Differential Cross Sections Research Articles

Features in the electron elastic scattering cross sections of atoms Sb, Xe and Bi, Rn

Abstract For atoms having pairwise similar electronic configurations, Sb([Cd]5p3), Xe([Cd]5p6) and Bi([Hg]6p3), Rn([Hg]6p6), features in the energy dependences of integral (ICSs) and differential (DCSs) cross sections of electron elastic scattering are considered theoretically. The positions of the Ramsauer-Townsend minimum (RT) and the low-energy maxima in the ICSs are calculated. The minima in the DCSs have been studied within the collision energy range from 0.1 (Sb, Xe, Bi) and 0.5 (Rn) eV up to 1000 (Sb), 2000 (Xe), 3000 (Bi) and 4000 (Rn) eV. The phase shifts, scattering amplitudes and cross sections have been calculated in the relativistic complex optical potential (OP) approximation. The results of the above OP calculation agree well with the experimental and the theoretical data. The energy dependences of the angular positions of the DCSs minima of these atoms are considered in detail. The energy and the angular positions of 15 (Sb), 17 (Xe and Bi) and 18 (Rn) critical minima (CM) in the DCSs have been found. The highest energy CM are located at: Sb – [727.6 eV; 131.89], Xe – [791.4 eV; 133.16], Bi – [1810.8 eV; 137.34], Rn – [1918.8 eV; 137.64]. A high-angle CM are located at: Sb – [233.6 eV; 151.08], Xe – [256.5 eV; 151.05], Bi – [180.3 eV; 157.30], Rn – [204.0 eV; 155.36].

Vibrational State-Resolved Differential Cross Sections of the F + CH4 → HF + CH3 Reaction at the Collision Energies of 3.1–13.8 kcal/mol

Vibrational State-Resolved Differential Cross Sections of the F + CH₄ → HF + CH₃ Reaction at the Collision Energies of 3.1–13.8 kcal/mol

Theoretical studies on the scattering of e± off the C2H2 molecule

Abstract By employing previous models [15,18], we report the differential, integrated elastic, inelastic, total (elastic+inelastic), viscosity and momentum transfer cross sections of e±- C2H2 collision dynamics, for the energy range of 1 eV-1 MeV. This report also incorporates Sherman spin polarization function and total ionization cross section. This work provides the first comprehensive study of electron/positron scattering from C2H2 over such a wide energy range. A complex optical model potential (OMP) has been used to represent the projectile-atom interaction. Relativistic Dirac equation has been solved, to get phase-shifts, needed for the calculations of scattering observables, using OMP. Our results are compared with the existing experimental data and theoretical calculations.

Differential cross section measurements of the 7Li(3He, p0)9Be, 7Li(3He, p2)9Be, and 7Li(3He, d0)8Be reactions from 2 to 4 MeV

The use of lithium in plasma facing components (PFCs) for fusion reactors is increasingly more prominent due to its ability to enhance plasma performance and potential to protect the underlying high-Z PFCs. In order to use nuclear reaction analysis (NRA) to investigate lithium depth profiles in fusion relevant experiments such as hydrogen retention in lithiated PFCs, there is a need for experimental measurements of the cross section of the reactions of interest over a wide range of energies and in a scattering angle in which the differential cross sections of other relevant species, such as deuterium and oxygen, have been measured. In this paper we report the differential cross sections of the 7Li(3He, p0)9Be, 7Li(3He, p2)9Be, and 7Li(3He, d0)8Be reactions from 2 to 3.919 MeV at a measurement angle of 135°. The measurements were performed on a lithium fluoride film target with the 7Li areal density determined using the 7Li(p, α)4He reaction at 2 MeV and 150°.

Electroweak corrections to Higgs boson pair production: the top-Yukawa and self-coupling contributions

We present results for the Yukawa-enhanced and Higgs self-coupling type electroweak corrections to di-Higgs production in gluon fusion. The calculation of the corresponding four-scale, two-loop amplitude is carried out retaining the exact symbolic dependence on all masses and scales during the reduction to master integrals. The resulting integrals are then evaluated at high precision using both the series expansion of the differential equations and sector decomposition. Differential cross sections for the di-Higgs invariant mass and the transverse momentum of a Higgs boson are shown, where we find that the corrections are most pronounced at low invariant mass and transverse momentum.

Manifestation of a1(1260) meson in the process e+e−→π+π−π0

The charge asymmetry in the process e+e−→π+π−π0 is studied taking into account a longitudinal polarization of electrons (positrons). The asymmetry arises due to interference of amplitudes corresponding to production of pions in states with charge parity odd and charge parity even. It is a manifestation of a1(1260) meson in the intermediate state. Polarization leads to additional correlations in the differential cross section, which simplifies the experimental study of the process. It is shown that the charge asymmetry can reach several percent. Published by the American Physical Society 2024

Regularized entanglement entropy of electron-positron scattering with a witness photon

Regularized quantum information metrics are calculated for the scattering process e−e+→γ,Z→μ−μ+ that has a witness photon entangled with the initial electron-positron state. Unitarity implies the correct regularization of divergences that appear in both the final density matrix and von Neumann entanglement entropies. The entropies are found to quantify uncertainty or randomness. The variation of information, entanglement entropy, and correlation between the muon’s and witness photon’s helicities are found to convey equivalent information. The magnitude of the muon’s expected helicity rises (falls) as the helicity entropy falls (rises). Area, or the scattering cross section, is a source of entropy for the muon’s helicity entropy and momentum entropy. The muon’s differential angular entropy distribution is similar to the differential angular cross section distribution, capturing the forward-backward asymmetry at high center-of-mass energies. Published by the American Physical Society 2024

Nonresonant central exclusive production from CMS+TOTEM

The central exclusive production of charged hadron pairs in pp collisions at a center-of-mass energy of 13[Formula: see text]TeV is examined, based on data collected in a special high-[Formula: see text] run of the LHC. Events are selected by requiring both scattered protons detected in the TOTEM Roman pots, exactly two oppositely charged identified particles in the CMS silicon tracker, and the energy–momentum balance of these four particles. The nonresonant continuum processes are studied with the invariant mass of the centrally produced two-pion system in the resonance-free region, [Formula: see text][Formula: see text]GeV or [Formula: see text][Formula: see text]GeV. Differential cross sections as functions of the azimuthal angle between the surviving protons, squared four-momenta, and two-hadron invariant mass are measured in a wide region of scattered protons with transverse momentum between 0.2 and 0.8[Formula: see text]GeV and for pion rapidities [Formula: see text]. A rich structure of interactions related to double pomeron exchange emerges. The parabolic minimum in the distribution of the two-proton azimuthal angle is observed for the first time. It can be understood as an effect of additional pomeron exchanges between the protons, and of the interference between the bare and the rescattered amplitudes. After model tuning, various physical quantities related to the pomeron cross section, proton–pomeron and hadron–pomeron form factors, trajectory slopes and intercepts, as well as coefficients of diffractive eigenstates of the proton are determined.

Measurement of differential ZZ + jets production cross sections in pp collisions at s\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\sqrt{s} $$\\end{document} = 13 TeV

Diboson production in association with jets is studied in the fully leptonic final states, pp → (Z/γ*)(Z/γ*) + jets → 2ℓ2ℓ′ + jets, (ℓ, ℓ′ = e or μ) in proton-proton collisions at a center-of-mass energy of 13 TeV. The data sample corresponds to an integrated luminosity of 138 fb−1 collected with the CMS detector at the LHC. Differential distributions and normalized differential cross sections are measured as a function of jet multiplicity, transverse momentum pT, pseudorapidity η, invariant mass and ∆η of the highest-pT and second-highest-pT jets, and as a function of invariant mass of the four-lepton system for events with various jet multiplicities. These differential cross sections are compared with theoretical predictions that mostly agree with the experimental data. However, in a few regions we observe discrepancies between the predicted and measured values. Further improvement of the predictions is required to describe the ZZ+jets production in the whole phase space.

Quark mass effects in Higgs production

We examine the effect of finite top- and bottom-quark masses on the Higgs production cross section in the gluon-gluon fusion channel. We employ both MS¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\overline{\ extrm{MS}} $$\\end{document} and on-shell renormalisation for the quark masses and provide a thorough comparison. Furthermore, we explore alternative treatments of quark masses, in particular in the four-flavour scheme, and investigate their impact on the cross section. Our work also presents novel predictions for differential cross sections in the Higgs rapidity. The results lead to a significant reduction of scale uncertainties, and our analysis enables us to offer well-grounded recommendations for future research in this area.

Study of electron and positron elastic scattering cross-sections of astro molecule H2S

Abstract The elastic, integrated, momentum transfer, viscosity, energy-dependent, and differential cross-sections and the Sherman function for electron and positron H2S scattering are reported at impact energies ranging from 1 eV to 1 MeV. The average orientations of the polar molecule H2S are considered, and the electron and positron elastic scattering cross-sections of H2S are typically calculated using single scattering-independent atom approximation. The relativistic Dirac equation is solved using the free atom optical potential, which includes the electrostatic interaction potential, exchange potential, correlation polarization potential, and imaginary absorption potential. The present computed cross-section results are compared with the available experimental and theoretical results, and a reasonable agreement is observed.

Elastic differential neutron-scattering cross section on even Neodymium isotopes

In this paper, we present an analytical formula for the neutron scattering cross section on even-even heavy nuclei, employing the rotational model and making certain assumptions, such as the use of the Yukawa potential shape for the neutron-nucleon interaction, the rigid rotor approximation, and the assumption of a uniformly distributed nuclear matter within the nucleus. Notably, a significant aspect of this study is the avoidance of any approximation of a central potential, in contrast to the commonly employed methods of expanding the potential based on the power of , utilizing the Legendre polynomial basis, or employing Fourier-Bessel analysis. Despite the simplicity of the chosen model (rigid rotor model and the two-parameter potential), our results yield satisfying and encouraging outcomes. This suggests the effectiveness of our approach in analyzing neutron scattering on even-even heavy nuclei. It is important to note that further investigations are warranted to deepen our understanding and refine the assumptions utilized in this study. Future research should explore the applicability of the proposed analytical formula to diverse nuclei and consider more complex models to expand our comprehension of neutron-nucleus interactions.

Electron-impact ionization of water molecules at low impact energies.

The electron-impact ionization of water molecules at low impact energies is investigated using a theoretical approach named M3CWZ. In this model, which considers exchange effects and post-collision interaction, the continuum electrons (incident, scattered, and ejected) are all described by a Coulomb wave that corresponds to distance-dependent charges generated from the molecular target properties. Triple differential cross-sections for low impact energy ionization of either the 1b1 or 3a1 orbitals are calculated for several geometrical and kinematical configurations, all in the dipole regime. The M3CWZ model is thoroughly tested with an extensive comparison with available theoretical results and COLTRIMS measurements performed at projectile energies of Ei = 81eV [Ren et al., Phys. Rev. A 95, 022701 (2017)] and Ei = 65eV [Zhou et al., Phys. Rev. A 104, 012817 (2021)]. Similar to other theoretical models, an overall good agreement with both sets of measured data is observed for the angular distributions. Our calculated cross-sections' magnitudes are also satisfactory when compared to the other theoretical results, as well as to the cross-normalized relative scale data at 81eV impact energy. The 65eV set of data, measured on an absolute scale, offers a further challenging task for theoretical descriptions, and globally the M3CWZ performs fairly well and comparably to other theories. The proposed approach with variable charges somehow allows to capture the main multicenter distortion effects while avoiding high computational costs.

State-resolved quantum dynamics and reaction mechanisms of the Ne + HD+(v = 1) reaction

In the work, accurate converged theoretical simulations of the Ne + HD + ( v = 1 ) reaction are presented with the time-dependent wave packet (TDWP) method using the accurate potential energy surface by Lv (J. Chem. Phys. 2010, 132, 014303). In particular, the effect of intramolecular substitution and the translational collision energy on the reactive dynamics is investigated in detail to discern the reaction mechanisms. Total and state-to-state integral cross sections (ICSs) and differential cross sections (DCSs) of the two channels are derived and compared over a wide range of collision energies up to 1.2 eV. The analysis of the ICSs in terms of the total angular momentum contributions shows that the contribution of the J partial wave varies in the two reactive channels at different collision energies. The product state-resolved DCSs reveal that two opposite mechanisms co-exist in the two reactive channels with different ratios at low and high collision energies. Overall, NeH + + D channel appears to form the products via collision complex formation, which survives long enough leading to a forward–backward symmetric total DCS at low collision energies. In comparison, the NeD + + H proceeds through a direct stripping reaction, with predominantly forward scattering in the DCSs.

Analytic continuation of differential cross-sections as a way to determine asymptotic normalization coefficients. Application to the 16O(d,p)17O reaction

Asymptotic normalization coefficients (ANC) are important nuclear characteristics. This paper discusses a method for determining ANC values from experimental data on differential cross-sections of nuclear transfer reactions. The method is based on the use of the analytic continuation of these cross-sections to the pole point of the reaction amplitude with respect to the variable [Formula: see text], where [Formula: see text] is the center-of-mass scattering angle. The method under consideration is used to determine the ANC for the channel [Formula: see text]O(1/2[Formula: see text]; 0.871[Formula: see text]MeV) [Formula: see text]O(0[Formula: see text]; 0[Formula: see text]MeV) [Formula: see text] from the data on the [Formula: see text]O(0[Formula: see text]; 0[Formula: see text]MeV)[Formula: see text]O (1/2[Formula: see text]; 0.871[Formula: see text]MeV) reaction. When determining the ANC, the corrections caused by the Coulomb interaction in the initial, final and intermediate states of the reaction were taken into account. It is shown that these corrections have a great impact on the extracted ANC value.

Measurements of inclusive and differential cross-sections of tt¯γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ t\\overline{t}\\gamma $$\\end{document} production in pp collisions at s\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ \\sqrt{s} $$\\end{document} = 13 TeV with the ATLAS detector

Inclusive and differential cross-sections are measured at particle level for the associated production of a top quark pair and a photon (tt¯γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ t\\overline{t}\\gamma $$\\end{document}). The analysis is performed using an integrated luminosity of 140 fb−1 of proton-proton collisions at a centre-of-mass energy of 13 TeV collected by the ATLAS detector. The measurements are performed in the single-lepton and dilepton top quark pair decay channels focusing on tt¯γ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ t\\overline{t}\\gamma $$\\end{document} topologies where the photon is radiated from an initial-state parton or one of the top quarks. The absolute and normalised differential cross-sections are measured for several variables characterising the photon, lepton and jet kinematics as well as the angular separation between those objects. The observables are found to be in good agreement with the Monte Carlo predictions. The photon transverse momentum differential distribution is used to set limits on effective field theory parameters related to the electroweak dipole moments of the top quark. The combined limits using the photon and the Z boson transverse momentum measured in tt¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ t\\overline{t} $$\\end{document} production in associations with a Z boson are also set.

Differential and integral elastic cross sections for electrons and positrons collisions with carbon dioxide molecules

This study investigates the elastic scattering of electrons and positrons by carbon dioxide (CO2) molecules over a wide energy range from 1 eV to 1 KeV. We have computed differential and integral elastic cross-sections (DCS and ICS) using partial wave analysis and compared the theoretical results with available experimental data. Our findings show a strong correlation with experimental results, particularly at mid to high-energy ranges, validating the employed theoretical frameworks. Additionally, the Sherman function was examined to explore spin polarisation effects during scattering events. This research provides crucial insights for applications in atmospheric physics, materials science, and molecular scattering processes, demonstrating its direct relevance to real-world problems and paving the way for further investigation into particle-molecule interactions.

The theoretical study of pp¯→Λ¯Ση\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$p\\bar{p}\\rightarrow \\bar{\\Lambda }\\Sigma \\eta $$\\end{document} reaction

We study the production of hyperon resonances in the pp¯→Λ¯Ση\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$p\\bar{p}\\rightarrow \\bar{\\Lambda }\\Sigma \\eta $$\\end{document} reaction within an effective Lagrangian approach. The model includes the production of Σ(1750)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Sigma (1750)$$\\end{document} and Λ(1670)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Lambda (1670)$$\\end{document} in the intermediate state excited by the K and K∗\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$K^*$$\\end{document} meson exchanges between the initial proton and antiproton. Due to the large coupling of Σ(1750)Ση\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Sigma (1750)\\Sigma \\eta $$\\end{document} vertex, Σ(1750)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Sigma (1750)$$\\end{document} is found a significant contribution near the threshold in this reaction. We provide total and differential cross section predictions for the reaction and discuss the possible influence of Σ(1750)Ση\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Sigma (1750)\\Sigma \\eta $$\\end{document} vertex coupling and model parameters, which will be useful in future experimental studies. This reaction can provide a platform for studying the features of Σ(1750)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Sigma (1750)$$\\end{document} resonance, especially the coupling to Ση\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Sigma \\eta $$\\end{document} channel.

Study on Quantum Dynamics of the Na + Na2 Exchanged Reaction and Lifetime Prediction of Na3 Complex Based on the Neural Network Potential Energy Surface.

A high-precision global potential energy surface (PES) is constructed for the Na3 system based on high-level ab initio calculations and the fundamental invariant neural network (FI-NN) method. The root-mean-square error (RMSE) of the PES is 2.88 cm-1. The state-resolved quantum dynamics of the ground-state Na + Na2 (v = 0, j = 0) → Na2 (v', j') + Na reaction is studied using the time-dependent wave packet (TDWP) method on the new PES. Analysis of the relevant integral cross sections revealed a complicated energy-transfer mechanism during collisions. Similarly, the characteristics of the differential cross sections indicate that the complex-forming mechanism plays a dominant role in the reaction, providing conditions for a comprehensive exploration of the lifetimes of the complexes. Based on the Rice-Ramsperger-Kassel-Marcus (RRKM) theory, the calculated lifetime of the Na3 complex is approximately 3.9 ns.

Topological features of trajectories of virtual photons and their effective interaction under multiple scattering in a system of conductive nanoparticles

It is shown that in conditions of strong light localization in a system of Rayleigh's resonance scatterers, effective photon–photon interaction appears. This interaction is associated with neither nonlinearity of medium nor nonlocal interaction of polarization-entangled photon pairs. It is related to complex topology of photon trajectories due to multiple scattering. Because of this interaction, acts of simultaneous elastic scattering of pair of photons in the considered system cease to be independent processes. The differential cross section of this cooperative process contains only an extra degree of small Rayleigh's factor in comparison with the classical scattering cross section of a single photon. This opens up the possibility of control of light fluxes by means of alternative low-intensity light fluxes without using slow optoelectronic converters. Light localization that provides the effective photon–photon interaction is considered in the framework of a new formalism different from traditional one. Equation of the Bethe–Salpeter for two-photon propagator is resolved directly in coordinate representation without traditional reducing of this equation to some transport equation. This allows in a new light to look on reason of weak light localization and to show that weak localization is one of consequences of strong localization.