Papers

The inelastic electroweak-doublet interpretation of the $248\,{\rm keV}$ recoil energy event reported by LUX-ZEPLIN faces strong constraints from solar capture. We propose an environment-dependent mass splitting generated by an ultralight scalar coupled quadratically to electrons. Its density-induced expectation value enhances the splitting in the Sun while preserving the laboratory value, providing a mechanism to suppress solar capture. We derive conditions for this mechanism and examine constraints from stellar cooling and electron-mass variations. We find that this scenario is phenomenologically viable, while it suffers from severe fine-tuning of the scalar potential.

Event-by-event mean-$p_T$ fluctuations probe initial-state fluctuations and their evolution through the dynamics of heavy-ion collisions. We study second-order mean-$p_T$ fluctuations in Au+Au collisions at $\sqrt{s_{\rm NN}}=3.0$–$19.6$ GeV using JAM2 in the RQMDv mean-field mode with the MH2 parameterization. The model qualitatively reproduces the measured identified-particle $p_T$ spectra, providing a single-particle baseline for the fluctuation analysis. The scaled fluctuation $k_2$ decreases with increasing $\langle N_{\rm part}\rangle$ and shows broad agreement with the available measurements at 7.7–19.6 GeV, whereas its calculated centrality dependence is stronger than that in the data at 3.0–4.5 GeV. For the combined proton-plus-antiproton sample, the unnormalized correlator $\langle c_2\rangle$ is positive and larger than that for charged pions. The charged-pion correlator $\langle c_2\rangle$ is negative or consistent with zero over most centrality intervals at 3.0 and 3.5 GeV, becomes weakly positive at 4.5 GeV, and remains positive at higher energies. Its energy evolution resembles the change in the reaction-plane elliptic flow, but this comparison does not establish a common microscopic origin. These calculations provide species-dependent predictions within a transport model without an explicit partonic stage. Isolating the contributions of mean fields, rescattering, and spectator interactions requires controlled variations of the transport dynamics.

We investigate strangeness production and transverse dynamics in heavy-ion collisions at $\sqrt{s_{\mathrm{NN}}}\approx 2.5-20~\mathrm{GeV}$ using the transport approach SMASH (Simulating Many Accelerated Strongly-interacting Hadrons), its extension with rope hadronization, and the SMASH+vHLLE hybrid approach. Results from the Pythia-based heavy-ion model Angantyr, with and without rope hadronization, are included for comparison. We study midrapidity particle yields and average transverse masses as functions of the number of wounded nucleons, as well as their energy dependence. For the $K^+/\pi^+$ ratio, SMASH+vHLLE overpredicts strangeness production at low energies but describes the higher-energy behavior reasonably well. SMASH+Ropes reproduces the ratio up to $\sqrt{s_{\mathrm{NN}}}\sim 10~\mathrm{GeV}$ but does not capture the turnover at higher energies. In contrast, the transverse-mass observables favor the hybrid approach, while the non-thermal models considered here do not generate sufficient collective transverse expansion. These results show that strangeness enhancement alone does not uniquely distinguish microscopic string interactions from a locally equilibrated medium. Simultaneously constraining strangeness production and transverse dynamics is therefore essential for disentangling thermal and non-thermal mechanisms in heavy-ion collisions.

Nature, at the shortest distances accessible to contemporary colliders, is described by the Standard Model of particle physics with remarkable precision. Since the discovery of the Higgs boson in 2012, progress has shifted from finding new resonances to precision studies of established theory. Here, quantum chromodynamics (QCD), describing the interactions of quarks and gluons, plays a central role. Collider observables involving hadrons are made theoretically accessible by factorization, which separates universal long-distance hadron dynamics encoded in parton distributions from process-specific short-distance coefficients calculable in perturbation theory. This thesis develops analytic methods for perturbative QCD with applications to collider phenomenology and proton structure. A major part is devoted to angular integrals, key building blocks of phase-space integrals. Methods originally developed for Feynman integrals, including integration-by-parts identities, expansion by regions, differential equations, and dimensional shifts, are adapted to angular integrals and yield several new results. The analytic structure of one-loop integrals is also studied, with spurious branch cuts removed using single-valued polylogarithms, leading to a compact representation of coefficient functions for semi-inclusive deep-inelastic scattering. A systematic expansion in higher powers of transverse momentum is developed and applied to the Drell-Yan process, refining the understanding of its factorization structure. Finally, a new semi-analytical ansatz for the evolution of parton distributions is explored. Together, these methods improve analytic control over radiative corrections, kinematic dependence, and scale evolution in processes relevant to the Electron-Ion Collider and other collider experiments.

Transverse momentum dependent parton distributions are objects that have gained substantial attention in the recent past as they are crucial for studying the 3-D structure of proton. These distributions at twist-3 are important for understanding phenomena like beam single spin asymmetries, which are observed in high-energy scattering experiments. However, due to the unavailability of direct phenomenological fits, currently one has to rely on simplified models of the proton in order to obtain these twist-3 distributions. In this work, we present the calculation of T-even twist-3 quark distributions using the quark target model.

Supercooled phase transitions can generate observable gravitational waves, but their bubble dynamics may also imprint large spatial inhomogeneities in the baryon asymmetry. For phase transitions below the TeV scale, ordinary baryon diffusion can be too slow to erase such inhomogeneities before Big Bang Nucleosynthesis, potentially leading to stringent constraints from the observed light-element abundances. We show that this problem can be naturally avoided in darkogenesis scenarios, where the phase transition first generates an asymmetry in a dark-sector particle that is subsequently transferred to visible baryons. The dark-sector particle can travel over much larger distances than ordinary baryons before decaying, erasing the inhomogeneity before the baryon asymmetry is established. We derive the conditions for efficient erasure in both the diffusive and collisionless transport regimes and translate them into constraints on the dark-sector interactions. For a representative dark phase transition with a reheating temperature of $\mathcal{O}(1) \,\mathrm{GeV}$, $\beta/H \simeq 10$, and a dark-sector particle lifetime of $0.1\,\mathrm{s}$, we find that the inhomogeneity is efficiently erased for a viable range of the interactions. Importantly, baryogenesis before the phase transition is challenged both by dilution from strong supercooling and by the subsequent imprinting of spatial inhomogeneities. This points toward darkogenesis associated with the phase transition as a consistent framework, in which dark-sector transport erases the inhomogeneity before it is transferred to visible baryons.

We study the topological non-Abelian string and its classical stability in models with two Higgs fields to achieve the symmetry breaking of ${\rm SU}(N) \otimes {\rm U}(1)_X\to {\rm SU}(N-1) \otimes {\rm U}(1)_{X^\prime}$. The topological origin is due to the global $\widetilde {\rm U}(1)$ symmetry and its breaking in the scalar potential. The most generic winding configurations of arbitrary integers of $(n_1\,, n_2)$ are considered. The stability of the topological string is analyzed based on the time-dependent perturbations to the string background and numerical solutions to the coupled Helmholtz equations of the perturbed Fourier modes. We present the constraints on the stable regions for the $(n_1\,, 0)$ configuration (or equivalently the $(0\,, n_2)$ configuration). For the general winding configurations of $(n_1\neq 0\,, n_2\neq 0)$, we point out the stable regions only exist in the semilocal limit of the large mixing angle of $\vartheta_N\to \frac{\pi}{2}$.

We evaluate the Hellinger-distance coherence of the two-flavor neutrino state subject to Lindblad damping of the mass-eigenstate interference term, and obtain a closed expression in terms of the flavor-basis density-matrix elements. In the two-flavor vacuum treatment with negligible wave-packet separation, the undamped state is pure, and the smallest eigenvalue of the damped state grows linearly with $\epsilon=1-\kappa$, where $\kappa=e^{-\Gamma L}$. An expansion about the pure state then yields a nonanalytic $\sqrt{\epsilon}$ correction to the Hellinger coherence, with coefficient $K=2\sqrt{2}\,u\sin2\theta/\sqrt{1-2u}$, whereas the flavor-transition probability, the $l_1$ coherence, the concurrence, the entanglement of formation and the local quantum Fisher information all respond linearly in $\epsilon$. Using representative Daya Bay, KamLAND and MINOS working points together with a current $90\%$ C.L. bound on energy-independent damping, we find fractional changes in the Hellinger coherence of $0.18\%$, $9.40\%$ and $21.51\%$, against $0.0009\%$, $0.43\%$ and $1.81\%$ for the concurrence. The comparison concerns the response of the quantifiers to the damping parameter and carries no implication about experimental resolution. The same mechanism operates, with a different coefficient, for a correlated dephasing channel acting on the flavor coherence, where the non-Markovian regime produces damped revivals.

We study the sensitivity of the associated Higgs production process $pp \rightarrow ZH$ to anomalous Higgs couplings within the Effective Field Theory framework. Event samples are generated using $ \text{MadGraph5\_aMC@NLO}$ at $\sqrt{s}=13$ TeV using the UFO model HPO\_ewk\_prod\_NLO, and analyzed using a dedicated Python analysis of HepMC events. We investigate several kinematic observables and derive constraints on the EFT parameter $\epsilon_{ZZ}$ using a $\chi^2$ statistical analysis. A 95% confidence level interval $-0.026 < \epsilon_{ZZ} < 0.383 $ is obtained from the simulated data.

We use quantum simulation to study how visible neutrino decay modifies the vacuum CP asymmetry in muon-to-electron oscillations within a $3+1$ neutrino scenario. The decay channel preserves CP symmetry, with CP violation arising from phases in the mixing matrix. We track the energy redistribution from visible decay and distinguish how parent attenuation and daughter regeneration modify the CP asymmetry. For the reference benchmark, the regenerated contribution is $4.85\times10^{-4}$, approximately $46\%$ of the total decay-induced shift. The full circuit for an effective two-energy model agrees with independent classical evolution. On an IBM quantum processor, we prepare the daughter state conditioned on decay and restore its physical normalization using fixed source and decay probabilities. After correction for measurement errors, the flavor-probability and coherence measurements both agree with the prediction within one standard error. Null controls test the suppression of the regenerated signal when daughter coherence or the relevant CP-sensitive mixing factor vanishes.

We propose a new method for measuring several characteristics of a fermion-boson medium formed during deep inelastic particle scattering. This method involves measuring the group and phase velocities of the accompanying wave process. The phase and group velocities of a wave process are related by the Rayleigh differential condition. The refractive index of a medium is determined by the phase velocity, while the group velocity characterises the medium's dispersion properties. In the case of deep inelastic $ep$ scattering under consideration, the wave process in an individual event is understood to be the exchange between an electron and a proton of an effective, non-perturbative mediator of interaction (${\cal B}$) with the quantum numbers of a neutral current. In the first report, we present new data on the group velocity of interaction carriers ${\cal B}$. We extracted the group velocity modulus values, $U_{_{\cal B}}^*$, from the HERA collider data using a formula derived from modified Heisenberg uncertainty relations and applying the indirect measurement method. The HERA data demonstrate that in the selected kinematic domain the speed of the mediator ${\cal B}$ exceeds the speed of light $c$ in free space, $U_{_{\cal B}}^* > c$. To compare with the obtained data on group velocity, we analyse a simplest model of dispersion relation occurring due to the relativistic relationship between the energy, mass and momentum of a particle, supplemented by de Broglie relations.

Short-range correlations (SRCs) dominate the nuclear force at short distances, including the repulsive core and intermediate-range attraction, and are one of the most fascinating aspects of the nucleon-nucleon (NN) interaction. In this work, we investigate the effects of SRCs on the final-state observables in $^{16}$O+$^{16}$O collisions at $\sqrt{s_{NN}}=5.36$~TeV, using the iEBE-VISHNU hybrid model with {T\raisebox{-0.5ex}{R}ENTo} initial conditions. We embed the nucleon configurations of $^{16}$O generated from variational Monte Carlo (VMC) simulations with realistic SRCs in the initial stage, along with uncorrelated VMC samples and Woods–Saxon distributions implementing a hard repulsive core or short-range attraction as comparison runs. We find that SRCs reduce both $v_2\{2\}$ and $v_2\{4\}$ in the most central collisions, with the decrease of $v_2\{4\}$ being more pronounced due to the event-by-event flow fluctuations. Meanwhile, SRCs noticeably enhance the correlation between the elliptic flow and the mean transverse momentum, $\rho_2(v_2^2,[p_T])$. These effects are mainly attributed to the strong repulsive core of the SRCs, which suppresses the probability of finding nucleon pairs at short relative distances and renders the initial geometry more uniform. This interpretation is supported by the calculations based on Woods–Saxon distributions with a hard repulsive core, which reproduce similar results, while the contribution from a pure intermediate-range attraction is negligible. Our results demonstrate that relativistic nuclear collisions provide a complementary probe of the short-range structure of the nuclear force, beyond the traditional nuclear experiments at low energies.

We investigate stellar oscillations driven by the time-dependent gravitational potential of ultralight dark matter (ULDM) in the de Broglie regime. The response is controlled by the ratio of the ULDM coherence time to the stellar mode damping time. When the field decoheres faster than the damping time, ULDM acts as a stochastic source that excites modes below a characteristic de Broglie frequency, while higher-frequency modes are suppressed. In the opposite, long-coherence regime, individual modes can be resonantly driven. Focusing on solar oscillations, we find a signal far below current sensitivity, and estimate that other stars are similarly unlikely to provide observable signals.

Earth matter effects are a leading systematic in long-baseline (LBL) determinations of the CP-violating phase delta13, and eV scale sterile neutrinos remain a phenomenologically open extension of the three-flavor paradigm motivated by short-baseline anomalies. We extend the constant density versus realistic Earth profile analysis of Ref. 1 to a four-flavor (3+1) framework, in which a fourth, mostly sterile mass eigenstate with deltam2 41 = 0.30 eV2 and active-sterile mixing angles theta14 = 8.13degree, theta24 = 5.40degree couples to the active sector both through its mixing and through an additional neutral current (NC) matter potential that acts on the active flavors but not on the sterile state. We derive an analytical, leading-order account of how the NC potential ANC enters the reconstructed delta13 bias through an effective non standard interaction like term generated by adiabatically integrating out the fast deltam241 oscillation; replace the four-shell Earth density model with the continuous, polynomial PREM profile of Dziewonski & Anderson (1981) for the layered true trajectory; and extend the baseline scan to four representative values of the sterile CP phase delta14 is 0, pi/2, pi, 3pi/2 and to a non-zero mixing angle theta34 = 5degree. Within this benchmark, the bias remains below our scan resolution for L <= 5000 km. It grows once the trajectory samples the lower mantle and core, with the sterile sector redistributing rather than uniformly amplifying or suppressing the bias across baseline, in agreement with our original finding and now traced to a specific interference mechanism identified analytically below.

In this article, we employ the QCD sum rules basing on three-point correlation function to systematically analyze the transition form factors for the semileptonic decays of the spin \(\frac{3}{2}^{+}\) bottom baryons (\(\Omega_{b}^{*}\), \(\Sigma_{b}^{*}\), and \(\Xi_{b}^{\prime *}\)) to their corresponding spin \(\frac{1}{2}^{+}\) charmed partners. On the phenomenological side, we eliminate the contaminations of the baryons with negative parity and those with lower spin states. The operator product expansion is carried out up to dimension-six condensates, including the perturbative part, quark condensate \(\langle \bar{q} q\rangle\), gluon condensate \(\langle g_{s}^{2}GG\rangle\), mixed condensate \(\langle \bar{q} g_{s}\sigma Gq\rangle\), and four-quark condensates \(\langle \bar{q} q\rangle^{2}\) and \(g_{s}^{2}\langle \bar{q} q\rangle^{2}\). The form factors are evaluated in the space-like region and then are fitted into the time-like physical region via a $z$-series expansion approach. Finally, the semileptonic decay widths for $\Omega_{b}^{*}$, $\Sigma_{b}^{*}$ and $\Xi_{b}^{\prime*}$ baryons are calculated with our predicted form factors, and various polarization observables are also predicted. The predicted results in this work are compared with those predicted by other collaborations, and are expected to be useful for studying the properties of these singly heavy baryons.

Building on proton light-front wave functions in the $|qqq\rangle$ and $|qqqg\rangle$ Fock sectors, obtained by diagonalizing the proton light-front Hamiltonian within the Basis Light-Front Quantization framework, we present a unified study of the proton's leading-twist transversity parton distribution functions, tensor charges, generalized tensor form factors, and chiral-odd skewed generalized parton distributions in the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi region. Our results compare reasonably with available phenomenological extractions and lattice-QCD simulations and follow similar qualitative trends.

We study the next-to-leading order (NLO) electroweak (EW) corrections to the polarization and correlation of $W$ boson pairs produced through photon-photon fusion in proton-proton ultra-peripheral collisions at the LHC, with both $W$ bosons decaying leptonically. The azimuthal correlation distributions of the charged leptons, which receive no contribution from anomalous quartic gauge couplings (AQGCs) at linear order, are perturbatively stable at the 0.40% level, whereas individual correlation coefficient $C_{2,2}$ receives relative corrections of up to $-33.84\%$. Some of correlation coefficients that vanish at leading order (LO) in the Standard Model but are sensitive to AQGCs acquire non-zero one-loop values of order $10^{-4}-10^{-3}$. We quantify the region of the ($a_0/\Lambda^2,a_c/\Lambda^2$) plane in which these loop-induced baselines compete with the AQGC contributions and find that, while irrelevant at the current experimental sensitivity, they must be included once the correlation coefficients are measured at the per-mille level.

In this work, the parton and hadron cascade model PACIAE is employed to simulate the events of Au+Au collisions at $\sqrt{s_{NN}}=$200 GeV within the 60-80 % centrality interval. Based on the abundant photons in final hadronic state, the statistical-mechanics-based coalescence model DCPC is applied to phenomenologically recombine post-freeze-out photon pairs into axion-like particles (ALPs) for the first time. The coalescence probability is constrained by the branching-ratio $B_r(a \rightarrow \gamma\gamma)=0.57$ under the threshold of twice of $K$ meson mass. The ALP observables including yields, transverse-momentum distributions and rapidity spectra are calculated for several benchmark ALP-mass bins. These theoretical predictions are worthy to be investigated by the experiments.

We study the thermal Higgsino dark matter in the Minimal Supersymmetric Standard Model (MSSM) with Generalized Minimal Supergravity (GmSUGRA) boundary conditions after the high-recoil event reported by the LUX–ZEPLIN experiment and the subsequent solar-neutrino limits inferred from IceCube data. The Higgs sector is implemented in a NUHM2-type parametrization with $\mu$ and $m_A$ as inputs, while the supersymmetry breaking soft terms obey the non-universal GmSUGRA relations. The numerical scan contains a Planck-compatible Higgsino branch near the thermal mass, with the neutral-state splitting extending continuously from the few-hundred-keV region to the MeV scale. The part of this branch with $\dmchi\simeq0.3$–$0.4$ MeV overlaps the kinematic interval relevant to the LZ event, but is disfavored by the current solar-capture reinterpretations for a full-density thermal Higgsino. The same high-scale branch persists at larger splittings, including representative spectra with $\dmchi\simeq0.85$, $1.10$, and $1.34$ MeV, beyond the quoted solar-capture limits. Our results demonstrate that the mass and sub-MeV splitting favored by the LZ high-recoil interpretation can be realized dynamically within a GUT-motivated supersymmetric construction, without imposing the neutralino compression as a weak-scale input. The combined data therefore select different parts of a common GmSUGRA Higgsino branch rather than excluding the thermal Higgsino construction itself.

Microwave cavity haloscopes search for dark-matter axions through the weak electromagnetic field generated by axion-photon conversion in a static magnetic field. Realistic synthetic signals are essential for end-to-end calibration of the receiver, validation of the analysis pipeline, measurement of signal recovery efficiency, and blind-injection studies. Here, we present a general method for producing stochastic synthetic axion waveforms by shaping Gaussian white noise in the frequency domain. The target axion power spectral density is imposed directly on the Fourier coefficients, and arbitrarily long continuous time streams are generated efficiently using an overlap-save implementation. The method reproduces both the ensemble-averaged spectral line shape and the time-domain fluctuations expected for a classical axion field, while providing direct control of the total injected power. Because the spectral model enters only through a replaceable transfer function, the routine can accommodate the Standard Halo Model as well as nonstandard velocity distributions and narrow substructure.

We investigate the impact of axions on the period-luminosity relation (PLR) of RR Lyrae stars. During the red giant branch phase, emission through the electron coupling cools the core, increasing its mass at ignition. The larger core produces more luminous horizontal-branch stars, systematically shifting the zero point of the RR Lyrae PLR toward brighter magnitudes. We model the RR Lyrae population of the globular cluster M3 using stellar evolution and pulsation calculations tailored to its age and composition, and compare the resulting synthetic $K_s$-band PLR with observations. For $\alpha_{26}\equiv 10^{26}g_{ae}^2/4\pi=0.5$, the axion-induced shift in the predicted PLR is comparable to the current uncertainty in the absolute M3 zero-point calibration.

Several experiments reported measurements of soft photons in hadronic collisions far above the predictions from QED. This work investigates possible production during the hadronisation process. It is shown that the assumption of isotropic emission of photons during the hadronisation process leads to a consistent description of the experimental data.

We study the cosmological evolution of the effective potential in a dark sector with a spontaneously broken Abelian gauge symmetry, populated out of equilibrium through the freeze-in mechanism. Initially dilute and in the broken phase, the dark sector is described by a temperature as well as a chemical potential that reflects the low occupancy of dark sector states. We show that the thermal corrections to the effective potential depend on both of these quantities, and that they are suppressed while the sector remains dilute, but grow as internal number-changing reactions increase the occupancy and drive the system toward chemical equilibrium. We solve the coupled evolution of the temperature and chemical potential and the resulting impact on the effective potential to show that, for sufficiently large portal couplings, chemical equilibration can evolve the effective potential across a first-order barrier and drive the dark sector toward its symmetric phase through an inverse phase transition.

The MiniBooNE low-energy excess and its subsequent exclusion by MicroBooNE provide an important test of sterile-neutrino explanations of short-baseline neutrino anomalies. Such a test is complicated by the fact that both experiments use different approaches to their analyses. In this contribution, we present a consistent approach to both experiments. We perform a joint fit of MiniBooNE and MicroBooNE data to a $3+1$ sterile-neutrino model omitting all data-driven factors, using MicroBooNE data from both the Booster Neutrino Beam (BNB) and Neutrinos at the Main Injector (NuMI) beamlines, and evaluate the parameter goodness-of-fit (PG) tension between the two experimental results. A rigorous frequentist treatment of both parameter fitting and PG tension is challenging. Existing methods require asymptotic assumptions known to be inaccurate for neutrino oscillation measurements or repeated likelihood optimization tasks. To this end, we use a previously developed frequentist fitting framework based on simulation-based inference (SBI) and introduce a new SBI-based method for evaluating PG tension that makes the required trial-based calibration computationally feasible. We find that the addition of MicroBooNE reduces the significance of the MiniBooNE preference for sterile-neutrino oscillations, with a trials-based preference for 3+1 remaining at $2.7 \sigma$. The two experiments exhibit a $\geq 2.5\sigma$ PG tension within the $3+1$ model.

We present an improved determination of the $B\to K_0^*(1430)$ transition form factors using light-cone sum rules (LCSR) with an expansion near the light cone. We include the one-loop radiative corrections to the twist-2 and asymptotic twist-3 distribution amplitudes of the scalar meson and perform the calculation consistently in the $\overline{\mathrm{MS}}$ scheme. It allowed us to quantify the impact of radiative corrections on the form factors for each twist. A daughter sum rule is used from the $B\to K_0^*(1430)$ LCSR to ascertain Borel mass and threshold parameter simultaneously. We find that the dominant theoretical uncertainties arise from the $K_0^*(1430)$ distribution amplitudes and its decay constant. Our results are presented in a form that facilitates the incorporation of future improvements in these nonperturbative inputs, including those from lattice QCD and experimental measurements, and can be readily extended to other scalar mesons.

Photon flux benchmark models and recent experimental estimates of pomeron energy fluxes and structure functions are implemented in Monte Carlo simulations to assess their impact on physical observables and signal strength uncertainty for the yet-to-be-observed semi-exclusive $t\bar{t}$ production in proton-proton ($pp$) collisions at Large Hadron Collider (LHC) and Future Circular Collider (FCC) energies. The expected cross sections increase by factors of approximately 50 and 22 for pomeron-induced and photon-induced processes, respectively, from LHC to FCC energies. TensorFlow deep neural networks discriminate semi-exclusive processes from the non-peripheral $t\bar{t}X$ background, achieving a test area under the receiver operating characteristic curve (AUC) of $0.9917 \pm 0.0002$ for the photon-induced signal. At detector level, using the CMS detector geometry at CERN, the minimum Hadronic Forward energy observable is identified as the most effective discriminator against this background. For low-pileup $pp$ data, an Asimov dataset analysis incorporating statistical uncertainties and systematic contributions from pomeron and photon schemes predicts a significance of $5\sigma$ for pomeron-induced and photon-induced $t\bar{t}$ production with integrated luminosities of 1 and 4.7 $\mathrm{fb}^{-1}$, respectively. The systematic contributions to the total uncertainty are 25.1% and 7.6%, respectively. These results highlight the potential for experimental observation using Run 2 and Run 3 LHC data and for further studies within the LHC forward physics program.

Core-collapse supernova neutrinos offer a unique probe of physics beyond the Standard Model over Galactic baselines. Yet even a high-statistics nearby burst may be limited by source uncertainties, especially for propagation effects that average over energy and appear only as an overall flux suppression. Inspired by near–far comparisons in terrestrial oscillation experiments, we show that next-generation MeV observations of the supernova gamma-ray echo—the delayed 511 keV signal induced by the neutrino burst in the stellar envelope—can serve as an astrophysical near detector for the emitted $\bar\nu_e$ fluence. Comparing this echo-inferred source fluence with the surviving flux measured at Earth gives a direct test of neutrino propagation between the stellar surface and the detector. For pseudo-Dirac neutrinos, this turns the fully averaged active–sterile oscillation regime from an unobservable source-normalization ambiguity into a measurable near–far deficit, with sensitivity for nearby progenitors to splittings $\delta m^2\gtrsim 10^{-18}~{\rm eV}^2(0.22~{\rm kpc}/D)(E_\star/15~{\rm MeV})$. The same near–far logic also applies to other propagation-induced modifications of the observed flux, including neutrino decay and neutrino interactions with Galactic dark matter.

Bandwidth constraints require many particle physics experiments to make real-time decisions on custom hardware or firmware running simplified algorithms, unlike offline analysis, where latency is usually not a limiting factor. For example, for particle jet tagging at colliders, state-of-the-art performance is achieved by foundation models with hundreds of millions of parameters pre-trained with billions of jets. We use knowledge distillation to transfer what such models have learned into efficient networks towards deployment in hardware accelerators. The teacher is the OmniLearned foundation model fine-tuned on top quark jet tagging; the student is an attention-free Deep Sets network. We demonstrate three ways the student's performance improves: adding a message-passing layer to the Deep Sets architecture, training on the teacher's soft labels rather than on ground-truth labels alone, and distilling from a pretrained teacher rather than from the same architecture trained from scratch. In each case the gain is largest in the background rejection at low signal efficiency, the regime that is most relevant for a trigger.

We revisit the bounds on the photon mass when it arises from an Abelian Higgs mechanism rather than a Proca term. Because the higgs is necessarily millicharged and light, the phase of the theory (Meissner, vortex, or symmetry-restored) depends on the ambient magnetic field, so the photon mass an experiment measures depends on the environment it is performed in. We classify existing experiments by the phases in which they apply, in analogy with Type I and Type II superconductors. For Type I photon masses, magnetic fields in galaxies and the intergalactic medium can restore the symmetry everywhere, allowing a vacuum photon mass as large as $0.3 \,{\rm MeV}$. Regions of photon mass as large as $10^{-5}\, {\rm eV}$ could be present in the Universe, and measurement of frequency dependent optical depth can potentially reveal these regions. For Type II photon masses, we show that the strongest constraints mainly arise from the requirement that the galactic dynamo generates the observed magnetic fields, which we derive by generalizing magnetohydrodynamics to a nonzero photon mass. Since the terrestrial magnetic field restores the symmetry in much of the remaining parameter space, laboratory searches performed inside large magnetically shielded volumes, or in space, could probe photon masses invisible to any experiment on Earth. Measurements of distant light sources, in particular, fast radio bursts, also offer unique sensitivity to parameters invisible to lab experiments.

We investigate the interplay between low-energy flavor physics and dark matter (DM) phenomenology within the dimension-6 dark Standard Model Effective Field Theory (dSMEFT), featuring a fermionic DM candidate. Focusing on a minimal set of effective operators, we analyze both single- and multi-operator scenarios under current flavor and DM constraints. We show that correlated multi-operator configurations are required to simultaneously satisfy all existing bounds, leading to tightly constrained benchmark regions with implications for future collider searches. We further present representative phenomenological predictions and discuss possible ultraviolet completions of the effective framework.