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Öğe Analysis of the anomalous electromagnetic moments of the tau lepton in gamma p collisions at the LHC(ELSEVIER SCIENCE BV, 2018) Koksal, M.; Inan, S. C.; Billur, A. A.; Ozguven, Y.; Bahar, M. K.In this study, we investigate the potential of the process pp -> p gamma*p -> p tau(nu) over bar (tau)q' X at the LHC to examine the anomalous electromagnetic moments of the tau lepton. We obtain 95% confidence level bounds on the anomalous coupling parameters with various values of the integrated luminosity and center-of-mass energy. The improved bounds have been obtained on the anomalous coupling parameters of electric and magnetic moments of the tau lepton alpha(tau) and vertical bar d(tau)vertical bar compared to the current experimental sensitivity bounds. The gamma p mode of photon reactions at the LHC have shown that it has great potential for the electromagnetic dipole moments studies of the tau lepton. (C) 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP(3).Öğe Electron-related nonlinear optical properties of cylindrical quantum dot with the Rosen-Morse axial potential(Iop Publishing Ltd, 2020) Ungan, F.; Bahar, M. K.; Pal, S.; Mora-Ramos, M. E.We present a theoretical study on the effects of intense laser field (ILF) and static electric field on the linear and nonlinear optical properties of a cylindrical quantum dot with Rosen-Morse axial potential under the framework of effective mass and parabolic band approximations. This study also takes into account the effects of the structure parameters (eta, V-1, and R). The analytical expressions of the linear, third-order nonlinear and total optical absorption coefficients (TOACs) and the relative refractive index changes (RRICs) are obtained by using the compact-density-matrix approach. The results of numerical calculations show that the resonant peak position of the TOACs and RRICs shifts towards lower energies and the magnitude of the peak increases with the effect of the static electric field and ILF. In addition, it is observed that while the resonant energies of the TOACs and RRICs of system shift towards the higher (lower) energies with the enhancement of eta, V-1, they decrease with the augmentation of R. Thus, the findings of this study show that the optical properties of the structure can be adjusted by changing the magnitude of structure parameters and applied external fields.Öğe The functionality of the external electric and magnetic field on optical specifications of Rosen-Morse quantum well(IOP PUBLISHING LTD, 2019) Ungan, F.; Bahar, M. K.In this study, for the first time, we probe the influences of the external electric and magnetic field (EF and MF) on the total refractive index changes (TRICs) and the total absorption coefficients (TACs) of quantum well (QW) with the Rosen-Morse (RM) potential confinement constituting by GaAs/GaAlAs heterostructure. To do this, the bound state energies and the wave functions of the Rosen-Morse quantum well (RMQW) under the influence of the external EF and MF are determined by solving the corresponding wave equation using the diagonalization method within the framework of the effective mass approach and the parabolic band approximation. As the purpose of the present work is to find out the functionality of the external EF and MF on TRICs and TACs of RMQW, same RMQW with V-1 = 250 meV, V-2 = 228 meV, eta = 0.01 cm(-1) is taken into consideration throughout the work. The TRICs and TACs of RMQW in the weak and strong regimes of the external fields are discussed in detail. The present work introduces to researches that how to and in what regimes apply the EF and MFs to be considered in devices designs and applications including RMQW.Öğe Generalized potential for confined positronium atom immersed in plasmas(Elsevier, 2020) Bahar, M. K.; Soylu, A.We suggest, for the first time, the more general exponential cosine screened Coulomb (MGECSC) potential to investigate the positronium (Ps) atom immersed in Debye and quantum plasmas. Ps atom immersed in Debye and quantum plasmas under spherical confinement is examined by solving the corresponding Schrodinger equation via the tridiagonal matrix method. The MGECSC potential has four different sets to model Debye and quantum plasmas. But, we consider only two sets as the screened Coulomb (SC) potential for Debye plasma and the MGECSC potential for quantum plasma. The results of the confinement and the plasma screening effects on the energies, radial matrix elements, dipole polarizabilities and oscillator strengths of Ps atom are obtained, discussing in detail. It is worthwhile to specify that the spectroscopic features of Ps atom located in only plasma environment enable detailed information about plasma environment. The MGECSC potential is proposed to model various interactions of Ps atom immersed in plasma environment. In this study, the necessity and details of the MGECSC potential is discussed.Öğe Optical analysis of quantum dot with velocity-dependent potential(Wiley, 2021) Bahar, M. K.; Ungan, F.; Kaya, H.; Akkoyun, S.In this study, for the first time, the velocity-dependent potential (VDP) effects on the total refractive index changes (TRICs) and the total absorption coefficients (TACs) of the parabolic quantum dot with spherical confinement, generated by GaAs/GaAlAs heterostructure, are comprehensively investigated. In order to obtain the subband energy spectra and the electronic wave function of the quantum dot system, the wave equation is numerically solved due to the VDP's complexity by using Runge-Kutta-Fehlberg method within the effective mass approximation. The nonlinear optical specifications of the quantum dot with velocity-dependent potential (QDVDP) are analyzed using the compact density matrix formalism within the framework of the iterative method. To investigate the optical specifications of QDVDP, the isotropic form factor of VDP is taken into consideration as the harmonic oscillator type, F(r) = gamma rho(0)r(2) (being gamma and rho(0) are constants). Optical analysis is also executed for parabolic encompassing under the influence of VDP, as well as VDP, analyzing for TRICs and TACs of QDVDP, for which the result is quite a change compared to cases without VDP due to the symmetry-breaking repercussion on system confinement of VDP. The main motivation of the present study is to clearly distinguish VDP effects on optical properties of the quantum dot, carrying out an analysis on optimal range and alternative parameter for optical properties.Öğe Optical properties of n-type asymmetric triple ?-doped quantum well under external fields(Iop Publishing Ltd, 2020) Ungan, F.; Bahar, M. K.; Mora-Ramos, M. E.We present a theoretical investigation about the the influence of external electric, magnetic and non-resonant intense laser fields on intersubband-related second harmonics generation (SHG) and the nonlinear optical rectification (NOR) coefficients in n-type asymmetric triple d-doped quantum wells (QWs). A particular design of asymmetric triple d-doped QW with Lw.=.200 A width and, respectively, in the left side, central and right side, N-D(L) = 3 x 10(12), N-D(C) = 5 x 10(12) and N-D(R) = 7 x 10(12) cm(-2) doping concentrations is taken into account. For QWs under the combined effect of the external electric, magnetic and laser fields, the time-dependent wave equation is modified by using Kramers-Henneberger transformation and the dipole approximation. The subband energy spectra and the electronic wave functions are obtained by solving numerically the wave equation. The originality of this work can be presented as; ( i) The results explain NOR and SHG characteristics of triple QW depending on external field effects in detail. The effects of the electric, magnetic and laser field on transition energies and NOR, SHG characteristics are presented detail. (ii) In addition to, the alternativeness to each other of the external fields is discussed by probing the features of SHG and NOR under the strong and weak regimes of external fields. (iii) These nonlinear optical responses to the external fields are compared, researching the optimum cases for these optical specifications. (iv) The control of SHG through the external fields in triple d-doped QWs reveals to be easier and more precise.Öğe Optical responses in asymmetric hyperbolic-type quantum wells under the effect of external electromagnetic fields(Elsevier, 2020) Ungan, F.; Bahar, M. K.; Martinez-Orozco, J. C.; Mora-Ramos, M. E.In the present work, some optical properties related to intersubband transitions in finite depth asymmetric hyperbolic-type quantum wells are theoretically investigated. The use of a hyperbolic potential configuration would account for the actual - non abrupt - confinement potential in the heterostructure, in the case of modulated growing or when compositional diffusion across the interfaces turns out to be relevant. In the investigation, the presence of externally applied electromagnetic fields is considered. Electron conduction band states are determined within the parabolic band an effective mass approximation. With the electronic structure information at hand, it is possible to evaluate the linear and third-order nonlinear light absorption and relative refractive index change coefficients, from expression arising in the framework of the compact density matrix approach. According to the theoretical outcome, it is found that: (i) There is a significant influence of the structural configuration on the magnitude and resonant peak position of the total optical coefficients. (ii) Under the effect of increasing external electric and magnetic fields, the peak energy positions are shifted towards higher values, whereas their amplitude decrease for the optical absorption case, and that of the refractive index relative variation is reduced. From these results it can be concluded that both the modification of the confinement profile and the presence of electric and/or magnetic fields are suitable tool to control the optical response of asymmetric hyperbolic-type semiconductor quantum wells.Öğe Optical specifications of laser-induced Rosen-Morse quantum well(ELSEVIER SCIENCE BV, 2019) Ungan, F.; Bahar, M. K.In this study, for the first time, the influences of a monochromatic linearly polarized laser field on the total refractive index changes (TRICs) and the total absorption coefficients (TACs) of quantum well (QW) with the Rosen-Morse potential confinement by constituting GaAs/GaAlAs heterostructure are considered. Time-dependent in the Schrodinger equation is modified through the Kramers-Henneberger (KH) transformation and the dipole approximation, and then the laser-dressed counterpart of well potential is generated by using the Ehlotzky approximation. The bound state energy values and the wave functions of the Rosen-Morse quantum well (RMQW) under the influence of the intense laser field (ILF) are obtained by using the diagonalization method in the framework of the effective mass approach and the parabolic band approximation. The effects of structure parameters on TRICs and TACs of RMQW are also explained in detail, as well as the ILF's ones. In addition to these, the alternativeness to each other of the structure parameters and the ILF on the optical specifications is also discussed. The results of the present work are necessary and crucial in optimization of the optical specifications of RMQW to be fabricated for devices applications.Öğe Search for the anomalous electromagnetic moments of tau lepton through electron-photon scattering at CLIC(ELSEVIER SCIENCE BV, 2017) Ozguven, Y.; Billur, A. A.; Inan, S. C.; Bahar, M. K.; Koksal, M.We have examined the anomalous electromagnetic moments of the tau lepton in the processes e(-)gamma -> nu(e)tau(nu) over bar tau (gamma is the Compton backscattering photon) and e(-)e(+)-> e(-)gamma*e(+) -> e(-)gamma -> nu(e)tau(nu) over bar tau (gamma* is the Weizsacker-Williams photon) with unpolarized and polarized electron beams at the CLIC. We have obtained 95% confidence level bounds on the anomalous magnetic and electric dipole moments for various values of the integrated luminosity and center-of-mass energy. Improved constraints of the anomalous magnetic and electric dipole moments have been obtained compared to the LEP sensitivity. (C) 2017 The Authors. Published by Elsevier B.V.Öğe Subband structure of p-type delta-doped GaAs as dependent on the acceptor concentration and the layer thickness(CAMBRIDGE UNIV PRESS, 2008) Ozturk, E.; Bahar, M. K.; Sokmen, I.For a uniform distribution we have theoretically studied the subband structure of p-type delta-doped GaAs inserted into a quantum well at T = 0 K. We will investigate the influence of the delta-doping concentration and the layer thickness. The electronic properties such as the depth of con. ning potential, the density pro. le, the Fermi level, the subband energies and the subband populations have been calculated by solving the Schrodinger and Poisson equations self consistently. In this study, we have seen that the heavy-hole subbands contain many more energy states than the light-hole ones, the population of the heavy-hole levels represent approximately 91% of all the carriers.Öğe The laser field controlling on the nonlinear optical specifications of the electric field-triggered Rosen-Morse quantum well(Elsevier, 2020) Ungan, F.; Bahar, M. K.We consider, for the first time, optical specifications such as the nonlinear optical rectification (NOR), the second harmonic generation (SHG) and the third harmonic generation (THG) of quantum well (QW) that has the Rosen-Morse potential confinement and is generated by GaAs/GaAlAs heterostructure. To do this, QW structure is firstly asymmetrized by applying an external electric field, as 10 kV/cm. Therefore, the electric field-triggered (F = 10 kV/cm) Rosen-Morse QW (eftRMQW) is taken into consideration throughout the study. In this study, it is elucidated that how to control NOR, SHG and THG optical responses through monochromatic linearly polarized intense laser field (ILF). In order to be able to investigate the ILF effects, the time-dependent of ILF is removed to potential energy term of the wave equation by using Kramers-Henneberger (KH) and the dipole approximations, building the laser-dressed potential. Then, the bound state energies and the wave functions of eftRMQW are obtained using the diagonalization method within the effective mass approach and the parabolic approximation. The influences of the ILF and structural parameters of eftRMQW on NOR, SHG and THG coefficients are discussed in detail. The optimum of structure is ferreted out for devices design and applications that will consider eftRMQW, and for this optimum the alternative parameter analysis is carried out. (C) 2020 Elsevier B.V. All rights reserved.Öğe Tuning of nonlinear optical characteristics of Mathieu quantum dot by laser and electric field (vol 137, 1138, 2022)(Springer Heidelberg, 2022) Bahar, M. K.; Baser, P.[Abstract Not Available]
