395 research outputs found

    Halo Structure Of C-19 Via The (p,d) Reaction

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    We have investigated the heaviest one-neutron halo candidate C-19 nucleus. Few-body model calculations of cross section angular distributions for the C-19(p,d)C-18 reaction, together with the test calculations carried out for the C-17(p,d)C-16 reaction, at a low incident energy are presented for different possible halo-neutron configurations. We show that there is a clear distinction between in particular â„“n=0\ell_{n}=0 and â„“n=2\ell_{n}=2 halo transfers. The sensitivity of the cross sections to the assumed C-19 single neutron separation energy is discussed.Comment: LaTEX (uses article.sty), 11 pages and 4 figures (in PS format). Please check http://physics.gantep.edu.tr/~nuclear/publications.html for other other studies of Nuclear Physics Group at University of Gaziantep. To be published in Few Body Systems Journal in May 200

    Significance Of Deuteron Breakup In A Halo Transfer Reaction

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    We discuss the quasi-adiabatic approximations to the three-body wavefunction in breakup processes, clarifying the assumptions underlying the model. This suggests alternative approximation schemes. Using different theoretical three-body models, calculated differential cross section angular distributions for the Be-11(p,d) reaction,for which new preliminary data have been reported at 35 MeV, are presented. We show that calculations are sensitive to the inclusion of deuteron breakup and to the breakup model used, particularly if used to deduce absolute spectroscopic information on the 0{+} and 2{+} Be-10 core state parentages. There is also considerable sensitivity to the model used in calculations of the relative cross sections to the two states.Comment: LaTEX (uses article.sty), 16 pages and 3 figures (EPS format). Please check http://physics.gantep.edu.tr/~nuclear/publications.html for other other studies of Nuclear Physics Group at University of Gaziante

    Multi-nucleon transfer in 58Ni+60Ni{}^{58}\text{Ni}+{}^{60}\text{Ni} and 60Ni+60Ni{}^{60} \text{Ni}+{}^{60}\text{Ni} in stochastic mean-field approach

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    The multi-nucleon exchange mechanism in 58Ni+60Ni{}^{58} \text{Ni}+{}^{60} \text{Ni} and 60Ni+60Ni{}^{60} \text{Ni}+{}^{60}\text{Ni} collisions is analyzed in the framework of the stochastic mean-field approach. The results of calculations are compared with the TDRPA calculations and the recent data of 58Ni+60Ni{}^{58} \text{Ni}+{}^{60} \text{Ni}. A good description of the data and a relatively good agreement with the TDRPA calculations are found.Comment: 6 pages, 6 figure

    Investigation of phase-equivalent potentials by a halo transfer reaction

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    Using the supersymmetric quantum mechanics we investigate the wave function-sensitive properties of the supersymmetric potentials which have received a lot of attention in the literature recently. We show that a superdeep potential and its phase-equivalent shallow-partner potential give very similar "rms" values for the weakly bound systems such as the deuteron and 11Be nuclei. Although the corresponding eigenstates differ in the node-number, our investigation on the 11Be(p,d)10Be single nucleon halo transfer reaction at 35 MeV show that also other physical quantities such as the cross section angular distributions calculated using these wave functions reflect the nodal structure rather weakly. This lends support to two nearly equivalent treatments of the Pauli principle.Comment: 20 pages article in LaTEX (uses standard article.sty). Figures can be obtained from author(s). Please check "http://www1.gantep.edu.tr/~ozer" for other studies of Nuclear Physics Group at University of Gaziante

    Importance of realistic phase space representations of initial quantum fluctuations using the stochastic mean-field approach for fermions

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    In the stochastic mean-field (SMF) approach, an ensemble of initial values for a selected set of one-body observables is formed by stochastic sampling from a phase-space distribution that reproduces the initial quantum fluctuations. Independent mean-field evolutions are performed with each set of initial values followed by averaging over the resulting ensemble. This approach has been recently shown to be rather versatile and accurate in describing the correlated dynamics beyond the independent particle picture. In the original formulation of SMF, it was proposed to use a Gaussian assumption for the phase-space distribution. This assumption turns out to be rather effective when the dynamics of an initially uncorrelated state is considered, which was the case in all applications of this approach up to now. Using the Lipkin-Meshkov-Glick (LMG) model, we show that such an assumption might not be adequate if the quantum system under interest is initially correlated and presents configuration mixing between several Slater determinants. In this case, a more realistic description of the initial phase-space is necessary. We show that the SMF approach can be advantageously combined with standard methods to describe phase-space in quantum mechanics. As an illustration, the Husimi distribution function is used here to obtain a realistic representation of the phase-space of a quantum many-body system. This method greatly improves the description of initially correlated fermionic many-body states. In the LMG model, while the Gaussian approximation failed to describe these systems in all interaction strength range, the novel approach gives a perfect agreement with the exact evolution in the weak coupling regime and significantly improves the description of correlated systems in the strong coupling regime.Comment: 12 pages, 10 figure

    A simplified BBGKY hierarchy for correlated fermionic systems from a Stochastic Mean-Field approach

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    The stochastic mean-field (SMF) approach allows to treat correlations beyond mean-field using a set of independent mean-field trajectories with appropriate choice of fluctuating initial conditions. We show here, that this approach is equivalent to a simplified version of the Bogolyubov-Born-Green-Kirkwood-Yvon (BBGKY) hierarchy between one-, two-, ..., N-body degrees of freedom. In this simplified version, one-body degrees of freedom are coupled to fluctuations to all orders while retaining only specific terms of the general BBGKY hierarchy. The use of the simplified BBGKY is illustrated with the Lipkin-Meshkov-Glick (LMG) model. We show that a truncated version of this hierarchy can be useful, as an alternative to the SMF, especially in the weak coupling regime to get physical insight in the effect beyond mean-field. In particular, it leads to approximate analytical expressions for the quantum fluctuations both in the weak and strong coupling regime. In the strong coupling regime, it can only be used for short time evolution. In that case, it gives information on the evolution time-scale close to a saddle point associated to a quantum phase-transition. For long time evolution and strong coupling, we observed that the simplified BBGKY hierarchy cannot be truncated and only the full SMF with initial sampling leads to reasonable results.Comment: 10 pages, 4 figure

    Muhasebe ve finans derslerinin askeri yuksekogretim programindaki onemi ve askerlik niteliginin kazandirilmasindaki rolu

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    The concept of war is in continuous change and development. Nowadays the visible face of iceberg is military battle, however the invisible face is economic competition. In today’s rapidly changing circumstances , the managers of Turkish Armed Forces (TAF) should realise the financial constraints and consider them while analyzing and managing cases. Giving only a military education in the schools will cause a one-dimensional evaluation. So, undergraduate programs in the military higher education which include Accounting-Finance aim to raise awareness about financial topics. The main goal is recognizing the importance of financial issues and making rational decison by students and in the war and peace. In this study, the relationship between military service and the requirements of the Accounting and Finance course will be studied.peer-reviewe

    Stochastic Semi-Classical Description of Fusion at Near-Barrier Energies

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    Fusion reactions of heavy ions are investigated by employing a simple stochastic semi-classical model which includes the coupling between relative motion and low frequency collective surface modes of colliding ions similarly to the quantal coupled-channels description. The quantal effect enters into the calculation through the initial zero-point fluctuations of the surface vibrations. Good agreement with the result of coupled-channels calculations as well as data is obtained for the fusion cross sections of nickel isotopes. The internal excitations in non-fusing events as well as the fusion time are investigated.Comment: 8 pages, 8 figures, Published in Phys. Rev.

    Imatinib Treatment Alone in Philadelphia-Positive Acute Lymphoblastic Leukemia: Is It Enough?

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    BCR-ABL fusion gene t(9;22)(q34;q11) occurs in only 3% of pediatric acute lymphoblastic leukemia (ALL) cases. Previously, less than 40% of Philadelphia-positive ALL patients were cured with intensive chemotherapy. The use of imatinib (340 mg/m2/day) added to an intensive chemotherapy regimen has improved the outcome in this population at 3 years to an event-free survival of 80%. Imatinib treatment alone was administered after remission induction chemotherapy to a patient with Philadelphia-positive ALL who presented with serious chemotherapy toxicity, so that intensive chemotherapy could not be maintained. This is the only patient in the literature who survived remission for more than 2.5 years with imatinib treatment only

    Primary renal carcinoid natural history of the disease for ten years: case report

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    BACKGROUND: Primary renal carcinoid is extremely rare and there are few reports on the natural history of the disease. CASE PRESENTATION: A 68-year-old male with a right renal mass who lost to follow-up for ten years has been presented. His only complaint was a mild flank pain. Upon admission to the hospital for his renal mass, he underwent a right radical nephrectomy and pathological examination revealed the diagnosis of primary renal carcinoid. CONCLUSIONS: In light of the presented case, primary renal carcinoma may have a prolonged natural history with no distant metastasis and any change in the quality of life of the patient
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