Hasil untuk "Elementary particle physics"

Tomasz Denkiewicz

We confront two future-singularity dark-energy templates—sudden future singularities (SFSs) and finite scale factor singularities (FSFSs)—with late-time geometric probes and redshift-space distortion growth data. We compute the observable growth <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>f</mi><msub><mi>σ</mi><mn>8</mn></msub><mrow><mo>(</mo><mi>z</mi><mo>)</mo></mrow></mrow></semantics></math></inline-formula> by solving the full linear perturbation system (including the standard fiducial cosmology rescaling of RSD measurements) and build a joint <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>χ</mi><mn>2</mn></msup></semantics></math></inline-formula> from Pantheon+SH0ES SNe Ia, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>H</mi><mo>(</mo><mi>z</mi><mo>)</mo></mrow></semantics></math></inline-formula>, DESI AP-only BAO, and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>f</mi><msub><mi>σ</mi><mn>8</mn></msub></mrow></semantics></math></inline-formula>. Parameter constraints are obtained via grid-based profiling over nuisance parameters and the singularity time location parameter. We compare the viability and goodness of fit of the singularity scenarios to the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="normal">Λ</mi></semantics></math></inline-formula>CDM reference.

D. Maurin, L. Audouin, E. Berti et al.

Cosmic-ray physics in the GeV-to-TeV energy range has entered a precision era thanks to recent data from space-based experiments. However, the poor knowledge of nuclear reactions, in particular for the production of antimatter and secondary nuclei, limits the information that can be extracted from these data, such as source properties, transport in the Galaxy and indirect searches for particle dark matter. The Cross-Section for Cosmic Rays at CERN workshop series has addressed the challenges encountered in the interpretation of high-precision cosmic-ray data, with the goal of strengthening emergent synergies and taking advantage of the complementarity and know-how in different communities, from theoretical and experimental astroparticle physics to high-energy and nuclear physics. In this paper, we present the outcomes of the third edition of the workshop that took place in 2024. We present the current state of cosmic-ray experiments and their perspectives, and provide a detailed road map to close the most urgent gaps in cross-section data, in order to efficiently progress on many open physics cases, which are motivated in the paper. Finally, with the aim of being as exhaustive as possible, this report touches several other fields -- such as cosmogenic studies, space radiation protection and hadrontherapy -- where overlapping and specific new cross-section measurements, as well as nuclear code improvement and benchmarking efforts, are also needed. We also briefly highlight further synergies between astroparticle and high-energy physics on the question of cross-sections.

Andreas Schachner

We review compactifications of type IIB string theory which produce de Sitter vacua to leading order in the $α^\prime$ and $g_s$ expansions in line with the scenario proposed by Kachru, Kallosh, Linde, and Trivedi. We detail specific Calabi-Yau orientifold compactifications incorporating the non-perturbative superpotential from Euclidean D3-branes, the full flux-induced superpotential, and the Kähler potential evaluated at string tree level but retaining all orders in $α'$. Each model hosts a Klebanov-Strassler throat featuring a single anti-D3-brane. The energy associated with this supersymmetry-breaking source, computed at leading order in $α'$, lifts the minimum to a metastable de Sitter vacuum with all moduli stabilised. A key open challenge is the identification of vacua that remain stable when including additional corrections; an endeavour for which this study provides a solid foundation. This work is a contribution to the proceedings of the Corfu Summer Institute 2024 "School and Workshops on Elementary Particle Physics and Gravity" (CORFU2024) and is based on arXiv:2406.13751.

John Mashford

An approach to gauge theory in the context of locally conformally flat space-time is described. It is discussed how there are a number of natural principal bundles associated with any given locally conformally flat space-time $X$. The simplest of these principal bundles is the bundle $P_X(G)$ with structure group $G=U(2,2)$. An 11 dimensional bundle $Q$ with structure group a certain 7 dimensional group $K$ is constructed by a method involving a reduction of structure group for the bundle $P_X(G)$. It is shown how the gauge groups $U(1)$, $SU(2)$ and $SU(3)$ can be derived from the geometry of locally conformally flat space-time. Fock spaces of multiparticle states for the fields of the standard model are constructed in the context of bundles with these groups as structure groups. Scattering and other particle interaction processes are defined in terms of linear maps between multiparticle state spaces. A technique for computing analytically and/or computationally the masses of the elementary particles is described. This method involves the computation of a certain quantity called the integral mass spectrum for a given family of particles and then the masses of the particles in the family are determined to be the locations of the peaks of the integral mass spectrum. The method is applied successfully in the electroweak sector to the cases of the charged leptons, $μ$ and $τ$, and the Z$^0$ particle.

Xuemei Zhang, Zhipeng Hu, Weitian Huang et al.

We present a comprehensive investigation of mid-infrared (MIR) flux variability at 3.4 μm (W1 band) for a large sample of 3816 blazars, using Wide-field Infrared Survey Explorer (WISE) data through December 2022. The sample consists of 1740 flat-spectrum radio quasars (FSRQs), 1281 BL Lac objects (BL Lacs), and 795 blazars of uncertain type (BCUs). Considering Fermi Large Area Telescope detection, we classify 2331 as Fermi blazars and 1485 as non-Fermi blazars. Additionally, based on synchrotron peak frequency, the sample includes 2264 low-synchrotron peaked (LSP), 512 intermediate-synchrotron peaked (ISP), and 655 high-synchrotron peaked (HSP) sources. We conduct a comparative analysis of short- and long-term intrinsic variability amplitude (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>σ</mi><mi>m</mi></msub></semantics></math></inline-formula>), duty cycle (DC), and ensemble structure function (ESF) across blazar subclasses. The median short-term <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>σ</mi><mi>m</mi></msub></semantics></math></inline-formula> values were <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0</mn><mo>.</mo><msubsup><mn>181</mn><mrow><mo>−</mo><mn>0.106</mn></mrow><mrow><mo>+</mo><mn>0.153</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0</mn><mo>.</mo><msubsup><mn>104</mn><mrow><mo>−</mo><mn>0.054</mn></mrow><mrow><mo>+</mo><mn>0.101</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0</mn><mo>.</mo><msubsup><mn>135</mn><mrow><mo>−</mo><mn>0.076</mn></mrow><mrow><mo>+</mo><mn>0.154</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0</mn><mo>.</mo><msubsup><mn>173</mn><mrow><mo>−</mo><mn>0.097</mn></mrow><mrow><mo>+</mo><mn>0.158</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0</mn><mo>.</mo><msubsup><mn>177</mn><mrow><mo>−</mo><mn>0.100</mn></mrow><mrow><mo>+</mo><mn>0.156</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0</mn><mo>.</mo><msubsup><mn>096</mn><mrow><mo>−</mo><mn>0.050</mn></mrow><mrow><mo>+</mo><mn>0.109</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0</mn><mo>.</mo><msubsup><mn>106</mn><mrow><mo>−</mo><mn>0.058</mn></mrow><mrow><mo>+</mo><mn>0.100</mn></mrow></msubsup></mrow></semantics></math></inline-formula> mag for FSRQs, BL Lacs, Fermi blazars, non-Fermi blazars, LSPs, ISPs, and HSPs, respectively. The median DC values were <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>71</mn><mo>.</mo><msubsup><mn>03</mn><mrow><mo>−</mo><mn>22.48</mn></mrow><mrow><mo>+</mo><mn>14.17</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>64</mn><mo>.</mo><msubsup><mn>02</mn><mrow><mo>−</mo><mn>22.86</mn></mrow><mrow><mo>+</mo><mn>16.97</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>68</mn><mo>.</mo><msubsup><mn>96</mn><mrow><mo>−</mo><mn>25.52</mn></mrow><mrow><mo>+</mo><mn>15.66</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>69</mn><mo>.</mo><msubsup><mn>40</mn><mrow><mo>−</mo><mn>22.17</mn></mrow><mrow><mo>+</mo><mn>14.42</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>71</mn><mo>.</mo><msubsup><mn>24</mn><mrow><mo>−</mo><mn>21.36</mn></mrow><mrow><mo>+</mo><mn>14.25</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>63</mn><mo>.</mo><msubsup><mn>03</mn><mrow><mo>−</mo><mn>33.19</mn></mrow><mrow><mo>+</mo><mn>16.93</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>64</mn><mo>.</mo><msubsup><mn>63</mn><mrow><mo>−</mo><mn>24.26</mn></mrow><mrow><mo>+</mo><mn>15.88</mn></mrow></msubsup></mrow></semantics></math></inline-formula> percent for the same subclasses. The median long-term <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>σ</mi><mi>m</mi></msub></semantics></math></inline-formula> values were <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0</mn><mo>.</mo><msubsup><mn>137</mn><mrow><mo>−</mo><mn>0.105</mn></mrow><mrow><mo>+</mo><mn>0.408</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0</mn><mo>.</mo><msubsup><mn>171</mn><mrow><mo>−</mo><mn>0.132</mn></mrow><mrow><mo>+</mo><mn>0.206</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0</mn><mo>.</mo><msubsup><mn>282</mn><mrow><mo>−</mo><mn>0.184</mn></mrow><mrow><mo>+</mo><mn>0.332</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0</mn><mo>.</mo><msubsup><mn>071</mn><mrow><mo>−</mo><mn>0.062</mn></mrow><mrow><mo>+</mo><mn>0.143</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0</mn><mo>.</mo><msubsup><mn>218</mn><mrow><mo>−</mo><mn>0.174</mn></mrow><mrow><mo>+</mo><mn>0.386</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0</mn><mo>.</mo><msubsup><mn>173</mn><mrow><mo>−</mo><mn>0.132</mn></mrow><mrow><mo>+</mo><mn>0.208</mn></mrow></msubsup></mrow></semantics></math></inline-formula>, and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>0</mn><mo>.</mo><msubsup><mn>101</mn><mrow><mo>−</mo><mn>0.077</mn></mrow><mrow><mo>+</mo><mn>0.161</mn></mrow></msubsup></mrow></semantics></math></inline-formula> mag for the same subclasses, respectively. Our results reveal significant differences in 3.4 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">μ</mi></semantics></math></inline-formula>m flux variability among these subclasses. FSRQs (LSPs) exhibit larger <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>σ</mi><mi>m</mi></msub></semantics></math></inline-formula> and DC values compared to BL Lacs (ISPs and HSPs). Fermi blazars display higher long-term <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>σ</mi><mi>m</mi></msub></semantics></math></inline-formula> but lower short-term <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>σ</mi><mi>m</mi></msub></semantics></math></inline-formula> relative to non-Fermi blazars, while DC distributions between the two groups are similar. ESF analysis further confirms the greater variability of FSRQs, LSPs, and Fermi blazars across a wide range of time scales compared to BL Lacs, ISPs/HSPs, and non-Fermi blazars. These findings highlight a close correlation between MIR variability and blazar properties, providing valuable insights into the underlying physical mechanisms responsible for their emission.

Ralf Aurich, Frank Steiner

The question of the global topology of the Universe (cosmic topology) is still open. In the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mo>Λ</mo></semantics></math></inline-formula>CDM concordance model, it is assumed that the space of the Universe possesses the trivial topology of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi mathvariant="double-struck">R</mi><mn>3</mn></msup></semantics></math></inline-formula>, and thus that the Universe has an <i>infinite</i> volume. As an alternative, in this paper, we study one of the simplest non-trivial topologies given by a cubic 3-torus describing a universe with a <i>finite</i> volume. To probe cosmic topology, we analyze certain structure properties in the cosmic microwave background (CMB) using <i>Betti functionals</i> and the <i>Euler characteristic</i> evaluated on excursions sets, which possess a simple geometrical interpretation. Since the CMB temperature fluctuations <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>δ</mi><mi>T</mi></mrow></semantics></math></inline-formula> are observed on the sphere <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow><mi mathvariant="double-struck">S</mi></mrow><mn>2</mn></msup></semantics></math></inline-formula> surrounding the observer, there are only three Betti functionals <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>β</mi><mi>k</mi></msub><mrow><mo>(</mo><mi>ν</mi><mo>)</mo></mrow></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>k</mi><mo>=</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>,</mo><mn>2</mn></mrow></semantics></math></inline-formula>. Here, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>ν</mi><mo>=</mo><mi>δ</mi><mi>T</mi><mo>/</mo><msub><mi>σ</mi><mn>0</mn></msub></mrow></semantics></math></inline-formula> denotes the temperature threshold normalized by the standard deviation <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>σ</mi><mn>0</mn></msub></semantics></math></inline-formula> of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>δ</mi><mi>T</mi></mrow></semantics></math></inline-formula>. The analytic approximations of the Gaussian expectations for the Betti functionals and an exact formula for the Euler characteristic are given. It is shown that the amplitudes of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>β</mi><mn>0</mn></msub><mrow><mo>(</mo><mi>ν</mi><mo>)</mo></mrow></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>β</mi><mn>1</mn></msub><mrow><mo>(</mo><mi>ν</mi><mo>)</mo></mrow></mrow></semantics></math></inline-formula> decrease with an increasing volume <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>V</mi><mo>=</mo><msup><mi>L</mi><mn>3</mn></msup></mrow></semantics></math></inline-formula> of the cubic 3-torus universe. Since the computation of the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>β</mi><mi>k</mi></msub></semantics></math></inline-formula>’s from observational sky maps is hindered due to the presence of masks, we suggest a method that yields lower and upper bounds for them and apply it to four Planck 2018 sky maps. It is found that the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>β</mi><mi>k</mi></msub></semantics></math></inline-formula>’s of the Planck maps lie between those of the torus universes with side-lengths <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>L</mi><mo>=</mo><mn>2.0</mn></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>L</mi><mo>=</mo><mn>3.0</mn></mrow></semantics></math></inline-formula> in units of the Hubble length and above the infinite <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mo>Λ</mo></semantics></math></inline-formula>CDM case. These results give a further hint that the Universe has a non-trivial topology.

Yun Yang, Huichao Li

Magnetohydrodynamic (MHD) numerical simulation has emerged as a pivotal tool in space physics research, witnessing significant advancements. This methodology offers invaluable insights into diverse space physical phenomena based on solving the fundamental MHD equations. Various numerical methods are utilized to approximate the MHD equations. Among these, the space–time conservation element and solution element (CESE) method stands out as an effective computational approach. Unlike traditional numerical schemes, the CESE method significantly enhances accuracy, even at the same base point. The concurrent discretization of space and time for conserved variables inherently achieves higher-order accuracy in both dimensions, without the need for intricate higher-order time discretization processes, which are often challenging in other methods. Additionally, this scheme can be readily extended to multidimensional cases, without relying on operator splitting or direction alternation. This paper primarily delves into the remarkable progress of CESE MHD models and their applications in studying solar wind, solar eruption activities, and the Earth’s magnetosphere. We aim to illuminate potential avenues for future solar–interplanetary CESE MHD models and their applications. Furthermore, we hope that the discussions presented in this review will spark new research endeavors in this dynamic field.

G. Aad, B. Abbott, K. Abeling et al.

A search for the decay of the Higgs boson to a Z boson and a light, pseudoscalar particle, a, decaying respectively to two leptons and to two photons is reported. The search uses the full LHC Run 2 proton–proton collision data at s=13 TeV, corresponding to 139 fb−1 collected by the ATLAS detector. This is one of the first searches for this specific decay mode of the Higgs boson, and it probes unexplored parameter space in models with axion-like particles (ALPs) and extended scalar sectors. The mass of the a particle is assumed to be in the range 0.1–33 GeV. The data are analysed in two categories: a merged category where the photons from the a decay are reconstructed in the ATLAS calorimeter as a single cluster, and a resolved category in which two separate photons are detected. The main background processes are from Standard Model Z boson production in association with photons or jets. The data are in agreement with the background predictions, and upper limits on the branching ratio of the Higgs boson decay to Za times the branching ratio a→γγ are derived at the 95% confidence level and they range from 0.08% to 2% depending on the mass of the a particle. The results are also interpreted in the context of ALP models.

Jorge F. Urbán, Petros Stefanou, José A. Pons

This study investigates the potential accuracy boundaries of physics-informed neural networks, contrasting their approach with previous similar works and traditional numerical methods. We find that selecting improved optimization algorithms significantly enhances the accuracy of the results. Simple modifications to the loss function may also improve precision, offering an additional avenue for enhancement. Despite optimization algorithms having a greater impact on convergence than adjustments to the loss function, practical considerations often favor tweaking the latter due to ease of implementation. On a global scale, the integration of an enhanced optimizer and a marginally adjusted loss function enables a reduction in the loss function by several orders of magnitude across diverse physical problems. Consequently, our results obtained using compact networks (typically comprising 2 or 3 layers of 20-30 neurons) achieve accuracies comparable to finite difference schemes employing thousands of grid points. This study encourages the continued advancement of PINNs and associated optimization techniques for broader applications across various fields.

The CMS collaboration, A. Hayrapetyan, A. Tumasyan et al.

Abstract A search for new physics in top quark production with additional final-state leptons is performed using data collected by the CMS experiment in proton-proton collisions at s $$ \sqrt{s} $$ = 13 TeV at the LHC during 2016–2018. The data set corresponds to an integrated luminosity of 138 fb −1. Using the framework of effective field theory (EFT), potential new physics effects are parametrized in terms of 26 dimension-six EFT operators. The impacts of EFT operators are incorporated through the event-level reweighting of Monte Carlo simulations, which allows for detector-level predictions. The events are divided into several categories based on lepton multiplicity, total lepton charge, jet multiplicity, and b-tagged jet multiplicity. Kinematic variables corresponding to the transverse momentum (p T) of the leading pair of leptons and/or jets as well as the p T of on-shell Z bosons are used to extract the 95% confidence intervals of the 26 Wilson coefficients corresponding to these EFT operators. No significant deviation with respect to the standard model prediction is found.

Cristiano Germani, Ravi K. Sheth

We review the nonlinear statistics of Primordial Black Holes that form from the collapse of over-densities in a radiation-dominated Universe. We focus on the scenario in which large over-densities are generated by rare and Gaussian curvature perturbations during inflation. As new results, we show that the mass spectrum follows a power law determined by the critical exponent of the self-similar collapse up to a power spectrum dependent cutoff, and that the abundance related to very narrow power spectra is exponentially suppressed. Related to this, we discuss and explicitly show that both the Press–Schechter approximation and the statistics of mean profiles lead to wrong conclusions for the abundance and mass spectrum. Finally, we clarify that the transfer function in the statistics of initial conditions for Primordial Black Holes formation (the abundance) does not play a significant role.

Allan D. Ernest

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.

The ATLAS collaboration, G. Aad, B. Abbott et al.

Abstract A measurement of novel event shapes quantifying the isotropy of collider events is performed in 140 fb −1 of proton-proton collisions with s $$ \sqrt{s} $$ = 13 TeV centre-of-mass energy recorded with the ATLAS detector at CERN’s Large Hadron Collider. These event shapes are defined as the Wasserstein distance between collider events and isotropic reference geometries. This distance is evaluated by solving optimal transport problems, using the ‘Energy-Mover’s Distance’. Isotropic references with cylindrical and circular symmetries are studied, to probe the symmetries of interest at hadron colliders. The novel event-shape observables defined in this way are infrared- and collinear-safe, have improved dynamic range and have greater sensitivity to isotropic radiation patterns than other event shapes. The measured event-shape variables are corrected for detector effects, and presented in inclusive bins of jet multiplicity and the scalar sum of the two leading jets’ transverse momenta. The measured distributions are provided as inputs to future Monte Carlo tuning campaigns and other studies probing fundamental properties of QCD and the production of hadronic final states up to the TeV-scale.

A. Tumasyan, W. Adam, J.W. Andrejkovic et al.

Measurements are presented of the Bs0→μ+μ− branching fraction and effective lifetime, as well as results of a search for the B0→μ+μ− decay in proton-proton collisions at s=13TeV at the LHC. The analysis is based on data collected with the CMS detector in 2016–2018 corresponding to an integrated luminosity of 140fb−1. The branching fraction of the Bs0→μ+μ− decay and the effective Bs0 meson lifetime are the most precise single measurements to date. No evidence for the B0→μ+μ− decay has been found. All results are found to be consistent with the standard model predictions and previous measurements.

Fatemeh Shojaei, Seyyed Hossein Zohdi, Hossein Atashi et al.

The study examined the potential use of MIL-53(Al), a metal-organic compound created through solvothermal synthesis, as a support for iron catalysts in Fischer-Tropsch Synthesis (FTS). Fischer-Tropsch synthesis is a crucial aspect of Gas-to-Liquid (GTL) technology used in the petrochemical industry to produce light olefins. The catalyst's activity was assessed under specific conditions, including a gas hourly space velocity (GHSV) of 2700 h-1, a hydrogen to carbon monoxide (H2/CO) feed ratio of 2:1, temperatures ranging from 310 to 330 ℃, and pressures ranging from 5 to 9 bar. The feasibility study indicated that MIL-53(Al) has the potential to be a suitable support for iron catalysts in FTS, resulting in the production of light olefins (24%) at high temperatures and low pressure.

Ehsan Kiani Aliabadi, Abdolreza Samimi, Davod Mohebbi-Kalhori et al.

The induced phase separation method was used to fabricate polyvinyl chloride (PVC) flat sheets for membrane distillation (MD) of RO brine feed by using dimethylformamide (DMF) and water as solvent and nonsolvent, respectively. Polyvinylpyrrolidone (PVP) and zinc oxide (ZnO) nanoparticles were utilized to improve the membrane structure and modify pore surfaces. The Taguchi experimental design approach was employed to investigate the impacts of concentrations of PVP and ZnO nanoparticles on the membrane's structural characteristics and performance. SEM, XRD, and FT-IR were used to characterize the surface and cross-sectional morphology, as well as the presence of crystalline phases and cross-linked organic groups, respectively. The water contact angle was measured to determine the wettability of the surface membrane and the impact of ZnO nanoparticles on its hydrophobicity. The membrane synthesis and MD process parameters were optimized for a Persian Gulf feed brine to obtain a maximum contact angle of 148°, under 80 °C and 12 L.min-1 circulating feed water, and resulted in high salt rejection (96.4%) and proper permeability water flux (4.2 L.m-2h-1).

Fulvia De Fazio

Our present understanding of elementary particle interactions is the synergic result of developments of theoretical ideas and of experimental advances that lead to the theory known as the Standard Model of particle physics. Despite the uncountable experimental confirmations, we believe that it is not yet the ultimate theory, for a number of reasons that I will briefly recall in this lecture. My main focus will be on the role that Flavour Physics has played in development of the theory in its present formulation, as well as on the opportunities that this sector offers to discover physics beyond the Standard Model.

Pavlos Laskos-Patkos, Polychronis S. Koliogiannis, Alkiviadis Kanakis-Pegios et al.

Over the last few years, the detection of gravitational waves from binary neutron star systems has rekindled our hopes for a deeper understanding of the unknown nature of ultradense matter. In particular, gravitational wave constraints on the tidal deformability of a neutron star can be translated into constraints on several neutron star properties using a set of universal relations. Apart from binary neutron star mergers, supernova explosions are also important candidates for the detection of multimessenger signals. Such observations may allow us to impose significant constraints on the binding energy of neutron stars. The purpose of the present study is twofold. Firstly, we investigate the agreement of finite temperature equations of state with established universal relations. Secondly, we examine the possible existence of a universal relation between the binding energy and the dimensionless tidal deformability, which are the bulk properties connected to the most promising sources for multimessenger signals. We find that hot equations of state are not always compatible with accepted universal relations. Therefore, the use of such expressions for probing general relativity or imposing constraints on the structure of neutron stars would be inconclusive (when thermal effects are present). Additionally, we show that the binding energy and the dimensionless tidal deformability exhibit a universal trend at least for moderate neutron star masses. The latter allows us to set bounds on the binding energy of a 1.4 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>M</mi><mo>⊙</mo></msub></semantics></math></inline-formula> neutron star using data from the GW170817 event. Finally, we provide a relation between the compactness, the binding energy and the dimensionless tidal deformability of a neutron star that is accurate for cold and hot isentropic equations of state.

Aifeng Li, Shiyu Yin, Maoyuan Liu et al.

Recent measurements of the spectra and anisotropy of cosmic rays (CRs) show a fine structure that reflects the spectral hardenings of CRs nuclei at the rigidity <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi mathvariant="script">R</mi></mrow></semantics></math></inline-formula> ∼ 200 GV followed by softenings at <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi mathvariant="script">R</mi></mrow></semantics></math></inline-formula> ∼ 10 TV, and reveal complicated energy dependence of the amplitude and phase of anisotropy from 100 GeV to PeV. Numerous studies have shown that the existence of nearby CR sources and a local interstellar magnetic field (LIMF) near the solar system are crucial for such CR spectral and anisotropic patterns. In this work, we analyze the CR spectra of different CR components and the anisotropy considering the nearby Geminga supernova remnants (SNRs) source. In the calculation process, we also introduce the anisotropic diffusion of CRs induced by the LIMF based on the spatial-dependent propagation (SDP) model. As a result, our model can simultaneously account for the CR spectra and the anisotropy from 100 GeV to PeV. Future high-precision measurements of the CR anisotropy, for example, by the LHAASO experiment, would be of the essence in the assessment of our proposed model.

Hilary M. Hurst, Benedetta Flebus

Non-Hermitian Hamiltonians provide an alternative perspective on the dynamics of quantum and classical systems coupled non-conservatively to an environment. Once primarily an interest of mathematical physicists, the theory of non-Hermitian Hamiltonians has solidified and expanded to describe various physically observable phenomena in optical, photonic, and condensed matter systems. Self-consistent descriptions of quantum mechanics based on non-Hermitian Hamiltonians have been developed and continue to be refined. In particular, non-Hermitian frameworks to describe magnonic and hybrid magnonic systems have gained popularity and utility in recent years, with new insights into the magnon topology, transport properties, and phase transitions coming into view. Magnonic systems are in many ways a natural platform in which to realize non-Hermitian physics because they are always coupled to a surrounding environment and exhibit lossy dynamics. In this perspective we review recent progress in non-Hermitian frameworks to describe magnonic and hybrid magnonic systems, such as cavity magnonic systems and magnon-qubit coupling schemes. We discuss progress in understanding the dynamics of inherently lossy magnetic systems as well as systems with gain induced by externally applied spin currents. We enumerate phenomena observed in both purely magnonic and hybrid magnonic systems which can be understood through the lens of non-Hermitian physics, such as PT and Anti-PT-symmetry breaking, dynamical magnetic phase transitions, non-Hermitian skin effect, and the realization of exceptional points and surfaces. Finally, we comment on some open problems in the field and discuss areas for further exploration.