Papers

We extend a Lagrangian formulation of dual electrodynamics by introducing electric and magnetic Higgs scalar fields. The scalars couple to Mandelstam nonlocal potentials which enter the electric and magnetic sectors. We consider the vacuum in which only the magnetic scalar has a nonzero expectation value. The generalised Maxwell equations remain local even though the scalar couplings are nonlocal. In this phase the local electric potential keeps a massless pole while the magnetic sector acquires a mass. The electric interaction is therefore Coulombian at large distances while the pole-pole and charge-pole interactions become short ranged. The magnetic charge is then screened in the sense of the Swieca theorem while the electric charge is not. The Dirac condition is inherited from the symmetric phase as a quantisation rule for the microscopic electric and magnetic couplings. We also comment on screened monopoles as possible dark sector degrees of freedom.

An effective strategy for constructing compact representations of integral coefficients in scattering amplitudes is to make their singularity structure manifest. This is naturally achieved by treating them as elements of fraction fields of polynomial quotient rings, where poles correspond to algebraic vanishing loci. Simplification via partial fraction decomposition relies on exploiting the structure of the numerators and is governed, at least in a first approximation, by their behaviour on irreducible codimension-two varieties. These are identifiable through primary decompositions of the associated ideals. Despite the availability of general algorithms, primary decompositions remain computationally challenging and often require tailored strategies. In this work, we extend an approach based on ideal saturation, identify an issue related to the breaking of Lorentz covariance in the choice of ideal generators, and present a solution based on fitting ansätze in special kinematic limits. We also provide substantial improvements to an algorithm for the generation of numerical points in proximity of given varieties and to one for testing primality of unmixed ideals, both of which rely on a semi-numerical procedure for computing independent sets and variety dimensions. Finally, we present new codimension-two primary decompositions for five-point massless amplitudes at higher powers in the dimensional regulator, and for finite remainders with five-point one-mass kinematics, where a new spurious singular locus appears.

After four decades of null-results, the experimental quest to discover a dark matter particle ardently continues. While confidence in the leading candidate, the Weakly Interacting Massive Particle (WIMP), is waning, its explanatory success still shapes current experimental approaches and theoretical expectations - from underground detecting efforts in Europe, China, and the U.S. to modern theories of cosmic structure. This paper traces the origins of this particle-based paradigm to a critical predecessor: the neutrino-dominated universe. Proposed in the early 1970s as a solution to extra-galactic anomalies, neutrinos became the leading explanation of 'missing matter' following experimental hints of neutrino mass in 1980. Although short-lived, the model's coherent picture of cosmic evolution and structure formation set strong conceptual and methodological standards - providing critical impetus to the field of particle cosmology. Examining this history invites renewed reflection on how such past aims and expectations continue to guide dark matter inquiry today.

We study cosmological stasis in coupled dark matter and dark energy models in which a scalar field drives the dark energy and sets the dark matter mass, with the Dark Dimension as the motivating realization. Treating dark matter, dark energy, baryons, and radiation as an autonomous dynamical system, we show that exact stasis requires exponential slopes along the trajectory, and that running slopes give exact stasis or a drifting quasi-stasis depending on whether the running is integrable. The constant abundance solutions are the stationary solutions of coupled quintessence, which we read as stasis epochs with computable lifetimes and exits. Anchoring the cosmology to the measured abundances at matter-radiation equality and today, we show that the stasis region for this model cannot accelerate for any initial conditions, and that the total equation of state is never phantom although the effective dark energy of a $\Lambda$CDM fit can appear so. For the Dark Dimension, capture into stasis in the future is excluded for geometric sources of the potential once dark fifth-force bounds are imposed, and dark matter production from the Standard Model brane supports a further stasis which the standard scenario does not reach. The stasis solutions provide analytic exclusions of the parameter space which do not depend on initial conditions.

We present a deep-learning surrogate for the Earth matter effect on solar neutrinos. The model uses a residual convolutional network conditioned on the solar neutrino oscillation parameters and is trained on numerical solutions computed over a grid of parameter values. It predicts the Earth-induced transition probabilities across neutrino energy and zenith angle, providing a fast approximation to the direct numerical calculation. For the reference electron-neutrino survival probability, the surrogate achieves a pointwise relative accuracy of approximately $2\%$ and a speed-up of about a factor of 60 in a laptop-CPU test. Since the network learns only the Earth-crossing propagation, it can be applied without retraining to new-physics scenarios that leave this propagation unchanged. The surrogate can also be retrained using alternative numerical implementations or extended parameter sets, providing a flexible and computationally efficient approach for solar-neutrino analyses. The code and simulation data are publicly available at \href{https://github.com/AI-Driven-HEP/NuMatterSurrogate}{\faGithub}.

Radiative capture in a non-relativistic system can become non-perturbative even when the underlying transition interaction is weak. We demonstrate this mechanism in a simple quantum-mechanical two-channel model with a systematic power counting, where strong mixing between scattering and bound states develops in a narrow region around a finite momentum $k_0$, leading to a perturbative violation of unitarity. In this regime, the enhanced contributions factorize, reducing the dynamics to a free scattering state interacting through a strong local coupling. Under RG evolution in the factorization scale, this local interaction approaches a unitary fixed point, analogous to that of systems with an anomalously large scattering length. This motivates an EFT organized around the finite-momentum surface $|\mathbf{k}|=k_0$, describing fermions at unitarity with a linear dispersion relation. The resummation resulting from the EFT restores unitarity and provides a systematic expansion for both elastic scattering and radiative capture.

We investigate the limitations of the two-qutrit quantum tomography in Higgs-boson decays to four charged leptons. At next-to-leading order, the standard reconstruction can yield an operator that is not positive semidefinite, even when radiatively improved spin-analysing powers are used. We trace this failure to the coherent combination of photon- and Z-mediated contributions to the off-shell dilepton system, whose distinct production and decay structures invalidate the assumed universal decay analysers. Nevertheless, the rank-two angular sector remains accessible and perturbatively stable, enabling a robust lower bound on the squared concurrence, and hence a reliable assessment of entanglement beyond leading order.

Quantum correlations have recently attracted significant attention in collider physics, with Nonlocal Advantage of Quantum Coherence (NAQC) representing the strongest form of quantum correlation studied so far. Owing to its strength, NAQC is considerably more challenging to observe than Bell nonlocality since it is only present in narrower regions of phase space. Unlike other systems, tau-lepton pair ($\tau^+\tau^-$) production in electron–positron ($e^+e^-$) collisions provides an ideal testing ground, as it exhibits strong quantum correlations and, in particular, NAQC over a large region of phase space. In this paper, we investigate NAQC in $e^+e^- \to \tau^+\tau^-$ production at center-of-mass energies of 10.58 and 91.19~GeV, corresponding to the ongoing Belle~II and future FCC-$ee$ experiments, respectively. Remarkably, for our experimental proposal, we develop a dedicated NAQC witness, which allows to certify NAQC presence by measuring one single magnitude. We estimate the experimental sensitivities needed to establish the presence of NAQC, finding that a large fraction of the number of events (specifically, 0.18 for Belle~II and 0.31 for FCC-$ee$) contribute to the NAQC signal. A 5$\sigma$ observation of NAQC requires a precision of approximately 1% at Belle~II, while a precision of a few percent is sufficient at FCC-$ee$. The resulting observation would constitute the strongest form of quantum correlation measured in a collider to date. In addition, we design an experimental scheme to implement the steering game leading to the NAQC definition, representing the first implementation of a steering game in a high-energy collider. Our results are easily extendable to other electron–positron colliders with different center-of-mass energies.

Asymmetric orbifolds provide concrete examples of non-geometric constructions dubbed T-folds. All Z2 point groups of six dimensional asymmetric order-two orbifolds are identified. The order-two T-fold configurations on the SO(12) lattice are classified at the fermionic point of type II string theories for all Z2 point groups. The spectra of the models on these configurations are presented parametrically, in terms of certain generalised GSO phases. The minimal effective Hodge numbers were found to be (h_{11},h_{12})=(1,1) for six T-fold configurations. Asymmetric generalisations of the mirror symmetry map are conjectured. The orientifoldable configurations using the basic worldsheet parity were identified within the classification. Twisted sectors corresponding to pure asymmetric twists may contain Rarita-Schwinger multiplets with spin-3/2 states. Throughout the paper, generalised GSO projections are chosen to preserve the maximal amount of supersymmetry possible. Relaxing this, the order-two point groups were identified for which non–supersymmetric T-folds can be constructed. Since some of them may enhance to N=1 or, even, N=2 supergravities, we argue that appearance of spin-3/2 states necessarily implies that the spectrum has reorder itself in a supersymmetric fashion and hence that the vacuum energy vanishes.

We establish a direct quantum Clausius relation for conformal fields inside the apparent horizon of a quasi-de Sitter spacetime. We compute the net heat flow across the horizon from the renormalized stress-energy tensor, and independently determine the time evolution of the renormalized von Neumann entropy using the replica method. At leading order in the Hubble-flow expansion, the two calculations agree exactly, without using the gravitational equations of motion. Beyond leading order, we find a scheme-independent entropy balance that includes the corresponding Wald entropy. Our results provide a quantum field theoretic realization of dynamical horizon thermodynamics beyond exact de Sitter equilibrium.

We investigate the determination of non-perturbative QCD contributions, associated with proton's transverse structure, from high-precision experimental data for electroweak boson production at the LHC. We demonstrate that these determinations are strongly affected by correlated uncertainties across transverse-momentum bins in the region of low boson's transverse momenta. We illustrate our results through a detailed analysis of LHCb measurements of $Z$-boson spectra at forward rapidities, and a comparison with CMS measurements at central rapidities. We further examine the influence on the extraction of the non-perturbative parameters from final-state electromagnetic radiation, photon-induced background, large-$x$ contributions to parton distributions in the forward region, matching to perturbative next-to-leading order. We comment on the comparison of our results with those from the underlying-event tuning of parton-shower Monte Carlo event generators.

Recent analyses of Planck and ACT CMB data report a $2\text{-}4\sigma$ hint of isotropic cosmic birefringence ($\beta \approx 0.3^\circ$), corresponding to a parity-violating rotation of polarization planes that points to potential new physics. We show that both the hint of cosmic birefringence and the observed baryon asymmetry can be simultaneously explained by the rotation of an axion-like field. The minimal setup predicts a positive birefringence angle, consistent with the CMB hint, and matter and kination domination ending around a temperature of $\mathcal O(3\text{-}50)$ MeV, making the model falsifiable by astrophysical probes and potentially giving rise to characteristic gravitational-wave signals. We also introduce a mechanism that can exponentially enhance the angular momentum of the rotation generated by the Affleck-Dine mechanism.

Relativistic heavy-ion collisions provide a unique experimental opportunity to study strongly interacting matter at extreme temperature and density, while lattice quantum chromodynamics (QCD) offers a first-principles approach to the equilibrium properties of such matter in the non-perturbative regime. The interplay between experiment and lattice QCD has therefore become central to establishing the properties and phase structure of QCD matter. Selected areas where this connection is particularly informative are discussed, including the QCD equation of state and its role in hydrodynamic descriptions of heavy-ion collisions, transport properties of the quark-gluon plasma, conserved-charge fluctuations and their relation to experimental cumulants, and the ongoing search for a critical point in the QCD phase diagram. Particular attention is given to the limitations involved in confronting equilibrium lattice calculations with the finite, dynamical and experimentally constrained systems produced in heavy-ion collisions. Recent developments increasingly allow quantitative tests of QCD thermodynamics over an extended range of temperature and baryon chemical potential. The continuing experimental programmes at RHIC and the LHC, together with future measurements at FAIR, NICA and the Electron-Ion Collider, provide important opportunities for an increasingly close interplay between lattice QCD, phenomenology and experiment.

We test the system-size dependence of bottomonium suppression using the same open-quantum-system transport framework for Pb-Pb, O-O, and Ne-Ne collisions. The microscopic transport coefficients are retained from previous Pb-Pb analyses. Using QTraj, we solve the next-to-leading-order pNRQCD Lindblad equation in anisotropic hydrodynamic backgrounds and calculate integrated $\Upsilon$ double ratios. The QGP-induced evolution reproduces the observed sequential hierarchy and overall magnitude of the O-O suppression measured by CMS and LHCb. We quantify the sensitivity to both transport coefficients and to the termination temperature of the in-medium evolution. The Ne-Ne measurement favors somewhat stronger suppression than predicted, although the present experimental uncertainty is large. The extension from Pb-Pb to light ions supports, at least for observables less sensitive to cold nuclear matter effects, a common microscopic origin of bottomonium suppression in deconfined matter, characterized by the same temperature-dependent transport coefficients despite the large change in collision-system size.

Can primordial cosmological correlations originate from statistical fluctuations of an early-universe thermal system? We connect grand-canonical thermodynamics, stochastic transport, and gauge-invariant cosmological perturbations for a charged fluid at finite chemical potential. Energy-charge susceptibilities determine curvature, charge-isocurvature, and cross-correlation amplitudes, while transport sets when each mode leaves equilibrium. For an isolated, adiabatic conformal plasma with conserved charge-to-entropy ratio and power-law diffusion, diffusive freeze-out yields the universal spectrum $\mathcal P_S(k)\propto k^3$, with $n_{\rm iso}=4$, while equal-time local-equilibrium curvature-isocurvature covariance vanishes in the conformal source basis. Thus neither finite chemical potential nor replacing Hubble crossing by diffusion crossing alone yields approximate scale invariance. We evade this obstruction with an open subsystem of massless Dirac fermions during a sourced quasi-de Sitter phase. There, grand-canonical energy cumulants generate a nearly scale-invariant red curvature spectrum. A benchmark gives $\mathcal P_{\zeta_X}(k_\star)=2.10\times10^{-9}$ and $n_s(k_\star)=0.9649$, stays within $0.30%$ of the fitted power law over $0.002\leq k/k_\star\leq4$, and predicts weak negative running and small positive intrinsic non-Gaussianity from higher-order cumulants, $f_{\rm NL}(k_\star)\simeq0.106$ and $g_{\rm NL}(k_\star)\simeq0.0158$. With a two-helicity vacuum tensor spectrum, the tensor-to-scalar ratio is $r_{t/s}(k_\star)=1.82\times10^{-4}$. This isolates the limitation of isolated conformal thermal seeding and the open-system ingredient needed to overcome it. Thermal energy-charge fluctuations thus provide a calculable source of realistic scalar correlations, while reservoir dynamics, equilibration, and later curvature-isocurvature transfer must come from a microscopic model.

Generic potentials in an inflationary landscape are typically too steep to support a prolonged period of cosmic inflation. Atypical flat regions of the landscape are required to support successful inflation. The occurrence of such regions leads broadly to two possibilities: a single prolonged period of slow-roll inflation (which we call single-stage inflation), or multiple shorter periods of inflation separated by transient departures from slow roll (which we call multi-stage inflation), giving rise to primordial features and other departures from the behavior of the simplest slow-roll model. The former is the possibility most commonly assumed when deriving the primordial density fluctuations for the Big Bang model. In this paper, using Gaussian random potentials as a simple model of the inflationary landscape, we study the relative occurrence of these two possibilities. We find a substantial fraction of multi-stage inflationary trajectories in landscapes with field-space dimensions one, two, and three, and this fraction increases with dimensionality at fixed typical landscape curvature. In constructing the inflationary landscapes and identifying successful inflationary trajectories, we also define several relevant quantities and classify detailed properties of both multi-stage and multi-field inflationary trajectories.

We investigate thermal leptogenesis in an extension of the Type-I seesaw in which a real singlet scalar couples non-diagonally to the right-handed neutrinos. The interactions $-y_{ij}\phi N_iN_j$, with $i\neq j$, introduce new sources of CP violation in heavy-neutrino decays with a negligible enhancement of the standard leptonic washout. We derive an analytic upper bound on the scalar-induced CP asymmetry and present numerical results using fully flavoured Boltzmann equations and the density-matrix formalism. We show that the observed baryon asymmetry can be generated with a hierarchical right-handed-neutrino spectrum at the electroweak scale. In the minimal Type-I seesaw, lowering the scale of decay leptogenesis typically requires either a tuned quasi-degeneracy of the right-handed-neutrino masses or cancellations between the tree-level and one-loop contributions to the light-neutrino masses, while hierarchical leptogenesis instead requires a high scale that aggravates the Higgs hierarchy problem. This singlet-scalar extension appears to avoid these tensions, allowing successful leptogenesis with a hierarchical right-handed-neutrino spectrum down to the electroweak scale.

The LUX-ZEPLIN (LZ) Collaboration has reported a nuclear-recoil candidate with reconstructed energy $248\pm23_{\rm stat}\pm23_{\rm sys}\,\mathrm{keV}$. We investigate an interpretation in terms of composite inelastic dark matter, in which a dimension-ten operator splits the lightest baryon of a confining $SU(3)_{\rm D}$ theory into two Majorana states. Endothermic scattering is mediated by a leptophobic vector coupled to baryon number. For a dark-baryon mass of $1\,\mathrm{TeV}$ and a splitting of $300\,\mathrm{keV}$, a reference nucleon cross section of $6.5\times10^{-43}\,\mathrm{cm^2}$ lies within LZ's published two-sided 90% confidence interval. This benchmark fixes $M_V/g_B\simeq9.9\,\mathrm{TeV}$, where $M_V$ and $g_B$ are the mediator mass and baryon-number gauge coupling, and is compatible with solar neutrino and dijet constraints.

We investigate whether cosmic ray boosted dark matter (CRDM) can explain the 248 keV nuclear recoil event observed by the LUX-ZEPLIN (LZ) collaboration. We consider spin-dependent interactions, mediated by a pseudoscalar, and incorporate relativistic kinematics in CRDM production, propagation, and detection. We find that spin-dependent interactions can produce sufficient number of nuclear recoils in the observed region of interest, without populating events at lower energies, which have not been observed. However, for a benchmark pseudoscalar interaction corresponding to the non-relativistic effective operator $\mathbb{O}_6$, the coupling required to produce the observed event corresponds to an energy scale comparable to the momentum transfer scales, thus making contact interaction approach challenging. Instead, we find that a pseudoscalar mediator with mass $\sim 300\,$MeV and $O(1)$ couplings can provide a promising solution to this unexplained event.

Ultracentral high-energy collisions between identical nuclei are very sensitive to the size and shape of the frozen configuration of nucleons at the instant of the collision, an information that is encoded in the ground state wave functions of the colliding nuclei. The relative standard deviation of the size of the colliding system soon after the collision has recently been inferred from event-by-event fluctuations of the momentum per particle in collisions of $^{208}$Pb nuclei at the LHC, and since a single collision event produces thousands of particles, this information is very precise. We connect this measurement to the magnitude of the zero-point fluctuations of the radius of the lead nucleus. The value that is extracted from the data is compatible with predictions from nuclear-structure calculations, but is overestimated by classical Glauber-type modeling of high-energy collisions. The role of the Pauli principle in suppressing the fluctuations is underlined. It leads to a distinctive $A$ dependence that could be checked in collisions of smaller systems.

The $12\%$ rule relates hadronic decays of the $J/\psi$ and $\psi(2S)$ through the ratio of their wave functions at the origin, but is strongly violated in several vector–pseudoscalar ($VP$) channels, most prominently in the $\rho\pi$ one. We study these decays within an effective chiral framework including strong and electromagnetic interactions, with the latter implemented through vector meson dominance. The $\psi(2S)\to VP$ data are described well by a relatively minimal model with three free parameters, yielding $\chi^2_{\rm red}\simeq 6.71/(9-3)=1.12$. In contrast, the corresponding description of the $J/\psi$ decays is insufficient ($\chi^2{\rm _{red}}\simeq 132/(11-3)=16.5$) and requires additional $\mathrm{SU}(3)$ flavor breaking and electromagnetic contributions for a fair agreement with data: $\chi^2_{\rm red}\simeq 9.87/(11-6)= 1.97$. In the past, a small mixing of $J/\psi$ with an invisible vector glueball was considered as a way to describe the decay patterns. However, we will show that our extended fits are `de facto' equivalent to those where a vector glueball mixes with the $J/\psi$, so that we cannot distinguish whether or not the vector glueball is present. Our results suggest that an important part of the $\rho\pi$ puzzle may arise from additional contributions to the $J/\psi\to VP$ amplitudes rather than from a suppression mechanism specific to the $\psi(2S)$.

Microscopic black holes may form at the centers of neutron stars through the accumulation and collapse of dark matter. While Standard Model particles produced by Hawking evaporation are efficiently absorbed by the dense stellar medium, sufficiently weakly interacting and long-lived particles can escape and subsequently decay into high-energy neutrinos, photons, or charged particles, providing an indirect probe of Hawking radiation. We examine the joint energy–angular distribution of these secondary particles, incorporating mediator propagation, energy-dependent decay, and relativistic decay kinematics. For relativistic mediators, the normalized energy-integrated angular profile becomes approximately independent of the black hole temperature, with its characteristic extent controlled primarily by the combination $c\tau_S/D$ of the mediator lifetime and source distance, as the boost enhancement of the decay length is compensated by relativistic beaming. We demonstrate the viability of this mechanism and illustrate its phenomenology with gravitationally coupled scalars, dark photons, dark-$Z$ bosons, and heavy neutral leptons. Comparing with monochromatic mediator production from dark matter annihilation, we find that the energy-integrated angular profiles can be nearly degenerate, while the energy spectra and energy-resolved angular distributions remain distinct. These complementary spectral and angular signatures provide targets for high-energy neutrino and gamma-ray searches.

In this contribution I present a calculation of the inclusive cross-section for the associated production of a top-anti-top pair and a W boson at next-to-next-to-leading order in QCD, based on the first exact computation of the two-loop QCD amplitude at leading colour. I discuss a strategy to express the amplitude in terms of a set of special functions with rational coefficients, overcoming the obstacle posed by the presence of elliptic functions. The special functions are evaluated through the method of differential equations, while the rational coefficients are computed using finite field techniques. For the computation of the inclusive cross-section, the double-virtual correction is evaluated by interpolating a five-dimensional grid.

A confining dark sector modeled after quantum chromodynamics provides a well-motivated framework for strongly-interacting dark matter. We show that dark vector mesons in a confining dark sector can be resonantly produced in high-energy neutrino scattering on the cosmic neutrino background, generating a distinctive absorption feature in the cosmic neutrino energy spectrum. Unlike conventional attenuation effects, this feature directly reflects the mass spectrum of dark resonances and can therefore serve as a spectroscopic signature of a strongly-interacting dark sector. We find that a broad range of dark-sector parameter space is within the reach of future neutrino telescopes, including IceCube-Gen2 Radio. Our proposal thus turns the cosmic neutrino background into a target for discovering dark-sector resonances, while simultaneously providing a novel probe of dark sector interactions with neutrinos.

We present a theoretical proposal for measuring correlation functions in a quantum field system based on the use of quantum quenches. Using the examples of massive and massless scalar field theories, we show that a short-term perturbation of the system leads to a dependence of the further evolution of the average field on the initial state's correlation functions. Considering two types of perturbations, namely local and nonlocal quenches, we show which correlation functions can be measured in each of these cases. The proposed procedure can be applied to study non-Gaussian correlations.

The effective-field-theory interpretation of generalized uncertainty principle (GUP) deformations does not by itself establish whether their tree-level operator content is closed under renormalization. We investigate this question in massless GUP-deformed quantum electrodynamics at one loop and to first order in the deformation parameter. We compute the ultraviolet divergences of the relevant Green functions and determine the counterterm structure. Our central result is that, after eliminating redundant operators, renormalization requires only one independent physical counterterm beyond those associated with the tree-level theory: an axial-axial four-fermion interaction. The original deformation therefore admits a minimal radiative completion at this order. We derive the leading logarithmic running of the induced Wilson coefficient and discuss its operator-level correspondence with the contact interaction arising in Einstein-Cartan gravity.

We study the Semi-Inclusive Deep Inelastic Scattering (SIDIS) cross-section at large values of hadron transverse momentum $P_t \gtrsim Q$, with $Q^2$ being the photon virtuality. This kinematic regime of SIDIS allows for a collinear factorization in terms of parton distribution functions (PDFs) and collinear fragmentation functions (FFs). On the other hand, at high energies, i.e., at small Bjorken $x$, the same SIDIS process can also be factorized within the Color Glass Condensate (CGC) framework in terms of eikonal dipole amplitudes. In this work, we perform a systematic comparison of the leading-order (LO) and next-to-leading-order (NLO) collinear and the LO CGC factorizations of this process based on the COMPASS and HERA data. We further provide comparisons of these two factorization frameworks for nucleon and nuclear large-$P_t$ SIDIS in the expected Electron Ion Collider (EIC) kinematics. We find, within the present theoretical uncertainties, that it might be difficult to distinguish between these two factorization schemes for nuclear SIDIS at the EIC. We also observe a significant dependence of the LO eikonal CGC predictions on the choice of longitudinal momentum fraction $x_g$, suggesting significant beyond-eikonal corrections for the EIC kinematics.

Dark matter (DM) direct detection searches look for nuclear recoils as a result of weakly interacting massive particles (WIMPs) scattering off nuclei. Calculating the rate associated with this WIMP-nucleus elastic scattering process involves input from several components, which include the direct detection experimental response functions, the high energy physics content employed, the DM halo velocity distribution, and the target nuclear structure information. Uncertainties in any of these components can impact the interpretation of experimental signals, and affect analysis of rate predictions. In this work, we focus on the uncertainties present due to the nuclear structure modelling of silicon and germanium targets, where a comprehensive set of nuclear form factors are employed through a non-relativistic effective field theory (NREFT) formalism. We show that these uncertainties, obtained from large-scale shell model calculations, impact the nuclear form factors and thus experimental exclusion limits for a SuperCDMS-like experiment. The impact of high energy physics content (through particle physics coefficients) on the magnitude of the nuclear uncertainties is also explored for several WIMP-nucleus scattering responses. Non-negligible nuclear uncertainties are present for several direct detection nuclear responses, indicating that nuclear structure must be accounted for in experimental analysis and interpretation.

It has long been a puzzle why the nuclear modification factor in relativistic $p$Pb collisions is consistent with unity, while the high-$p_T$ elliptic flow is significantly positive. The latter is traditionally interpreted as path-length-dependent energy loss, whereas the former is consistent with zero energy loss. In this Letter, we propose that even at high $p_T$ a hard parton coalesces with a boosted thermal medium parton whose energy is correlated with the angle-dependent radial flow. We compare this flow for $pp$, $p$Pb, $p$O, OO and PbPb collision systems and conclude in particular that the $p$Pb flow is large and anisotropic. The collective medium pushes out the hard partons, and more so in $p$Pb, or in-plane, than in $pp$ collisions, or out-of-plane. The mechanism qualitatively agrees with experiment and predicts a significantly smaller elliptic flow signal for jets than for hadrons.

Axion relic pockets are phase-transition remnants consisting of regions of false vacuum stabilised from collapse by a hot axion gas. Axion relic pockets can comprise dark matter, but little is known about their phenomenology. We consider trapped axions coupled to electromagnetism and derive the axion to photon conversion rate accounting for the pocket's compactness and spherical geometry. As a case study, we show that axion-photon conversion occurs in atomic electric fields, leading to high-energy electromagnetic cascades that may be detectable by neutrino, cosmic-ray, and dark-matter experiments. The distribution of electromagnetic showers is inherently isotropic, and upward-going showers provide a smoking-gun signal for the model. Using recent data from the IceCube neutrino telescope, we derive the first limits from terrestrial experiments on axion relic pockets as dark matter. However, for the simplest realisation of the model, only a small part of the parameter space can give signals strong enough to be constrained by current data. We also comment on the prospects for discovering axion relic pockets using fluorescence and radio Cherenkov detection by atmospheric instruments and balloon-borne payloads, as well as traditional dark matter direct detection experiments. These results provide the necessary tools to initiate phenomenological studies of axion relic pockets across different environments.