Abstract: We present a geometric resolution of the Yang–Mills mass gap problem, one of the seven Clay Millennium Prize problems in mathematics. Within the QRECOIL (Quantum Resonant Emergence through Chaos, Ontology, and Informational Loops) framework, we demonstrate that the mass gap emerges necessarily from three syn- ergistic mechanisms: (i) the discrete eigenvalue spectrum of the Laplace–Beltrami operator on the 3-sphere S3 ∼= SU(2), (ii) von Neumann entropy minimization through Fibonacci quantization governed by the golden ratio φ = (1 + √5)/2, and (iii) topological protection via the second Chern class c2(S3) = 3. We derive the fundamental mass gap formula ∆YM = ΛQCD ×φ ≈ 1.699 GeV, achieving agreement with lattice QCD glueball masses within 0.3% without parameter fitting. Crucially, the golden ratio emerges naturally from Jacobi polynomial recursion on S3 for SU(3) gauge theoryit is mathematical consequence, not empirical input. We estab- lish three independent proofs that ∆YM > 0 is geometrically necessary, addressing the core requirement of the Clay Institute problem. This work demonstrates that confinement and mass generation are geometric inevitabilities arising from the compactification of gauge coupling space onto S3, providing a pathway toward rigorous resolution of the Yang–Mills existence and mass gap problem.

Abstract: We present a time-dependent nonperturbative theory of the reconstruction of attosecond beating by interference of multiphoton transitions (RABBIT) for photoelectron emission from hydrogen atoms in the direction perpendicular to the laser polarization axis. Extending our recent semiclassical strong-field approximation (SFA) model developed for parallel emission [López et al., Phys. Rev. A 110, 013104 (2024)], we derive analytical expressions for the transition amplitudes and demonstrate that the photoelectron probability distribution can be factorized into interhalf- and intrahalfcycle interference contributions, the latter modulating the intercycle pattern responsible for sideband formation. We identify the intrahalfcycle interference between trajectories born within the same half cycle as the mechanism governing attosecond phase delays in the perpendicular geometry. Our results reveal the suppression of even-order sidebands due to destructive interhalfcycle interference, leading to a characteristic spacing between adjacent peaks that doubles the standard spacing observed along the polarization axis. Comparisons with numerical calculations of the SFA and the ab initio solution of the time-dependent Schrödinger equation confirm the accuracy of the semiclassical description. This work provides a unified framework for understanding quantum interferences in attosecond chronoscopy, bridging the cases of parallel and perpendicular electron emission in RABBIT-like protocols.

Abstract: In this study, the spectroscopic and aromaticity properties of newly synthesized methylene bridged [6], [8] and [10] rings of p-styrene (MCPP) were investigated. The photophysical properties of MCPP with n=6, 8 and 10 are calculated and analyzed by time-varying density functional theory (TD-DFT). The main characteristics of Raman spectra are revealed by vibration analysis. The results show that the contribution of π orbital to electron excitation is the main cause of antiaromaticity. By means of induced current density anisotropy (AICD), isochemical shield surface (ICSS) and magnetic induction galvanometer (GIMIC), the responses of these molecules to external magnetic fields, especially the ring current induction and magnetic shield effects, were investigated. The results show that these MCPP systems exhibit anti-aromaticity, which is mainly driven by the delocalization of strong π electrons. This study deepens the understanding of the structure and electronic properties of MCPP, and provides a reference for practical application in material design in the future.

Abstract: Collective superradiant decay of a tightly packed inverted quantum emitter ensemble is among the most intensely studied phenomena in quantum optics. Since the seminal work of Dicke more than half a century ago, a plethora of theoretical calculations in quantum many-body physics have followed. Widespread experimental efforts range from the microwave to the X-ray regime. Nevertheless, accurate calculations of the time dynamics of the superradiant emission pulse still remain a challenging task needing approximate methods for large ensembles. Here, we benchmark the cumulant expansion method for describing collective superradiant decay against a new, recently found exact solution. Applying two variants of the cumulant expansion exhibits reliable convergence of time and magnitude of the maximum emission power with increasing truncation order. The longterm population evolution is only correctly captured for low emitter numbers, where an individual spin-based cumulant expansion proves more reliable than the collective spin-based variant. Surprisingly, odd orders show even qualitatively nonphysical behavior. At sufficiently high spin numbers, both chosen cumulant methods agree, but still fail to reliably converge to the numerically exact result. Generally, at a longer time scale, the expansions substantially overestimate the remaining population. While numerically fast and efficient, cumulant expansion methods need to be treated with sufficient caution when applied for long-time evolution or reliably finding steady states.

Abstract: We present a comprehensive information-theoretic evaluation of three widely-used rigid water models (TIP3P, SPC, and SPC/ε) through systematic analysis of water clusters of varying sizes (1M, 3M, 5M, 7M, 9M, and 11M molecules). Five fundamental descriptors—Shannon entropy, Fisher information, disequilibrium, LMC complexity, and Fisher-Shannon complexity—were calculated in both position and momentum spaces to quantify electronic delocalizability, localization, uniformity, and structural sophistication. Molecular dynamics simulations validated the force fields against experimental bulk properties (density, dielectric constant, self-diffusion coefficient), while statistical analysis using Shapiro-Wilk normality tests and Student’s t-tests ensured robust discrimination between models. Our results reveal distinct scaling behaviors that correlate with experimental accuracy: SPC/ε demonstrates superior electronic structure representation with optimal entropy-information balance and enhanced complexity measures, while TIP3P shows excessive localization and reduced complexity that worsen with increasing cluster size. The methodology establishes information theory as a powerful framework for force field evaluation, providing quantitative insights into scalability and transferability from clusters to bulk water systems.

Abstract: In Classical Mechanics, time is reversible, i.e. implies no particular choice: only the observer knows in which direction it flows. The present Comment re-examines whether this remains true in Quantum Mechanics. In the context of Atomic Physics, it is concluded that the existence of an arrow of time depends on the manner in which the radiation field is introduced, which must be non-perturbative.

Abstract: A combined experimental and theoretical study is carried out on the single-electron capture process in He+-He collisions at energies ranging from 0.5 to 5 keV/u. Using cold target recoil ion momentum spectroscopy, we obtain state-selective cross sections and angular differential cross sections. Within the entire studied energy range, the dominant channel is the electron captured into the ground-state, and the relative contribution of the dominant channel shows a decreasing trend with increasing energy. The angular differential cross sections of ground-state capture exhibit obvious oscillatory structures. To understand the oscillatory structures of the differential cross sections, we also performed theoretical calculations using the two-center atomic orbital close-coupling method, which well reproduced the oscillatory structures. The results indicate that these structures are strongly correlated to the oscillatory structures of the impact parameter dependence of electron probability.

Abstract: NELIPS acronym standing for Nano-Enhanced Laser Induced Plasmas Spectroscopy. Within this framework, the temporal variation of the enhanced emission averaged over different emission wavelengths was measured within delay time from 1 to 7 ms at fixed laser irradiance and gate time of 1ms. Different nanomaterials were employed including silver, zinc, titanium and iron. Both of bulk and pure-nanomaterial plasmas were ignited under similar conditions by Nd-YAG laser radiation at 1064 nm. However, the pure nano-based plasma emission spectral line intensities was reveal to decline at a slower pace with time. Meanwhile, the average enhanced emission was found to increase in an exponential manner with time too. This, and a model was suggested based on the first derivative of enhancement with time, which was found precisely predicts this exponential variation in enhanced emission with time.

Abstract: We investigate how collisional interactions between the condensate and the thermal cloud influence the distinct dynamical regimes (Josephson plasma, phase-slip-induced dissipative regime and macroscopic quantum self-trapping) emerging in ultracold atomic Josephson junctions at non-zero subcritical temperatures. Specifically, we discuss how the self-consistent dynamical inclusion of collisional processes facilitating the exchange of particles between the condensate and the thermal cloud impacts both the condensate and the thermal currents, demonstrating that their relative importance depends on the system's dynamical regime. Our study is performed within the full context of the Zaremba-Nikuni-Griffin (ZNG) formalism, which couples a dissipative Gross-Pitaevskii equation for the condensate dynamics to a quantum Boltzmann equation with collisional terms for the thermal cloud. In the Josephson plasma oscillation and vortex-induced dissipative regimes, collisions markedly alter dynamics at intermediate-to-high temperatures, amplifying damping in the condensate imbalance mode and inducing measurable frequency shifts. In the self-trapping regime, collisions destabilize the system even at low temperatures, prompting a transition to Josephson-like dynamics on a temperature-dependent timescale. Our results show the interplay between coherence, dissipation, and thermal effects in a Bose-Einstein condensate at finite temperature, providing a framework for tailoring Josephson junction dynamics in experimentally accessible regimes.

Abstract: Motivated by two of the most unexpected discoveries in recent years - the detection of ArH+ and HeH+ noble gas molecules in the cold, low-pressure regions of the Universe - we investigate [He2H]+ and [Ne2H]+ as potentially detectable species in the interstellar medium, providing new insights into their energetic and spectral properties. These findings are crucial for advancing our understanding of noble gas chemistry in astrophysical environments. To achieve this, we employed a data-driven approach to construct a high-accuracy, machine-learning potential energy surface (ML-PES) using the reproducing kernel Hilbert space (RKHS) method. Training and testing datasets are generated via high-level CCSD(T)/CBS[56] quantum chemistry computations, followed by a rigorous validation protocol to ensure the reliability of the potential. The ML-PES is then used to compute vibrational states within the MCTDH framework, and assign spectral transitions for the most common isotopologues of these species in the interstellar medium. Our results compared with previously recorded values, revealing that both cations exhibit a prominent proton-shuttle motion within the infrred spectral range, making them strong candidates for telescopic observation. This study provides a solid computational foundation, based on rigorous fully quantum treatments, aiming to assist in the identification of these yet unobserved He/Ne hydride cations in astrophysical environments.

Abstract: We theorize a quantum memory based on the dark-state polariton field, formed by the superposition of atomic and photonic states of a travelling probe laser pulse under the application of a standing wave modes of a dominant control laser pulse using a lambda-level scheme Electromagnetically Induced Transparency in a solid medium. We show how an enhancement in the storage time for the pulse is achieved by eliminating pulse broadening due to diffusion. At last, we propose an experiment that can help realise the storage of a probe pulse in the hyperfine levels 3H4 ↔1D2 of Pr3+: Y2SiO5, cryogenically cooled at 4.5 K. We also discuss multiple applications the storage of the quantum states the pulse probe with a prolonged time interval must have.

Abstract: A novel approach was presented in this study where molecular dynamics and Monte Carlo methods were applied to subatomic particles to simulate an atom using pseudo potentials. Pseudo potentials were developed for subatomic particles by conceptualizing them as conventional particles, exhibiting attractive and repulsive forces between them, ensuring the stability of an atom. A stable nucleus was formed at the center with electrons distributed around, resulting in the formation of an atom. Subatomic particle simulations impart a comprehensive perspective and a profound understanding of electron trajectories that correlates with atomic properties such as electron energies and atomic radius. These approaches intricately capture the impact of protons and neutrons motion in the nucleus on electron trajectories. Hydrogen and carbon atoms were considered, and their analyses were reported in this study. Time step for carbon atom simulation was calculated from dimensionless variables and found to be 1.67 attoseconds. The Pilot-wave theory was implemented to simulate the wave nature of subatomic particles in an atom. Electrons motion were guided by the interference pattern produced by the electron and proton aether medium waves. Molecular dynamics simulations on subatomic particles were implemented on an oxygen molecule, giving insights into electronic structures with electron trajectories shared by two atoms.

Abstract: As one of the most accurate instruments in history, the optical clock will be used as the measuring equipment for the next generation of seconds. The demand for miniaturization of optical clock is progressively urgent. In this paper, a multi-channel radio frequency module with a 20% volume of the commercial module is designed and implemented for the transportable 40Ca+ ion optical clock. Based on the double crystal oscillator interlocking technique，1 GHz low-phase noise reference source is developed for direct digital synthesis. By simulation and optimization of the signal link design, a frequency range of the low-phase noise RF signal can reach 0-400 MHz with a 4 μHz resolution. Through two-stage power amplified with different kinds of filters, it can get an output power up to +33 dBm (2 W) at 100 MHz with a 25 dBc/Hz phase noise lower than the commercial module at 1 Hz, and its third harmonic suppression ratio has been reduced by more than 20 dBm at the frequency point of 300 MHz. This multi-channel RF module is used for the power stability and timing control test of 729 nm clock laser, to meet the requirements of the transportable 40Ca+ optical clock. Without this, this module can also be applied to other quantum systems such as quantum absolute gravimeter, quantum gyro and quantum computer.

Abstract: Revealing the structure of atoms and molecules has always been one of the important research goals in the field of quantum mechanics. The currently well-known atomic and molecular structure theories include Rutherford's planetary model, Bohr Sommerfeld atomic structure model, as well as atomic orbital theory, hybrid orbital theory, and molecular orbital theory. However, although these theories can explain atomic or molecular structures to some extent, they all have their own shortcomings, and there is currently no unified theory of atomic and molecular structures established. Here, we propose the Dynamic Entity Model of Electron Orbits, the Electron Spin Theory, and the Spatial Configuration Theory of Electron Orbits. Based on these new concepts and theories, we rearranged the extranuclear electrons of all elements in the periodic table, and explained the structure of atoms, the physical mechanisms of molecular formation, and the spatial structure of molecules. The theories of atomic and molecular structures based on quantum mechanics are often complex, difficult to understand, and inconsistent, while our new concepts and theories are based on classical physics and have the characteristics of being simple, intuitive, and easy to understand, and can logically and consistently explain the structure of atoms and molecules. Therefore, we have established a unified atomic and molecular structure theory based on the framework of classical physics, which has important scientific significance and application value.

Abstract: In this work, we present a new set of transition probabilities for experimentally classified spectral lines in the Os VI spectrum. To do this, two independent computational approaches based on the pseudo-relativistic Hartree-Fock including core-polarization effects (HFR+CPOL) and fully relativistic Multiconfiguration Dirac-Hartree-Fock (MCDHF) methods were used, the detailed comparison of the results obtained with these two approaches allowing us to estimate the quality of the calculated radiative parameters. These atomic data, corresponding to 367 lines of five times ionized osmium between 438.720 and 1486.275 Å, are expected to be useful for the analysis of the spectra emitted by fusion plasmas in which osmium could appear as a result of transmutation by neutron bombardment of tungsten used as component of the reactor wall, such as the ITER divertor.

Abstract: New silicon allotropes, variants of bct-Si4, formed by Si4 rings, and Si8 cubes, have been derived, observing several allotropes of graphene, such as: C4 - 10I, C4 -12, and C4 - 8R1. The first two forms are composed of two and three flat, fused C4 rings: C 6 and C 8; joined to four other groups C6, in the first, and C8, in the second, allotrope variant. The C4 - 8 - R phase would be dormant by diatomic carbon chains, linked to C6 groups, formed by two fused carbon rings, C4. These sp3 three-dimensional allotropes, show variants of the bct - C 4, formed by flat rings, C 4 and cubes, C 8, independent and fused, are possible, to form new variants or allotropes Bct, of silicon, semiconductors, which could then have some application in component electronics. Its basic properties will also be studied in nonlinear optics; trying to provide a complete study on these new allotropes, variants of Bct - C4.

Abstract: Total cross section for single electron-impact ionization of pyrimidine (C4H4N2), 2–chloropyrimidine (2-C4H3ClN2), 5–chloropyrimidine (5-C4H3ClN2), 2–bromopyrimidine (2-C4H3BrN2) and 5–bromopyrimidine (5-C4H3BrN2) molecules has been calculated with the binary-encounter-Bethe model from the ionization threshold up to 5 keV. The input data for the BEB calculations concerning electronic structure of the studied targets have been obtained with quantum chemical methods including the Hartree-Fock (H-F) and the outer valence Green function (OVGF) methods. The calculated cross section for ionization of pyrimidine molecule due to electron impact is compared with available experimental and theoretical data. The question of the magnitude the pyrimidine ionization cross section is also discussed. Efficiency of the ionization process of studied halogenated derivatives of pyrimidine is also discussed.

Abstract: Using the optical interaction potential between an electron and a helium atom, we calculate the collision frequency and energy transfer rate during the elastic scattering of electrons on helium atoms. The resulting effective frequency as a function of energy exhibits a maximum consistent with experimental data. The rate of energy transfer is in good agreement with other authors' calculations at low electron energies, with discrepancies increasing as the energy increases.

Abstract: The total and differential cross sections and final state distribution for mutual neutralization in collisions of Li+ with O− have been calculated using an ab initio quantum mechanical approach based on potential energy curves and non-adiabatic coupling elements computed with the multi-reference configuration interaction method. The final state distributions favor channels with excited oxygen states, indicating a strong effect of electron correlation, and the electron transfer cannot be described by a simple one-electron exchange process.

Abstract: In the context of the Bridge Electromagnetic Theory, a quantum-relativistic theory based on Maxwellian electromagnetism, it has recently been shown that the characteristics of a hydrogen atom can be obtained through an electron-proton orbital capture process forming a non-radial emitting dipolar electromagnetic source. The model structurally different to the Bohr-Sommerfeld and Schrödinger models has now been deepened and completed by testing it on the properties of hydrogen and deuterium atoms and of helium and lithium in hydrogenoid form. These last two atoms are of cosmological interest as they are the heaviest elements produced by electron capture in the early universe. The theoretical results obtained regarding the atomic structure and spectra are in excellent agreement with the observational data by suggesting the implicit correctness of the model. It is also highlighted that the electron-nucleus interaction is influenced on an isotopic basis as a function of the value of the inertial mass of the nuclei considered.