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The theory of triple differential cross-sections, developed previously within the framework of nonrelativistic Schrödinger formalism, is extended to the relativistic treatment by using the Dirac-Volkov formalism. At high energies, the colliding particles lose their Coulomb character and the channel of the symmetric coplanar geometry is opened. In the first Born approximation, we have studied theoretically the laser-assisted relativistic ionization of hydrogen atoms by positron impact in this geometry. Triple differential cross-sections are calculated by using two approaches: (i) RPWSG to describe relativistic plane wave in the symmetric geometry, (ii) DVPWSG (Dirac- Volkov plane wave in the symmetric geometry) in which we take full account of the relativistic dressing effects, has been proposed to study the influence of laser field on the colliding particles. To check the consistency of our model, we have used, for comparison, the nonrelativistic approach: nonrelativistic plane wave in the symmetric geometry. Numerical results for the variation of relativistic triple differential cross-sections and their dependences on laser field parameters (intensity, frequency) and incident positron energy are also presented. As for the laser modifications, by summing over a very large number of exchanged photons, the laser-assisted triple differential cross-sections usually tends to approach the laser-free triple differential cross-sections, obeying the famous Kroll-Watson sum rule for positron projectile. In the absence, of any experimental data at high energies for this particular ionization process, we are not in a position to compare the present results with the experimental findings. [ABSTRACT FROM AUTHOR]

In the framework of the first Born approximation and using the Dirac-Volkov formalism, we investigate the relativistic model describing the laser assisted elastic differential cross sections (DCSs) for positron scattering by the hydrogen atom. Both the DCSs for electron and positron are notably modified by the circularly polarized laser field, particularly in the regime of high energies and medium intensities. Comparing the two numerical DCSs, we recover the well-known result that the elastic scattering differential cross sections with and without laser field for a hydrogen atom by electron and positron impact are the same (Greiner and Reinhardt. Quantum Electrodynamics, 2nd ed., Springer Verlag, New York, Berlin, Heidelberg. 1994). The numerical results reveal that the differential cross section for positron - hydrogen atom scattering is significantly reduced with the increase of the electric field strength. [ABSTRACT FROM AUTHOR]

In the framework of the first Born approximation, we present a semirelativistic theoretical study of the inelastic excitation (1s1/2 → 2s1/2) of hydrogen atom by electronic impact. The incident and scattered electrons are described by a free Dirac spinor and the hydrogen atom target is described by the Darwin wave function. Relativistic and spin effects are examined in the relativistic regime. A detailed study has been devoted to the nonrelativistic regime as well as the moderate relativistic regime. Some aspects of this dependence as well as the dynamic behavior of the differential cross-section in the relativistic regime have been addressed. [ABSTRACT FROM AUTHOR]

In this work, we review and correct the first Born differential cross section for the process of Mott scattering of a Dirac–Volkov electron, namely, expression (26) derived by Szymanowski et al. (Phys. Rev. A, 56, 3846 (1997)). In particular, we disagree with the expression of (dσ/dΩ) that they obtained and we give the exact coefficients multiplying the various Bessel functions appearing in the scattering differential cross section. Comparison of our numerical calculations with those of Szymanowski et al. shows qualitative and quantitative differences when the incoming total electron energy and the electric-field strength are increased particularly in the direction of the laser propagation. Such corrections are very important since the relativistic electronic dressing of any Dirac–Volkov charged particle gives rise to these coefficients that multiply the various Bessel functions, and the relativistic study of other processes (such as excitation, ionization, etc....) depends strongly upon the correctness and reliability of the calculations for this process of Mott scattering in the presence of a laser field. Our work has been accepted, Attaourti and Manaut (Phys. Rev. A, 68, 067401 (2003)) but only as a comment. In this paper, we give full details of the calculations as well as a clear explanation of the large discrepancies that their results could cause when working in the ultra relativistic regime and using a very strong laser field corresponding to an electric field strength ε = 5.89 au. [ABSTRACT FROM AUTHOR]

This study employs a first-principles approach to comprehensively examine the structural, electronic, optical, and magnetic properties of the thermodynamically stable scintillating double perovskite halides A 2 N a T a X 6 ( A = C s , R b ; X = C l , B r , I ). The dynamic stability of these materials were explained based on deduced phonon properties. Our analysis reveals that these compounds exhibit intriguing electronic behavior with spin polarization, demonstrating half-metallicity. In spin-up, the band gap is found to be zero, while in spin-down, it falls within the range of 3 to 4 eV with the incorporation of DFT+U corrections. Notably, the optical properties assessment highlights the exceptional UV and high-energy absorption capabilities of A 2 N a T a I 6 , making it a promising candidate for scintillation applications in particle detection. This research sheds light on the unique and versatile properties of these materials, with implications for various technological and scientific applications. [ABSTRACT FROM AUTHOR]

This research work investigates the structural, electronic, optical, and thermoelectric characteristics of VFeZ (Z = N and P) half‐Heusler compounds. The study employs the full‐potential linearized augmented plane wave (FP‐LAPW) method integrated into the WIEN2K algorithm, serving as the underpinning framework for density functional theory (DFT) analysis. In the study, we use the PBE generalized gradient approximation (PBE‐GGA) to identify numerous parameters associated with structural and elastic properties. Lattice parameter results are in agreement with previous outcomes. Moreover, computed elastic parameters satisfy the criterion for stability. In the cubic structure VFeZ (Z = N and P) is ductile, to enhance the computations of electronic characteristics, Tran and Blaha's modified Becke‐Johnson potential (TB‐mBJ) is used. Our simulations demonstrate that the materials exhibit semiconductor behavior, with a direct band gap for VFeZ (Z = N and P). Strong UV absorption is found via optical experiments suggest compounds are suitable for optical application. Furthermore, study of the thermoelectric properties suggests its application in the thermoelectric generators. [ABSTRACT FROM AUTHOR]

The two-body leptonic decays of both light and heavy-charged mesons X l 2 ± are investigated in the first Born approximation in the presence of a monochromatic and circularly polarized laser field. As a result of using Volkov functions, the analytic study of these processes has brought a change in the parameters associated with each decay process. The decay width, lifetime, and branching ratio of each decay process are affected by increasing the classical parameter ξ of the meson. A comparison between the matter decay X l 2 + and that of the anti-matter X l 2 - in the presence of a circularly polarized laser wave, indicates that increasing laser field strength (increasing the classical parameter ξ ) can induce a slight dominance of matter over antimatter or vise versa. [ABSTRACT FROM AUTHOR]

In the 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 1 0 8 V/cm. [ABSTRACT FROM AUTHOR]

The Full Potential Linearised Augmented Plane Wave method (FP-LAPW) is used to design the structural, elastic-mechanical, electronic, magnetic, and thermoelectric prop-erties of new cubic double perovskite oxides X 2 C e V O 6 (X = S r , B a) . The tolerance factor and elastic parameters show and ensure the stability and formation of both perovskites in the cubic phase. Additionally, the predicted mechanical constants show that X 2 C e V O 6 (X = S r , B a) behave as stable ductile materials. Then, spin-polarized calculations show ferromagnetic and half-metallic behavior for both compounds with a total magnetic moment equal to 1 μ β . Thermoelectric parameters of both materials show high power factor and n-type conductivity, due to the multiple oxidation states of Vanadium. Therefore, these results show that the proposed perovskites X 2 C e V O 6 (X = S r , B a) can be promising materials for spintronic and thermoelectric applications. [ABSTRACT FROM AUTHOR]

In a previous paper, we showed theoretically that the total cross-section of the top-quark pair production by electron–positron annihilation is strongly reduced by the presence of a circularly polarized laser field. In this paper, we present the result for the case of a linearly polarized laser field. This time, the total cross-section is significantly enhanced by the laser field. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In this research paper, we consider the process of neutral Higgs production from e+e– annihilation in Inert Higgs Doublet Model (IHDM) in the absence and presence of an external field. The latter is assumed to be a plane and monochromatic wave with linear polarization. In the theoretical framework, we present the analytic calculation of the lowest order differential cross section by using the scattering matrix approach and Dirac–Volkov formalism for charged incident particles. The total cross section is computed by performing a numerical integration of the differential cross section over the solid angle. The results obtained are analyzed and discussed for different centre of mass energies and laser parameters. We found that inserting a laser wave with linear polarization is a suitable mechanism to enhance the total cross section of the process. Indeed, the probability of the process to occur increases with the presence of a linearly polarized laser field, especially with low frequency and high strength. [ABSTRACT FROM AUTHOR]

Various properties of S r 2 M W O 6 (M = V , R h , R u) are investigated based on the DFT theory using the full-potential linearized augmented plane wave (FP-LAPW) method. Their magnetic properties show a half metallic bahavior for M = V and Rh with high magnetic moments. However, for S r 2 R u W O 6 , the bands for up and down spins are symmetric and thus this material is non-magnetic with an energy band gap of 1.4 e V . The presence of Ru and Rh in S r 2 M W O 6 structure increases the absorption of this material, especially in the visible light range. The elastic constants C α β for all studied compounds were obtained using Elastic1.1 and satisfy the Born stability criterion. This indicates that all the compounds are mechanically stable. Finally, electrical properties were determined using BoltzTraP package leading to interesting aspects. The obtained results are comparable with other perovskite phases. Therefore, these coupled features of the title compounds make them promising material for different applications. [ABSTRACT FROM AUTHOR]

Owing to their proper characteristic, simple halide perovskites became engaged over time for thermoelectric applications. In this work, several physical properties of simple halide perovskite materials AInBr 3 (A = K, Rb) are predicted based on density functional theory (DFT) within the Wien2k code. The tolerance factor and negative formation energy demonstrate the stability and formation of these compounds, and the Born criteria shows their mechanical stability and inherent ductility. Notably, the modified Becke-Johnson potential (mBJ) was used to calculate the optoelectronic characteristics. The AInBr 3 (A = K, Rb) perovskites present semiconducting aspects. Analyses of their optical characteristics, including refractive index, reflectivity, were performed. AInBr 3 (A = K, Rb) transport properties were studied. The highest figure of merit was attained by AInBr 3 (A = K, Rb) which had a high Seebeck coefficient and high electrical conductivity. Finally, all studied properties of simple halide perovskites give a new way for efficient applications in thermoelectric. • The structural, electrical, optical, and thermoelectric properties of cubic perovskite AInBr 3 (A = Rb, K) are demonstrated. • The compounds are suitable for optoelectronic applications since their maximal absorption occurs in the visible spectrum. • The high-power factor and figure of merit of AInBr 3 (A = Rb, K) indicate that the examined compounds are appropriate for thermoelectric applications. [ABSTRACT FROM AUTHOR]

We analyse a light charged Higgs boson in the 2-Higgs Doublet Model (2HDM) Type-I, when its mass satisfies the condition MH±< Mt + Mb and the parameter space is consistent with theoretical requirements of self-consistency as well as the latest experimental constraints from Large Hadron Collider (LHC) and other data. Over such a parameter space, wherein the Standard Model (SM)-like state discovered at the LHC in 2012 is the heaviest CP-even state of the 2HDM, it is found that the decay modes of the charged Higgs boson are dominated by H±→ W±(∗)h. Furthermore, the light neutral Higgs boson h dominantly decays into two photons. Under these conditions, we find that the production and decay process pp → H±h → W±(∗)hh → ℓνℓ + 4γ (ℓ = e, μ) is essentially background free. However, since the W±(∗) could be largely off-shell and the h state is very light, so that both the lepton coming from the former and the photons coming from the latter could be rather soft, we perform here a full Monte Carlo (MC) analysis at the detector level demonstrating that such a W± + 4γ signal is very promising, as it would be yielding significant excesses at the LHC with an integrated luminosity of L = 300 fb−1 at both s = 13 and 14 TeV. [ABSTRACT FROM AUTHOR]

At the Large Hadron Collider (LHC), both the ATLAS and CMS Collaborations have been searching for light charged Higgs bosons via top (anti)quark production and decays channels, like pp → t t ¯ with one top (anti)quark decaying into a charged Higgs boson and a b (anti)quark, when the decay is kinematically open (i.e., when m H ± ≲ mt). In this paper, we propose new searches at the LHC involving light charged Higgs bosons via their pair production channels like pp → H±h/A and pp → H+H− in the 2-Higgs Doublet Model (2HDM) Type-I and -X scenarios. By focusing on the case where the heavy H state plays the role of the Standard Model (SM)-like Higgs boson with a mass near 125 GeV, we study the aforementioned Higgs boson pair production channels and investigate their bosonic decays, such as H± → W±h and/or H± → W±A. We demonstrate that for a light charged Higgs boson state, with m H ± ≲ mt, at the LHC, such di-Higgs production and decay channels can give rise to signatures with event rates much larger than those emerging from pp → t t ¯ → t b ¯ H− + c.c. We specifically study h/A → b b ¯ and τ+τ− decays. We, therefore, claim that the discussed combination of new production and decay modes can result in an alternative discovery channel for charged Higgs bosons lighter than the top (anti)quark at the LHC within the above two 2HDM Types. Finally, in order to motivate experimentalists in ATLAS and CMS to search for such signatures, we propose 16 Benchmark Points (BPs) which are compatible with both theoretical and experimental constraints. [ABSTRACT FROM AUTHOR]

The uptake of U and Th in different parts of some selected plants used in traditional treatment of hypertension and diabetes in south-eastern Morocco (Errachidia area) has been studied using two different types of solid state nuclear track detectors (SSNTDs) LR-115 type II and CR-39. Plant uptake of radionuclides is one of many vectors for introduction of contaminants into the human food chain. Thus, it is critical to understand soil-plant relationships that control nuclide bioavailability. Soil concentrations of uranium ranged from 6.10 to 11.62 ppm, with a mean of 7.90 ppm. Soil concentrations of thorium ranged from 2.70 to 4.80 ppm, with a mean of 3.41 ppm. Mean uranium specific activities were 8.38 Bq kg in root tissue, 5 Bq kg in stem tissue and 6.02 Bq kg in leaf tissue. Mean thorium specific activities were 2.53 Bq kg in root tissue, 1.64 Bq kg in stem tissue and 1.96 Bq kg in leaf tissue. The transfer factors of U and Th from soil to different parts (root, stem, leaf, seed and fruit) of studied plant samples have been investigated. The transfer factors obtained for root plants were markedly higher than those for leaf, stem, fruit and seed plants. Soil-to-plant transfer factor (TF) is one of the most important parameters to be used in transfer models for predicting the concentration of radionuclides in agricultural crops and for estimating dose impacts to man. This study of uranium and thorium uptake in plants used in traditional medicine is also significant as far as the health hazard effects of uranium and thorium in human being are concerned. [ABSTRACT FROM AUTHOR]

The electronic, elastic, structural, thermoelectric and optical parameters of Pb-based cubic perovskites P b R E O 3 (R E = C e , N d , G d) were calculated using the WIEN2k Package. The mechanical optimization and structural stabilities were evaluated. The found results are in full agreement with the experimental ones. The obtained elastic results show that these perovskites behave as stable ductile materials, and their higher Y value gives them rigid structures. The P b C e O 3 presents n-type semiconductor while P b R E O 3 (R E = N d , G d) exhibit p-type semi-conductors with gap energies of 2. 60 eV , 1. 02 eV and 1. 55 eV , respectively. The optical properties show that P b R E O 3 (R E = C e , N d , G d) have significant absorption in the visible light region with low reflectivity. The thermoelectric properties present a desired electrical performance at room temperature for all materials. For these generation of materials, the effect of RE on Pb-based cubic perovskite oxides can be exploited in manufacturing of thermoelectric, mechanic and optoelectronic devices. • Physical properties of PbCeO3, PbNdO3 and PbGdO3 were studied. • Structural and elastic properties present a stable behavior of the studied compounds. • The electronic properties indicate the semiconductor behavior of all studied. • Optical properties presents an important absorption coefficient in the visible region. • Thermoelectric properties show the charge carriers responsible of the conduction. [ABSTRACT FROM AUTHOR]

Various physical properties (electronic, optical and thermoelectric) of cubic perovskite oxides Sr X O 3 (X = Sc, Ge, Si) are investigated by using the density functional theory (DFT) within Wien2K code. This code is based on different approximations such as generalized gradient approximation GGA, PBEsol, LDA, WC and the modified Becke–Johnson exchange potentials (mBJ, nmBJ and unmBJ). Structural properties and the optimization have been calculated using PBEsol functional which showed a significant results that are in good agreement with the experimental ones. The results for physical properties such as electronic, thermoelectric and optical are analyzed in detail by using the nmBJ approximation. The obtained results present an opening gap for SrSiO 3 , SrGeO 3 and a metallic behavior for SrScO 3. An average of transmittance which is about 94% to 97% was observed in the range of visible light. The increase of electrical conductivity with temperature confirms the effect of thermal agitation on the concentration of charges carriers using BolzTrap2 Package. Lastly a phonon dispersion was made and show that for X = Ge and Si, the structure is relatively stable while SrScO 3 is dynamically unstable. These results prove the ability that these materials can be exploited in many applications and manufacturing of optoelectronics for Sensors. [ABSTRACT FROM AUTHOR]

A search for charged Higgs may yield clear and direct signs of new physics outside the realm of the Standard Model (SM). In the Two-Higgs Doublet Model (2HDM), we investigate two of the main single charged Higgs production channels at the Large Hadron Collider (LHC), assuming that either h or H replicates the detected resonance at ∼ 125 GeV. We consider the possibility of the charged Higgs boson production through the p p → H ± W ∓ and p p → H ± b j production processes that may present additional significance at the LHC experiments. Considering the H ± → W ± h i / A decay channels and mainly concentrating on the b b ¯ , ττ and γγ decays of h i and A , we examine the possible signatures arising from the aforementioned charged Higgs production and decay in both type-I and type-X realizations of 2HDM. Our study shows that these signatures can have sizable rates at low tan ⁡ β as long as the condition M H ± < m t − m b is satisfied. As a result, we propose the bb , ττ and γγ final states associated with WW or Wbj as an encouraging experimental avenue that would complement the LHC search for a charged Higgs boson. [ABSTRACT FROM AUTHOR]

Within the framework of electroweak theory, we investigate the elastic scattering process e − + ν μ → e − + ν μ 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 et al. (2012) [24] and for the circularly polarized field by El Asri et al. (2021) [23]. We find that the differential cross section is significantly enhanced for linear polarization and reduced for circular and elliptical polarizations. [ABSTRACT FROM AUTHOR]

A theoretical treatment, using the first Born approximation, is presented to analyse the results of relativistic laser-assisted proton - hydrogen atom scattering. Specific calculations are carried out for excitation of hydrogen atoms from 1s1/2 to 2s1/2 states by proton impact. We work in an approximation in which the incoming proton may be described by Dirac-Volkov states in the presence of a laser field. Semi-relativistic Darwin wave functions are used to describe the hydrogen atom in its initial and final states, while relativistic, spin, and laser interaction effects are also accounted for. The results presented in this paper show that the differential cross section for this process depends not only upon the energy of the incident proton, but also upon its interaction with the laser field through intensity and frequency. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]