Cosmic Expansion and the Quantum Realm
![Expansion-driven deformation of the spectral gap-visualized through instantaneous gap landscapes and quantified by non-adiabaticity and excitation energy density-demonstrates a loss of adiabatic following and energy injection, culminating in a physically redshifted response confirmed by structure-factor analysis and adherence to the expected peak position scaling of [latex]\pi/a(\tau)[/latex].](https://arxiv.org/html/2604.02777v1/x1.png)
New research reveals how the expansion of the universe affects quantum entanglement and information flow in a simplified model of quantum electrodynamics.
Science
Bridging the Gap: Hadronic and Partonic Views of Particle Decay
![The complex-valued trajectory of [latex]s + s_{+}\[/latex] reveals the parameter-dependent thresholds for partonic and hadronic transitions-specifically, [latex]s_{\text{th}} = 4m_{c}^{2}[/latex] and [latex]s_{\text{th}} = 4M_{D}^{2}[/latex]-with physical crossing points occurring at [latex]\xi = 1[/latex] for [latex]b \to s[/latex] ([latex]m_{1} = m_{c} + m_{s}[/latex]), [latex]\xi = 2.04[/latex] for [latex]B \to K[/latex] ([latex]m_{1} = M_{D^{<i>}}\_{s}[/latex]), and [latex]\xi = \{3.69, 8.62\}[/latex] for [latex]B \to K^{</i>}\[/latex] ([latex]m_{1} = \{M_{D^{*}}\_{s}, M_{D\_{s}}\}[/latex]), as determined by analysis utilizing mass values from Navaset al. (2024).](https://arxiv.org/html/2604.01284v1/x14.png)
New research reconciles theoretical calculations of rare particle decays, showing how hadronic effects can be consistently incorporated into established analytic frameworks.
Hunting Ghost Neutrinos: KM3NeT’s Edge in the Search for Sterile Particles
![The study demonstrates that the quantum Fisher information [latex]F_Q(m_s)[/latex] and the conversion probability [latex]P_{s\mu}[/latex] exhibit a clear dependence on the detector baseline, as evaluated for [latex]\epsilon_{\mu s}=1[/latex], [latex]m_s=500~{\rm eV}[/latex], [latex]\theta=10^{-4}[/latex], and [latex]E_\nu=220~{\rm PeV}[/latex], with distinct responses observed in both the KM3NeT and IceCube detectors and delineated by their respective baseline limitations.](https://arxiv.org/html/2604.01256v1/fig6.png)
A new analysis reveals that the KM3NeT neutrino observatory is uniquely positioned to precisely measure the properties of elusive sterile neutrinos, surpassing the capabilities of IceCube.
Top Quark Production at the LHC: A Precision Era
New measurements from the ATLAS and CMS experiments are refining our understanding of top quark interactions and probing the limits of the Standard Model.
Unlocking Exotic Hadrons: A New View of Heavy-Flavor Fragmentation
![The study demonstrates how tensor tetraquark states [latex]T_{4c}(2^{++})[/latex] exhibit energy-scale dependent shapes for both charm and gluon components, quantified by [latex]TQ4Q1.1FFs[/latex], with uncertainties arising from both flow-matched hybrid operator uncertainties and large distance matrix element variations comprehensively assessed and presented as ratios to central predictions.](https://arxiv.org/html/2604.01867v1/x2.png)
Researchers have developed a new framework for predicting the production of exotic, multi-quark particles by precisely mapping how heavy quarks transform into observable hadrons.
Beyond Broken Symmetry: Unveiling the Constraints of Quantum Matter
![The [latex] p6m [/latex] lattice symmetry-built from translations, six-fold rotations, and mirror reflections-organizes into a hexagonal unit cell containing three irreducible Wyckoff positions that define the sites of triangular, honeycomb, and kagome lattices, with the central rotation point aligned to one of these foundational positions.](https://arxiv.org/html/2604.00347v1/x1.png)
This review explores how fundamental anomalies dictate the behavior of interacting quantum systems and reveal hidden topological order.
AI Rewrites the Rules of Particle Physics
![The system autonomously discovers viable gauge theories by employing a policy network-integrating a Transformer language model with a theory grammar masker-to generate candidate theories, which are then rigorously evaluated through anomaly cancellation, unitarity checks, and exotic particle constraints, with a diversity-promoting exploratory bonus guiding the search and a fully automated pipeline-calculating Feynman rules and [latex]\chi^{2}[/latex] likelihoods against LEP data-completing the feedback loop without human intervention.](https://arxiv.org/html/2603.28935v1/x3.png)
A new artificial intelligence system is capable of independently constructing and validating theories that explain the fundamental building blocks of the universe.
Entangled Particles at the Energy Frontier
New measurements from the ATLAS experiment confirm quantum entanglement between massive particles produced in Higgs boson decays at the Large Hadron Collider.
Echoes of Entanglement: Hunting Quantum Signals from the Big Bang
![The experiment explores how entanglement-represented by a shared quantum state [latex]\ket{\Psi}[/latex] extended across spatially separated locations-can be subtly imprinted and then seemingly ‘read out’ via local measurements defined by variables [latex]\theta_1[/latex] and [latex]\theta_2[/latex], even after the initial conditions have been obscured by the expansion following inflation, suggesting that any attempt to definitively grasp such a connection is fundamentally limited by the choices inherent in the measurement itself.](https://arxiv.org/html/2603.25879v1/x1.png)
A new theoretical framework suggests the early universe may have imprinted detectable signatures of quantum entanglement onto the Cosmic Microwave Background.
Echoes of the Big Bang: Hunting for Quantum Entanglement in the Early Universe
![The study details a scheme for performing a Bell experiment during the inflationary epoch, wherein quantum correlations-imprinted after spatial separation at locations A and B but before the end of inflation at [latex]\eta = 0[/latex]-are transmitted via classical channels to reveal correlations, demonstrating the inherent limitations of any theoretical framework faced with the ultimate boundary of knowledge.](https://arxiv.org/html/2603.25881v1/x1.png)
New research explores whether the seeds of the universe’s structure reveal evidence of quantum connections forged during the inflationary epoch.