70 research outputs found

    Quantum Mechanical Treatment of the Problem of Constraints in Nonextensive Formalism Revisited

    Get PDF
    The purity of Werner state in nonextensive formalism associated with two different constraints has been calculated in a previous paper by G. B. Bagci et al. [G. B. Bagci et al., Int. J. Mod. Phys. 20, 2085 (2006)]. Two different results have been obtained corresponding to ordinary probability and escort probability whereas the former has been shown to result in negative values thereby leading authors to deduce the advantage of escort probabilities over ordinary probabilities. However, this results have been only for a limited interval of q values which lie between 0 and 1. In this paper, we solve the same problem for all values of nonextensive index q by using a perturbative approach and show that the simultaneous use of both types of constraint is necessary in order to obtain the solution for whole spectrum of nonextensive index. In this sense, the existence of these different constraints in nonextensive formalism must not be seen as a deficiency in the formalism but rather must be welcomed as a means of providing solution for all values of parameter q.Comment: 7 page

    Bound States of the Klein-Gordon Equation for Woods-Saxon Potential With Position Dependent Mass

    Full text link
    The effective mass Klein-Gordon equation in one dimension for the Woods-Saxon potential is solved by using the Nikiforov-Uvarov method. Energy eigenvalues and the corresponding eigenfunctions are computed. Results are also given for the constant mass case.Comment: 13 page

    Effective-Mass Dirac Equation for Woods-Saxon Potential: Scattering, Bound States and Resonances

    Get PDF
    Approximate scattering and bound state solutions of the one-dimensional effective-mass Dirac equation with the Woods-Saxon potential are obtained in terms of the hypergeometric-type functions. Transmission and reflection coefficients are calculated by using behavior of the wave functions at infinity. The same analysis is done for the constant mass case. It is also pointed out that our results are in agreement with those obtained in literature. Meanwhile, an analytic expression is obtained for the transmission resonance and observed that the expressions for bound states and resonances are equal for the energy values E=±mE=\pm m.Comment: 20 pages, 6 figure

    Scattering of Woods-Saxon Potential in Schrodinger Equation

    Full text link
    The scattering solutions of the one-dimensional Schrodinger equation for the Woods-Saxon potential are obtained within the position-dependent mass formalism. The wave functions, transmission and reflection coefficients are calculated in terms of Heun's function. These results are also studied for the constant mass case in detail.Comment: 14 page

    Exact Spin and Pseudo-Spin Symmetric Solutions of the Dirac-Kratzer Problem with a tensor potential via Laplace Transform Approach

    Full text link
    Exact bound state solutions of the Dirac equation for the Kratzer potential in the presence of a tensor potential are studied by using the Laplace transform approach for the cases of spin- and pseudo-spin symmetry. The energy spectra is obtained in the closed form for the relativistic as well as non-relativistic cases including the Coulomb potential. It is seen that our analytical results are in agrement with the ones given in literature. The numerical results are also given in a table for different parameter values.Comment: 8 page

    Spinal cord stimulation in failed back surgery

    Get PDF
    Objective: Spinal cord stimulation is used for treating failed back surgery syndrome, chronic arachnoiditis, peripheral neuropathies, postamputation phantom pain, complex regional pain syndrome and pain secondary to spinal cord injury. In this study we present 7 cases with intractable neuropathic radicular pain which developed following spine surgery. Material and Methods: Spinal cord stimulation was applied to 7 (3male/4 female) patients who had failed back surgery syndrome and pain resistant to medical and invasive methods, with the council decision, which included neurosurgery, neurology, and psychiatry. One week stimulation trial was applied to all cases. Results:The mean age of the patients was 54.85±7.64 years. The mean of pain intensity in Visual Analog Scale was 8.71±0.74 at preoperative status and post operative pain intensity was 2.27±0.67 at 6 months. Pain intensity significantly decreases after spinal cord stimulation (p=0.000). One of the three cases who had unsuccessful trial period received morphine pump implantation, and percutaneous lumbar sympathectomy was applied to another one. One case who received permanent implantation was replaced to another location due to skin erosion. There was no morbidity. Conclusion: Spinal cord stimulation is an effective tool in reducing pain, in patients who have unsuccessful lower back surgery with the correct indications

    Analytical Solutions of Klein-Gordon Equation with Position-Dependent Mass for q-Parameter Poschl-Teller potential

    Get PDF
    The energy eigenvalues and the corresponding eigenfunctions of the one-dimensional Klein-Gordon equation with q-parameter Poschl-Teller potential are analytically obtained within the position-dependent mass formalism. The parametric generalization of the Nikiforov-Uvarov method is used in the calculations by choosing a mass distribution.Comment: 10 page

    Approximate Solution of the effective mass Klein-Gordon Equation for the Hulthen Potential with any Angular Momentum

    Full text link
    The radial part of the effective mass Klein-Gordon equation for the Hulthen potential is solved by making an approximation to the centrifugal potential. The Nikiforov-Uvarov method is used in the calculations. Energy spectra and the corresponding eigenfunctions are computed. Results are also given for the case of constant mass.Comment: 12 page

    The sensitivity of the zero position of the forward--backward asymmetry to new physics effects in the B -> K^\ast \mu^+ \mu^- decay

    Full text link
    Starting with the most general effective Hamiltonian comprising scalar and vector operators beyond the standard model, we discuss the impact of various operators on the zero of the forward--backward asymmetry in the dileptonic B decay B -> K^\ast \mu^+ \mu^-. We find that, zero of the asymmetry is highly sensitive to the sign and size of the vector--vector operators and opposite chirality counterparts of the usual operators. The scalar--scalar four--fermion operators, on the other hand, have mild effect on the zero of the asymmetry. Our results are expected to be checked in the near future experiments.Comment: 16 pp, 6 ps fig
    corecore