Particle Candidates Research Articles

Assessment of Particle Candidates for Falling Particle Receiver Applications Through Irradiance and Thermal Cycling

Abstract Falling particle receiver (FPR) systems are a rapidly developing technology for concentrating solar power applications. Solid particles are used as both the heat transfer fluid and system thermal energy storage media. Through the direct irradiation of the solid particles, flux and temperature limitations of tube-bundle receivers can be overcome, leading to higher operating temperatures and energy conversion efficiencies. Candidate particles for FPR systems must be resistant to changes in optical properties during long-term exposure to high temperatures and thermal cycling in highly concentrated solar irradiance. Seven candidate particles—two previously tested particles such as CARBOBEAD HSP 40/70 and CARBOBEAD CP 40/100 and the five novel particles such as CARBOBEAD MAX HD 35, CARBOBEAD Solar HSP, CARBOBEAD Solar CP, CARBOBEAD Solar MAX HD, and WanLi Diamond Black—were tested using simulated solar flux cycling and tube furnace thermal aging. Each particle candidate was exposed for 10,000 cycles (simulating the exposure of a 30-year lifetime of a concentrated solar power plant) using a shutter to attenuate the solar simulator flux. Feedback from a pyrometer temperature measurement of the irradiated particle surface was used to control the maximum temperatures of 775 °C and 975 °C. Particle solar-weighted absorptance and emittance were measured at 2000 cycle intervals. Particle thermal degradation was also studied by heating particles to 800 °C, 900 °C, and 1000 °C for 300 h in a tube furnace purged with bottled unpurified air. Here, particle absorptance and emittance were measured at 100-h intervals. Measurements taken after irradiance cycling and thermal aging were compared to measurements taken from as-received particles. WanLi Diamond Black particles had the highest initial value for solar-weighted absorptance, 96%, but degraded up to 4% in irradiance cycling and 6% in thermal aging. CARBOBEAD HSP 40/70 particles currently in use in the prototype FPR at the National Solar Thermal Test Facility had an initial value of 95% solar absorptance with up to a 1% drop after irradiance cycling and 4% drop after 1000 °C thermal aging.

Observational prospects of self-interacting scalar superradiance with next-generation gravitational-wave detectors

Abstract Current- and next-generation gravitational-wave observatories may reveal new, ultralight bosons. Through the superradiance process, these theoretical particle candidates can form clouds around astrophysical black holes and result in detectable gravitational-wave radiation. In the absence of detections, constraints—contingent on astrophysical assumptions—have been derived using LIGO-Virgo-KAGRA data on boson masses. However, the searches for ultralight scalars to date have not adequately considered self-interactions between particles. Self-interactions that significantly alter superradiance dynamics are generically present for many scalar models, including axion-like dark matter candidates and string axions. We implement the most complete treatment of particle self-interactions available to determine the gravitational-wave signatures expected from superradiant scalar clouds and revisit the constraints obtained in a past gravitational-wave search targeting the black hole in Cygnus X-1. We also project the reach of next-generation gravitational-wave observatories to scalar particle parameter space in the mass-coupling plane. We find that while proposed observatories have insufficient reach to self-interactions that can halt black hole spin-down, next-generation observatories are essential for expanding the search beyond gravitational parameter space and can reach a mass and interaction scale of ∼ 10 − 13 –10−12 eV / c 2 and ≳ 10 17 GeV, respectively.

Generalized and high-efficiency arbitrary-positioned buffer for smoothed particle hydrodynamics

This paper develops a generalized, high-efficiency buffer for particle generation and deletion at arbitrary-positioned in-/outlets in the smoothed particle hydrodynamics method. To achieve generality, we standardize the position comparison of particles with an arbitrary-positioned in-/outlet bound by introducing coordinate transformation. To enhance efficiency, particle candidates subjected to position comparison at a specific in-/outlet are restricted to those within the local cell-linked lists near the defined buffer region, thereby avoiding the inefficiency in the straightforward approach of sequentially checking all fluid particle positions across the computational domain. We validate the effectiveness and versatility of the developed buffer through two-dimensional and three-dimensional non-orthogonal and orthogonal, uni- and bidirectional flows with arbitrary-positioned in- and outlets, driven by pressure or velocity boundary conditions.

Revisiting for maximal flavor violating Zeμ′ and its phenomenology constraints

Lepton flavor violation (LFV), observed conclusively in neutrino oscillations, remains a pivotal area of investigation due to its absence in the Standard Model (SM). Beyond the Standard Model (BSM) physics explores charged lepton flavor violation (CLFV), particularly through new particle candidates such as the Z′. This article focuses on maximal LFV interactions facilitated by the Z′ boson, specifically targeting its off-diagonal interactions with the first and second generations of charged and neutral leptons. In our ultraviolet (UV) model for the origin of the Z′, inspired by the work of [R.Foot et al., Phys.Rev. D50 (1994) 4571-4580], we utilize the discrete Z2 symmetry to investigate the maximal LFV mediated by the Z′ between the muon (μ) and electron (e) arising from the additional scalars. This symmetry prohibits flavor-conserving interactions between Z′ and μ+μ−, e+e−. In conjunction with collider, (g – 2)μ, (g – 2)e, inverse μ decay, Muonium-to-Antimuonium conversion and LFV decay constraints, we provide forecasts for anticipated limits derived from processes such as νμN → νeμ+e−N in neutrino trident experiments like the DUNE search at the first time. These limits highlight the prospective scope and significance of LFV investigations within these experimental frameworks. Within the mass range of 0.01 GeV to 10 GeV, the most stringent limit arises from Bμ→e+X+γ when MZ′<mμ, while ∆ae provides effective constraints as MZ′ approaches 10 GeV. Looking ahead, the proposed Muonium-to-Antimuonium Conversion Experiment (MACE) is expected to impose the most stringent constraints on Muonium-to-Antimuonium oscillation, improving sensitivity by about one order of magnitude against ∆ae.

A single dose of an ALVAC vector-based RABV virus-like particle candidate vaccine induces a potent immune response in mice, cats and dogs

Rabies, caused by the Rabies virus (RABV), is a highly fatal zoonotic disease. Existing rabies vaccines have demonstrated good immune efficacy, but the complexity of immunization procedures and high cost has impeded the elimination of RABV, particularly in the post-COVID-19 era. There is a pressing need for safer and more effective rabies vaccines that streamline vaccination protocols and reduce expense. To meet this need, we have developed a potential rabies vaccine candidate called ALVAC-RABV-VLP, utilizing CRISPR/Cas9 gene editing technology. This vaccine employs a canarypox virus vector (ALVAC) to generate RABV virus-like particles (VLPs). In mice, a single dose of ALVAC-RABV-VLP effectively activated dendritic cells (DCs), follicular helper T cells (Tfh), and the germinal center (GC)/plasma cell axis, resulting in durable and effective humoral immune responses. The survival rate of mice challenged with lethal RABV was 100%. Similarly, in dogs and cats, a single immunization with ALVAC-RABV-VLP elicited a stronger and longer-lasting antibody response. ALVAC-RABV-VLP induced superior cellular and humoral immunity in both mice and beagles compared to the commercial inactivated rabies vaccine. In conclusion, ALVAC-RABV-VLP induced robust protective immune responses in mice, dogs and cats, offering a novel, cost-effective, efficient, and promising approach for herd prevention of rabies.

Capture of field stars by dark substructures

ABSTRACT We use analytical and N-body methods to study the capture of field stars by gravitating substructures moving across a galactic environment. The majority of stars captured by a substructure move on temporarily bound orbits that are lost to galactic tides after a few orbital revolutions. In numerical experiments where a substructure model is immersed into a sea of field particles on a circular orbit, we find a population of particles that remain bound to the substructure potential for indefinitely long times. This population is absent from substructure models, initially placed outside the galaxy on an eccentric orbit. We show that gravitational capture is most efficient in dwarf spheroidal galaxies (dSphs) on account of their low velocity dispersions and high stellar phase-space densities. In these galaxies, ‘dark’ sub-subhaloes, which do not experience in situ star formation, may capture field stars and become visible as stellar overdensities with unusual properties: (i) they would have a large size for their luminosity, (ii) contain stellar populations indistinguishable from the host galaxy, and (iii) exhibit dark matter (DM)-dominated mass-to-light ratios. We discuss the nature of several ‘anomalous’ stellar systems reported as star clusters in the Fornax and Eridanus II dSphs that exhibit some of these characteristics. DM sub-subhaloes with a mass function ${\rm d}N/{\rm d}M_\bullet \sim M_\bullet ^{-\alpha }$ are expected to generate stellar systems with a luminosity function, ${\rm d}N/{\rm d}M_\star \sim M_\star ^{-\beta }$, where $\beta =(2\alpha +1)/3=1.6$ for $\alpha =1.9$. Detecting and characterizing these objects in dSphs would provide unprecedented constraints on the particle mass and cross-section of a large range of DM particle candidates.

Dark matter and its candidate particles

Theoretically predicted unseen matter called dark matter may be present in the universe. Even though it might be the primary component of cosmic matter, it is not a part of any known material that makes up a visible celestial body. Despite the fact that dark matter has not yet been directly observed, there is a wealth of evidence to support its existence, for example, through the autobiographical curve of the Milky Way, the mass distribution of galaxy clusters, the background radiation of the universe microwaves, and the formation of large-scale structures of the universe. Although great progress has been made in cosmic observation, we are still unable to determine what the constituent particles of dark matter are.There are the following speculations about what particles dark matter is composed of: baryon dark matter, such as MACHOs, rogue planets, and other possibilities; Non-baryonic dark matter: Weakly Interacting Massive Particles (WIMPs); Axion; Neutrino, etc.

Model for bubble nucleation efficiency of low-energy nuclear recoils in bubble chambers for dark matter detection

Bubble chambers are promising technologies for detecting low-energy nuclear recoils from the elastic scattering of dark matter particle candidates. Bubble nucleation occurs when the energy deposition exceeds a specific threshold defined traditionally by the “heat-spike” Seitz threshold. In this paper, we report on a physical model that can account for observed discrepancies between the current Seitz model and the measured nucleation efficiency of low-energy nuclear recoils, which is necessary for interpreting dark matter signals. In our work, we combine molecular dynamics and Monte Carlo simulations together with the Lindhard model to predict bubble nucleation efficiency and energy thresholds for C3F8, CF3I, and xenon with enhanced accuracy over the Seitz model when compared to existing experimental data. We use our model to determine the effect on cross-section limits for spin-dependent and spin-independent interactions and compare it to the current PICO dark matter experiment. Our technique can also be applied to estimate the efficiency of future target fluids where no experimental data are available. As an example, we predict the nucleation efficiency, the energy threshold, and the cross-section limits in the spin-independent channel for the Scintillating Bubble Chamber experiment filled with superheated liquid argon. Published by the American Physical Society 2024

The excess of diffuse radio emission in galaxy clusters A4038 and A1664

The excess of diffuse radio emission in galaxy clusters A4038 and A1664

A Flexible and Efficient Approach to Missing Transverse Momentum Reconstruction

Missing transverse momentum is a crucial observable for physics at hadron colliders, being the only constraint on the kinematics of “invisible” objects such as neutrinos and hypothetical dark matter particles. Computing missing transverse momentum at the highest possible precision, particularly in experiments at the energy frontier, can be a challenging procedure due to ambiguities in the distribution of energy and momentum between many reconstructed particle candidates. This paper describes a novel solution for efficiently encoding information required for the computation of missing transverse momentum given arbitrary selection criteria for the constituent reconstructed objects. Pileup suppression using information from both the calorimeter and the inner detector is an integral component of the reconstruction procedure. Energy calibration and systematic variations are naturally supported. Following this strategy, the ATLAS Collaboration has been able to optimise the use of missing transverse momentum in diverse analyses throughout Runs 2 and 3 of the Large Hadron Collider and for future analyses.

Dissecting dark matter candidates: A comprehensive evaluation of axions, sterile neutrinos, and WIMPs

This article provides a comprehensive review of the three most popular candidates for dark matter: axions, sterile neutrinos, and WIMPs (Weakly Interacting Massive Particles). The article explores the theoretical origins of these candidates and their characteristic properties. It also examines the various observational constraints placed on them by different experiments, including direct and indirect detection experiments, as well as astrophysical and cosmological observations. The article also discusses the implications of these particle candidates on the development of cosmic structures, such as galaxies and galaxy clusters. This review aims to enhance comprehension of the present status in dark matter studies and the challenges faced in identifying the nature of dark matter. In summary, this comprehensive review provides a comparative analysis of the most promising dark matter candidates, shedding light on the latest developments in this exciting field of research.

Bottom-up dust nucleation theory in oxygen-rich evolved stars

Context. Spinel (MgAl2O4) and krotite (CaAl2O4) are alternative candidates to alumina (Al2O3) as primary dust condensates in the atmospheres of oxygen-rich evolved stars. Moreover, spinel was proposed as a potential carrier of the circumstellar 13 μm feature. However, the formation of nucleating spinel clusters is challenging; in particular, the inclusion of Mg constitutes a kinetic bottleneck. Aims. We aim to understand the initial steps of cosmic dust formation (i.e. nucleation) in oxygen-rich environments using a quantum-chemical bottom-up approach. Methods. Starting with an elemental gas-phase composition, we constructed a detailed chemical-kinetic network that describes the formation and destruction of magnesium-, calcium-, and aluminium-bearing molecules as well as the smallest dust-forming (MgAl2O4)1 and (CaAl2O4)1 monomer clusters. Different formation scenarios with exothermic pathways were explored, including the alumina (Al2O3) cluster chemistry studied in Paper I of this series. The resulting extensive network was applied to two model stars, a semi-regular variable and a Mira-type star, and to different circumstellar gas trajectories, including a non-pulsating outflow and a pulsating model. We employed global optimisation techniques to find the most favourable (MgAl2O4)n, (CaAl2O4)n, and mixed (MgxCa(1−x)Al2O4)n isomers, with n = 1–7 and x∈[0..1], and we used high level quantum-chemical methods to determine their potential energies. The growth of larger clusters with n = 2–7 is described by the temperature-dependent Gibbs free energies. Results. In the considered stellar outflow models, spinel clusters do not form in significant amounts. However, we find that in the Mira-type non-pulsating model CaAl2O3(OH)2, a hydroxylated form of the calcium aluminate krotite monomer forms at abundances as large as 2 × 10−8 at 3 stellar radii, corresponding to a dust-to-gas mass ratio of 1.5 × 10−6. Moreover, we present global minimum (GM) candidates for (MgAl2O4)n and (CaAl2O4)n, where n = 1–7. For cluster sizes n = 3–7, we find new, hitherto unreported GM candidates. All spinel GM candidates found are energetically more favourable than their corresponding magnesium-rich silicate clusters with an olivine stoichiometry, namely (Mg2SiO4)n. Moreover, calcium aluminate clusters, (CaAl2O4)n, are more favourable than their Mg-rich counterparts; the latter show a gradual enhancement in stability when Mg atoms are substituted step by step with Ca. Conclusions. Alumina clusters with a dust-to-gas mass ratio of the order of 10−4 remain the favoured seed particle candidate in our physico-chemical models. However, CaAl2O4 could contribute to stellar dust formation and the mass-loss process. In contrast, the formation of MgAl2O4 is negligible due to the low reactivity of the Mg atom.

Search for magnetic monopoles and stable particles with high electric charges in 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 pp collisions with the ATLAS detector

We present a search for magnetic monopoles and high-electric-charge objects using LHC Run 2 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 proton-proton collisions recorded by the ATLAS detector. A total integrated luminosity of 138 fb−1 was collected by a specialized trigger. No highly ionizing particle candidate was observed. Considering the Drell-Yan and photon-fusion pair production mechanisms as benchmark models, cross-section upper limits are presented for spin-0 and spin-1/2 magnetic monopoles of magnetic charge 1gD and 2gD and for high-electric-charge objects of electric charge 20 ≤ |z| ≤ 100, for masses between 200 GeV and 4000 GeV. The search improves by approximately a factor of three the previous cross-section limits on the Drell-Yan production of magnetic monopoles and high-electric charge objects. Also, the first ATLAS limits on the photon-fusion pair production mechanism of magnetic monopoles and high-electric-charge objects are obtained.

Preparation and immunoprotective effects of a virus-like particle candidate vaccine of the dominant epidemic D3 genotype coxsackievirus A6 in China

Preparation and immunoprotective effects of a virus-like particle candidate vaccine of the dominant epidemic D3 genotype coxsackievirus A6 in China

Axion-assisted resonance oscillation rescues the Dodelson–Widrow mechanism

The keV\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ extrm{keV}$$\\end{document} scale sterile neutrino was a qualified candidate for dark matter particles in the Dodelson-Widrow mechanism. But the mixing angle, needed to provide enough amount of dark matter, is in contradiction with the astrophysical observations. To alleviate such tension, we introduce an effective interaction, i.e. ga(ϕ/Λ)∂μaνα¯γμγ5να\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$g_a (\\phi /\\Lambda )\\partial _{\\mu }a \\overline{\ u _\\alpha }\\gamma ^{\\mu } \\gamma _5 \ u _\\alpha $$\\end{document}, among Standard Model neutrino να\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ u _\\alpha $$\\end{document}, axion a, and singlet ϕ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\phi $$\\end{document}. The axial-vector interaction form is determined by the axion shift symmetry, and the singlet ϕ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\phi $$\\end{document} with dynamically varied vacuum expectation value is introduced to reinforce the axial-vector coupling strength and evade the stringent neutrino oscillation constraints. The effective potential generated by the new interaction could cancel the SM counterpart, resulting in an enhanced converting probability between SM neutrino and sterile neutrino. Hence, the production rate of sterile neutrinos can be substantially enlarged with smaller mixing compared to the DW mechanism.

Optimization of Flow Imaging Microscopy Setting Using Spherical Beads with Optical Properties Similar to Those of Biopharmaceuticals

Flow imaging microscopy (FIM) is widely used to characterize biopharmaceutical subvisible particles (SVPs). The segmentation threshold, which defines the boundary between the particle and the background based on pixel intensity, should be properly set for accurate SVP quantification. However, segmentation thresholds are often subjectively and empirically set, potentially leading to variations in measurements across instruments and operators. In the present study, we developed an objective method to optimize the FIM segmentation threshold using poly(methyl methacrylate) (PMMA) beads with a refractive index similar to that of biomolecules. Among several candidate particles that were evaluated, 2.5-µm PMMA beads were the most reliable in size and number, suggesting that the PMMA bead size analyzed by FIM could objectively be used to determine the segmentation threshold for SVP measurements. The PMMA bead concentrations measured by FIM were highly consistent with the indicative concentrations, whereas the PMMA bead size analyzed by FIM decreased with increasing segmentation threshold. The optimal segmentation threshold where the analyzed size was closest to the indicative size differed between an instrument with a black-and-white camera and that with a color camera. Inter-instrument differences in SVP concentrations in acid-stressed recombinant adeno-associated virus (AAV) and protein aggregates were successfully minimized by setting an optimized segmentation threshold specific to the instrument. These results reveal that PMMA beads can aid in determining a more appropriate segmentation threshold to evaluate biopharmaceutical SVPs using FIM.

Biological and physico-chemical characterization of human norovirus-like particles under various environmental conditions

Human noroviruses (HuNoVs) are the predominant etiological agent of viral gastroenteritis in all age groups worldwide. Mutations over the years have affected noroviruses' responses to environmental conditions due to the arrangement of amino acid residues exposed on the VP1 capsid surface of each strain. The GII.4 HuNoV genotype has been the predominant variant for decades, while the GII.17 genotype has often been detected in East Asia since 2014. Here, GII.17 and GII.4 baculovirus-expressed VLPs (virus-like particles) were used to study the biological (binding to HuNoV ligand, namely the ABO and Lewis antigens) and physicochemical properties (size, morphology, and charge) of the HuNoV capsid under different conditions (temperature, pH, and ionic strength). GII.17 showed stability at low and high ionic strength, while GII.4 aggregated at an ionic strength of 10mM. The nature of the buffers influences the morphology and stability of the VLPs. Here, both VLPs were highly stable from pH 7-8.5 at 25°C. VLPs retained HBGA binding capability for the pH, ionic strength and temperature encountered in the stomach (fed state) and the small intestine. Increasing the temperature to above 65°C altered the morphology of VLPs, causing aggregation, and decreased their affinity to HBGAs. Comparing both isolates, GII.17 showed a better stability profile and higher affinity to HBGAs than GII.4, making them interesting candidate particles for a future norovirus vaccine. Biological and physicochemical studies of VLPs are as pertinent as ever in view of the future arrival of VLP-based HuNoV vaccines.

Can Neutrino Self-interactions Save Sterile Neutrino Dark Matter?

Sterile neutrinos only interact with the standard model through the neutrino sector, and thus represent a simple dark matter (DM) candidate with many potential astrophysical and cosmological signatures. Recently, sterile neutrinos produced through self-interactions of active neutrinos have received attention as a particle candidate that can yield the entire observed DM relic abundance without violating the most stringent constraints from X-ray observations. We examine consistency of this production mechanism with the abundance of small-scale structure in the universe, as captured by the population of ultrafaint dwarf galaxies orbiting the Milky Way, and derive a lower bound on the sterile-neutrino particle mass of 37 keV. Combining these results with previous collider and X-ray limits excludes 100% sterile-neutrino DM produced by strong neutrino self-coupling, mediated by a heavy (≳1 GeV) scalar; however, data permits sterile-neutrino DM production via a light mediator.

Gravitational Quantum Mechanics—Implications for Dark Matter

The laboratory verification of the existence of gravitational eigenstates and studies of their properties in the Earth’s gravitational field raises the question of whether the prediction of particle behaviour in gravitational wells would be any different if it were analysed using quantum theory rather than classical physics. In fact, applying Schrodinger’s equation to the weak gravity regions of large gravitational wells shows that particles in these wells can have significantly reduced optical interaction cross sections and be weakly interacting compared to classical expectations. Their cross sections are dependent on their wavefunctional form and the environment in which they exist. This quantum phenomenon has implications for the dark matter (DM) problem. Analysis using gravitational quantum mechanics (GQM) has shown that a proton, electron, or any other particle within the standard model of particle physics (SMPP) could potentially function as a “dark matter particle” when bound in a gravity well, provided the gravitational eigenspectral ensemble of their wavefunction contains a sufficient proportion of the gravitational well’s weakly interacting gravitational eigenstates. The leading theoretical paradigm for cosmic evolution, Lambda Cold Dark Matter (LCDM), currently lacks a suitable weakly interacting DM candidate particle, and gravitational quantum theory could provide a resolution to this. This article reviews the GQM approach to DM and provides some new results derived from the GQM analysis of particles held in the weak gravity regions of deep gravitational wells. It also outlines some predictions of the gravitational quantum approach that might be tested through observation.

A Neural-Network-Based Competition between Short-Lived Particle Candidates in the CBM Experiment at FAIR

Fast and efficient algorithms optimized for high performance computers are crucial for the real-time analysis of data in heavy-ion physics experiments. Furthermore, the application of neural networks and other machine learning techniques has become more popular in physics experiments over the last years. For that reason, a fast neural network package called ANN4FLES is developed in C++, which will be optimized to be used on a high performance computer farm for the future Compressed Baryonic Matter (CBM) experiment at the Facility for Antiproton and Ion Research (FAIR, Darmstadt, Germany). This paper describes the first application of ANN4FLES used in the reconstruction chain of the CBM experiment to replace the existing particle competition between Ks-mesons and Λ-hyperons in the KF Particle Finder by a neural network based approach. The raw classification performance of the neural network reaches over 98% on the testing set. Furthermore, it is shown that the background noise was reduced by the neural network-based competition and therefore improved the quality of the physics analysis.