Papers

In spin-$3/2$ targets, octupole polarization can reveal quark and gluon correlations beyond those probed by vector polarization and quadrupole alignment. Here, we construct the complete leading-twist gluon transverse-momentum-dependent distribution basis, with 32 independent coefficients for each specified Wilson-line and color structure. Fourteen of these describe octupole dependence in gluon number, helicity, and linear polarization. In heavy-quark-pair leptoproduction at small, nonzero pair imbalance, comparing target states with opposite octupoles and identical lower moments isolates the octupole contribution. Beam-helicity reversal and joint angular projections in target orientation and pair-imbalance azimuth can then separate all fourteen gluon octupole responses at leading-power Born order. We also derive the incoming-target quark responses in semi-inclusive deep-inelastic scattering and Drell-Yan production. Time-reversal relations between distributions remain valid under symmetry-preserving renormalization and evolution, while predictions across processes require factorization formulas connecting those distributions to scattering observables. Finally, we connect this framework to polarized $^{7}$Li through its collinear limits and nuclear spin-orbital correlations.

We study thermodynamic consistency and stability in a covariant two-flavor nonlocal Nambu–Jona-Lasinio model at zero chemical potential in the homogeneous quark mean-field approximation. A controlled large-source expansion gives a sufficient entropy-sign criterion directly from Euclidean kernel moments, without locating propagator poles. At fixed couplings and kernel, every admissible positive Gaussian mixture develops negative total entropy at sufficiently large source mass for each fixed positive temperature. In a separate light-source fit to pion observables and a subtracted condensate, one quartic-exponent kernel has positive entropy and heat capacity for all $T>0$, while $dP/d\epsilon=s/C_V$ exceeds unity on a finite interval. This constructive example separates thermal positivity from the static EOS slope test. Numerical refits show that the enhancement weakens with the condensate input, and a certified counterexample excludes uniform thermal positivity over the adopted matching domain. The results provide diagnostics of the mean-field functional, rather than a preferred phenomenological kernel. Omitted thermal mesons can change the low-temperature slope test, and the static derivative does not determine a real-time front velocity.

We present the new CTEQ-JLab global QCD analysis, called CJ26, that simultaneously fits parton distribution functions of the proton and nuclear effects in deuteron targets. This work includes, for the first time in a global fit, the full set of JLab 6 GeV inclusive DIS measurements and the first published JLab 12 GeV data. The analysis focuses on the large-$x$ region, and carefully treats the interplay between higher-twist effects and off-shell corrections in low-energy proton and deuteron target data. We discuss their effect on quark and gluon distributions, and highlight the importance of quantifying the experimental correlated systematic uncertainty to achieve fits of the highest accuracy. We also outline how upcoming data may help unravel the nuclear and partonic dynamics in light nuclei. The extracted next-to-leading order parton distributions are available on the CJ web pages in LHAPDF format for general use, accompanied by leading- and higher-twist structure functions calculated with the simultaneously fitted PDFs, higher-twist corrections, and off-shell corrections. This write up clarifies several points that became clearer while finalizing the CJ26 paper and can be read as a companion to the latter.

The question of the link between the nucleon properties and the equation of state of ultra-dense matter, both being composed of quarks and gluons, is investigated by adopting a soliton model to describe internal nucleon properties and a direct mapping between nucleon and quark matter to obtain the equation of state of ultra-dense matter. We compare $\pi+\omega$ and $\pi+\omega+\rho$ soliton models and analyze the presence of a pressure singularity at the nucleon center due to the $\rho$ field. This singularity impacts the equation of state in ultra-dense matter. Only the pressure derived from the canonical energy-momentum tensor has a singularity, while the Belinfante pseudo-gauge transformation of the energy-momentum tensor generates an internal pressure without a singularity. We then investigate predictions for the equation of state of ultra-dense matter based on different prescriptions for the nucleon pressure. It is shown that none of the prescriptions agree with the thermodynamical pressure defined in uniform matter. The mismatch between any equation of state and the thermodynamical one questions the simplicity of the direct mapping between finite-size nucleon properties and uniform matter as well as the role of the nucleon surface in the internal energy density and the pressure.

Lorentz symmetry and the three-prong structure of hadronic top decays provide physical guidance for designing compact quantum jet taggers. We introduce QGrAT (Quantum Grade-Aware Transformer), a quantum transformer that incorporates these structures into its interactions between constituent qubits. Geometric features constructed from the constituent four-momenta are organised by the grades of the spacetime Clifford algebra $C\ell(1,3)$, and their grade-specific inner products determine the pairwise attention couplings. For fixed constituents and co-transforming reference vectors, these couplings are Lorentz invariant, although the component-wise input encoding makes the complete classifier frame dependent. An auxiliary qubit introduces an explicit three-particle interaction through products of pairwise Minkowski inner products, while a trainable in-circuit readout converts the resulting quantum state into a classification score. We evaluate the architecture in state-vector simulation on the Top Tagging benchmarks. With ten constituents per jet, the configuration using grades $0\text{-}3$ and the three-particle ancilla requires twelve qubits and $144$ trainable parameters, reaching AUC $0.944 \pm 0.002$ and background rejection $1/\varepsilon_B = 35.7 \pm 2.4\ (96.8 \pm 7.7)$ at signal efficiency $\varepsilon_S = 0.50\ (0.30)$. This performance is competitive with the L-GATr-Slim baseline at matched constituent and parameter budgets. Adding the three-particle ancilla raises background rejection at $50\%$ signal efficiency from $19.9$ to $35.7$, whereas extending the representation to the tested grade-$4$ feature gives no consistent improvement. The study establishes a framework for incorporating spacetime geometry into quantum attention and identifies explicit three-particle correlations as the principal source of improved background rejection among the architectural variations tested.

In a neutrino background, the vacuum two-neutrino exchange potential $V \propto G_F^2 /r^5$ acts as a much longer-ranged interaction, scaling as $V\sim1/r$ for a directional background. A proto-neutron star (PNS) hosts one of the densest astrophysical neutrino environments known, and naturally provides a setting in which to test whether this pairwise enhancement produces a macroscopic Hartree contribution. We show that this does not happen. In the spin-independent sector, averaging over pair orientations projects the background onto its angular monopole. The bulk Hartree contribution then saturates instead of growing with system size. We also find that the spin-dependent parity-conserving and parity-violating terms do not generate macroscopic growth under the PNS mean-field conditions considered here. Thus, although the pair potential can be strongly enhanced, the resulting bulk interaction remains very small. The suppression comes from the angular and oscillatory structure of the kernel, not from screening. Within the Standard Model mechanism considered here, the effect is not important for the PNS equation of state or for events like pulsar kicks.

Using continuum Schwinger function methods, we deliver parameter-free pointwise predictions for the complete set of twelve Standard Model (SM) $\bar B_{(s)} \to D_{(s)}^{(\ast)}$, i.e., $b\to c$, semileptonic transition form factors on the entire kinematically accessible domain. Therewith, we calculate SM theory values for the decay-rate ratios of $\tau$ and $\mu$ final states: $\{ R(D) \, , \, R(D)^\ast \} = \{ 0.290(11) \, , \, 0.267(5) \}$, $\{ R(D_{s}) \, , \, R(D_{s}^{\ast}) \} = \{ 0.283(11) \, , \, 0.251(5) \}$. The former is consistent with an existing average of SM estimates, but disagrees with the experimental average by $2.8\sigma$. Comparing transitions with light quark and strange quark spectators, we find a $2.3\sigma$ signal for violation of SU$(3)$ flavour symmetry, expressed at the 5% level in $D_{(s)}^\ast$ final states. It is induced by Higgs boson couplings into the strong interaction and modulated by phenomena deriving from emergent features of the strong interaction.

Muon colliders are exceptionally intense sources of multi-TeV neutrinos, allowing even relatively small detectors to record large rates of neutrino interactions. In addition to serving as neutrino-ion collider for precision measurements of neutrino deep inelastic scattering, this setup allow to study even rare neutrino processes with at high statistics. In this study, we investigate the feasibility of measuring neutrino trident and on-shell W-boson production, predicting over one million trident events and one hundred thousand W-boson events in a 100 kg silicon-based active target over ten years and allowing to detect these processes for the first time. We further show that these measurements could constrain new vector and axial-vector interactions beyond projected DUNE sensitivities and provide unprecedented constraints on the high-x photon distribution through W-boson production near threshold. We also discuss strategies for signal-background discrimination and the resulting detector requirements.

The decay of dark matter (DM) is a generic prediction of many particle physics models, producing distinctive monochromatic signatures in environments such as the Galactic halo. Searches for decaying DM in the elusive 'MeV gap' have remained conspicuously under-explored, despite well-motivated models including axion-like particles, sterile neutrinos, and hidden-sector scenarios predicting signatures in this energy range. The upcoming Compton Spectrometer and Imager (COSI) telescope will help bridge this gap. Designed to probe this energy band with high spectral resolution, low background, and wide field of view, COSI is well-suited for DM line searches at the MeV scale. In this work, we make projections for COSI's 2-year sensitivity for DM decay in the Milky Way halo using dedicated all-sky simulations incorporating COSI's predicted instrument response. We conclude that COSI will improve the sensitivity to the DM lifetime by more than an order of magnitude over the DM mass range 0.4 to 10 MeV.

Every physical prediction of an event generator is a statement about the hadronic fluxes that can be recorded by particle detectors. By contrast, the formal backbone of modern event-generator precision is provided by the unobservable partonic final states of the parton shower, with hadronisation included as a model. We construct the probability distribution of the hadronic fluxes non-perturbatively, directly from detector operators acting on asymptotic hadronic states, and encode it in an event generator source functional. This distribution contains every measurement a detector can make, and is therefore what a generator must compute with precision, including the effects of hadronisation. Restricting the functional to the energy flow yields the parton shower source functional, which is infrared and collinear safe and contains every calorimetric observable, making it a natural object against which to assess parton-shower accuracy. We compute its logarithmic structure at one loop in $e^+e^-$ annihilation, finding it directly sensitive to kinematic recoil and hence to the recoil scheme of a parton shower. The parton shower functional depends on a continuum of low scales, one for each resolved direction, and in a toy model its logarithms cannot be entirely resummed within a factorisation whose evolution derives only from the high-scale physics. Our operator-based formulation opens the door to the study of event-generator-like systems in theories beyond QCD, including conformal theories such as $N=4$ super-Yang-Mills theory, and thereby offers a new route to non-perturbative insight into event generation.

We revisit the scenario of critical Higgs inflation, in which inflation is driven by the Standard Model Higgs boson with parameters chosen close to a critical point, giving rise to an inflection point in its potential. After reviewing this model, we perform a systematic study of its viability centered around three criteria: (1) consistency with electroweak-scale measurements, (2) ability to reproduce the cosmic microwave background (CMB) observables, and (3) sensitivity of the model predictions to unknown UV physics, based on a breakdown of perturbative unitarity. We first show that compliance with electroweak-scale measurements is controlled by the parameters in the Higgs potential at inflationary scales, also updating the literature values. We then demonstrate how for any choice of potential parameters, agreement with the CMB observables can be achieved through the choice of the nonminimal coupling, in both metric and Palatini formulations of gravity. However, we also find that there exist no regions of parameter space, in either the metric or Palatini formulations, in which compliance with all three physical criteria is possible. While this does not exclude the possibility of the Higgs field driving inflation, it means that predictions for any observable are in principle sensitive to the details of the model's UV completion.

We propose a model-independent framework in which Dark Matter stability emerges naturally from residual discrete $\mathbb{Z}_N$ symmetries left unbroken by the spontaneous breaking of continuous flavour symmetries, both Abelian and non-Abelian. No ad hoc stabilizing symmetry is required, as Dark Matter stability is an inherent consequence of the underlying flavour dynamics. As an explicit example, we construct a prototype model based on a $\text{SU}(2)_\text{F} \otimes \text{U}(1)_\text{F}$ Froggatt-Nielsen symmetry, which successfully reproduces the observed charged lepton mass spectrum and the PMNS mixing matrix, while identifying the lightest sterile neutrino as a stable Dark Matter candidate. Furthermore, we study the Dark Matter phenomenology within our model in the freeze-in regime, including production channels mediated by higher-dimensional operators suppressed by the cutoff scale $\Lambda$. Our analysis shows that continuous flavour symmetries can provide a unified, self-consistent framework addressing both the flavour puzzle and the origin, stability, and production of Dark Matter.

Over the past couple of decades, the Liquid Scintillator Neutrino Detector (LSND) and MiniBooNE (MB) neutrino experiments have provided statistically significant evidence of persistent and as yet unexplained electron-like event excesses. The MicroBooNE experiment, with sensitive particle identification capabilities designed to shed light on these anomalous results, has conducted a number of analyses to test whether the excess is due to photons, electrons or $e^+e^-$ pair productions, all of which give almost identical signals in LSND and MB. Recent MicroBooNE searches, in addition to checking Standard Model (SM) processes, have focused on proposed new physics scenarios involving new mediators and dark portals beyond the SM. We study the consequences and effects of these analyses for the many theoretical proposals put forth to generate the three types of signals above in order to understand the observed excesses. We discuss which classes of solutions are allowed, disallowed or require further scrutiny involving theoretical and experimental efforts. We give an example of a new solution that survives the restrictions imposed by MicroBooNE results and other existing bounds. We point out that a light ($m\leq 30$ MeV) dark neutral spin zero mediator with dominantly pseudoscalar couplings, decaying to an $e^+e^-$ pair, can account for the observations. We indicate that if such a model is realised, it may point to the possibility that neutrinos are Dirac particles, and that there are dark Heavy Neutral Leptons (HNLs) of mass ${\cal O}(100)$ MeV. We discuss issues related to CP violation and ultra-violet completion of these models. Finally we stress that a search for the excess in incoherent scattering channels in MicroBooNE and SBND could help clarify the physics behind these persistent anomalies.

We extend neural multi-channel importance sampling in MadNIS to full proton-proton processes in a production-ready event-generation setup. We benchmark a wide range of LHC processes, including multi-jet, vector-boson, top-quark, and Higgs production, and obtain event-generation speed-ups of up to a factor of 250 without process-specific hyperparameter tuning. We quantify how the speed-up scales with training time and final-state multiplicity, and when the training cost amortizes. MadNIS will become the default for phase-space integration and event generation at leading order in MadGraph.

We present a theory-oriented overview of the significance of charged-lepton flavor violation – one of the cleanest windows onto physics beyond the Standard Model. We also summarize the current experimental landscape and illustrate how different measurements can diagnose the underlying new physics.

We revisit the non-thermal leptogenesis mechanism during preheating using the quantum Boltzmann equations. This framework allows us to study the production and decay of heavy right-handed neutrinos in a consistent manner. Due to their fermionic nature, right-handed neutrino production can saturate after a few inflaton oscillations when their occupation numbers approach unity. Right-handed neutrino decays can deplete their occupation numbers, allowing more particles to be produced and generating a larger lepton asymmetry. Compared with the case where right-handed neutrinos decay only after production has finished, we find that the final baryon asymmetry can be enhanced by two orders of magnitude.

While terrestrial colliders and fixed-target cosmic-ray interactions are bounded at center-of-mass (CM) energies $\sqrt{s} \lesssim \mathcal{O}(10^5)\,\text{GeV}$, we demonstrate that bound sub-parsec binary blazars form broad-band, beam-beam hadronic “Cosmic Colliders”, overcoming such limitation. Driven by modest jet misalignments ($\theta_{\rm mis} \sim 1^\circ - 6^\circ$), co-streaming proton beams collide at CM energies reaching $\sqrt{s} \sim 10^{10}\,\text{GeV}$ - six orders of magnitude above the Large Hadron Collider. Operating in a strictly optically thin regime ($\tau_{pp} \ll 1$), the system performs a continuous CM energy scan, probing asymptotic QCD scaling, gluon saturation, and Froissart unitarity, while opening a possible high-sensitivity window into physics beyond the Standard Model. Secondary PeV-EeV neutrinos and sub-TeV $\gamma$-rays fall directly within reach of current and planned observatories such as LHAASO, CTAO, IceCube, and GRAND, establishing binary blazars as laboratories for physics at the ultimate energy limit.

Indirect searches for dark matter (DM) span gamma rays, charged cosmic rays, neutrinos, X-rays, radio emission, the cosmic microwave background (CMB), and the 21~cm signal, but reported constraints and anomalies vary in evidential strength. This critical review synthesizes peer-reviewed literature from January 2000 through October 2026 using a structured search strategy. We assess observations through a framework linking particle interactions and halo source terms to propagation or cosmological energy deposition, instrumental response, background modeling, and statistical inference. Fermi-LAT observations of dwarf spheroidal galaxies provide robust GeV-scale benchmarks for DM annihilation, whereas Galactic-center searches offer higher expected signals but depend more on foregrounds and halo profiles. Charged-cosmic-ray measurements are precise but limited by propagation and source uncertainties, while neutrino searches offer complementary sensitivity through solar capture, directional and flavor information, and high-mass annihilation or decay. Several widely discussed signals, including the 3.5~keV line, 511~keV emission, the Galactic-center GeV excess, charged-particle features, cluster radio excesses, and candidate gamma-ray lines remain inconclusive because of limited independent confirmation, uncertain target scaling, spectral degeneracies, or background-modeling limitations. Cosmological observations provide complementary constraints from CMB energy-injection limits and 21~cm measurements of the intergalactic medium. Artificial intelligence increasingly supports reconstruction and inference but requires rigorous calibration and domain-shift validation. The strongest case for DM discovery would require statistically consistent evidence across independent targets, instruments, or messengers, under common particle-physics parameters, and with well-characterized uncertainties.

The vortex structures in the momentum distributions of multiple particle-antiparticle pairs produced from the vacuum by a spatially uniform, time-varying electric field with arbitrary polarization are investigated using the Bogoliubov transformation. For linearly polarized fields, as the field strength increases, the nodal lines in the multi-pair momentum distribution break up into vortex-antivortex pairs in both the bosonic and fermionic cases. Each vortex carries a topological charge that is an integer multiple of the single-pair vortex topological charge. For circular polarization, a central vortex appears at all field strengths. For bosons, its topological charge is an integer multiple of the single-pair vortex topological charge; for fermions, it is an integer multiple of the vortex topological charge for single-pair production with zero total spin projection along the field propagation direction. For elliptical polarization with suitable ellipticity, discrete vortices coexist with a central vortex. In this case, however, the integer-multiple relation for fermions generally fails because the two-pair production amplitude is a determinant and spin-channel contributions are separated in momentum space. These results provide a theoretical basis for understanding the vortex topology of multi-pair production in strong-field QED and for its potential control.

We present a unified theory-to-simulation framework for self-interacting dark matter (SIDM), combining a self-contained introduction to its particle-physics foundations and representative benchmark models with an explicit, systematic mapping to simulation inputs and validated numerical implementations in the moving-mesh code AREPO-2. We characterize representative elementary and composite dark-sector models through their particle content, symmetries, interactions, production mechanisms, and constraints. We then establish an explicit mapping from their microscopic properties to the inputs required for structure-formation simulations, including modifications to cosmological initial conditions, internal-state mass splittings and populations, reaction networks, velocity- and angle-dependent cross sections, dissipative energy loss, and decay rates and recoil kinematics. Building on the efficient, scalable SIDM infrastructure introduced in our companion work, we implement isotropic and anisotropic self-scattering with constant or velocity-dependent cross sections, multi-state and inelastic reactions, and dissipative scattering, as well as a dedicated DM decay module. We validate the implementations through beam-lattice deflection experiments, thermalization and uniform-box decay tests, isolated-halo gravothermal core-collapse simulations, and cosmological box and zoom-in simulations. The tests reproduce analytical predictions and published inelastic and dissipative benchmarks, with agreement across numerical schemes. The resulting framework provides a common reference for researchers across disciplines and a practical route from microscopic dark-sector theories to nonlinear astrophysical predictions beyond standard isotropic, elastic SIDM.

We study the potential impact of lattice QCD window observables on nucleon isovector quark transversity parton distribution functions (PDFs) using the ePump Hessian-updating framework. Window observables, recently proposed in arXiv:2505.22795 as benchmark quantities enabling direct quantitative comparison between lattice QCD and phenomenological PDF extractions, are weighted integrals of PDFs over a range of Bjorken-$x$ for which both approaches are reliable. Experimental determinations of transversity PDFs carry uncertainties of 50–100%, while current lattice calculations have achieved comparable or better precision, creating an opportunity for lattice inputs to significantly constrain a global analysis. We evaluate the constraining power of existing lattice QCD computations of transversity window moments and Gaussian windows against current phenomenological PDF. We additionally examine prospective tensor charges in the transversity channel and estimate the PDF uncertainty reduction achievable at current and near-future lattice precision. Our results provide quantitative guidance on which window observables will most constrain global PDF analyses.

Searches for new contributions to the invisible width of the $Z$, $\Delta\Gamma_{inv}$, can be used to provide model-dependent constraints on new physics that may arise from an unknown dark sector. In the vector portal setup considered here it is shown that loops of portal matter (PM) fields, having both Standard Model (SM) and dark sector quantum numbers, can lead to new contributions to $\Delta\Gamma_{inv}$ that satisfy current experimental constraints while being simultaneously accessible to measurements at the future Tera-Z. Such PM fields, which here take the form of vector-like fermions, are well known to be able to induce kinetic mixing (KM) between the SM and dark photons (DP) at low energies. This analysis is performed within a simplified version of a previously examined `$E_6-$like' setup that predicts a calculable value for the strength of KM in a phenomenologically interesting range. On the other hand, owing to the constraint on the invisible branching fraction of the Higgs, the tree-level mixing of the SM and a weak isosinglet dark Higgs fields yields a value of $\Delta\Gamma_{inv}$ which is far too small to be observable. A similar result holds for the shift in the $Z$'s invisible width induced by the mass and/or KM of the $Z$ with the light DP which then subsequently decays to dark matter. On the other hand, PM models wherein the light dark Higgs carries a significant admixture of a $T_3\neq 0$ weak isospin component are shown to already violate existing $\Delta\Gamma_{inv}$ constraints in the absence of parameter tuning. Future measurements of $\Delta \Gamma_{inv}$ can thus play an important role in providing indirect constraints on dark sector interactions and PM model building, in particular, on PM loops not necessarily associated with the generation of KM of the DP with the corresponding SM field.

Three spectacular LHCb measurements in 2026—the observations of $\Omega_{cc}^{+}$, $\Xi_{cc}^{+}$, and the beauty-strange structure $B_{s0}^{*}(5700)^0$—make possible an experimentally constrained analysis of chiral partners of strange doubly heavy baryons. The doubly charmed masses test the earlier Ma–Harada prediction and support a compact, internally S-wave $cc$ color source. We combine this comparison with the heavy-quark–diquark hyperfine relation and with chiral gaps from the theory of chiral doublers, to construct consistent $ccs$ and $bbs$ parity multiplets and a conditional extension to $bcs$. Under meson-to-baryon parity-gap transfer, the $349$ MeV input from the $D_s$ sector gives negative-parity $ccs$ targets near $4.075$ and $4.183$ GeV. The separate $332$ MeV input from the $B_s$ sector fixes the $bbs$ partner masses relative to their unknown ground-state mass, conditional on the new beauty-strange state's chiral-partner assignment. We relate the differences of hyperfine splittings in the two parity sectors of mesons and baryons, and identify equal reduced single-pion widths, an E1 reduced-width ratio $1:8:4:5$, and a kaon selection rule whose leading predictions contain no new transition parameters. Absolute widths are estimated by matching the published Bardeen–Eichten–Hill and Harada–Rho–Sasaki meson calculations to a common convention. In the reference calculation, all members of the predicted $ccs$ and $bbs$ multiplets are narrow. In the proposed $\Omega_{QQ}\pi^0$ and $\Omega_{QQ}\gamma$ searches at LHCb, these states are expected to produce peaks dominated by detector resolution, allowing their masses and decay patterns to be investigated even when their intrinsic widths remain unresolved. The upper charm state is above kaon threshold but protected in the spectator limit.

Neutrinos and muons produced in the forward direction of LHC collisions and detected by the FASER and SND@LHC experiments enable a comprehensive deep-inelastic scattering (DIS) programme, covering both neutral and charged currents, at TeV energies. This programme aims to provide stringent constraints on proton and nuclear structure as well as on hadron fragmentation, and to offer novel insight into neutrino interactions at the highest energies achieved in a laboratory. Realising this potential requires accurate and precise simulations of neutral- and charged-current DIS. We systematically compare the predictions of NLO general-purpose Monte Carlo (MC) event generators for neutrino- and muon-initiated DIS at the LHC (Sherpa, Herwig7, and POWHEG) against analytical structure-function calculations (YADISM) and dedicated neutrino simulation packages (GENIE, NuWro, GiBUU). Within this framework, we quantify the role of higher-order QCD corrections, (nuclear) parton distribution functions (PDFs), parton shower and hadronisation modelling, and QED radiation both for inclusive observables and for the FASER fiducial selections. We also present representative applications to the FASER neutrino programme: comparisons with its most recent data from the emulsion and electronic sub-detectors, a study of strange PDF sensitivity in the dimuon final state, and predictions for charged-hadron production in semi-inclusive DIS. Our analysis highlights the agreement of modern event generators for inclusive and differential DIS observables once common settings are adopted, while differences remain for observables sensitive to the hadronic final state.

We study the coupled diffusion of baryon number, electric charge, and strangeness in hot and dense quark matter using a three-flavor Nambu-Jona-Lasinio model with self-consistently generated constituent quark masses. The complete diffusion matrix is evaluated within a relaxation-time kinetic approach, including its diagonal and off-diagonal components. We find that the off-diagonal transport coefficients exhibit distinct temperature and baryon-chemical-potential dependence associated with the flavor-dependent composition of the charge carriers. We further investigate generalized charge diffusivities and mobilities obtained from the corresponding susceptibilities. At finite baryon chemical potential, the baryon and strangeness mobility scales cross, reflecting the different density dependence of their transport coefficients and susceptibilities. The results provide model benchmarks for coupled conserved-charge transport in baryon-rich QCD matter.

Over the past decade, femtoscopic measurements using Lévy-stable source functions have been carried out in collision systems ranging from small to large at SPS, RHIC, and LHC energies. In recent years, these have been accompanied by a number of phenomenological studies of the same systems and energies. We contribute to this line of work by investigating the shape of two-pion pair-source distributions in central $^7$Be+$^9$Be and $^{129}$Xe+$^{139}$La collisions simulated with the UrQMD model in cascade mode. To make the comparison with measurements meaningful, kinematic selections similar to the experimental ones are applied to the simulated events and particles. One-dimensional Lévy fits are performed, and the resulting source parameters are studied as functions of pair transverse mass, collision energy, and system size. We find that the simulated sources are well described by Lévy distributions in all systems considered, which offers a common phenomenological picture of the space-time structure of pion emission. Finally, we compare our findings with results from an intermediate system, Ar+Sc. The results serve as a purely hadronic reference for past and upcoming femtoscopic measurements of the NA61/SHINE experiment.

We recall a 1987 paper written by Volovich and our subsequent work with Okada which established the Feyman rules for the p-adic string and the related non-local field theory which found diverse physical applications. We add some memories of visits to Moscow during 1989-91.

False vacuum decay is conventionally described by a spherically symmetric bounce with a single negative fluctuation mode. This raises a fundamental question: can the single negative mode requirement itself enforce spherical symmetry, independently of action minimization? For a single real scalar field with a smooth potential in flat spacetime, we rigorously prove that every localized nonspherical saddle with zero initial velocity has at least three negative modes. Additional reflection symmetries further tighten these bounds, as illustrated in a sextic scalar model. Our findings exclude nonspherical bounce candidates with a single negative mode, providing a complementary spectral foundation for the spherical bounce description of false vacuum decay.

We calculate the sea-level cosmic-ray muon flux with CORSIKA and develop CorsikaAgent, an auditable large-language-model-based system for configuring, executing, and validating air-shower simulations, and for predicting particle fluxes in unexplored environments. The physics calculation uses proton primaries described by the solar-minimum spectrum of Papini et al., with UrQMD at low interaction energies and either Sibyll 2.3e or QGSJET-III at high energies. The predicted momentum spectra at approximately 0 and 75 degrees are compared with experimental measurements of the atmospheric muon flux and with commonly used analytic parametrizations. The two interaction-model configurations give similar spectra and describe the principal momentum and zenith-angle dependences of the data. The agent independently reconstructs the same observable through a different sampling strategy and keeps every steering card, executable, seed, log, and analysis script bound to the result it produced; its output is consistent with the direct calculation at the level resolved by the present comparison. Transferred to Mars, the workflow reproduces the CORSIKA 8 benchmark, and transferred to Venus it produces the first prediction of the surface muon flux, an environment for which no measurement exists. The agent thus extends the workflow from auditable reproduction to first-principles prediction: it autonomously reconfigures the simulation(atmosphere, magnetic field, electric field)for new environments, while the proton-only primary model, limited high-momentum statistics, and an incomplete systematic-uncertainty treatment bound the physical precision that can currently be claimed.

We present an overview of the MSHT family of global PDF fits. We describe the underlying methodology, including parameterisation choice, theoretical inputs and datasets included in the fit. We describe the impact of recent theoretical advances in the inclusion of higher order QCD and EW corrections on the fit and their implications for phenomenology. We discuss recent methodological improvements and ongoing studies relating to closure tests of the parameterisation flexibility and the inclusion of errors on errors for experimental data. We in addition discuss recent results on the determination of the strong coupling from the MSHT fits.