In the presented article, the next-to-the-leading-order calculation of the differential cross-section of the Compton scattering subprocess $qg \rightarrow qγ$ for prompt photon production in proton-proton collisions at NICA energies has been carried out, both without and taking into account the longitudinal polarization of colliding protons. It is shown that the contribution of the next-to-leading order to the differential cross-section is significant at high energies of colliding protons and constitutes around $15\%$ of the leading-order calculation. The influence of the polarization of colliding protons on the next-to-leading-order calculation is more significant than on the leading-order calculation.

Where do gauge symmetries come from? These lectures develop the idea that the Standard Model might be emergent, with its gauge symmetries dissolving in some phase transition deep in the ultraviolet. The (meta-)stability of the Higgs vacuum may be pointing to some new critical phenomena at very high energy scales, with the Higgs connecting physics at LHC laboratory energies to that in the deep ultraviolet. In the emergence scenario, the dark energy scale comes out similar to the size of light Majorana neutrino masses. These two quantities appear at the same order in a low energy expansion in inverse powers of the scale of emergence, about $10^{16}$ GeV. Dark matter candidates include axions and phonon like excitations of degrees of freedom above the scale of emergence. Possible tests of these ideas involve neutrinos as well as gravitational-waves-related signals from the early Universe, which are sensitive to physics at very high energy scales.

The electroweak phase transition (EWPT) is a central topic in particle physics and cosmology, connecting collider phenomenology, baryogenesis, and gravitational-wave observatories. Its analysis requires a technically demanding, convention-sensitive, and model-dependent pipeline, from constructing the finite-temperature effective potential to tracking thermal histories, computing bubble nucleation rates, and predicting gravitational-wave spectra. We present LeWRON (Learning ElectroWeak phase tRansitiON), an agentic framework that orchestrates this pipeline starting from an input Lagrangian. LeWRON combines audited toolbox construction with an Explorer module that uses the generated model-specific code for further analysis, including scans and plots. Intermediate analytic outputs are checked by auditor agents and stored as structured artifacts, enabling reproducible human inspection and downstream use through both a command-line interface and a public Python API. The framework supports a reproduction mode, which infers conventions from the literature and reproduces published results, and a discovery mode, which guides users through structured checkpoints for new models. We demonstrate LeWRON across representative beyond-the-Standard-Model scenarios and release the code on GitHub.

The success of DUNE's MeV physics program depends upon high-precision knowledge of the charged-current (CC) $ν_e+\mathrm{^{40}Ar}$ cross section. While there are indirect constraints at the 10% level for the nuclear transitions that constitute this cross section, the only direct measurement in the MeV range has an uncertainty of $\sim$50%. We show, surprisingly, that the cross section can be precisely measured using the solar-neutrino data themselves. This is possible because of independent knowledge of the $^8$B flux and survival probability, plus the distinctive angular distributions of the Fermi and Gamow-Teller transitions that comprise the cross section. We propose new methods to extract the transition strengths, considering both intuitive groupings and a Principal Component Analysis. Under pessimistic assumptions about detection, but taking detector uncertainties to be controlled, we demonstrate that a precision of $\lesssim$2% on the cross section can be achieved in the 9-15 MeV energy range. These results will be an important foundation for studying the cross section up to several tens of MeV, where the complexity increases significantly due to nuclear breakup channels but where reducing uncertainties is critical for supernova and atmospheric neutrino studies.

Theories with massless particles contain $t$-channel (forward scattering) singularities that cause standard fixed order expressions for partial-wave amplitudes to be ill-defined. This presents an obstruction to systematically improvable partial-wave unitarity bounds. In this work, we study the construction of partial-wave amplitudes in a modified perturbation theory that incorporates long-range interactions focusing on the role of off-shell Coulomb modes. We find that there exists a universal description of the forward scattering region that renders the amplitudes renormalization scale independent. The resulting partial-wave amplitudes become well defined single-scale objects without spurious dependence on the infrared regulator, and we present a practical method for their computation order-by-order in perturbation theory.

In an early matter-dominated era, density and temperature inhomogeneities of the radiation bath grow more efficiently than in the standard radiation-dominated history. If the axion mass depends on temperature, these inhomogeneities induce spatial fluctuations of the axion mass, providing a new source term for axion density perturbations. We show that this mechanism is most efficient when the reheating temperature lies just below the mass-saturation scale $T_Λ$, and can drive axion overdensities to order unity by matter--radiation equality. For the QCD axion saturating the observed dark matter abundance, the nonlinear spectrum at equality exhibits two characteristic regions: one associated with the gravitational enhancement already present in moduli-driven cosmologies, and another produced by the temperature dependence of the axion mass. We estimate the resulting minicluster masses and discuss the possible formation of axion miniclusters and axion-star substructure.

A variety of experiments are operating or planned to search for displaced decays of light long-lived dark sector particles. In case such a state is discovered, the next step is determining its quantum numbers. We identify an angular observable, reconstructible solely from the decay products' four-momenta, that exhibits an anisotropic distribution for vector bosons from light meson decays and an isotropic distribution for scalars. We demonstrate that searches at DUNE, SHiP and FASER2 will be able to identify the mediator spin in sizable regions of yet unconstrained parameter space.

We revisit flavor oscillations in vacuum in terms of the propagation time of intermediate states. In the limit of a long propagation time (or distance), degenerate intermediate states exhibit oscillatory behavior, as described by the Jacob--Sachs (or Grimus--Stockinger) theorem within wave-packet quantum field theory. By explicitly evaluating the relevant integrals using the saddle-point method, we derive an extended expression for the flavor-changing amplitude that remains valid even for shorter propagation times. We show that oscillations occur only when the propagation time exceeds a threshold set by the energy uncertainty of the external wave packets and by the decay width of the propagating particle. For shorter propagation, the intermediate particle behaves as a purely virtual state, in the sense that it cannot propagate over a macroscopic distance. Although a direct experimental test of the transition from virtual to real propagation is challenging, since it typically occurs at microscopic scales, our result implies that the Jacob--Sachs theorem holds to higher accuracy than previously expected, even at short propagation times. Our formalism applies not only to neutrinos but also to other propagating particles, and future improvements in energy resolution may make this threshold observable.

We perform a comprehensive analysis of a charged parent freeze-in dark matter model, focusing on scenarios where the Universe reheats to a temperature comparable to or lower than the mass scales of the theory. In such configurations, dark matter production is Boltzmann-suppressed, allowing for stronger couplings between dark matter and the Standard Model thermal bath while still reproducing the observed relic abundance. We emphasize the non-trivial interplay between the reheating temperature, the mediator and dark matter masses and the coupling strength. We show that tracking the number density evolution of both dark matter and the mediator is essential to obtain reliable predictions, including unexpected behaviors such as the mediator non-equilibration due to fast decays. Lastly, we explore the phenomenological implications of this scenario, updating constraints from LHC searches and lepton flavour-violating decays and highlighting the complementarity of these searches in probing the cosmologically viable parameter space.

We present micrOMEGAs7, a major upgrade of the micrOMEGAs package for the computation of dark matter observables in generic models. This release introduces a generalized treatment of the Boltzmann equations, allowing for user-defined modifications of the Hubble expansion rate, entropy evolution, and non-thermal dark matter production from late-decaying cosmological components, thereby extending the framework beyond the standard radiation-dominated cosmology. The relic density can now be computed in scenarios such as low-temperature reheating, early matter domination, and kination. The new version also improves the treatment of sub-GeV dark matter, in particular annihilation into light mesons through scalar mediators, and provides updated spectra for indirect detection. Several experimental and observational constraints have been implemented or revised, including CMB bounds from Planck on energy injection during recombination and Fermi-LAT limits from dwarf spheroidal galaxies. For direct detection, a recast of recent LZ results has been included, and the code now takes into account effective electromagnetic couplings of spin-$1/2$ and spin-1 dark matter. Collider observables have also been extended through the implementation of CMS dilepton resonance constraints on $Z'$ mediators. Additional improvements include a more flexible treatment of effective relativistic degrees of freedom and an updated LHAPDF interface.

We study the exclusive production of dileptons in proton--proton collisions as a probe of the proton radius. Using a dipole form factor model, we compare the conventional choice of $Λ^2=0.71$~GeV$^2$ with PDG test scenarios corresponding to $r_p=0.8751$~fm and $r_p=0.84087$~fm. The sensitivity is greatest at large dilepton invariant masses and forward/backward rapidity. Fitting to the current ATLAS and CMS data within the adopted model gives $Λ^2 = 0.465 \pm 0.056~\mathrm{GeV}^2$, corresponding to an effective radius $r_p = 1.002 \pm 0.038~\mathrm{fm}$, which indicates non-trivial sensitivity on the proton radius scale, but is not yet a definitive solution to the proton radius puzzle.

We propose a unified framework that connects inflationary dynamics with dark matter production within a supersymmetric $U(1)_{B-L}$ extension of the Standard Model. The setup is based on smooth hybrid inflation embedded in supergravity, with a non-minimal Kahler potential ensuring control of higher-order corrections. The model involves three scalar fields: the inflaton $σ$, an auxiliary field $ζ$ responsible for ending inflation, and a singlet mediator $η$ that links the inflationary and dark sectors. Dark matter is realized as an inert scalar stabilized by a $\mathbb{Z}_2$ symmetry and produced non-thermally via reheating dynamics. We show that reproducing the observed dark matter relic abundance imposes strong constraints on the inflationary sector, significantly reducing the allowed parameter space. As a result, the scalar spectral index is tightly constrained to $n_s \simeq 0.972 - 0.974$, consistent with current observational bounds. While the inflaton-dark matter coupling has a negligible effect on the background evolution, it induces observable modifications in the tensor-to-scalar ratio and the spectrum of primordial gravitational waves. This establishes a direct link between dark matter physics and inflationary observables.

Any observation of charged lepton flavor violation (CLFV) would be a clear signal of beyond-the-Standard-Model physics. Here, we propose a novel CLFV search using neutrino telescopes with their large cosmic-ray muon samples. Specifically, we use a recent IceCube cosmic-ray muon dataset and propose a new search for muon-to-tau conversion inside the IceCube detector. We illustrate our idea with CLFV interactions described by model-independent Effective Field Theory (EFT) operators and present the IceCube sensitivity on the relevant EFT scale. We also consider a specific realization of the EFT operator in terms of an axial-vector $Z'$ interaction and show sensitivities in the $Z'$ mass-coupling plane. We compare our sensitivities with those from low-energy CLFV searches, as well as from current and future collider experiments. We also show projections from next-generation neutrino telescopes, such as IceCube-Gen2 and HUNT, and demonstrate how neutrino telescopes can provide a powerful complementary probe of CLFV.

We explore microscopic black holes at the Large Hadron Collider (LHC) in the context of the ADD model for the centre-of-mass energy $\sqrt{s} = 14~\mathrm{TeV}$ at an integrated luminosity of $349.4~\mathrm{fb}^{-1}$ and provide constraints on the black hole mass, $M_{\mathrm{B}}$ by taking into account the effects of loss during the formation process of black holes through the parameter $ζ$. Our analysis reveals that for $ζ= 0$, black holes with $M_{\mathrm{B}} \leq 11.83~\mathrm{TeV}$ are disfavored in the case of three extra dimensions ($\mathcal{D}$), for the reduced Planck scale ($Λ_{\mathcal{D}}$) of about a TeV. The corresponding values for $Λ_{\mathcal{D}} = 9~\mathrm{TeV}$ turned out to be about $10.33~\mathrm{TeV}$. A significant reduction in the aforementioned limits is observed while the loss gets higher, e.g. for $ζ= 0.35$, $M_{\mathrm{B}}$ reduces to $7.65 (6.82)~\mathrm{TeV}$ at $Λ_{\mathcal{D}} = 1 (9)~\mathrm{TeV}$. These limits change to $12.03 ~(10.88)~\mathrm{TeV}$ and $7.80~ (7.03)~\mathrm{TeV}$ respectively for $ζ= 0~(0.35)$ for $Λ_{\mathcal{D}} = 1 (9)~\mathrm{TeV}$ at 95\% C.L. in case $\mathcal{D}$ is raised to seven.

We assess the tension between theoretical predictions and the values quoted by the Particle Data Group (PDG) for the partial decay width and branching fraction associated with the radiative charmonium decay $J/ψ\toγη_c$. A profile scan over the most recent PDG data depending on the branching fraction $\mathcal{B}(J/ψ\toγη_c)$ suggests that the correlation between measured branching fractions is compatible with lattice QCD determinations of the partial decay widths $Γ(J/ψ\toγη_c)$ and $Γ(η_c\toγγ)$. We propose a theoretically grounded photon line shape for the radiative decay spectrum and a prescription for the extraction of (product) branching fractions involving the magnetic dipole (M1) transition $J/ψ\toγη_c$. This approach obviates the need to modify the photon energy spectrum line shape using empirical damping functions, as done in the most recent experimental extractions of $\mathcal{B}(J/ψ\toγη_c)$ from the photon line shape, thereby eliminating an inherent ambiguity in the determination of the derived observables.

With initial state radiation, the multi-TeV muon collider can be regarded as an electroweak boson collider. The dominant production mode of the certain process becomes the vector boson fusion channel, because the corresponding cross section typically increases logarithmically at high energies. This also holds true for new physics beyond the standard model. Within the $U(1)$ gauged extension of seesaw models, the heavy neutral lepton has additional interactions with the new gauge boson $Z'$ and heavy Higgs $H$. In this paper, we investigate the production of heavy neutral lepton $N$ via the new vector boson fusion processes $Z'Z'\to H\to NN$ with and $Z'Z'\to NN$ without heavy Higgs at the multi-TeV muon collider. Different from the canonical vector boson fusion processes $WW/ZZ\to H\to NN$, the new process $Z'Z'\to H\to NN$ is not suppressed by the small mixing angle $α$ between the Higgs bosons. Meanwhile, the pair production process $Z'Z'\to NN$ is also viable even for heavy Higgs $m_H> \sqrt{s}$. Therefore, these new avenues provide alternative pathways to probe the intrinsic feature of the heavy neutral lepton. We then perform a detailed analysis of the lepton number violation signals via the new vector boson fusion with heavy Higgs $μ^+μ^-\to μ^+μ^- H \to μ^+μ^- NN$ and without heavy Higgs $μ^+μ^-\to μ^+μ^- NN$, followed by $N\to μ^\pm jj$, where the two jets from $W$ boson decay are treated as one fat-jet $J$.

The recent LHCb observation of $Ξ_{cc}^{+}$ opens the ultra-low-$Q$ transition $Ξ_{cc}^{++}\toΞ_{cc}^{+}$ as an experimentally motivated null test of charged-current new physics. Our two- and three-body analyses show sensitivity to effective baryon-level couplings of $\mathcal{O}(10^{-6}-10^{-7})$ for MeV-scale recoil momenta. We establish a practical no-go result for a universal light charged scalar $ϕ^+$: with a first-generation $ϕ^+\bar u d$ coupling, existing electroweak-precision and beta-decay constraints are parametrically stronger than the projected LHCb sensitivity. We then identify a two-charm-selective charged-current portal whose leading operator has a nonzero matrix element in doubly charmed baryons but vanishes at leading order in pions, nucleons, nuclei, and singly charmed mesons. In this class of models, $Ξ_{cc}^{++}\toΞ_{cc}^{+}$ transitions can provide the leading direct probe of the portal interaction.

Vector-boson scattering with semileptonic final states has recently been measured at the LHC, and future experiments are expected to further increase the precision of its measurement, calling for adequate theoretical predictions. In this work, we present a calculation of the NLO QCD and electroweak corrections to the process $\text{p}\text{p} \to \ell^+ ν_\ell + 4\text{j}$ in two different fiducial regions relevant for vector-boson scattering. In a fully off-shell calculation, we provide results for the leading electroweak contribution of $\mathcal{O}\left(α^6\right)$ and the corresponding corrections of $\mathcal{O}\left(α^7\right)$ and $\mathcal{O}\left(α_\text{s} α^6\right)$ for fiducial cross sections and a selection of differential distributions.

We present the first systematic and comprehensive scan of two-flavon Froggatt-Nielsen (FN) models, employing artificial intelligence techniques to explore the high-dimensional, mixed discrete-continuous parameter space. Extending the standard single-flavon FN framework to a two-flavon setup in which separate flavon fields couple independently to the up- and down-type sectors, we demonstrate that the relative phase between their vacuum expectation values (vevs) provides a natural and generic source of CP violation absent in single-flavon models. To explore this enlarged model space, we cast the search for phenomenologically viable models as a multi-objective optimisation problem, formulating each experimental constraint as a separate objective, and employ the Non-dominated Sorting Genetic Algorithm III to simultaneously fit all 18 FN charges, 45 Wilson coefficients, and flavon parameters to both the quark and lepton sectors. Our approach requires no separate training phase and identifies phenomenologically viable models orders of magnitude faster than prior reinforcement learning methods. Imposing experimental constraints on CKM and PMNS mixing angles and CP phases, charged fermion masses, and neutrino squared-mass differences, we discover over $100\,000$ unique viable models with a remarkably low duplication rate, indicating that the space of valid two-flavon FN realisations has not been exhausted. Both Normal and Inverted neutrino mass squared orderings are realised, with the relative hierarchy between the flavon vevs producing qualitatively distinct predictions for the effective neutrinoless double beta decay mass $m_{ee}$. We further demonstrate the existence of minimal FN realisations with maximal flavon exponent as small as three, and of models reproducing charged fermion masses to within $6\%$ without any dedicated continuous parameter optimisation.

Extensions of the Standard Model featuring both an enlarged scalar sector and vector-like fermions arise naturally in a wide class of well-motivated theoretical frameworks. In such scenarios, vector-like Quarks (VLQs) can exhibit non-standard decay modes involving additional Higgs states, giving rise to distinctive collider signatures that remain largely unexplored by existing experimental searches. We investigate the prospects of probing this possibility at the high-luminosity Large Hadron Collider (HL-LHC) through the decay of vector-like top partner ($T$) to charged Higgs ($H^{\pm}$) followed by the decay, $H^\pm\toτν$, producing a final state containing two tau leptons, two $b$-jets, and missing transverse energy. A model-independent collider analysis is performed using global kinematic observables constructed from visible objects and the missing transverse momentum vector to suppress the dominant backgrounds. Polarization-sensitive observables built from the hadronic $τ$ decay products are also examined as complementary probes of the spin-$0$ origin of the $τ$ leptons. The expected discovery sensitivity is evaluated using the Asimov significance for an integrated luminosity of $3$ ab$^{-1}$ at $\sqrt{s}=14$ TeV. Our results demonstrate that the $2τ\:+\:2b\:+$ missing $E_T$ channel provides a promising and largely orthogonal avenue to search for non-standard VLQ decays in extended Higgs sectors, with discovery-level sensitivity achievable for VLQ masses up to approximately $1.9$ TeV.

Recent experimental advances in the baryon sector, including the observation of doubly charmed states, have renewed interest in the production mechanisms of increasingly heavy hadronic systems, calling for precision and uncertainty-controlled descriptions. We present the OMG3Q1.1 framework for the fragmentation of same-flavor all-heavy $Ω_{3Q}$ baryons in high-energy hadronic collisions. The construction combines diquark-inspired inputs for constituent-heavy-quark and gluon channels with threshold-aware DGLAP evolution within the HF-NRevo scheme. A replica-based strategy consistently quantifies perturbative missing-higher-order effects (F-MHOUs) and nonperturbative wave-function uncertainties (F-NPWFs), yielding the first uncertainty-resolved fragmentation-function set for the $Ω_{3Q}$ sector. The resulting LHAPDF6 grids are employed to investigate semi-inclusive $Ω_{3Q}$ plus jet production at the HL-LHC and future FCC within the (sym)JETHAD environment. The OMG3Q1.1 framework establishes a precision-oriented baseline for rare triply heavy baryons and provides a foundation for future studies of the heavy-flavor baryon landscape.

We present a simple Dirac scoto-seesaw framework based on the anomaly-free $U(1)_{B-L}$ charge assignment $(-4,-4,5)$ for $ν_R$. This chiral charge assignment naturally accounts for the observed neutrino mass-squared differences, with $Δm^2_{\rm atm}$ generated at tree level and $Δm^2_{\rm sol}$ arising radiatively. After the spontaneous breaking of gauged $U(1)_{B-L}$, a residual $Z_6$ symmetry stabilizes the dark matter candidate. We investigate two minimal realizations of the framework, finding that both normal and inverted orderings are viable in one case, whereas only normal ordering survives in the other, with distinctive features for neutrino observables. Moreover, the chiral nature of the $U(1)_{B-L}$ charges suppresses the dilepton branching fraction of $Z'$, resulting in weaker ATLAS mass bounds than in the conventional vector $B-L$ scenario, thereby easing constraints on the dark sector. We explore the dark matter phenomenology of the singlet scalar and fermionic dark matter candidates. While singlet scalar DM is often severely constrained, the presence of the $Z'$ portal together with annihilation and co-annihilation channels substantially broadens the allowed parameter space. Thus, the framework offers a predictive scenario for neutrino and dark matter phenomenology that can be probed in future experiments.

A new Monte Carlo generator of hadronic collisions, QGSb, is applied for studying model uncertainties regarding calculations of the development of extensive air showers (EAS) initiated by interactions of high energy cosmic rays in the atmosphere. More specifically, we investigate possibilities to modify the model predictions for two EAS characteristics mostly used in experimental studies of cosmic ray composition: air shower maximum depth and the muon number at ground level. For all the considered modifications of the model, we discuss in some detail the underlying physics mechanisms and investigate the impact of the changes, regarding a comparison of the model results to relevant accelerator data.

We present a systematic study of the three-particle di-light-cone distribution amplitudes (DLCDAs) of the $B$-meson. They are defined through $B$-meson--to--vacuum matrix elements of trilocal HQET operators, in which the light antiquark and the gluon field-strength tensor are located on two back-to-back light rays. In this sense, the DLCDAs generalise the conventional $B$-meson light-cone distribution amplitudes to configurations where soft fields couple to collinear degrees of freedom in two distinct directions. As such, they parametrise the non-perturbative dynamics associated with non-factorisable soft-gluon contributions in rare and non-leptonic exclusive $B$-meson decays. We derive the complete Lorentz decomposition of the matrix elements of generic trilocal operators, identify eight independent DLCDAs, and organise them in a basis of definite twist. Using local operator identities and equations-of-motion constraints, we obtain tree-level relations for their normalisation integrals and first moments in terms of a minimal set of hadronic parameters. These relations allow us to construct simple momentum-space models for all independent DLCDAs. For the leading-twist distribution, we further incorporate the perturbative radiative tail at order $α_s$ and discuss its impact on the resulting parametrisation.

We investigate the implications of the Witten effect in the Standard Model with a general global gauge group structure and determine the values of the three $θ$-parameters that lead to distinct families of allowed spectra of dyons. We construct and classify the corresponding dyonic charge lattices consistent with the Standard Model gauge structure. This approach enables us to re-derive the known global-group--dependent periodicities of the $θ$ angles and to determine all CP-invariant points in $θ$-space. The electromagnetic subgroup $U(1)_{\mathrm{em}}$ is shown to arise \emph{prior} to electroweak symmetry breaking by factoring out the effect of the anomalous $B+L$ transformations, which reduces the physical $θ$-parameter space from a three-torus to a two-torus. Our phenomenological conclusions include an observation that a discovery of a $U(1)_{\mathrm{em}}$ monopole carrying non-zero electric charge would determine the last remaining unknown parameter of the Standard Model. Lastly we study how $θ$-space shapes axion physics with emphasis on the axion-photon coupling and show that a single axion is insufficient to render the Standard Model vacuum fully CP invariant.

We explore signatures of a massive right-handed neutrino (RHN) in angular distributions of $\bar{B} \to D^* (\to D π) τ(\to πν_τ) \bar X$ decays, where $X$ is an invisible state. We assume the new physics is described by the standard model effective field theory extended with an RHN in the MeV-GeV mass range. We calculate for the first time the full differential distributions in terms of the visible final states, including the decay of the $τ$ lepton. We evaluate the sensitivity of various distributions to the new physics operators.

The Light Dark Matter eXperiment (LDMX), DarkSHINE, and LOHENGRIN are proposed new experiments. They aim to search for missing momentum signals sourced by the direct production of dark photons with masses in the MeV-GeV range in bremsstrahlung processes, in which an electron beam of a few GeV scatters off a fixed target. So far, the signal characteristics, i.e. the behavior of the recoiling electron, have mostly been studied in coherent Bethe-Heitler electron-nucleus scattering with a dark photon that couples only to the Standard Model charged leptons. In this work, we present the calculations of the differential cross sections of all contributing real emission processes up to third order in the electromagnetic fine structure constant and fourth order in the kinetic mixing parameter associated with the dark photon. We consider a dark photon coupling to both the beam electron and the hadronic target and we take into account the scattering off both the target nucleus and its nuclear constituents. Besides real emission processes, we also discuss virtual dark photon contributions and their relevance for the signal prediction. After discussing the different phase space regions and constraints emerging from the experimental setups, we show numerical results of the cross sections and differential distributions, including the signal and dominant background. Within our framework, we find that the LOHENGRIN experiment will require an extension of its HCAL to effectively veto background processes originating from diffractive scattering. Apart from that, the contributions beyond coherent Bethe-Heitler scattering, in the presence of realistic experimental selections, have only a limited effect on the predicted signal and background in the relevant dark photon mass range.

Defining $γ_5$ within dimensional regularization remains a fundamental challenge. Larin's prescription addresses this by introducing additional renormalization constants to restore standard and chiral Ward identities. While these constants are known up to four loops in pure quantum chromodynamics, current precision Standard Model phenomenology requires extending these corrections to mixed gauge sectors. In this article, we propose a novel technique utilizing form factors and the universality of infrared divergences to compute these constants. Applying this framework, we present the new three-loop results for the renormalization constants, as well as the pure-singlet contributions to the quark axial-vector form factor, for a mixed $SU(N) \times U(1)$ gauge group.

We perform a global Bayesian analysis of coherent and incoherent diffractive $\mathrm{J}/ψ$ photoproduction in $γ+p$ and $γ+\mathrm{Pb}$ collisions using a Color Glass Condensate (CGC)-based framework and ultraperipheral collision data from the Large Hadron Collider (LHC), corrected for the expected effect of electromagnetic dissociation (EMD). Using Gaussian-process emulators of the underlying CGC calculations, we infer model parameters from a combined set of HERA and LHC measurements. We find that the $γ+\mathrm{Pb}$ data with EMD correction substantially reduce the previously observed tension between proton and nuclear datasets, enabling a consistent simultaneous description of diffractive $\mathrm{J}/ψ$ production in $γ+p$ and $γ+\mathrm{Pb}$ collisions within the CGC framework.

We investigate the first-order phase transition that terminates thermal inflation and evaluate the associated stochastic gravitational-wave signals. The transition is first characterized through semi-analytic calculations of the bounce action, which are compared with numerical results obtained using CosmoTransitions. We then study its real-time evolution in a three-dimensional Langevin lattice simulation that incorporates Hubble expansion and the corresponding temperature evolution throughout the transition. The lattice dynamics are consistent with the bounce-action estimates: the transition proceeds through localized bubble nucleation and subsequent bubble growth, rather than through a phase-mixing instability. Using the resulting transition parameters, we estimate the gravitational-wave spectra generated by bubble collisions and acoustic motions in the plasma. The predicted stochastic background lies within the projected sensitivity ranges of future gravitational-wave observatories, including BBO and DECIGO.