arXiv subjects

S. Taj

Publications and source records attributed to S. Taj.

At least 19 recordsLinked to original sources

arXiv2026

Laser-assisted production of the light charged Higgs boson from top quark decay in the type-I two Higgs doublet model

We investigate the impact of a circularly polarized laser field on the top quark decay process into a charged Higgs boson ($t\rightarrow bH^+$) within the type-I two Higgs doublet model. Our study aims to explore how an external electromagnetic field can modify key observables and potentially facilitate the experimental detection of the charged Higgs boson, addressing challenges related to missing energy in collider experiments such as the LHC. Employing the Dirac-Volkov formalism, we model the interaction between charged particles and the laser field and demonstrate that the presence of the laser can notably influence the decay branching ratios under suitable conditions. The analysis reveals that both the intensity and frequency of the laser field play a crucial role in determining the decay width. In particular, for a laser field strength of $3.8\times 10^{14}$ V/cm and a photon energy of $0.117$ eV, the branching ratio of the top quark decaying into a charged Higgs boson with mass in the range $80$-$150$ GeV and a bottom quark reaches $0.97$, surpassing the standard $t\rightarrow bW^+$ channel. These results suggest that strong electromagnetic fields can serve as an effective mechanism to enhance signals of new particles, offering promising avenues for experimental searches beyond the Standard Model.

hep-ph↗

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

Relativistic elastic scattering of a muon neutrino by an electron in an elliptically polarized laser field

Within the framework of electroweak theory, we investigate the elastic scattering process $ e^{-} + \nu_{\mu} \rightarrow e^{-} + \nu_{\mu}$ in the presence of an intense elliptically polarized laser field. We derive an analytical expression for the spin-unpolarized differential cross section using the first Born approximation and the Dirac-Volkov states to describe the incident and scattered electrons. Our results generalize those found for the linearly polarized field by Bai \textit{et al.} [Phys. Rev. A \textbf{85}, 013402 (2012)] and for the circularly polarized field by El Asri \textit{et al.} [Phys. Rev. D \textbf{104}, 113001 (2021)]. We find that the differential cross section is significantly enhanced for linear polarization and reduced for circular and elliptical polarizations.

hep-ph↗

arXiv2022

Laser-assisted charged Higgs boson decay in Two Higgs Doublet Model -- type II

In this paper, we investigate the charged Higgs boson decay in the context of the type-II two-Higgs-doublet model in the presence of a circularly polarized electromagnetic field of laser radiation. The calculations are performed by adopting the Furry picture approach of non-perturbative interactions with the external electromagnetic field. Using the method of exact solutions for charged particles states in the presence of a circularly polarized electromagnetic wave field and evaluating the $S$-matrix elements, an exact analytic expression is derived for the decay width of leptonic, hadronic and bosonic decay modes. The branching ratios of different decay modes with multiple photon emission and absorption from the laser beam are analyzed and found to be dramatically modified in the region of superstrong fields. The dependencies of the decay width on the laser field strength and frequency are also examined. The results obtained may be interesting for future experimental and theoretical investigations.

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 $e^{+}e^{-}\rightarrow\mu^{+}\mu^{-}H$ is reduced more significantly, while that of the process $e^{+}e^{-}\rightarrow\nu\bar{\nu}H$ 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 $e^{-}+\nu_{\mu}\longrightarrow e^{-}+\nu_{\mu}$ 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

Effect of electron spin polarization in laser-assisted electron-proton scattering

This work aims to study theoretically the electron-proton scattering for initially spin-polarized electrons in the presence of a circularly polarized electromagnetic field. Using the first Born approximation and the Dirac-Volkov states for dressed electrons, we derive an analytic expression for the differential cross-section with the help of the spin-helicity formalism. Meanwhile, a well-known concept of spin-flip and spin non-flip differential cross sections is applied. The influence of the electromagnetic field on the degree of polarization of the scattered electron is investigated, and the effect of electron spin polarization is examined. We found that the initial spin of the electron can be affected depending on its kinetic energy during the scattering process. This work is a continuation of a recent paper in which we studied the unpolarized electron-proton scattering in the presence of a laser field (Dahiri, et al., Laser Phys. Lett. 18 (2021) 096001).

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 $\gamma$ 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 $d\Omega$. 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 $\gamma$ 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

Analysis of the geometric effect on laser-assisted decay processes

Choosing a specific direction for the propagation of laser field waves often presents a challenge for researchers studying laser-assisted ultrafast quantum processes. They are faced with the question of why exactly this direction and not another. This paper resolves the discussion in this issue regarding decay processes. Therefore, we study theoretically the pion decay process in the presence of a circularly polarized laser field propagating along an arbitrary general direction. Using the first Born approximation and the Dirac-Volkov states for charged particles, we derive an analytic expression for the decay rate. The direction of the laser field was found to have no significant effect on the nature of the result obtained. This study generalizes the results found for a field with a wave vector along the $z$-axis in a recent paper (Phys Rev D 102:073006, 2020). This paper will serve as a justification for the choice of a specific direction for the laser field in laser-assisted decay processes. The effect of the laser field on the total decay rate has also been reported and discussed.

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 ${e}^{+} {e}^{-} \rightarrow{\mu}^{+} {\mu}^{-}$ 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

Relativistic elastic scattering of an electron by a muon in the field of a circularly polarized electromagnetic wave

Within the framework of quantum electrodynamics, the scattering of an electron by a muon in the presence of a circularly polarized monochromatic laser field is investigated theoretically in the first Born approximation. The expressions for the amplitude and the differential cross section are derived analytically by adopting the Furry picture approach in which the calculations are carried out using exact relativistic Dirac-Volkov functions. We begin by studying the process taking into account the relativistic dressing of only the electron without muon. Then, in order to reveal the effect of the muon dressing, we fully consider the relativistic dressing of the electron and muon together in the initial and final states. As a result, the differential cross section is significantly reduced by the laser field. We find that the effect of laser-dressing of muon becomes noticeable at laser field strengths greater than or equal to $10^{9}~\text{V cm}^{-1}$ and therefore must be taken into account. The influence of the laser field strength and frequency on the differential cross section and multiphoton process is revealed. An insightful comparison with the laser-free results is also included.17

quant-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 $\gamma$ 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↗