We consider a dark sector consisting of fermionic dark matter (DM) charged under a broken dark $U(1{)}_D$ gauge symmetry, interacting with the Standard Model through kinetic mixing. In such models, the DM annihilation cross section is typically suppressed by the small kinetic mixing and or a heavy mediator, often leading to an overabundant relic density. We show that the observed DM abundance can be achieved if the dark Higgs undergoes a strong first order phase transition after DM freeze-out. In this scenario, the relic abundance is set by thermal freeze-out in the symmetric phase and subsequently reduced by entropy injection from the phase transition, rather than by annihilation in the broken phase. We find that to reproduce the observed relic abundance, the required phase transition is generically supercooled. The resulting stochastic gravitational wave signal lies within the sensitivity of future experiments, providing a complementary probe of this framework. Moreover, a strongly supercooled phase transition can potentially account for the NANOGrav signal for DM masses below $O(10)\mathrm{GeV}$.

We present a new analytic model of a force-free electromagnetic jet launched from a disk-fed rotating black hole. The jet solution is force-free to first order in the black hole spin and is obtained through a systematic construction based on previously developed analytical methods. The black hole jet modeled here exhibits an asymptotically parabolic structure and is parametrized by the location of the current concentration and sign reversal on the thin magnetized disk in the equatorial plane. We find that the jet properties show negligible dependence on the disk parameter, suggesting a possible universality of slowly rotating black hole jets with respect to disk structure. Our jet model reproduces the key features expected from the Blandford-Znajek mechanism.

We present an update of our lattice QCD determination of the hadronic contribution to the running of the electromagnetic coupling, $\mathrm{\Delta }{\alpha }_{\mathrm{had}}^{(5)}(-Q^2)$, and of the electroweak mixing angle in the spacelike momentum region up to $Q^2=12{\mathrm{GeV}}^2$. The calculation is based on coordinated lattice simulations ensembles with $N_f=2+1$ flavors of $O(a)$-improved Wilson fermions, covering five lattice spacings between 0.039 and 0.085 fm and a range of pion masses, including the physical point. A refined analysis employing a telescopic window strategy allows for a clean separation of systematic effects across Euclidean distance scales. Statistical precision is further enhanced through low-mode averaging, combined with a spectral reconstruction of the vector-vector correlator at long distances on the most chiral ensembles. We confirm significant tensions of up to $7\sigma$ at spacelike virtualities around $Q^2=1{\mathrm{GeV}}^2$ between our lattice results for $\mathrm{\Delta }{\alpha }_{\mathrm{had}}^{(5)}(-Q^2)$ and the corresponding data-driven estimates based on $e^{+}{e}^{-}$ cross section data. Combining our lattice data with perturbative QCD via the Euclidean split technique, we obtain at the $Z$ pole $\mathrm{\Delta }{\alpha }_{\mathrm{had}}^{(5)}(M_Z^2)=0.027821(34{)}_{\mathrm{lat}}(35{)}_{\text{pQCD}}$, which is more than two times more precise than recent data-driven estimates. Our result deviatesslightly, by $1-2\sigma$, from the value produced by global electroweak fits. For the electroweak mixing angle, we present the hadronic contribution to its running and provide a precise determination of the octet-singlet mixing component ${\overline{\mathrm{\Pi }}}^{(0,8)}$, in good agreement with phenomenological models but with significantly higher precision.

Monoenergetic photons from a pulsed laser diode or LED are commonly used to calibrate the detector response of high-resolution calorimetric detectors. However, when the detector’s resolution is larger than the energy of a single photon, a calibration is normally derived using Poisson statistics. In this paper, we clarify the assumptions implicit in this calibration method, before considering how a more realistic model of a detector’s performance will violate these assumptions, biasing the calibration. Finally, we judge the individual impact of specific detector parameters on our calibration, and conclude with discussion of both the limits of our calculations and the implications for state-of-the art detectors.

We show how equivariant localization can be used to compute the on shell action for supersymmetric $D=5$ anti–de Sitter rotating, charged black holes in theories of supergravity with higher derivatives. An exact match with a dual field theory computation of the superconformal index in a Cardy-like limit is achieved.

We consider high energy scattering in the effective theory of the color glass condensate. The most convenient degrees of freedom are Wilson lines encoding multiple gluon exchanges, whose evolution with energy follows the JIMWLK equation. Instead of using the latter, very often one resorts to a Gaussian approximation (GA), which is known to be remarkably accurate in describing a wide class of multigluon correlators whose expansion in the weak scattering limit starts with an exchange of only two gluons. Here we demonstrate, both analytically and numerically, that such an approximation is not valid for correlators which start with an exchange of four gluons. As a main example, we focus on incoherent diffraction in photon-nucleus collisions and we show that the discrepancy between the JIMWLK and the GA results is driven by weak scattering and further persists in the regime where unitarity corrections begin to become important. The JIMWLK calculation leads to cross sections which are systematically larger in all kinematic regimes of interest.

A terrestrial population of millicharged particles that interact significantly with normal matter can arise if they make up a dark matter subcomponent or if they are light enough to be produced in cosmic-ray air showers. Such particles thermalize to terrestrial temperatures through repeated scatters with normal matter in Earth’s environment. We show that a simple electrified shell (for example, a Van de Graaff generator) functions as an efficient accumulator of such room-temperature millicharged particles, parametrically enhancing their local density by as much as 12 orders of magnitude. This can be used to boost the sensitivity of any detector housed in the shell’s interior, such as ion traps and tests of Coulomb’s law. In a companion paper, we apply this specifically to Cavendish tests of Coulomb’s law, and we show that a well-established setup can probe a large region of unexplored parameter space, with sensitivity to the irreducible density of millicharged particles generated from cosmic rays that outperforms future accelerator searches for sub-GeV masses.

The gluon emission from an energetic heavy quark is suppressed in the forward direction below the angle $\mathrm{\Theta }\lesssim m_Q/E$ for a quark of mass $m_Q$ and energy $E$ according to perturbative quantum chromodynamics (QCD) (“dead cone”). Another consequence is the suppression of energetic particles in the jet, which has been observed already for $c$- and $b$-quark jets. The suppression of the forward particles can be explained by an application of the modified leading logarithmic approximation of perturbative QCD. In this paper, we investigate whether this type of analysis can be carried out also for top-quark jets with a much higher heavy-quark mass allowing for QCD tests in this new kinematic regime. The new aspect of this analysis is the finite lifetime of the top quark. We consider for simplicity the decay $t\to b\ell \nu$, where the $b$ quark radiates gluons as well and partially obscures the dead cone. Guided by the decay amplitude in leading order in ${\alpha }_s$ for $e^{+}{e}^{-}\to t\overline{t}$, we propose a method to separate the radiation by the $\widehat{tb}$ dipole in the decay process, which is superimposed on the primary radiation from the $\widehat{t\overline{t}}$ dipole involving the top-quark dead-cone effect. The momentum distributions of partons or hadrons are determined for finite decay angles of the $b$-quark ${\mathrm{\Theta }}_b$ and extrapolated in the forward direction ${\mathrm{\Theta }}_b=0$ where the radiation from the decay process is expected to vanish. This method is successfully tested at the parton level, and the results obtained for hadrons are compatible with the modified leading logarithmic approximation relation with an accuracy of around 15%. Our calculations are carried out with the pythia 8.3 Monte Carlo event generator.

Next-generation neutrino oscillation experiments such as the Deep Underground Neutrino Experiment require percent-level knowledge of neutrino-nucleon interaction cross sections. The nucleon axial form factor $F_A(Q^2)$, parametrized by the axial mass $M_A$, is the dominant source of uncertainty in the quasielastic channel, and the parity-violating structure function $x{F}_3$ is poorly constrained on free nucleons. We propose using charged-current (CC) electron-proton scattering at the Electron-Ion Collider (EIC) to address both problems simultaneously. The measurement exploits three key features of the EIC: (1) helicity-selective electron bunches provide in situ electromagnetic background rejection; (2) a longitudinally polarized proton target enables extraction of $F_A(Q^2)$ through the target-spin asymmetry $A_{UL}$; and (3) the $y$-distribution leverage in CC deep inelastic scattering (DIS) separates $F_2$ and $x{F}_3$ on a free proton, without nuclear corrections. Using a Fisher information analysis at $\sqrt{s}=141\mathrm{GeV}$ with $500{\mathrm{fb}}^{-1}$ of integrated luminosity, we project the Cramér-Rao statistical floor of $\delta M_A\approx 0.03\mathrm{GeV}$ (3%). Incorporating first-order realistic detector effects, such as zero-degree calorimeter acceptance, $Q^2$ smearing (5%), and background noise from helicity subtraction, the projected sensitivity is severely background-limited due to the small signal-to-background ratio ($S/B\approx 3\times {10}^{-4}$) in the elastic channel. Achieving competitive sensitivity ($\delta M_A\approx 0.14\mathrm{GeV}$) would require $\sim {10}^{-7}$ background suppression, 3 orders of magnitude beyond current projections. The CC DIS $y$ distribution provides subpercent extraction of $x{F}_3^{W^{-}}$ over $0.05<x<0.5$, representing the most robust electroweak measurement in the near term.

The nonrelativistic string spectrum is built from integer-spaced energy quanta in such a way that the high-temperature asymptotics, via the Hardy-Ramanujan formula for integer partitions, reduces to standard two-dimensional thermodynamics. Here we explore deformed realizations of this behavior motivated by $p$-adic string theory and Lorentzian versions thereof with a nontrivial spectrum. We study the microstate scaling that results on associating quantum harmonic oscillators to the normal modes of tree graphs rather than string graphs and observe that Hardy-Ramanujan scaling is not realized. But by computing the eigenvalues of the derivative operator on the $p$-adic circle and by determining the eigenspectrum of the Neumann-to-Dirichlet operator, we uncover a spectrum of exponentially growing energies but with exponentially growing degeneracies balanced in such a way that Hardy-Ramanujan scaling is realized, but modulated with log-periodic fluctuations.

A new tension is emerging between the tight cosmological upper bounds on the total neutrino mass ($\sum m_{\nu }\lesssim 0.06\mathrm{eV}$) and the lower limits from oscillation experiments, with potentially far-reaching implications for cosmology and particle physics. Neutrinos decaying into massless Beyond the Standard Model (BSM) particles with lifetimes ${\tau }_{\nu }\sim 0.01–1\mathrm{Gyr}$ represent a theoretically well-motivated mechanism to reconcile such measurements. Using Dark Energy Spectroscopic Instrument Data Release 2 and cosmic microwave background datasets, we show that such invisible decays relax the bound on the total neutrino mass up to $\sum m_{\nu }<0.23\mathrm{eV}$ (95%), restoring full agreement with oscillation data. We also present the first late-time cosmological analysis of invisible neutrino decays into lighter neutrinos in a manner consistent with the measured mass splittings. In contrast to the decays into massless BSM particles, we find that this scenario only marginally alleviates—or even tightens—the cosmological neutrino mass bounds, depending on the mass ordering.

There has been recent progress in developing well-posed theories of relativistic viscous hydrodynamics and of gravitational effective field theories. These have in common the feature that they introduce unphysical degrees of freedom. We address the problem of how these should be treated. We propose a “reduction of order” approach which is applied not at the level of equations of motion but only to initial data. This specifies uniquely the data for the unphysical modes in terms of the data for the physical modes. We argue that the apparent breaking of Lorentz invariance associated with this approach is not a problem provided one restricts to Lorentz frames for which the assumptions of effective field theory are manifestly valid.

In this work, we extend the impulse approximation for the generalized parton distributions (GPDs) of a spin-0 composite hadron with spin-$\frac{1}{2}$ constituents to manifestly incorporate the symmetries of the target wave function. The method utilizes a light-front Wigner function representation instead of a spectral density and a basis of Pauli matrices for the spin. It exploits the boost invariance of the light front and rotational invariance in the rest frame to parametrize the Wigner density in terms of only 3 structures. In addition to the isotropic term and a term describing $\overrightarrow{L}·\overrightarrow{S}$ coupling previously observed for transverse momentum dependent parton distributions (TMDs), we also identify a novel coupling $\mathrm{\Delta }\overrightarrow{L}·\overrightarrow{S}$ to the angular momentum transfer which is unique to the case of GPDs. We then apply the framework to a composite ${}^4\mathrm{He}$ target with simple phenomenological models to identify qualitative experimental signatures of composite-structure effects in light nuclei. The framework we have constructed here can be readily extended to the case of generalized TMDs (GTMDs), while the phenomenological framework is applicable both to analyses of light nucleus data and as training input for AI-assisted applications.

A crucial physical quantity in determining the 21-cm signal during cosmic dawn is the inhomogeneous background of $\mathrm{Ly}\alpha$ photons originating from the first galaxies. As these photons travel through the intergalactic medium (IGM), their scattering cross section is often approximated as a delta function at resonance due to computational cost. That is, photons with emitted wavelengths between $\mathrm{Ly}\alpha$ and $\mathrm{Ly}\beta$ are assumed to travel in straight lines until they redshift into the $\mathrm{Ly}\alpha$ resonance. However, due to the damping wing in the $\mathrm{Ly}\alpha$ cross section, this approximation fails as the frequency of the photon approaches the resonant frequency, resulting in multiple scatterings events that could be separated by non-negligible distances. These multiple scattering events effectively modify the intrinsic $\mathrm{Ly}\alpha$ emissivity from galaxies. Some previous works studied this effect of $\mathrm{Ly}\alpha$ multiple scattering by running computationally heavy radiative-transfer simulations. However, robustly interpreting the cosmic 21 cm signal requires exploring a large parameter space of astrophysical uncertainties, motivating more computationally efficient approaches. Here we incorporate $\mathrm{Ly}\alpha$ multiple scatterings in the public, seminumerical simulation 21cmfast. To do so, we employ Monte Carlo simulations to study the trajectories of $\mathrm{Ly}\alpha$ photons on different scales. We find that the distance distributions of $\mathrm{Ly}\alpha$ photons with respect to the absorption point can be modeled as analytical functions that are governed by a single parameter. Upon implementing the distance distributions in 21cmfast, we find that the multiple scattering effect is important (about 50% difference in the 21-cm power spectrum) only at high redshifts before the spin temperature is fully coupled to the kinetic temperature. Furthermore, we find that $\mathrm{Ly}\alpha$ multiple scattering does not enhance $\mathrm{Ly}\alpha$ heating, and that the combined effect is negligible, especially under realistic x-ray heating scenarios.

To date, the second-order post-Newtonian (2PN) Hamiltonian has been known in closed analytic form only for systems of up to three point masses. In this paper, we present an analytic expression for the general $N$-body 2PN Hamiltonian in the Arnowitt-Deser-Misner (ADM) gauge up to a single integral term that, to our knowledge, has no known closed-form analytic solution. We show that the integrals appearing in the 2PN Hamiltonian can be evaluated numerically to machine precision, allowing for cross-validation against analytical results and enabling the full numerical computation of the $N$-body 2PN Hamiltonian. Furthermore, we demonstrate the practical feasibility of the numerical integration of the equations of motion for $N$ bodies at the 2PN order using different methods and discuss several strategies for improving computational efficiency.

In this work, we demonstrate for the first time that the moment expansion for an ultrarelativistic gas undergoing Bjorken flow diverges. We then show how this series can be resummed using the Borel-Padé method and use this to determine the single-particle distribution function of the gas. Finally, we compare the exact resummed solution of the single-particle distribution function with solutions of the Boltzmann equation in the hydrodynamic limit and verify that the system displays considerable deviations from local equilibrium.

Modeling the intrinsic alignment (IA) of galaxies poses a challenge to weak lensing analyses. Using the Dark Energy Survey Year 3 shape catalog, we expect less impact from IA when we limit the sample to blue, star-forming galaxies. The cosmological parameter constraints from this blue cosmic shear sample are stable to IA model choice, unlike passive galaxies in the full DES Y3 sample, the goodness-of-fit is improved and the ${\mathrm{\Omega }}_{\mathrm{m}}$ and $S_8$ better agree with the observations from Planck on the cosmic microwave background. Mitigating IA with sample selection in DES, rather than flexible model choices, can reduce uncertainty in $S_8$ by a factor of 1.5.

We present a nonperturbative determination of the pion valence parton distribution function (PDF) moment ratios $⟨x^{n-1}⟩/⟨x⟩$ up to $n=6$, using the gradient flow in lattice quantum chromodynamics (QCD). As a testing ground, we employ SU(3) isosymmetric gauge configurations generated by the OpenLat initiative with a pseudoscalar mass of $m_{\pi }\simeq 411\mathrm{MeV}$. Our analysis uses four lattice spacings and a nonperturbatively improved action, enabling full control over the continuum extrapolation, and the limit of vanishing flow time, $t\to 0$. The flowed ratios exhibit O($a^2$) scaling across the ensembles, and the continuum-extrapolated results, matched to the $\overline{\mathrm{MS}}$ scheme at $\mu =2\mathrm{GeV}$ using next-to-next-to-leading order matching coefficients, show only mild residual flow-time dependence. The resulting ratios, computed with a relatively small number of configurations, are consistent with phenomenological expectations for the pion’s valence distribution, with statistical uncertainties that are competitive with modern global fits. These findings demonstrate that the gradient flow provides an efficient and systematically improvable method to access partonic quantities from first principles. Future extensions of this work will target lighter pion masses toward the physical point, and applications to nucleon structure such as the proton PDFs and the gluon and sea-quark distributions.

Future proposed lepton collider experiments will reach unprecedented levels of accuracy. To ensure the success of these experiments, and to fully exploit their wealth of data, the precision of theory calculations must reach comparable or even better levels. One bottleneck in achieving this precision target lies in the systematic, process-independent inclusion of higher-order corrections at next-to-next-to-leading order in the electroweak coupling while ensuring the correct matching with modern all-orders resummation techniques. Here, we present a solution to this problem, based on the Yennie-Frautschi-Suura theorem, which employs a local IR subtraction to remove divergences and its matching to an all-order resummation of the soft and soft-collinear logarithms.

We present the largest galaxy weak lensing mass map of the late-time Universe, reconstructed from 270 million galaxies in the DECADE and DES Year 3 datasets, covering 13,000 square degrees. We validate the map through systematic tests against observational conditions (depth, seeing, etc.), finding the map is statistically consistent with no contamination. The large area covered by the mass map makes it a well-suited tool for cosmological analyses, cross-correlation studies and the identification of large-scale structure features. We demonstrate its potential by detecting cosmic filaments directly from the mass map for the first time and validating them through their association with galaxy clusters selected using the Sunyaev-Zeldovich effect from Planck and ACT DR6.