the sizes of different states of those nuclei, as well as some other physical properties, using some models and approximations. We mainly work with the cluster models known as the Resonating Group Method (RGM) and the Orthogonality Condition Model (OCM) which are rather well-known in the field of the cluster physics. We then compare the results we obtain from our calculations with the experimental measurements and some other theoretical methods. To calculate the systems in question, we need some sort of interaction between the clusters. For this, we classify our models of calculations into a Local model (in which local potentials are used) and a semi-microscopic model (in which non-local potentials are used). In the Local model, the local potentials used for the cluster-cluster interactions consider the clusters as point particles, and the potentials are set phenomenologically in order to fit the cluster-cluster scattering phase shifts data. The results of this model are not usually satisfactory compared to the experiment and the more reliable fully-microscopic calculations. Therefore, it is very interesting to test what may happen if we switch off the local potentials (while using the same frame of work) and switch on more sophisticated potentials, namely non-local potentials. This is the second model; the semi-microscopic model [1]. In Refs. [2, 3] we show that using local potentials for the 12 C nucleus considered as a 3α system gives poor results, whatever the potential is deep or shallow. But when using the semi-microscopic model, the results are much more improved, comparing them to experiment and fully-microscopic calculations. This was
expected because of the fact that the cluster-cluster interaction should be intrinsically non-local, since the cluster is actually a composite particle. Local potentials, however, which consider the clusters as point particles, are just commonly used due to their simplicity in making calculations. In the semi-microscopic model, the non-local cluster-cluster potential is microscopically founded from a nucleon-nucleon (NN) effective interaction based on the RGM equation. The two-cluster RGM kernels are non-local and reproduce the observables of two-cluster sub-systems very well. The interesting aspect in our calculations is that we eliminate the energy-dependence of the RGM kernels [3], the thing which even strengthened the importance of the non-locality of the interactions between composite particles. In Ref. [4] we show that using such an energy-independent non-local potential works very well for the nuclei 12 C (3α), 6 He (α+2n) and 9 Be (2α+n). The results are much better than those of the Local model, comparing them to experiment and the fully-microscopic model. The semi-microscopic model is called so in the sense that exchanges involving two clusters are taken into account in the non-local part of the potential, but exchanges involving all clusters are neglected. This is a useful tool to learn about the significance of the three-body exchange effects in three-body systems, if we compare with a fully-microscopic model in which the exchange effects are taken into account not only among two clusters but among the three clusters as well. Also the semi-microscopic model has the very good advantage that its use can be extended to systems more than three clusters; the thing which cannot be done using a fully-microscopic model. Moreover, removing the energy-dependence from the potential allows us to calculate many states having the same symmetry at one time calculation. This is a very big merit of having an energy-independent potential. So our semi-microscopic model with the energy-independent non-local potentials is a powerful model from two basic points of view, first it gives more realistic results than the simple Local model, and secondly it is less complicated
than the fully-microscopic model; the thing which allows us to go to many-cluster systems, more than just three clusters. From the promising results which we have for the three-cluster systems 12 C, 9 Be and 6 He, it is an interesting matter to see the performance of using such a nonlocal energy-independent potential for more than three-cluster systems, and so nowadays we are applying this semi-microscopic model for calculating the nucleus 16 O considered as a 4α system. The calculation is still in progress, and we expect satisfactory results. One of the attractive things in studying the α-systems like 12 C (3α) and 16 O (4α) is that it allows us to investigate the interesting phenomenon known as the α-condensation. General speaking, obtaining good converged energies, and hence good wave functions for the nuclei under investigation, is a very useful tool because the obtained wave functions can be used to calculate many properties for the different states of those nuclei, and also for making calculations of reactions involving those nuclei. - References: [1] Y. Fujiwara et al., Prog. Theor. Phys. 107 (2002) 993. [2] H. Matsumura, M. Orabi, Y. Suzuki and Y. Fujiwara, Nuclear Physics A 776 (2006) 1. [3] Y. Suzuki et al., Phys. Lett. B 659 (2008) 160. [4] M. Theeten et al., Phys. Rev. C 76 (2007) 054003. List of Publications
1) H. Matsumura, M. Orabi, Y. Suzuki and Y. Fujiwara Removal of forbidden states in a three-α system Nuclear Physics A 776, 1-16 (2006) 2) Y. Suzuki, Y. Fujiwara, W. Horiuchi, H. Matsumura and M. Orabi Dynamics of macroscopic and microscopic three-body systems Nuclear Physics A 790, 223c-228c (2007) 3) M. Theeten, H. Matsumura, M. Orabi, D. Baye, P. Descouvemont, Y. Fujiwara and Y. Suzuki Three-body model of light nuclei with microscopic nonlocal interactions Physical Review C 76, 054003 (2007) 4) Y. Suzuki, H. Matsumura, M. Orabi, Y. Fujiwara, P. Descouvemont, M.Theeten and D. Baye Local versus nonlocal αα interactions in a 3α description of 12 C Physics Letters B 659, 160-164 (2008) 5) Y. Suzuki, W. Horiuchi, M. Orabi and K. Arai Global-vector representation of the angular motion of few-particle systems II Few-Body Systems 42, 33-72 (2008) 6) M. Orabi, Y. Suzuki, H. Matsumura, Y. Fujiwara, D. Baye, P. Descouvemont and M. Theeten 3α description of 12 C with microscopic nonlocal potential J. Phys. Conf. Ser. 111, 012045 (2008) 7) M. Theeten, D. Baye, P. Descouvemont, Y. Fujiwara, H. Matsumura, M. Orabi and Y. Suzuki Three-cluster models for light nuclei J. Phys. Conf. Ser. 111, 012046 (2008) 8) M. Orabi, Y. Suzuki and Y. Fujiwara Nonlocal αα potential for 12 C as a 3α system AIP Conf. Proc. 1011, 165 (2008) 9) M. Orabi Removing the forbidden states in a 4α system Few-Body Systems 51, 45-58 (2011)