Interaction Cross Sections Research Articles

The study of hadronic rescattering on K∗0 resonance yield in baryon-rich QCD matter

Abstract The effect of hadronic rescattering on K ∗0 resonance yield can be studied by measuring K ∗0/K ratio as a function of centrality or multiplicity. This study investigates how the size of the system and the chemical composition (meson–meson versus meson–baryon interaction) of the matter formed in heavy-ion collisions impact the process of hadronic rescattering. It is shown that existing calculation of K ∗0/K ratio, which considers the interaction of K ∗0 and K mesons with only light mesons in the hadronic medium (neglecting interactions with baryons), fails to explain the measured K ∗0/K ratio at RHIC beam energy scan (BES) energies. To understand the multiplicity dependence of the K ∗0/K ratio at RHIC BES and SPS energies ( s NN < 20 GeV), the ultra relativistic quantum molecular dynamics (UrQMD) model is employed. UrQMD calculations suggest that for a given multiplicity, K ∗0/K is more suppressed in Au+Au collision at s NN = 7.7 GeV, compared to that in s NN = 200 GeV. This is possibly because of formation different type of quantum chromodynamics medium at 200 and 7.7 GeV, and change in interaction cross-section between hadrons with change in particle type and energy.

Recent Results from the FASER Experiment at the LHC

The ForwArd Search ExpeRiment (FASER), is an LHC experiment that aims to: (1) detect and study TeV-energy neutrinos, the most energetic neutrinos ever detected from a humanmade source and (2) search for new light and very weakly interacting particles. The FASER detector is located 480 m downstream of the ATLAS p-p interaction point, along the beam collision axis. FASER was designed, constructed, installed, and commissioned during 2019–2022 and has been taking physics data since the start of LHC Run 3 in July 2022. Recently, FASER reported the first measurement of ve and vμ interaction cross sections at the LHC with its sub-detector FASERv , FASER’s emulsion detector, first results on Axion-Like Particles at FASER and dark photons limits. These results will be reported in this article.

Investigation of the Nuclear Cross-Sections for Proton Capture Reactionsin the Star Formation Process of the Galaxies

Understanding the CNO cycle and the proton-proton (p-p) chain is essential for comprehending the development of main sequence stars in the initial stages of spiral and elliptical galaxy formation. This study investigates two nuclear reactions that occur in spiral galaxies and elliptical galaxies. Using theoretical computer software (e.g. OriginPro. software program), we summarized the excitation functions to analyze the (p,γ) interaction cross sections of 7Be(p,γ)8B, 12C(p,γ)13N, 14N(p,γ)15O, and 15N(p, γ)12C. In the p-p series and CNO cycle with energy up to 8 MeV. In this work, we compared the theoretical values from the ENDF/B-VII library with the estimated database of nuclear fusion cross sections in hydrogen-burning stellar objects from CSC-GM and TALYS. For these nuclei, cross sections can be calculated at low energies within the pp chain and CNO cycle. Therefore, we were able to calculate only four finite elements in the CNO cycle and the pp series.

MATXCOM—an x-ray/gamma-ray attenuation calculator for arbitrary materials based on EPICS2023 evaluated photon data library

A program called MATXCOM was developed for the calculation of x-ray/gamma-ray interaction cross-sections, the mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), half and tenth value layers (HVL and TVL), mean free path (MFP), total atomic and electronic cross-sections (ACS and ECS), effective atomic number (Zeff), effective electron density (Neff), effective conductivity (Ceff), and energy absorption and exposure buildup factors (EABF and EBF) for arbitrary materials based on the EPICS2023 evaluated photon data library (EPDL). MATXCOM was implemented as a stand-alone program written in Fortran featuring a streamlined input/output interface. This design allows it to be easily integrated into scripts or wrapper functions, making it adaptable for use in large computational projects.

Nanodosimetric investigation of the track structure of therapeutic carbon ion radiation part2: detailed simulation

Objectivea previous study reported nanodosimetric measurements of therapeutic-energy carbon ions penetrating simulated tissue. The results are incompatible with the predicted mean energy of the carbon ions in the nanodosimeter and previous experiments with lower energy monoenergetic beams. The purpose of this study is to explore the origin of these discrepancies.Approachdetailed simulations using the Geant4 toolkit were performed to investigate the radiation field in the nanodosimeter and provide input data for track structure simulations, which were performed with a developed version of the PTra code.Main resultsthe Geant4 simulations show that with the narrow-beam geometry employed in the experiment, only a small fraction of the carbon ions traverse the nanodosimeter and their mean energy is between 12% and 30% lower than the values estimated using the SRIM software. Only about one-third or less of these carbon ions hit the trigger detector. The track structure simulations indicate that the observed enhanced ionization cluster sizes are mainly due to coincidences with events in which carbon ions miss the trigger detector. In addition, the discrepancies observed for high absorber thicknesses of carbon ions traversing the target volume could be explained by assuming an increase in thickness or interaction cross-sections in the order of 1%.Significancethe results show that even with strong collimation of the radiation field, future nanodosimetric measurements of clinical carbon ion beams will require large trigger detectors to register all events with carbon ions traversing the nanodosimeter. Energy loss calculations of the primary beam in the absorbers are insufficient and should be replaced by detailed simulations when planning such experiments. Uncertainties of the interaction cross-sections in simulation codes may shift the Bragg peak position.

Dark matter (h)eats young planets

We study the effect of dark matter annihilation on the formation of Jovian planets. We show that dark matter heat injections can slow or halt Kelvin-Helmholtz contraction, preventing the accretion of hydrogen and helium onto the solid core. The existence of Jupiter in our solar system can therefore be used to infer constraints on dark matter with relatively strong interaction cross sections. We derive novel constraints on the cross section for both spin-dependent and spin-independent dark matter. We highlight the possibility of a positive detection using future observations by JWST, which could reveal strongly varying planet morpholoiges close to our Galactic Center.

Double polarized deuteron–deuteron scattering and test of T-invariance

A component of the total cross section of the deuteron-deuteron interaction connected with the vector polarized ([Formula: see text]) one initial deuteron and tensor polarized ([Formula: see text]) another one constitutes a null-test signal of the T-invariance violation but P-parity conservation. The energy dependence of this signal is calculated here at beam kinetic energies per nucleon of 0.1–1[Formula: see text]GeV within the Glauber spin-dependent theory of multiple scattering in the S-wave approximation for the deuteron wave function.

Solar neutrinos in cryogenic detectors

Coherent elastic neutrino-nucleus scattering (CEνNS) poses an irreducible background in the search for dark matter-nucleus elastic scatterings, which is commonly known as the neutrino floor. As direct dark matter search experiments keep improving their sensitivity into so far unexplored regions, they face the challenge of approaching this neutrino floor. A precise description of the CEνNS signal is therefore crucial for the description of backgrounds for future DM searches. In this work we discuss the scenario of detecting neutrinos in low-threshold, high-exposure cryogenic solid state experiments optimized for the search of low-mass dark matter. The energy range considered is completely dominated by solar neutrinos. In absence of any dark matter events, we treat solar neutrinos as the main signal of interest. We show that sensitivity to the flux of neutrinos from different production mechanisms can be achieved. In particular we investigate the sensitivity to the flux of pp and 7Be neutrinos, as well as CNO neutrinos. Furthermore, we investigate the sensitivity to dark matter signals in the presence of a solar neutrino background for different experimental scenarios, which are defined by three parameters: the target material, the energy threshold and the exposure. We show that experiments with thresholds of O(eV) and exposures of O(tonne-years), using CaWO4 or Al2O3 targets, have discovery potential for dark matter interaction cross sections in the neutrino floor.

Phonon Drag Contribution to Thermopower for a Heated Metal Nanoisland on a Semiconductor Substrate.

The possible contribution of phonon drag effect to the thermoelectrically sustained potential of a heated nanoisland on a semiconductor surface was estimated in a first principal consideration. We regarded electrons and phonons as interacting particles, and the interaction cross-section was derived from the basic theory of semiconductors. The solution of the equation of motion for average electrons under the simultaneous action of phonon drag and electric field gave the distributions of phonon flux, density of charge carriers and electric potential. Dimensional suppression of thermal conductance and electron-phonon interaction were accounted for but found to be less effective than expected. The developed model predicts the formation of a layer with a high density of charge carriers that is practically independent of the concentration of dopant ions. This layer can effectively intercept the phonon flow propagating from the heated nanoisland. The resulting thermoEMF can have sufficient magnitudes to explain the low-voltage electron emission capability of nanoisland films of metals and sp2-bonded carbon, previously studied by our group. The phenomenon predicted by the model can be used in thermoelectric converters with untypical parameters or in systems for local cooling.

Observation of molecular resonant double-core excitation driven by intense X-ray pulses

The ultrashort and intense pulses of X-rays produced at X-ray free electron lasers (XFELs) have enabled unique experiments on the atomic level structure and dynamics of matter, with time-resolved studies permitted in the femto- and attosecond regimes. To fully exploit them, it is paramount to obtain a comprehensive understanding of the complex nonlinear interactions that can occur at such extreme X-ray intensities. Herein, we report on the experimental observation of a resonant double-core excitation scheme in N2, where two 1σ core-level electrons are resonantly promoted to unoccupied 1πg*\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$1{\\pi }_{g}^{* }$$\\end{document} molecular orbitals by a single few-femtosecond broad-bandwidth XFEL pulse. The production of these neutral two-site double core hole states is evidenced through their characteristic decay channels, which are observed in good agreement with high-level theoretical calculations. Such multi-core excitation schemes, benefiting from the high interaction cross sections and state- and site-selective nature of resonant X-ray interactions, should be generally accessible in XFEL irradiated molecules, and provide interesting opportunities for chemical analysis and for monitoring ultrafast dynamic processes.

Gamma absorption and radiation shielding properties of apatite-wollastonite containing SiO2, Fe2O3, and TiO2

This research presents the gamma interaction parameters of glass-ceramics with the apatite-wollastonite (AW) crystal structure within the SiO2–CaO–Al2O3–MgO–P2O5–CaF2 glass (AW) doped with 10% SiO2 (AW-10Si), Fe2O3 (AW-10Fe), and TiO2 (AW-10Ti) by weight. The density of the glass ceramics was determined based on the Archimedes method while the mass attenuation coefficients (MACs) of the glasses were estimated using the PHITS simulation code for gamma photons within the 15 keV-15MeV energies. The obtained densities of AW, AW-10Si, AW-10Ti, and AW-10Fe are 2.90, 2.92, 2.91, and 3.05 g/cm3, respectively. The linear attenuation coefficients of the glasses followed the order LACAW<LACAW−10Si<LACAW−10Ti<LACAW−10Fe. The addition of the metal oxides improves the attenuation coefficients of AW. A gradual increase in the HVLs was observed as the glass density decreased. AW-10Fe has the best photon absorption and scattering interaction cross-sections among the investigated glasses. This study showed that AW-x glasses are nontoxic, cheaper, environmentally friendly, and effective shields compared to some commercial and recently researched shielding glasses.

Synthesis and characterization of metakaolin-based geopolymers doped with CRT waste glass for radiation shielding applications

This study presents the influence of CRT glass on the gamma-ray interaction processes in metakaolin-based geopolymers. Four batches of G-CRT composites (namely, G, G-10CRT, G-20CRT, and G-30CRT, which represent geopolymer (G) samples doped with 0, 10, 20, and 30 wt% of CRT glass) were prepared using the cold hydrostatic press method. The mass attenuation coefficients of the prepared C-xCRT samples were computed using XCOM and FLUKA simulations for photons within the energy range of 15 keV–15 MeV. The density of the pristine geopolymer increased from about 1.86 g/cm3 to 2.09, 2.26, and 2.34 g/cm3 for G-10CRT, G-20CRT, and G-30CRT, respectively. The photon mass and linear attenuation coefficients of the geopolymers increased with CRT glass concentration. The half-value layer and mean free path were within the ranges 0.070–18.079 cm and 0.101–26.083 cm for G; 0.036–15.110 cm and 0.052–21.799 cm for G-10CRT; 0.024–13.197 cm and 0.014–19.039 cm for G-20CRT; and 0.018–12.074 and 0.026–17.419 cm for G-30CRT. The G-30CRT had the best gamma attenuating prowess in contrast to other G-xCRT. CRT-rich G-xCRT had a higher effective atomic number. For 10 mm thick geopolymer, the absorbed dose rates were 0.211 μR/h, 0.66 μR/h, 1.11 μR/h, and 1.55 μR/h for G, G-10CRT, G-20CRT, and G-30CRT, respectively, for 100 keV photons. The introduction of CRT glass into the geopolymer matrix improved their photon interaction cross-section. The geopolymers showed outstanding photon interaction ability compared to ordinary concrete and some shielding glasses at low photon energies. The CRT glass-doped geopolymer samples are useful for preparing radiation shielding concrete.

Enhanced radiation shielding efficiency of polystyrene nanocomposites with tailored lead oxide nanoparticles

In this study, we investigated a novel polymer nano-composite, PS-PbO, containing two distinct nano-sizes of lead oxide nanoparticles (PbO-A and PbO-B), in addition to the bulk size (PbO-K). These nanoparticles were embedded separately in a polystyrene (PS) matrix at different weight percentages (10%, 15%, 25%, and 35%) using roll mill mixing and compressing molding. Our evaluation focused on the radiation attenuation ability of PS-PbO and the effect of particle size, considering gamma-ray energies ranging from 0.06 to 1.3 MeV (from sources like 241Am, 133Ba, 137Cs, and 60Co). The linear attenuation coefficient (LAC) was determined by analyzing samples of the synthesized composite with different thicknesses. Then, various shielding parameters were calculated, including total molecular, atomic, and electronic cross-sections (σmol, σatm, σel), as well as the effective atomic number and the electron density (Zeff and Neff). Surprisingly, modifying PbO particle sizes had a significant impact on shielding efficiency. For instance, the composite with 25 wt% of the smallest PbO-B particles showed a 26.7% increase in LAC at 0.059 keV compared to the composite with 25 wt% of PbO-K (larger particles). Notably, the LAC peaked at low energy (0.059 keV), close to the K-edge of Pb, where interaction is directly proportional to Z4. With increasing PbO concentrations, the LAC of PS-PbO composites increased steadily. Additionally, as PbO concentration increased, the composite’s effective atomic number Zeff and the electron density Neff increased, leading to a greater total Gamma-ray interaction cross-section. Furthermore, when comparing the Half-Value Layers of the novel nanocomposite to traditional lead shielding, a 70% reduction in mass was observed. Notably, the composite containing the smallest nano-size of PbO exhibited the highest radiation-shielding efficiency among all combinations and could therefore be used to create inexpensive and lightweight shields.

Interaction of exotic states in a hadronic medium: the Z c (3900) case

We investigate the interactions of the charged exotic state Z c (3900) in a hadronic medium composed of light mesons. We study processes such as Zcπ→DD¯ , Zcπ→D*D¯* , Zcπ→DD¯* and the inverse ones. Using effective Lagrangians and form factors calculated with Quantum Chromodynamics (QCD) sum rules (treating the Z c (3900) as a tetraquark) we estimate the vacuum and thermally-averaged cross-sections of these reactions. We find that the Z c (3900) has relatively large interaction cross sections with the constituent particles of the hadronic medium. After that, we use the production and suppression cross sections in a rate equation to estimate the time evolution of the Z c multiplicity. We include the Z c decay and regeneration terms The coalescence model is employed to compute the initial Z c multiplicity for the compact tetraquark configuration. Our results indicate that the combined effects of hadronic interactions, hydrodynamical expansion, decay and regeneration affect the final yield, which is bigger than the initial value. Besides, the dependence of the Z c final yield with the centrality, center-of-mass energy and the charged hadron multiplicity measured at midrapidity [dNch/dη(η<0.5)] is also investigated.

Continuous gravitational waves: A new window to look for heavy nonannihilating dark matter

Sunlike stars can transmute into comparable mass black holes by steadily accumulating heavy nonannihilating dark matter particles over the course of their lives. If such stars form in binary systems, they could give rise to quasi-monochromatic, persistent gravitational waves, commonly known as continuous gravitational waves, as they inspiral toward one another. We demonstrate that next-generation space-based detectors, e.g., Laser Interferometer Space Antenna (LISA) and Big Bang Observer (BBO), can provide novel constraints on dark matter parameters (dark matter mass and its interaction cross-section with the nucleons) by probing gravitational waves from transmuted sunlike stars that are in close binaries. Our projected constraints depend on several astrophysical uncertainties and nevertheless are competitive with the existing constraints obtained from cosmological measurements as well as terrestrial direct searches, demonstrating a notable science case for these space-based gravitational wave detectors as probes of particle dark matter. Published by the American Physical Society 2024

Tunable single emitter-cavity coupling strength through waveguide-assisted energy quantum transfer

The emitter-cavity strong coupling manifests crucial significance for exploiting quantum technology, especially in the scale of individual emitters. However, due to the small light-matter interaction cross-section, the single emitter-cavity strong coupling has been limited by its harsh requirement on the quality factor of the cavity and the local density of optical states. Herein, we present a strategy termed waveguide-assisted energy quantum transfer (WEQT) to improve the single emitter-cavity coupling strength by extending the interaction cross-section. Multiple ancillary emitters are optically linked by a waveguide, providing an indirect coupling channel to transfer the energy quantum between target emitter and cavity. An enhancement factor of coupling strength g̃/g>10\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\widetilde{g}/g > 10$$\\end{document} can be easily achieved, which dramatically release the rigorous design of cavity. As an extension of concept, we further show that the ancillae can be used as controlling bits for a photon gate, opening up new degrees of freedom in quantum manipulation.

First Measurement of ν_{e} and ν_{μ} Interaction Cross Sections at the LHC with FASER's Emulsion Detector.

The first results of the study of high-energy electron neutrino (ν_{e}) and muon neutrino (ν_{μ}) charged-current interactions in the FASERν emulsion-tungsten detector of the FASER experiment at the LHC are presented. A 128.8kg subset of the FASERν volume was analyzed after exposure to 9.5 fb^{-1} of sqrt[s]=13.6 TeV pp data. Four (eight) ν_{e} (ν_{μ}) interaction candidate events are observed with a statistical significance of 5.2σ (5.7σ). This is the first direct observation of ν_{e} interactions at a particle collider and includes the highest-energy ν_{e} and ν_{μ} ever detected from an artificial source. The interaction cross section per nucleon σ/E_{ν} is measured over an energy range of 560-1740GeV (520-1760GeV) for ν_{e} (ν_{μ}) to be (1.2_{-0.7}^{+0.8})×10^{-38} cm^{2} GeV^{-1} [(0.5±0.2)×10^{-38} cm^{2} GeV^{-1}], consistent with standard model predictions. These are the first measurements of neutrino interaction cross sections in those energy ranges.

Response of a high-pressure 4He scintillation detector to nuclear recoils up to 9 MeV

Helium-4-based scintillation detector technology is emerging as a strong alternative to pulse-shape discrimination-capable organic scintillators for fast neutron detection and spectroscopy, particularly in extreme gamma-ray environments. The 4He detector is intrinsically insensitive to gamma radiation, as it has a relatively low cross-section for gamma-ray interactions, and the stopping power of electrons in the 4He medium is low compared to that of 4He recoil nuclei. Consequently, gamma rays can be discriminated by simple energy deposition thresholding instead of the more complex pulse shape analysis. The energy resolution of 4He scintillation detectors has not yet been well-characterized over a broad range of energy depositions, which limits the ability to deconvolve the source spectra. In this work, an experiment was performed to characterize the response of an Arktis S670 4He detector to nuclear recoils up to 9 MeV. The 4He detector was positioned in the center of a semicircular array of organic scintillation detectors operated in coincidence. Deuterium–deuterium and deuterium–tritium neutron generators provided monoenergetic neutrons, yielding geometrically constrained nuclear recoils ranging from 0.0925 to 8.87 MeV. The detector response provides evidence for scintillation linearity beyond the previously reported energy range. The measured response was used to develop an energy resolution function applicable to this energy range for use in high-fidelity detector simulations needed by future applications.

Cosmology and terrestrial signals of sexaquark dark matter

We investigate the hypothesis that sexaquarks, hypothetical stable six-quark states, could be a significant component of the dark matter. We expand on previous studies of sexaquark cosmology, accounting for the possibility that some relevant interaction cross sections might be strongly suppressed below expectations based on dimensional analysis. We update direct-detection constraints on stable sexaquarks comprising a subdominant fraction of the dark matter, as well as limits on the annihilation of an antisexaquark component from Super-Kamiokande. We argue that the scenario where sexaquarks comprise a O(1) fraction of the dark matter would require either a suppression of O(10−19) in sexaquark interactions with baryons, combined with a very high yield of net sexaquark number from the quark-hadron transition, or else a very strong suppression of the cross section for antisexaquark annihilation on nucleons (24+ orders of magnitude below the QCD scale). Independently, we find that a sexaquark component comprising more than O(10−3) of the dark matter can be excluded from direct-detection bounds, unless its scattering cross section is severely suppressed compared to the expected scale of strong and even electromagnetic interactions. Published by the American Physical Society 2024

Energy-dependent boosted dark matter from diffuse supernova neutrino background

Diffuse neutrinos from past supernovae in the Universe present us with a unique opportunity to test dark matter (DM) interactions. These neutrinos can scatter and boost the DM particles in the Milky Way halo to relativistic energies allowing us to detect them in terrestrial laboratories.Focusing on generic models of DM-neutrino and electron interactions, mediated by a vector or a scalar boson, we implement energy-dependent scattering cross-sections and perform detailed numerical analysis of DM attenuation due to electron scattering in-medium while propagating towards terrestrial experiments. We set new limits on DM-neutrino and electron interactions for DM with masses in the range ∼ (0.1, 104) MeV, using recent data from XENONnT, LUX-ZEPLIN, and PandaX-4T direct detection experiments. We demonstrate that consideration of energy-dependent cross-sections for DM interactions can significantly affect constraints previously derived under the assumption of constant cross-sections, modifying them by multiple orders of magnitude.