Narrow Results

A detailed study of fragmentation of vector mesons at the next-to-leading order (NLO) in QCD is given for e⁺e^- scattering. A model with broken SU(3) symmetry using three input fragmentation functions α(x, Q²), β(x, Q²) and γ(x, Q²) and a strangeness suppression parameter λ describes all the light quark fragmentation functions for the entire vector meson octet. At a starting low energy scale of for three light quarks (u, d, s) along with initial parametrization, the fragmentation functions are evolved through DGLAP evolution equations at NLO and the cross-section is calculated. The heavy quarks contribution are added in appropriate thresholds during evolution. The results obtained are fitted at the momentum scale of for LEP and SLD data. Good-quality fits are obtained for ρ, K*, ω and ϕ mesons, implying the consistency and efficiency of this model. Strangeness suppression in this model is understood both in terms of ratios of quark fragmentation functions alone as well as in terms of observables; the latter yield a suppression through the K*/ρ multiplicity ratio of about 0.23 while the x dependence of this suppression is also parametrized through the cross-section ratios.

A combined analysis of both $e^{+}{e}^{-}$ (LEP, SLD) and $pp$ (RHIC-PHENIX and LHC-ALICE) hadroproduction processes are done for the first time for the vector meson nonet at the next-to-leading order (NLO) using a model with broken SU(3) symmetry. The transverse momentum ($p_T$) and rapidity ($y$) dependence of the differential cross-section for $\omega$ and $\varphi$ mesons of the $pp$ data are also discussed. The input universal quark (valence and singlet) fragmentation functions at a starting scale of $Q_0^2=1.5{\mathrm{\text{GeV}}}^2$, after evolution, have values that are consistent with the earlier analysis for $e^{+}{e}^{-}$ at NLO. However, the universal gluon fragmentation function is now well determined from this study with significantly smaller error bars, as the $pp$ hadroproduction cross-section is particularly sensitive to the gluon fragmentation since it occurs at the same order as the quark fragmentation, in contrast to the $e^{+}{e}^{-}$ hadroproduction process. Additional parameters involved in describing the strangeness and sea suppression and octet–singlet mixing are found to be close to the earlier analysis; in addition, a new relation between the gluon and sea suppression in $K^{\ast }$ and $\varphi$ hadroproduction has been observed.

The explanation of the small neutrino mass can be depicted using some handsome models like type-I and inverse seesaw where the Standard Model gauge singlet heavy right-handed neutrinos are deployed. The common thing in these two models is a lepton number violating parameter, however, its order of magnitude creates a striking difference between them making the nature of the right-handed heavy neutrinos a major play factor. In the type-I seesaw a large lepton number violating parameter involves the heavy right-handed neutrinos in the form of Majorana fermions while a small lepton number violating parameter being involved in the inverse seesaw demands the pseudo-Dirac nature of the heavy right-handed neutrinos. Such heavy neutrinos are accommodated in these models through the sizable mixings with the Standard Model light neutrinos. In this paper we consider the purely inverse seesaw scenario to study the pair production of the pseudo-Dirac heavy neutrinos followed by their various multilepton decay modes through the leading branching fraction at the leading order and next-to-leading order QCD at the LHC with a center-of-mass energy of 13 TeV and a luminosity of 3000 fb${}^{-1}$. We also consider a prospective 100 TeV hadron collider with luminosities of 3000 fb${}^{-1}$ and 30,000 fb${}^{-1}$, respectively to study the process. Using anomalous multilepton search performed by the CMS at the 8 TeV with 19.5 fb${}^{-1}$ luminosity we show prospective search reaches of the mixing angles for the three lepton and four lepton events at the 13 TeV LHC and 100 TeV hadron collider.

The widespread use of nonlinear optical (NLO) materials for contemporary technologies has sparked intense interest in their production with the creation of materials with a continuous endeavor. In this theoretical study, we investigate the NLO responses of doped superalkali (SA) metal salts with planar boron sheets (PBSs). We consider four different substrates (B${}_{10}$, B${}_{10}$F₃, B${}_{16}$, and B${}_{16}$F₃) to create 12 new surfaces (1-12) by doping SAs (Li₂F, Li₂OF, Li₂O₂) with them. We optimize the geometries of these surfaces and analyze their frontier molecular orbitals (FMOs) and natural bond orbitals (NBO) to obtain insights into their global chemical reactivity. We also examined their NLO responses ranging as 1.22–$1.67\times 10^{-21}$, 3.39–$7.59\times 10^{-24}$, and $3.5\times 10^{-24}$e.s.u. Our results reveal that the doped surfaces exhibit stronger NLO responses compared to the undoped surfaces, and that the strongest NLO response is found in the B${}_{16}$F₃-doped surface. The role of various segments in FMOs is investigated using the TDOS and PDOS spectral analyses. To comprehend the relationship between the SA and the B${}_{10}$F₃ substrates molecule more effectively, non-covalent interaction (NCI) investigation is carried out. Additionally, Time-dependent DFT (TD-DFT) simulations are done for UV–Vis analysis to observe significant redshifts up to 1050nm. All the SA-doped surfaces are thermodynamically stable NLO materials with improved NLO responses, so these materials are proposed to be used during the construction of advanced NLO responses.

The strategy of introducing the chromophores with low ground state dipole moment had been discussed to overcome the effect of the electrostatic interaction between the chromophores in the poled polymer films on its nonlinearity. As a result, the effective nonlinear optical coefficient d₃₃ of the poled films, containing the chromophores with μ_g in the range of 3.5–5.5 D, will enhance at least 15%, even over 30%, compared to that of 7.5 D if the first hyperpolarizabilities (β) of chromophores are in the same magnitudes. And, under the above assumption, the same level of the d₃₃ could even be achieved by utilizing the chromophores with μ_g as low as 2.2 D.

A theoretical analysis of the condition of scalar phase-matched second harmonic generation and optical parametric oscillation (OPO) in single-crystalline samples Zn_0.52Mg_0.48Se is presented. The calculated range of pumping for second harmonic generation with phase matching is 5.1-13 μm. The tuning range of the optical parametric oscillator based on Zn_0.52Mg_0.48Se is determined. The combination of active media and nonlinear converter for OPO in the same optical element are proposed.

In the present study, L-alanine crystal is grown with cobalt chloride as dopant by low temperature solution growth using slow evaporation technique at room temperature. The lattice parameters of the grown pure and cobalt chloride doped L-alanine crystals were determined by the single crystal X-ray diffraction technique. The presence of the elemental composition such as cobalt chloride present in the L-alanine lattice was confirmed by energy dispersive X-ray analysis. The optical transmittance, absorbance, reflectance was measured and used to study the optical properties of the pure and doped L-alanine crystal. The pure L-alanine crystal has high optical transmittance in the whole visible range and UV transparency with lower cutoff wavelength at 240nm. By adding cobalt chloride to L-alanine crystal, the transmittance decreases the value of cutoff shifts to the higher wavelengths. Nonlinear optical studies reveal that the SHG efficiency and laser damage threshold energy increases when the L-alanine crystal is doped with cobalt chloride. From microhardness studies, it is observed that the cobalt chloride doped L-alanine crystal is harder than the pure crystal.

Organic single crystal of nicotinium tartrate (NT), an efficient nonlinear optical (NLO) material for frequency conversion, has been grown at a constant temperature at 40${}^{\circ }$C within a period of 20 days by slow evaporation solution technique (SEST). Structural information and lattice dimensions were determined using powder X-ray diffractometer (PXRD) analysis. The functional groups and vibrational frequencies were identified using FTIR spectrum analysis with the range of 4000–450cm${}^{-1}$. Mechanical properties of the grown crystal were studied using Vickers microhardness tester. The optical properties of grown crystal were investigated using UV–Vis NIR spectrum analysis and it is confirmed that the crystal has very low absorption in the entire visible region. The dislocations and defects were studied by photoluminescence spectrum. The crystal has single stage melting, which was observed at 180${}^{\circ }$C and there was no decomposition before its melting point. Piezoelectric, photoconductivity and chemical etching analysis have also been performed on the grown NT single crystals and the observed results were discussed. Nonlinear optical property of the material was measured using the powder Kurtz–Perry technique.

Second-order nonlinear optical (NLO) effects can be observed in materials with noncentro symmetric structures. In order to achieve such structure in the initially isotropic-doped polymer films, they were aligned in an electric field during heating up to the glass transition temperature. In this experimental work, we studied the NLO thin film properties of azo dye as guest molecules oriented in a polymer host by corona-onset poling. Also, the orientational order of nonlinear molecules is measured. We have shown that corona-onset poling at elevated temperature (COPET) is effective in orienting optically nonlinear guest molecules in a host polymer.

In this study, the effects of introducing a zinc cation into a zinc-phthalocyanine (ZnPc) cluster are examined in relation to organic phthalocyanine material. The Au/ZnPc/Si-based organic diode is made using the thermal evaporation method. The optical properties of the filter are checked and a selected wavelength of 360nm is recorded. Au/ZnPc/Si/Al exhibits high rectifying performance, and the organic device’s primary conduction mechanism is Space Charge Limited Current. ZnPc film’s superior transparency is shown in the visible spectrum, and its optical bandgap of 3.32eV is found. According to this result, ZnPc is a semiconductor. ZnPc has a weak exciton binding energy (600meV), a high chemical stability, and non-zero value of second hyperpolarizability (4.7310${}^{-36}$esu). These features can offer our ZnPc-based organic device a wide range of applications, including microelectronics, solar cells, and nonlinear optical devices.

Quantum chemical calculations of the structure, molecular electrostatic potential and thermodynamic functions have been performed using the density functional (DFT/B3LYP) method with the 6-311++G(d,p) basis set for the title compound 1-[N-(2-pyridyl)aminomethylidene}-2(1H)-Naphtalenone. The energetic behavior of the title compound in solvent media has been examined by applying the Onsager and the polarizable continuum model. To investigate second order nonlinear optical properties of the title compound, the electric dipole μ, the polarizability α and the first hyperpolarizability β were computed using the density functional B3LYP and CAM-B3LYP methods with the 6-311++G(d,p) basis set. According to our calculations, the title compound exhibits nonzero β value revealing second order NLO behavior. The changes of thermodynamic properties for the formation of the title compound with the temperature ranging from 200 K to 500 K have been obtained using the statistical thermodynamic method. The relationship between formation enthalpy and entropy changes has been investigated with the entropy–enthalpy compensation. Besides, natural bond orbital and frontier molecular orbital analysis of the title compound were investigated by theoretical calculations.

The pyrazole compounds 4-(3-(2-amino-3,5-dibromophenyl)-1-(4-substitutedbenzoyl)-4,5-dihydro-1H-pyrazol-5-yl) benzonitriles (4–6) have been synthesized and characterized by elemental, IR, ¹HNMR spectral methods. In addition, the synthesized compounds were subjected to density functional theory for further understanding of the molecular architecture and optoelectronic properties. The optimized geometric parameters were in support of the corresponding experimental values. The FT-IR spectra of 4–6 have been investigated extensively using DFT employing B3LYP/6-31G (d,p) level theory. The molecular electrostatic potential analysis has been utilized to identify reactive sites of title compounds. Natural bonding orbital analysis proved the inter- and intra-molecular delocalization and acceptor–donor interactions based on the second-order perturbation interactions. The calculated band gap energies revealed that charge transfer occurs within the molecule. The polarizability and hyperpolarizability were calculated which show that compounds posses nonlinear optical nature.

The single crystal XRD analysis has been used to examine the structure of the centrosymmetric crystal 4-Methoxy acetanilide. The material delineated in orthorhombic system with the space group of Pbca. FTIR and Raman spectrum analysis have been executed to comprehend the molecular interactions and to study the vibrational nature of the functional groups presented in the title molecule. Characteristic studies like optical, dielectric and thermal stability have also been carried out. Detailed explorations have been conducted on the optical properties of the crystal using both quantum chemical calculations and experimental data.

This study is based on the valuation of a few model molecules. The objective of this research is focussed on the nonlinear optical (NLO) improvement of four organometallic molecules and one organic molecule. These molecules have been subjected to several calculations by different functionals: CAM–B3LYP, LC–BLYP, LC–wPBE, wB97X, M11, M06–2X, M08–HX and M08–SO. These functionals gave three orders of classification of the ${\beta }_{\mathrm{\text{tot}}}$ parameters. The CAM–B3LYP functional recorded very good agreement between ${\beta }_{\mathrm{\text{tot}}}$ parameters and gaps ($\mathrm{\Delta }{E}_{\text{H}-\text{L}})$. Significant first hyperpolarizabilities (${\beta }_{\mathrm{\text{tot}}})$ have been obtained around 880 * 10${}^{-30}$esu. The mechanisms of intramolecular charge transfer (ICT) have shown energetic passages from donor groups to acceptors and vice versa. The substitution of metals influences the location of $\pi$ electrons at the level of the chromophores. Finally, the lengthening of the aromatic chains between the acceptor and donor groups shows significant NLO improvements. The first and second hyperpolarizabilities (${\beta }_{\mathrm{\text{tot}}})$ and (${\gamma }_{\mathrm{\text{tot}}})$ for a chain of several benzene rings are of the order of 21,663.16 * 10${}^{-30}$esu and 16,464.65 * 10${}^{-35}$esu, respectively.

Two major reasons limit porphyrins photonic applications: (i) the difficulty of handling them in liquid solutions and (ii) their degradation with long exposure to light. This necessitates the use of appropriate solid matrices to host the porphyrin compounds such as Nafion (117), a stable and inert ion exchange polymer. The first part of this publication confirms such a possibility. In addition to their effective NLO properties, an enhancement of the Soret and Q-bands' absorbance width have been observed by blending three different porphyrin molecules in the Nafion column matrix membrane. This is an important development towards achieving efficient photon-harvesting medium for possible application in photonic devices. The second part of this contribution reports on the self-assembly/molecular recognition of a specific class of porphyrins giving rise to tubular nano-systems with potential THG nonlinear properties.

This work is devoted to studying the aggregation effect on the nonlinear optical (NLO) and charge transport (CT) properties of low-symmetry phthalocyanines bearing a cyclotriphosphazene moiety, a monomer, and clamshell-type bis-phthalocyanine. FE-SEM and AFM studies revealed ordered nanoaggregation in these compounds, represented as repeating objects of regular configuration, globules (340–480 nm), which contain small aggregates inside their cavity, similar to smoothed polygons (ca. 40 nm). Such specificity is not characteristic of other functionalized phthalocyanines, which we dealt with earlier. A new spectral method for estimating the aggregation threshold based on the change in extinction with increasing concentration of solutions was also implemented, and the effect of aggregation on optical limiting was demonstrated. The behavior of isomers and rotamers of bis-phthalocyanine in the presence of electric fields of various strengths was investigated with the DFT calculations, and that partially corresponds to the impact of laser radiation on molecules. It was shown that the unusual behavior of the trans-isomer in FF-DFT calculations is the reason for the worsening of the NLO and CT characteristics of bis-phthalocyanine, in which the macrocycles are strapped through a phosphazene spacer. An advanced method of multiparametric analysis has been implemented to evaluate the NLO and CT properties of the dyes in general.

Electric field-mediated chemistry provides fertile ground for interdisciplinary research, where theoretical ideas and experimental data converge to unravel the complexities of molecular behavior under the influence of electric fields, offering unprecedented opportunities for scientific research and technological innovation. Thus, this work is devoted to the study underscoring the importance of oriented external electric fields (OEEFs) in modulating the structural and electronic properties of low-symmetry monophthalocyanines, which is crucial for enhancing their reactivity and nonlinear optical response. The highlight of this article is that the OEEFs lead to molecular conductivity due to reduced energy gap and electron density shifting towards the phosphazene ring. Additionally, there is a tendency for the elimination of chlorine atoms in the trans- position relative to the phthalocyanine macrocycle. Also, the use of the previously created CORRELATO algorithm has allowed the demonstration of the relationship between structural changes and microscopic parameters responsible for the appearance of NLO properties of final dye materials.

In this study, a new alkylaminophenol compound was synthesized and characterized by spectroscopic techniques (FT-IR, NMR, UV). The optimized molecular geometry and the vibrational wavenumbers were calculated using density functional theory (DFT) B3LYP/WB97XD and HF methods with 6-311++ G($d$, $p$) basis set. Thus, theoretical data were compared within themselves before comparing with experimental data. The detailed interpretation of the vibrational spectra has been carried out by VEDA program. ¹H-NMR and ${}^{13}$C-NMR chemical shifts of the compound were calculated using GIAO/IEFPCM method in CDCl3. Using time-dependent (TD-DFT) approach electronic properties such as HOMO and LUMO energies, the electronic spectrum of the title compound has been studied and reported. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Linear polarizability, anisotropic linear polarizability and hyperpolarizability values of the title compound were found to be higher than the values of the pNA compound that are used as a standard substance in the NLO analysis. Molecular electrostatic potential (MEP), the thermodynamic properties (heat capacity, entropy and enthalpy) were calculated. Also, to investigate the biological properties of the title compound, molecular docking was done with DNA(PDB ID: 414D). It has been observed that the effective interaction is hydrogen bonds.

Nanoclusters such as ${\text{Al}}_{12}$${\text{N}}_{12}$ have received increased attention due to their diverse applications in the fields of optoelectronics and energy storage. In this paper, we have investigated a series of alkaline earth metal (AEM)-encapsulated ${\text{Al}}_{12}$${\text{N}}_{12}$ nanoclusters for hydrogen adsorption. Thermodynamic adsorption parameters, optical and nonlinear optical properties were investigated using density functional theory (DFT) at the B3LYP/6-31G(d,p) level of theory. Encapsulation of AEMs (Be, Mg and Ca) is an effective strategy to improve the NLO reaction and thermodynamic and adsorption properties of ${\text{Al}}_{12}$${\text{N}}_{12}$ nanoclusters. The adsorption energies ranging from $-$26.57kJ/mol to $-$213.33kJ/mol for the three guests (Be, Mg and Ca) capsulated ${\text{Al}}_{12}$${\text{N}}_{12}$ nanoclusters are observed. The adsorption energy is affected by the size of the nanocage. Therefore, Ca- and Mg-encapsulated cages show higher values of adsorption energy. Overall, an increase in adsorption energy ($E_{\mathrm{\text{ad}}}=-31.91$kJ/mol to $-$91.06kJ/mol) is observed for (Be, Mg and Ca) encapsulated ${\text{Al}}_{12}$${\text{N}}_{12}$ nanoclusters compared to untreated ${\text{Al}}_{12}$${\text{N}}_{12}$ and H₂-${\text{Al}}_{12}$${\text{N}}_{12}$ cages. Moreover, adsorption of hydrogen on AEMs encapsulated in ${\text{Al}}_{12}$${\text{N}}_{12}$ leads to a decrease in the HOMO-LUMO energy gap with an enhancement of linear and nonlinear hyperpolarizability. All hydrogen-adsorbed AEMs ${\text{Al}}_{12}$${\text{N}}_{12}$ nanocages exhibit large ${\alpha }_{\mathrm{\text{total}}}$ and $\beta o$ values, suggesting that these systems are potential candidates for optical materials. Various geometrical parameters such as frontier molecular orbitals (FMOs), partial density of states, global quantum descriptor of reactivity, natural bond orbital testing and molecular electrostatic strength analyses were performed to investigate the thermodynamic stability of all the studied systems. The results obtained confirmed that the designed systems are suitable for hydrogen storage. Therefore, we recommend that these systems be investigated for their hydrogen storage and optical properties.

Nonlinear optical (NLO) materials have attracted bounteous scientific attention in the modern era because of their optoelectronic and biological applications. In this respect, an attempt is made to present thermodynamically stable superalkali metals (Li₃N, Li₃O, Li₃S and Li₃F)-doped sumanene (C${}_{21}$H${}_{12}$)-based complexes with fine NLO response properties. Nine isomers (I–III of Li₃N@Sumanene, I–II of Li₃O@Sumanene, I–II of Li₃S@Sumanene and I–II of Li₃F@Sumanene) are proposed, and their geometric, thermodynamic, electronic and NLO properties are explored by using density functional theory (DFT) calculations. Computational results reveal that the $E_{H-L}$ gap is reduced up to 0.56eV for doped complexes. The maximum hyperpolarizability response is calculated $1.084\times 10^5$a.u. for isomer II of the Li₃F@Sumanene series. The participation of distinct fragments, type of interaction, and charge transfer are computed by the corresponding TDOS and PDOS, NCI and NBO analysis. For UV–Vis analysis and crucial excitation state, TD-DFT calculations are carried out, which exhibits that all doped complexes are transparent in the UV region. NCI analysis confirmed the Van-der Waals interactions as an important mode of adsorption between superalkalis and sumanene. This report provides an efficient superalkali doping technique for creating highly effective future NLO systems and recommends superalkali-doped sumanene systems as ideal NLO prospects for future NLO applications.