arXiv subjects

M. Ouali

Publications and source records attributed to M. Ouali.

16 recordsLinked to original sources

arXiv2023

Enhancement in physical properties of Pb-Based Perovskite Oxides ($PbGeO_{3}$): Ab initio Calculation

In the present paper, the electronic, structural, thermodynamic, and elastic properties of cubic $PbGeO_{3}$ perovskite oxide are presented and computed using the WIEN2K code. The structural properties have been evaluated and they are in good agreement with the theoretical and experimental data. A phonon dispersion is made and it reveals that the cubic $PbGeO_{3}$ perovskite is dynamically stable. In addition, the electronic properties of $PbGeO_{3}$ shows an opening gap energy, meaning a semiconductor behavior with an indirect band gap equal to $1.67 eV$. Moreover, the obtained elastic constants of cubic $PbGeO_{3}$ satisfy Born's mechanical stability criteria, and this indicates that our compound behaves as a stable ductile material. The temperature-pressure effects on thermodynamic parameters are investigated using the Gibbs$2$ package. Finally, based on the obtained results about the cubic $PbGeO_{3}$ perovskite properties, we assume that this compound will have potential applications.

cond-mat.mtrl-sci↗

arXiv2022

Laser-induced proton decay

In this research paper, we investigate the decay of the proton into neutron, positron and electron neutrino in the presence of an external electromagnetic field with circular polarization. Different physical quantities related to this decay process, such as proton's decay rate and its lifetime, are calculated based on the S-matrix approach. The proton and positron are treated as Dirac-Volkov states, while the neutron and electron neutrino are free-states. We have found that, though it can not occur in vacuum, the proton's decay process into neutron, positron and electron neutrino becomes possible in the presence of laser field with high intensities near or close to the Schwinger limit. In addition, near this limit and for some frequencies, the proton's lifetime can be comparable to that of the neutron, and the required laser strength, from which this decay becomes possible, depends on the chosen laser source.

hep-ph↗

arXiv2022

Laser-assisted electron-nucleon scattering

In both absence and presence of a circularly polarized monochromatic electromagnetic pulse, we have analyzed the electron-nucleon scattering process, where the nucleon is assumed to be spinless with a spherical shape. We have provided the theoretical calculation of the differential cross section (DCS) by using the Dirac-Volkov formalism. This research paper aims to provide two comparisons: We first compare the DCS in the absence of the laser field with its corresponding laser-assisted DCS. A second comparison is made between the electron-proton and electron-neutron scattering processes to study the effect of the laser on both processes. The results obtained about the effect of the laser field on the DCS and the electric form factor have been discussed for both scattering processes. We have found that the DCS is reduced when the laser field is applied for both processes. In addition, the form factor is also decreased by raising the incident electron energy in electron-proton scattering, but it increases in electron-neutron scattering. Moreover, the form factors for both scattering situations are unchanged by raising the laser field strength up to $10^{8}\,V/cm$.

hep-ph↗

arXiv2022

Production of Higgs boson in association with a pair of fermions in the presence of a circularly polarized laser field

In the centre of mass frame, we have investigated the process of Higgs production in association with a pair of fermions, $e^{+}e^{-}\rightarrow f\bar{f} H$, at the leading order inside an intense electromagnetic field with circular polarization. Our analytical calculations are based on the Narrow Width Approximation (NWA), which is valid in the leading order. We have considered only the initial particles inside the laser field as a first step. In the second part, we have embedded both initial and final particles in the laser field. We have analyzed the angular distribution of the produced Higgs boson as a function of the laser parameters in both cases. We have found that in the case where both initial and final particles are embedded in the laser field, the order of magnitude of the differential cross-section of the process $e^{+}e^{-}\rightarrowμ^{+}μ^{-}H$ is reduced more significantly, while that of the process $e^{+}e^{-}\rightarrowν\barνH$ is enhanced.

hep-ph↗

arXiv2022

Laser-assisted scattering of a muon neutrino by an electron within the Electroweak theory

In accordance with the electroweak theory, we perform, in the first-Born approximation, a detailed analytical treatment of the differential cross-section (DCS) for the elastic scattering process $e^{-}+ν_μ\longrightarrow e^{-}+ν_μ$ in both absence and presence of a circularly polarized laser field. This scattering process is examined by using Dirac-Volkov wave functions for charged particles within an external laser field. The theoretical results obtained for the differential cross-section without laser field are compared with other theoretical results within the framework of Fermi theory. These results revealed to us the most important points that contribute to the understanding of the electroweak theory role in solving the problem of unitarity violation of the differential cross-section in Fermi theory. The differential cross section is modified significantly by inserting the electrons into an electromagnetic field. In addition, the influence of the laser strength and its frequency on the photons exchange between the colliding system and the laser field are also included and discussed. These effects are heavily related to the order and argument of the ordinary Bessel functions introduced in the theoretical calculation.

hep-ph↗

arXiv2022

Laser-assisted doubly charged Higgs pair production in Higgs triplet model (HTM)

In the framework of Higgs triplet model (HTM), we study the pair production process of doubly charged Higgs bosons via $e^{+}e^{-}$ annihilation in the presence of a laser field with circular polarization . We begin our work by presenting the theoretical calculation of the differential cross section in the centre of mass frame including both $Z$ and $γ$ diagrams. Then, from the numerical analysis of the production cross section's dependence on the laser field parameters, we have shown that the laser-assisted total cross section decreases as far as the electromagnetic field intensity enhances or by decreasing its frequency. Finally, we analyze the variation of the total cross section versus the mass of the doubly charged Higgs boson by fixing the laser field parameters and the centre of mass energy, and we have found that the order of magnitude of the cross section decreases as long as $M_{H^{\pm\pm}}$ increases.

hep-ph↗

arXiv2021

Laser-assisted CP-odd and CP-even Higgs bosons production in THDM

In this paper, we have theoretically studied the neutral Higgs pair production in Two Higgs Doublet Model (THDM) in the presence of a circularly polarized laser field. The laser-assisted differential partial cross section is derived in the centre of mass frame at the leading order including $Z$ diagram. The total cross section is computed numerically by integrating the differential cross section over the solid angle $dΩ$. Two benchmark points are discussed for the THDM parameters. In the first step, we have analyzed the total cross section of ${e}^{+}{e}^{-}\rightarrow h^{0}A^{0}$ by considering $H^{0}$ as the standard model-like Higgs boson. Then, the process ${e}^{+}{e}^{-}\rightarrow H^{0}A^{0}$ is studied by taking $h^{0}$ as the Higgs boson of the standard model. For both benchmark points, the laser-assisted total cross section of the studied processes depends on the produced neutral Higgs masses, the centre of mass energy and the laser field parameters. In addition, the maximum cross section occurs at high centre of mass energy for the process ${e}^{+}{e}^{-}\rightarrow H^{0}A^{0}$ as compared to that of ${e}^{+}{e}^{-}\rightarrow h^{0}A^{0}$.

hep-ph↗

arXiv2021

Analysis of $e^{+}e^{-}\rightarrow H^{\pm}W^{\mp}$ in the presence of a circularly polarized laser field

In this study, we have investigated the production of a charged Higgs boson in assiciation with a charged weak $W$-boson ($H^{\pm}W^{\mp}$) at tree level via $e^{+}e^{-}$ annihilation in the presence of a laser field with circular polarization. At first step and by using analytical techniques, we have derived the expression of the differential cross section involving both $Z$ and $γ$ diagrams. Next, we have shown that the cross section of this process inside the laser field is proportional to the form factor $F_{HWV}$, and it depends on the mass of the charged Higgs boson and the energy of the center of mass. Then, we have analyzed the dependence of the total laser-assisted cross section on the number of photons exchanged for two different cases of form factor. Finally, we have found that the maximum number of photons that can be transferred depends only on the laser parameters.

hep-ph↗

arXiv2021

Muon pair production via $e^{+}e^{-}$ annihilation in the presence of a circularly polarized laser field

In this paper, we have investigated the elementary particle reaction ${e}^{+} {e}^{-} \rightarrowμ^{+} μ^{-}$ that results from the electron-positron interaction, at the leading order, with an intense laser wave of circular polarization. We have derived, by annalytical means, the laser-assisted differential cross section expression by using the scattering matrix approach. We have analyzed the energy and the number of exchanged photons dependence of muon pair production in electron-positron annihilation at different centre of mass energies including the $Z$-boson peak. For this reason, a wide range of high centre of mass energies relevant to future $e^{+}e^{-}$ collider were covered to study the cross section behavior. We have found that, for a given number of exchanged photons, laser field strength and frequency, the circularly polarized laser field decreases the total cross section by several orders of magnitudes.

hep-ph↗

arXiv2021

Laser-assisted charged Higgs pair production in Inert Higgs Doublet Model (IHDM)

The production of a pair of charged Higgs bosons from $e^{+}e^{-}$ annihilation in the presence of a circularly polarized laser field is investigated in Inert Higgs doublet Model (IHDM) at ${e}^{+}{e}^{-}$ colliders. We have derived the analytical expression for the laser-assisted differential cross section by using the Dirac-Volkov formalism at leading order including the $Z$ and $γ$ diagrams. Since the laser-free cross section of this process depends, in the lowest order, only on the mass of the charged Higgs boson and the energy of the center of mass, we have analyzed the dependence of the total laser-assisted cross section on these parameters and also on the laser parameters such as the number of photons exchanged, the laser field intensity and its frequency. The results found indicate that the electromagnetic field decreases the order of magnitude of the total cross section as much as the laser field intensity increases or by decreasing its frequency. Moreover, it becomes high for low charged Higgs masses and low center of mass energies.

hep-ph↗

arXiv2021

Laser-assisted neutral Higgs-boson pair production in Inert Higgs Doublet Model (IHDM)

In the framework of the Inert Higgs Doublet model (IHDM), we have investigated, in the center of mass frame, the neutral Higgs-boson pair production in the presence of an intense and circularly polarized laser field via ${e}^{+} {e}^{-}$ annihilation $({e}^{+} {e}^{-}\rightarrow H^{0}A^{0})$ at the lowest order. By using the scattering matrix method, we have derived the analytical expression of the differential cross section. The latter is numerically integrated over the solid angle to obtain the total cross section. Then, we have shown how this total cross section depends on the outgoing particles mass for different number of exchanged photons. Next, we have illustrated its variation as a function of the centre of mass energy for different neutral Higgs-boson masses. Finally, we have indicated how it changes as a function of the laser field amplitudes for both different number of exchanged photons and different neutral Higgs-bosons masses.

hep-ph↗

arXiv2021

Laser-assisted kaon decay and CPT symmetry violation

In this paper, we have investigated the charged kaons decay at the lowest order in the presence of a circularly polarized laser field. To be more precise, we have examined the leptonic decay of both positive (matter) and negative (antimatter) kaon which weakly decay via the exchange of $W$ boson. Indeed, we have derived the expression of the leptonic decay width, the leptonic branching ratio, the leptonic ratio and the charged kaon lifetime by using the decay matrix approach. In addition, by using numerical computation, we have presented and discussed how the laser field influences these physical quantities. Moreover, we have analyzed the effect of the laser field on the parameter associated with the CPT symmetry. Then, we have concluded that, in the presence of an electromagnetic field and based on this CPT symmetry parameter, it is possible to control the dominance of matter over antimatter or vice-versa by applying an external field to either violate or conserve the CPT symmetry.

hep-ph↗

arXiv2021

$Z$-boson production via the weak process $e^+e^- \to μ^+μ^-$ in the presence of a circularly polarized laser field

In the centre of mass frame, we have studied theoretically the $Z$-boson resonant production in the presence of an intense laser field via the weak process $e^+e^- \to μ^+μ^-$. Dressing the incident particles by a Circularly Polarized laser field (CP-laser field), at the first step, shows that for a given laser field's parameters, the $Z$- boson cross section decreases by several orders of magnitude. We have compared the the Total Cross Section (TCS) obtained by using the scattering matrix method with that given by the Breit-Wigner approach in the presence of a CP-laser field and the results are found to be very consistent. This result indicates that Breit-Wigner formula is valid not only for the laser-free process but also in the presence of a CP-laser field. The dependence of the laser-assisted differential cross section on the Centre of Mass Energy (CME) for different scattering angles proves that it reaches its maximum for small and high scattering angles. At the next step and by dressing both incident and scattered particles, we have shown that the CP-laser field largely affects the TCS, especially when its strength reaches $10^{9}\,V.cm^{-1}$. This result confirms that obtained for the elastic electron-proton scattering in the presence of a CP-laser field [I. Dahiri et al., arXiv:2102.00722v1]. It is interpreted by the fact that heavy interacting particles require high laser field's intensity to affect the collision's cross section.

hep-ph↗

arXiv2021

Higgs-strahlung boson production in the presence of a circularly polarized laser field

In the framework of the electroweak standard model, we investigated, in the center of mass frame, the Higgs boson production in the presence of an intense laser field via ${e}^{+} {e}^{-}$ annihilation $({e}^{+} {e}^{-}\rightarrow ZH)$. By comparing our results with those obtained by Djouadi \cite{1} for laser-free process, we show that the circularly polarized laser field affects significantly the $s$-channel Higgs boson production. We find that for a given number of exchanged photons, laser field strength and frequency, the total cross section decreases by several orders of magnitude. These effects of laser field on cross section are found to be consistent with what was found for muon pair production via QED process in the presence of a circularly polarized laser field \cite{2}.

hep-ph↗

arXiv2017

Characterization of spatiotemporal chaos in Kerr optical frequency {comb generators} and in fiber cavity

Complex spatiotemporal dynamics have been a subject of recent experimental investigations in optical frequency comb microresonators and in driven fiber cavities with a Kerr-type media. We show that this complex behavior has a spatiotemporal chaotic nature. We determine numerically the Lyapunov spectra, allowing to characterize different dynamical behavior occurring in these simple devices. The Yorke-Kaplan dimension is used as an order parameter to characterize the bifurcation diagram. We identify a wide regime of parameters where the system exhibits a coexistence between the spatiotemporal chaos, the oscillatory localized structure, and the homogeneous steady state. The destabilization of an oscillatory localized state through radiation of counter propagative fronts between the homogeneous and the spatiotemporal chaotic states is analyzed. To characterize better the spatiotemporal chaos, we estimate the front speed as a function of the pump intensity.

nlin.CD↗

arXiv2016

Extended and localized Hopf-Turing mixed-mode in non-instantaneous Kerr cavities

We investigate the spatio-temporal dynamics of a ring cavity filled with a non-instantaneous Kerr medium and driven by a coherent injected beam. We show the existence of a stable mixed-mode solution that can be either extended or localized in space. The mixed-mode solutions are obtained in a regime where Turing instability (often called modulational instability) interacts with self-pulsing phenomenon (Andronov-Hopf bifurcation). We numerically describe the transition from stationary inhomogeneous solutions to a branch of mixed-mode solutions. We characterize this transition by constructing the bifurcation diagram associated with these solutions. Finally, we show stable localized mixed-mode solutions, which consist of time-periodic oscillations that are localized in space.

nlin.PS↗