Cross Section Research Articles

Research on soft errors induced by alpha particles and atmospheric neutrons based on 28 nm field programmable gate array

ABSTRACT The susceptibility of 28 nm static random access memory (SRAM)-based field programmable gate arrays (FPGAs) to soft errors was evaluated using alpha particles and atmospheric neutrons at the China Spallation Neutron Source (CSNS). A single event effect (SEE) test system was established to assess the sensitivity of various FPGA modules, including the configuration RAM (CRAM), block RAM (BRAM), configurable logic module (CLM), and arithmetic processing module (APM), utilizing both dynamic and static methods. The SEE error types for different sensitive modules were identified, and the SEE cross sections were calculated. The findings of this study can serve as a useful theoretical foundation for the design of radiation-hardened FPGA to enhance their reliability in radiation-prone environments.

Calculation of the abundance of $$^{187}Re $$–$$^{187}Os $$ nuclear clock nuclides in S-process and sensitivity analysis of Maxwellian-averaged neutron capture cross sections

Calculation of the abundance of $$^{187}Re $$–$$^{187}Os $$ nuclear clock nuclides in S-process and sensitivity analysis of Maxwellian-averaged neutron capture cross sections

Nozzle Geometry Evaluation for Cold Spray Applications by Using 3D-CFD Calculations

Abstract In cold spray applications, optimum process conditions to accelerate particles may vary with different densities of the feedstock. These conditions could depend on the geometry of the spray nozzle, suggesting possible benefits of material-specific nozzle designs. The present study developed a nozzle geometry optimization concept based on three-dimensional computational fluid dynamics (3D-CFD) simulations to provide a specific nozzle design. Applying a design of experiments (DoE) approach, the proposed model seeks an optimal nozzle geometry, using aluminum Al6061 and pure copper with mean particle diameters of 40 µm as examples. Different geometry parameters were varied to reach the highest particle velocities before impact on the substrate, such as the nozzle’s divergent section length, throat cross section, and expansion ratio. The process gas was nitrogen with set stagnation pressure and temperature of 5 MPa and 500 °C, respectively. For high particle impact velocities, the simulation identified the divergent section length as the most influential parameter, followed by the throat cross section. In addition, the results show that the expansion ratio must be carefully tuned to avoid over-expansion of the gas already inside the nozzle, which is detrimental to the particle acceleration.

Pauli form factor contributions to the inelastic proton bremsstrahlung and dark photon production

Abstract We study the production of hypothetical vector particles, dark photons γ′, with masses in the range 0.4–1.8 GeV via inelastic proton bremsstrahlung. We further develop the approach of refs. [1–3], where for the first time we considered the contributions to the cross section that are associated with the Pauli form factor in ppγ′ vertex and obtained new splitting functions. We demonstrate numerically the importance of these corrections to full inelastic proton bremsstrahlung cross section and refine the sensitivity of the ongoing and future fixed-target experiments T2K, DUNE and SHiP to the parameters of dark photon model. A dedicated experiment on measurements of the proton electromagnetic form factors in the time-like region below the proton-antiproton threshold, like those suggested in PANDA at FAIR, would help to obtain the robust predictions for the dark photon production by a proton beam at fixed target.

Ultraheavy multiscattering dark matter: DUNE, CYGNUS, other kilotonne detectors, and tidal streams

In direct searches of dark matter, multiscatter signatures are now being sought to probe scattering cross sections that are large enough to make the detector optically thick to incident particles. We provide some significant updates to the multiscatter program. Using considerations of energy deposition, we derive the reaches in cross section and mass of various proposed large-volume detectors: a kilotonne fiducial mass “module of opportunity” at DUNE, a kilotonne xenon detector suggested for neutrinoless double beta decay, the gaseous detector CYGNUS, and the dark matter detectors XLZD and Argo. Where the velocity vector can be reconstructed event-by-event, the Galactic dark matter velocity distribution may be inferred. We exploit this to show that halo substructure such as tidal streams can be picked up if they make up about 10% of the local dark matter density. Published by the American Physical Society 2025

Coulomb corrections for coherent neutrino nucleus scattering

Abstract In this work we consider sub-leading O(Z 2 α 3) corrections to coherent elastic neutrino nucleus scattering (CEvNS). These corrections are not negligible by power counting since nuclei with large coherent cross sections have sizeable nuclear charges e.g. Zα ∼ 0.4. We find that the corrections are much smaller than naive power counting in Zα would suggest and that Coulomb corrections do not substantially alter predictions for CEvNS in the Standard Model. We comment on similarities to older literature on mesonic and muonic atoms.

Dimuon and ditau production in photon-photon collisions at next-to-leading order in QED

Abstract Next-to-leading-order (NLO) quantum electrodynamics (QED) corrections to the production of muon and tau pairs in photon-photon collisions, γγ → μ + μ − , τ + τ − , are calculated in the equivalent photon approximation. We mostly consider γγ processes in ultraperipheral collisions of hadrons at the LHC, but the γγ → τ + τ − process in e+e − collisions at LEP is also discussed. The NLO terms are found to modify the total fiducial cross sections by up to 5%, increasing the tails of the dilepton acoplanarity and transverse momentum distributions, and depleting by up to 15% the yields at high masses, with respect to the leading-order predictions including the very small virtuality of the colliding photons. At the LHC, the calculations obtained with the charge form factor for protons and lead ions including the NLO QED corrections improve the data-theory agreement for all measured differential distributions, and prove an indispensable ingredient for the extraction of precision quantities in photon-photon processes, such as the anomalous magnetic moment of the tau lepton.

Prediction of both diffusive and hydraulic conductance in the pore network model extracted from 3D images using deep learning

Abstract Pore network modeling (PNM) with network extracted from 3D images is widely used for studying mass transport in porous media, with its accuracy heavily dependent on the precise determination of hydraulic and diffusive conductance values of local pore pairs. Deep learning (DL) prediction based on true pore geometry offers a promising approach for conductance estimation. However, due to arbitrarily orientation and the lack of explicit inlet and outlet surfaces in 3D extracted pore pair geometries, existing studies [24,25] have relied only on 2D cross section images for hydraulic conductance prediction. A custom finite difference method was recently developed, capable exclusively of estimating diffusion conductance from 3D pore geometry [26]. In this work, a convolutional neural network (CNN) was trained to estimate both diffusive and hydraulic conductance values, with reference ground truth values obtained by applying the Lattice Boltzmann Method (LBM) on 3D pore pair geometries. The predicted pore pair conductance values from the CNN closely matched the LBM results on unseen segmented image data. This study highlights the importance of using the full 3D pore pair geometry for accurate hydraulic conductance evaluation, rather than relying solely on 2D throat cross sections. To evaluate the generality of our method, we calculated the permeability and diffusivity of 3D porous media across a wide range of porosities using PNM with local conductance values predicted by our DL model. Comparisons with results of LBM indicate that while diffusivity was accurately predicted, permeability was underestimated. This underestimation is attributed to the over-segmentation of pore spaces, which resulted in an underestimated flow rate.

Production of J/ψ within the Soft Gluon Resummation Approach and Nonrelativistic QCD

In our study we analyse prompt J/ψ production in proton-proton collisions within the Soft Gluon Resummation approach, collinear parton model and nonrelativistic QCD. We extract a set of long-distance matrix elements for octet color states from experimental data at √s = 200 GeV. We use the InEW scheme for matching cross section and description of J/ψ production in a domain of intermediate transverse momenta. We also provide prediction for J/ψ production using fitted matrix elements at the kinematics of SPD NICA.

Low Energy Electron Induced Dissociation of Acetylacetone.

We report a detailed investigation of the dissociative electron attachment (DEA) to acetylacetone, an important molecule for industrial and atmospheric chemistry. We find that the DEA process leads to several dissociation channels, leading to the formation of and other anions with m/z 39, 41, 43, 57, 83, and 85, with the H- and OH- being the most dominant channels. The absolute cross sections for both of these channels peak around 8.8 and 9 eV with cross-section values of 3.1 × 10-18 and 3.7 × 10-19 cm2, respectively. We also report the DEA dynamics for these channels based on the Velocity Slice Images that were obtained. We also compare the dissociation pattern from DEA with that from photodissociation reported for 248 and 266 nm wavelengths and propose the possibility of the neutral excited state's role as the underlying parent state for the negative ion resonance.

Detection of Electron Temperature Anisotropy by an X-ray Crystal Spectrometer in the Large Helical Device

Abstract We examine Ar XVI spectra measured by an X-ray crystal spectrometer to estimate electron temperature anisotropy in high-temperature electron cyclotron heated plasmas in the Large Helical Device (LHD). We calculate the atomic structure and electron impact excitation cross section between magnetic sublevels of Ar XVI. By assuming a bi-Maxwellian electron distribution function and considering the mount parameters of the X-ray spectrometer in LHD, we model the expected intensity ratio q/r as a function of Te⊥B and Te||B, where ⊥ B and ||B denote perpendicular and parallel components to the magnetic axis of the toroidal plasma, respectively. The calculation results show that the intensity ratio of q and r, which are formed by inner-shell excitation from the ground state of Ar15+, is sensitive to electron temperature anisotropy. We apply the calculation results to the LHD experiments. The ratio of q/r changes with variations in electron density and collision frequency. In the core and low νe region, Te⊥B is predominant, and the electron temperature becomes isotropic above νe > 104 Hz. By combining electron temperature measurements from Thomson scattering and radial profile of Ar15+ ions estimated using the extreme ultraviolet spectrometer, local values of Te⊥B/Te||B are quantitatively estimated using the q/r ratio. The derived Te⊥B/Te||B is compared with collision frequency, radial electric field, and effective helical ripple, and the experimental results are explained qualitatively.

Two-loop master integrals for e+e− → μ+μ− process with account of electron mass

Abstract We calculate a subset of two-loop master integrals relevant for the differential cross section of e + e − → μ + μ − process. We consider only those families for which the account of the electron mass m is necessary. Our results have the form of the Frobenius series in m with coefficients expressed via Goncharov’s polylogarithms.

Particle production by γ−γ interactions in future electron-ion colliders

The particle production in photon-photon (γγ) interactions present in electron-ion collisions is investigated. We present calculations for the total cross sections and event rates related to the production of light mesons [η,η′,f0 and f2], charmonium [ηc and χc], and charmoniumlike [X(3915),X(3940),X(4140), and X(6900)] states, considering the Electron - Ion Collider, Electron - ion collider in China, Large Hadron electron Collider, and Future Circular Collider - electron hadron energies. Our predictions demonstrate that experimental studies of these processes are feasible and useful to constrain the properties of light mesons and quarkonium states and shed some light on the configuration of the considered charmoniumlike states. Published by the American Physical Society 2025

Effect of SiO+ Rotational Excitation on Dynamics of SiO+ + H2 → SiOH+ + H Reaction.

Quasi-classical trajectory calculations and quantitative trajectory classification using DBSCAN and K-NN algorithms have been employed to study the specifics of the significant promotion of the SiO+ + H2 reaction by high rotational excitation of SiO+. There are three different reaction pathways identified. Path-I is a direct reaction process in which the product is formed when H2 collides with the O atom side of SiO+ and the H-H bond breaks. H2 first collides with the Si atom in path-II, then bounces back, and encounters the O atom to complete the reaction. Path-III is characterized by the formation of an HSiOH+ complex, is less affected by rotational excitation, and has the smallest contribution to the entire reaction. At low collision energies, rotational excitation slightly promotes the reaction, possibly due to the coupling of the rotational mode of SiO+ and the reaction coordinate of the submerged saddle point. However, this effect weakens with increasing rotational excitation, leading to a complex change in the total integral cross section. Among them, only path-I shows increased reactivity at high rotational excitation. At high collision energies, the integral cross section of the reaction is less sensitive to the rotational quantum number of the reactant, and only a slight increase is observed at the high rotational excitation of SiO+.

Diagnostics of Spin-Polarized Ions at Storage Rings

Polarized heavy ions in storage rings are seen as a valuable tool for a wide range of research, from the study of spin effects in relativistic atomic collisions to the tests of the Standard Model. For forthcoming experiments, several important challenges need to be addressed to work efficiently with such ions. Apart from the production and preservation of ion polarization in storage rings, its measurement is an extremely important issue. In this contribution, we employ the radiative recombination (RR) of polarized electrons into the ground state of initially hydrogen-like, finally helium-like, ions as a probe process for beam diagnostics. Our theoretical study clearly demonstrates that the RR cross section, integrated over photon emission angles, is highly sensitive to both the degree and the direction of ion polarization. Since the (integrated) cross-section measurements are well established, the proposed method offers promising prospects for ion spin tomography at storage rings.

Entanglement enabled intensity interferometry in ultrarelativistic ultraperipheral nuclear collisions

An important tool in studying the subfemtoscale spacetime structure of matter in ultrarelativistic heavy-ion collisions is Hanbury Brown–Twiss (HBT) intensity interferometry of identical particles in the final state of the collisions. We propose that a variant of the entanglement enabled intensity interferometry (E2I2) framework introduced by Cotler and Wilczek can provide a powerful alternative to HBT interferometry in extracting fundamental nonperturbative features of quantum chromodynamics at high energies. We apply this framework to demonstrate that the spatial distributions of color singlet (pomeron) configurations in nuclei are sensitive to measurements of exclusive resonant decays of ρ mesons into π± pairs in ultrarelativistic ultraperipheral nuclear collisions (UPCs) at the Relativistic Heavy Ion Collider and the Large Hadron Collider. A preliminary analysis suggests that the model-independent extraction of pomeron distributions will require careful treatment of the interplay of E2I2 in the vector meson exclusive decay with the incoherent cross section for exclusive vector meson production. The E2I2 framework developed here is quite general. It can also be employed as a tool to extract information on the spin structure of pomeron couplings as well as enhance the discovery potential for rare odderon configurations from exclusive vector meson decays into few-particle final states both in UPCs and at the Electron-Ion Collider. Published by the American Physical Society 2025

Associated production of J/ψ and direct photon in the parton Reggeization approach

We study the associated J/ψ and direct photon production in the high energy factorization, as it is formulated in the parton Reggeization approach, using two different models for the hadronization of a heavy quark-antiquark pair into a heavy quarkonium, namely the non-relativistic quantum chromodynamics (NRQCD) and the improved color evaporation model (ICEM). We find essential differences in predictions for cross section and transverse momenta spectra obtained using the NRQCD and the ICEM, which can be used for the discrimination between these models. Our prediction for cross sections of the associated J/ψ and direct photon production at the LHC energies slightly overestimate the results early obtained in the next-to-leading order (NLO) calculation in the collinear parton model (CPM). We predict different two-particle correlation spectra in the associated J/ψ and direct photon production which may be interesting for an experimental study

The impact of data from future lepton colliders on light hadrons fragmentation functions

In this work, we study the constraining power of future lepton colliders on fragmentation functions (FFs) to light charged hadrons from quarks and gluon in the framework of QCD collinear factorization. We perform analyses of FFs at NLO by including a wide range of pseudo-data from future lepton colliders, such as measurements on hadron multiplicities in the production of two jets and W boson pairs, at various center of mass energies, and from hadronic decays of the Higgs boson, including both to heavy quarks and to gluons. The high luminosity and high energies of future lepton colliders allow for quark flavor separations and ensure a precise determination of FFs based solely on data from electron-positron collisions. We find that either the CEPC, FCC-ee or ILC can significantly reduce the uncertainties of FFs in a wide kinematic range, compared to the NPC23 set obtained with a global analysis to current world data. We also discuss the impact of higher-order QCD corrections, and the potential constraints from measurements of three-jet production. Furthermore, we describe an update of the FMNLO program allowing for calculating hadron production cross sections at next-to-next-to-leading order in QCD, which is used in this study.

Uncertainty Quantification of a Collisional-Radiative model for Hydrogen plasmas

Abstract A collisional-radiative model for the Balmer emission from low-temperature Hydrogen plasma is studied. The model is based on the most accurate cross sections available for the relevant processes. An uncertainty quantification study based on Polynomial Chaos Expansion is performed for ionizing and recombining plasmas with conditions typical of the tandem discharge used in Neutral Beam sources for magnetically confined fusion reactors. Results show that uncertainties in the model results larger than a factor of 5 are obtained, much larger than the typical uncertainty in the measurements. The approach, however, allows to identify few processes that have the largest role in propagating the uncertainties and where increased accuracy has the largest impact.

Investigation of positron scattering from 2H-pyran, 4H-pyran, and pyrrole molecules

Abstract The scattering cross-sections for positron-biomolecule interaction are an essential input for the Monte-Carlo simulation techniques. In the present work, we have reported the elastic integral, differential, momentum transfer, and total ionization cross-sections for scattering of positron from 2H-pyran, 4H-pyran, and pyrrole molecules. The single-center expansion (SCE) method is employed for the elastic scattering calculations and the binary-encounter-Bethe model for ionization. We have also reported the elastic integral and differential cross-sections for benzene and furan, which are structurally similar to the pyran isomers and pyrrole, respectively, and compared them with the experimental and theoretical data available in the literature to validate the efficacy of the SCE method and the codes used. A comparative analysis of the elastic cross-sections for the isomers: 2H-pyran and 4H-pyran, and the pyrrole molecule that is isoelectronic with furan is also presented.