70 research outputs found
Quantum Mechanical Treatment of the Problem of Constraints in Nonextensive Formalism Revisited
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
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
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 .Comment: 20 pages, 6 figure
Scattering of Woods-Saxon Potential in Schrodinger Equation
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
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
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
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
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
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
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