Calculations of neutral-current neutrino-nucleus scattering cross sections are important for interpreting low- and intermediate-energy neutrino data, where terrestrial measurements remain limited. The first observation of coherent elastic neutrino-nucleus scattering (CEvNS) in 2017 with a CsI[Na] detector at the Spallation Neutron Source reported results consistent with Standard Model expectations, motivating improved theoretical descriptions beyond the purely coherent regime. In this work, we calculate neutral-current scattering cross sections for 127I and 133Cs within a unified analytical framework that consistently incorporates coherent elastic, incoherent excitation, and spin-dependent axial contributions relevant for odd-A nuclei. A consistent distinction between nuclear and nucleon form factors is maintained throughout the formalism. The incoherent contribution is evaluated using structure-function methods, providing a physically motivated decomposition of the total cross section. Electroweak effects are included through momentum-transfer-dependent sin^2(theta_W) corrections in the MS-bar scheme together with flavor-dependent neutrino charge-radius contributions implemented consistently in the vector couplings. Cross sections are presented as functions of neutrino energy and for decay-at-rest neutrino spectra in the low-to-intermediate energy region where elastic and quasi-elastic processes dominate. Inclusion of incoherent and axial contributions enhances the total cross section near Enu ~ 10 MeV, while the incoherent component becomes dominant around Enu ~ 50 MeV. Expected interaction rates for decay-at-rest neutrinos are of order 0.1 events kg^-1 yr^-1 near a 40 keV recoil threshold. The results provide a systematic assessment of subleading contributions relevant for CsI-based detectors and astrophysical neutrino applications.

Gravitational wave backgrounds from strong first-order cosmological phase transitions are key observational targets predicted by many SM extensions and might be observed by current and future observatories like LISA, the Einstein Telescope or pulsar timing arrays (PTAs). Still, their precise forecast given a specific model remains a challenge. In this article, we present TransitionListener v2.0, a Python framework for precision studies of cosmological phase transitions and their associated gravitational wave (GW) signals. The code provides an end-to-end pipeline from a user-defined scalar potential to GW spectra and signal-to-noise ratios, enabling both benchmark studies and large-scale parameter scans. Version 2 introduces a self-consistent treatment of the transition dynamics, including the evolution of the true-vacuum fraction and its backreaction on the Hubble expansion, as well as a consistent description of reheating during percolation. A direct computation of the mean bubble separation allows to faithfully map to the GW spectral templates from bubble collisions, sound waves, and turbulence stemming from state-of-the-art simulations. TransitionListener includes built-in sensitivity curves for space- and ground-based detectors and PTAs, interfaces to PTA likelihoods, and wrappers for Bayesian model inference and high-dimensional parameter scans. Compared to existing public tools, TransitionListener v2.0 improves the physical consistency and numerical stability of GW predictions across a wide range of models, with particular emphasis on the strongly supercooled and ultraslow transition regime where conventional approximations break down and the most promising GW signals are expected.

Magnetic fields between a supernova (SN) and Earth convert axions into gamma rays. The absence of such a signal in coincidence with SN 1987A neutrinos, using the coherent Milky Way field, provides well-studied constraints on $g_{ap}\times g_{a\gamma}$ (axion-proton times axion-photon couplings) and on $g_{a\gamma}$ alone. We show that the small-scale power of the turbulent magnetic field component boosts axion-photon conversion and, crucially, extends sensitivity to larger masses. The turbulent field components of the Milky Way and of the Large Magellanic Cloud (hosting SN 1987A) yield improvements of up to two orders of magnitude in $g_{ap}\times g_{a\gamma}$. Turbulence should likely impact the sensitivity of other searches based on other axion-photon conversion sites, such as starburst galaxies.

We analyze the potential of the Universal SMEFT as a tool to study universal new physics in the neutral and charged Drell-Yan processes at the high-luminosity LHC. In order to do so, we generated pseudo-data containing the contributions of beyond the standard model vector bosons to the dilepton production. Our results show that fits with the minimal theoretical bias can be used not only to unveil the existence of new physics but also to accurately extract its properties. Moreover, the results are rather stable with respect to the order of truncation of the effective field theory.

We develop a framework in which Yukawa hierarchies arise from powers of fully anarchic spurions transforming in higher representations of the flavor symmetry group $SU(2)^{n_2}\times SU(3)^{n_3}$. The core mechanism is the progressive lifting of Yukawa ranks through successive outer products of composite doublets and triplets. We formulate the general construction in detail and build explicit models realizing it. We then investigate whether renormalizable scalar potentials for higher $SU(2)$ representations can dynamically generate anarchic spurions with non-vanishing composites. The framework predicts distinctive patterns in flavor-changing neutral currents and potentially observable stochastic gravitational-wave backgrounds.

Scalar sectors with several Higgs doublets, a CP invariant potential, and a CP violating vacuum, possess a mass spectrum in which, unexpectedly, new scalars cannot have masses much larger than the electroweak scale once perturbativity requirements are imposed on the quartic couplings of the Higgs potential and despite the presence of free quadratic (mass) terms that can be arbitrarily large. The minimal model in which this behavior is manifest involves 3 Higgs doublets. We analyze and illustrate in detail that kind of scenario including an additional simplifying assumption: the quartic part of the potential is shaped by some discrete symmetry. Besides analytic results, a numerical analysis is presented together with some phenomenological consequences derived only from the properties of the scalar sector alone.

We propose a one-point charge-correlator (OPCC) probe of the Sivers effect in back-to-back deep-inelastic scattering. This measurement uses only the signs and directions of charged tracks, with no calorimetric or particle-identification information required. The observable weights the final state by its electric charge and measures the azimuthal correlation between the charge flow and the transverse spin of the proton. This probe is shown to be IRC finite and admits a factorization involving the usual Sivers distribution and a perturbatively calculable charge-weighted jet function for small transverse seperation $b\ll \Lambda_{\rm QCD}^{-1}$, with no reliance on non-perturbative fragmentation functions or track functions due to charge conservation. We validate the factorization against the full fixed-order QCD and present resummed predictions at N\(^3\)LL accuracy for the unpolarized distribution and N\(^2\)LL for the Sivers asymmetry. The OPCC provides a theoretically clean and simple experimental measurement, and establishes a charge-and-angle measurement paradigm for spin physics at a future Electron-Ion Collider.

We study the production of pairs of doubly-charged bileptons and assess their discovery potential in light of the integrated luminosities available at the High-Luminosity LHC. The production rates are governed primarily by the bilepton mass, $(m_Y)$, and the mass of the exotic heavy quarks, $(m_D)$. We consider two complementary production channels: (i) direct bilepton pair production and (ii) bilepton production mediated through heavy-quark decays. Notably, the latter typically yields significantly enhanced cross sections and gives rise to distinctive LHC signatures, even when the bileptons are produced off-shell. The two mechanisms therefore probe complementary regions of parameter space, with direct production being predominantly sensitive to $m_Y$, while the heavy-quark-mediated channel depends mainly on $m_D$. Owing to the essentially background-free signature of four energetic leptons at the LHC, we show that Run-2 data allow a discovery only for $m_D \lesssim 1\,\mathrm{TeV}$, whereas the HL-LHC can achieve a $5\sigma$ discovery up to $m_D \lesssim 2.5\,\mathrm{TeV}$ (nearly independently of $m_Y$) and/or for $m_Y \lesssim 2\,\mathrm{TeV}$ (even if $D$ is heavy).

To ensure anomaly cancellation the $E_6$ inspired $U(1)$ extensions of the minimal supersymmetric (SUSY) standard model (MSSM) involve extra exotic matter. The lightest exotic neutralino in these models can be stable contributing to the cold dark matter density. We consider the interactions of such neutralino with nucleons within a specific extension of the MSSM with an additional $U(1)_N$ gauge symmetry (SE$_6$SSM). The constraints on the couplings of this state, which are set by the present experimental bounds caused by the direct detection experiments, are examined. The obtained results can be generalised to other $E_6$ inspired SUSY models with extra $U(1)$ gauge symmetry.

We investigate inclusive forward single-hadron production in high-energy proton--proton collisions using a CGC-inspired Monte Carlo event generator, MC-CGC. We carried out a systematic study of the sensitivity of the running-coupling Balitsky-Kovchegov (rcBK) evolution equation to its initial conditions by comparing three parameterizations: the McLerran-Venugopalan (MV) model and its two HERA DIS-constrained variants, MV$^\gamma$ and MV$^e$. Our results indicate that the current LHCb data favor the MV$^\gamma$ and MV$^e$ models, while the differences from the original MV model become more pronounced at higher transverse momentum and at mid-rapidity. As a complementary analysis, we also compared the dilute-dense (DHJ factorization) and dense-dense ($k_T$ factorization) frameworks. We found that the $k_T$ factorization framework provides a better description of the particle production spectra at mid-rapidity than the DHJ framework, where both the projectile and target are in the dense regime at LHC energies. Predictions for the FoCal measurements at ALICE, including the production of identified neutral mesons and jets, are also presented.

The formation of baryon asymmetry in the Universe is considered in the left-right weak interaction model. In this model, the nature of CP violation is associated with the presence of a right vector boson admixture, with a mixing angle of different signs for W^- and W^+. This leads to the fact that lifetimes of neutrons and antineutrons that decay through W^- and W^+ differ. This difference gives rise to baryon asymmetry during the hadronization of quark-gluon plasma at temperatures below 150 MeV. During the phase transition from quark-gluon plasma to hadronic liquid, all three of A.D. Sakharov's conditions for the generation of baryon asymmetry in the Universe are satisfied: CP violation and process nonstationarity, resulting in baryon number violation due to the difference in the decay probabilities of neutrons and antineutrons. The generation of lepton asymmetry in the Universe in the left-right model is associated with the presence of sterile (right) neutrinos, which do not thermalize and leave the cosmic plasma, takes away a lepton asymmetry with a sign opposite to the baryon asymmetry. Generally, baryon-lepton asymmetry arises during the hadronization of quark-gluon plasma, preserving the difference between the baryon and lepton numbers. A mechanism for the formation of dark matter by sterile neutrinos is presented. The possibility of increasing the experimental accuracy of neutron decay asymmetry measurements is noted, increasing the level of confidence in the validity of the left-right model of weak interactions.

We propose a near-cutoff parallel-plate waveguide haloscope for sub-meV dark matter. The concept retains the large-area openness of a dish antenna while providing cavity-like field enhancement through slow-wave response and coherent accumulation, without relying on a closed standing-wave resonance. For a copper waveguide, the projected dark photon sensitivity reaches $\varepsilon\simeq2.1\times10^{-15}$ near $m_{A'}\simeq 0.1\,\mathrm{meV}$. With an external magnetic field, the same transducer can approach QCD axion parameter space. The waveguide haloscope highlights a sensitive and scalable route toward future sub-meV bosonic dark matter searches.

Double parton scattering provides a sensitive probe of multi parton correlations inside hadrons. In this work we present a numerical study of unintegrated double parton distribution functions constructed from non-factorized collinear DPDFs. As input we use the GS09 DPDFs and evolve them to unequal scales with a numerical double DGLAP evolution framework, which is validated through the corresponding momentum sum rule. We investigate MRW-inspired prescriptions for generating transverse momentum dependence in the double parton case. In particular, we study the double modified KMRW approach (DMKMRW), the double virtuality ordered MRW (DVO-MRW) model, and a normalization-matched version of the latter. These prescriptions can be applied directly to the full collinear DPDF, including its non-homogeneous component, and avoid the piecewise treatment required in the conventional LO-MRW construction. We analyze the normalization, transverse momentum dependence, flavor dependence, and sensitivity to longitudinal DPDF correlations of the resulting distributions. The DMKMRW model is normalization preserving by construction, while the DVO-MRW model shows nontrivial normalization deviations that are removed in the matched version. Non-factorized effects are strongly channel dependent: in DMKMRW they enter mainly through longitudinal DPDF correlations, whereas in the virtuality ordered models they also modify the transverse momentum shape. The largest deviations occur near the double parton kinematic boundary and in channels affected by valence-number and quark-antiquark correlations.

A hard hadron-collider event is treated here as a single geometric object - the kinematics and the discrete object-type labels of all reconstructed final-state particles encoded in one multivector $\evMV\in\Cl(1,3)\otimes\Vflav$ - rather than as the customary list of four-momenta with separate label fields attached. The natural mathematical setting for this view is geometric algebra, whose grade decomposition is shown to organise essentially every observable in current use for collider analyses: inner products and invariant masses at grade zero, four-momenta at grade one, decay-plane bivectors at grade two, oriented three-volumes at grade three, and the CP-odd pseudoscalar at grade four. The high-level invariants, the low-level recipe, and the equivariant-network inputs are recovered as projections onto specific grades. An explicit per-grade dictionary of $34$ classical observables is provided, and the spacetime, discrete and approximate symmetries acting on $\evMV$ are listed. The Cayley--Menger lemma settles the question of new Lorentz-invariant scalars: none are unlocked beyond $\{p_i\!\cdot\!p_j,\,m_i^2\}$; the genuine non-trivial channel is the CP-odd sign of the pseudoscalar. The event-as-geometric-object representation is intended as a uniform input layer for foundation models of collider physics, and a grade-resolved pre-training strategy is outlined. The methodology is illustrated on the resonance-topology separation with a Lorentz-equivariant multivector transformer type whose per-particle grade-$0\!\oplus\!1$ tokens are complemented by event-level pairing tokens that surface the grade-two and grade-three candidate-pairing content of the multi-resonance topology at the input layer.

We investigate the viability of one-zero neutrino mass textures within the framework of resonant Type-II leptogenesis. Considering a two-triplet scalar realization of the Type-II seesaw mechanism, we analyze the compatibility between neutrino texture structures, CP asymmetry generation, and the observed baryon asymmetry of the Universe. We perform extensive numerical scans over the neutrino parameter space and classify the phenomenologically viable one-zero textures under both hierarchical and resonant leptogenesis scenarios. We show that several one-zero textures remain compatible with neutrino oscillation data while simultaneously generating sizable CP asymmetries through resonant enhancement. We further investigate the thermal evolution of the generated asymmetry using Boltzmann equations and demonstrate the freeze-out behavior of the baryon asymmetry. Extending the analysis to a flavor-resolved framework, we study the separate evolution of electron, muon, and tau asymmetries and show that flavor-dependent washout effects play a crucial role in determining the final baryon asymmetry. Our analysis establishes a direct connection between neutrino flavor textures, resonant thermal leptogenesis, and flavor-dependent baryogenesis dynamics.

The inclusive cross sections for charm ($\mathrm{c}\overline{\mathrm{c}}$) and bottom ($\mathrm{b}\overline{\mathrm{b}}$) quark-antiquark pair production in proton-proton, proton-antiproton, and proton-nucleus collisions are studied over a wide range of center-of-mass energies, $\sqrt{s}\approx 10$ GeV--400 TeV. All existing data over $\sqrt{s}\approx 10$ GeV--14 TeV are collected and compared to calculations at next-to-next-to-leading-order (NNLO) accuracy using the new fixed-order MaunaKea open-source code for varying sets of parton distribution functions (PDFs). Relative to next-to-leading-order (NLO) predictions, the NNLO cross sections are enhanced by up to a factor of two, with the associated theoretical scale uncertainties reduced by the same amount, leading to agreement with experimental data over the full range of collision energies. The NNLO results are also compared with NLO predictions obtained within the SACOT-$m_{_\mathrm{T}}$ general-mass variable-flavour-number scheme. Despite still sizable theoretical and experimental uncertainties, $\mathrm{c}\overline{\mathrm{c}}$ cross section at multi-TeV energies can provide extra constraints on the gluon density at very small-$x$ in global PDF analyses. In the bottom sector, more precise cross section measurements at low energies, $\sqrt{s}\approx 10$--100 GeV, can help constraint the bottom-quark pole mass.

Monte Carlo event generators are the central interface between theoretical calculations and experimental measurements in collider physics. Over several decades, a comprehensive and highly modular ecosystem of tools has developed around them, encompassing matrix-element calculations, parton showers, hadronisation models, and their integration with detector simulation, event-level analysis and statistical inference. While these tools are ubiquitous in modern research, the conceptual scope and technical structure of the full simulation chain can be challenging to navigate, particularly for researchers entering the field. In this primer, we provide a structured and up-to-date overview of the high-energy physics Monte Carlo ecosystem, focusing primarily on event-generator methodologies and their role within the broader collider workflow. We discuss the conceptual foundations of modern generators, the computational and organisational challenges of large-scale simulations, and the principles that enable interoperability and reproducibility across theory and experiment. We also examine the evolving computing landscape and sustainability considerations that will shape the future development of these tools. Aimed primarily at early-stage doctoral researchers while serving as a reference for the broader community, this article seeks to clarify architecture, methodology, and long-term trajectory of Monte Carlo event generation in collider physics.

Inflaton decay inevitably emits gravitons through bremsstrahlung during reheating. We show that the soft part of this emission amplitude, fixed by Weinberg's soft-graviton theorem, becomes an irreducible stochastic gravitational-wave (GW) background after accounting for cosmological evolution. The theorem fixes the infrared branch of the spectrum, $\Omega_{\rm GW}\propto f$, independently of the microscopic operator responsible for inflaton decay, while the normalization is controlled by the hard inflaton decay rate and by a phase-space factor. We carry this out for inflaton $n$-body decays, including the phase-space integrals, finding that the maximum of the spectrum scales as $2/n$ relative to the $n=2$ case. The signal can reach $\Omega_{\rm GW}h^2\sim \mathcal O(10^{-17})$ at frequencies above the GHz scale. This predicts a stochastic graviton floor from perturbative reheating: a larger signal would require either other processes beyond perturbative bremsstrahlung or inflationary scenarios beyond conventional single-field slow roll.

We investigate the model of spontaneous baryogenesis, considering two extensions to the background paradigm. Firstly, we introduce a non-minimal coupling between gravity and the inflaton, increasing the effective mass squared of the latter. In this way, the inflaton decays more likely into fermion-antifermion pairs during reheating, through baryon-number violating processes. Accordingly, we obtain an overall baryon asymmetry consistent with cosmological observations. Then, we consider a complex scalar spectator field interacting with the inflaton through a biquadratic coupling and non-minimally with gravity, and analyze the impact in terms of baryon asymmetry production. In this scenario too, the background model results significantly enhanced, but the predicted baryon-to-entropy ratio remains smaller than the experimental data.

Inclusive deep inelastic scattering factorization combines two features that are often treated separately: an asymptotic reconstruction of the current-current matrix element from hard and long-distance data, and an invariance under finite changes of collinear scheme or operator basis. We formulate these two features as a single proof object. The construction packages the leading-region analysis, overlap subtraction, Wilson-line reduction, finite scheme kernels and physical measurement into a typed, filtered structure on a compactified space of asymptotic regimes. Its central carrier is the balanced hard-collinear core over the interface algebra of finite scheme transformations. The hard QCD input is the construction of a scheme-balanced comparison map from this core to the collinear collar of the regime algebra. Once this comparison is an equivalence through the chosen power accuracy and the measurement descends to convolution, the standard DIS convolution formula follows formally and independently of the chosen scheme presentation. We separate this formal implication from the analytic QCD obligations needed to construct the collar equivalence, describe Collins-style subtraction as descent and Möbius inversion on the region poset, and give a finite check relating $\overline{\mathrm{MS}}$ and DIS presentations. The framework is intended as proof infrastructure rather than as a new calculation of DIS coefficient functions. It supplies diagnostics for missing regions, nonclosed operator sectors, nonbalanced measurements and failed collar equivalences, and it gives a typed interface for future proof-assistant and machine-learning implementations of factorization workflows.

When a rapidly-rotating, highly magnetized white dwarf (WD) approaches the Chandrashekhar limit through mass accretion, it can undergo an accretion-induced collapse (AIC) to form a proto-neutron star or protomagnetar. The protomagnetar can drive a magnetically-dominated relativistic outflow, whose low entropy can lead to efficient formation of heavy nuclei. In this work, we propose that such relativistic outflows from AIC of WDs can contribute as sources of ultra high-energy cosmic rays (UHECRs). We model the acceleration of heavy nuclei in these relativistic outflows, and show that AICs can dominantly power the observed UHECRs, if a majority of them host relativistic outflows. Accounting for uncertainties in the acceleration mechanisms and AIC rates, AICs can contribute $\sim$ a few $10^{43} - 10^{45}\ {\rm erg \ Mpc}^{-3} {\rm yr}^{-1}$ in UHECR energy generation rate density, assuming iron-like nuclei.

We generalize lower limits on the dark matter (DM) particle mass $m$ derived from Milky Way (MW) satellite galaxy abundances to scenarios in which DM is an ultralight scalar field produced with a field power spectrum peaked at a subhorizon wavenumber $k_*$. In these models, the DM field free-streams similar to warm dark matter while also exhibiting significant small-scale wave interference effects. The resulting dimensionless density power spectrum shows two effects: (i) free-streaming suppression at $k_{\rm fs}\sim k_{\rm eq}/[(k_*/a_{\rm eq}m)\ln(a_{\rm eq}m/k_*)]$; (ii) Poisson-like enhancement related to wave interference, at $k\gtrsim10^{-2}k_*$, which saturates near the Jeans scale $k_{\rm J}\sim k_{\rm eq}/(k_*/a_{\rm eq}m)$. Comparing these predictions with established constraints on a free-streaming cutoff in the linear matter power spectrum from the MW satellite population, we obtain $m>6\times10^{-18}\,{\rm eV}\,(k_*/10^4\,{\rm Mpc}^{-1})$ for $k_*>10^4\,{\rm Mpc}^{-1}$ at 95\% confidence. For smaller $k_*$, Poisson-noise enhancement on MW satellite scales weakens the constraint, yielding $m>6\times10^{-18}\,{\rm eV}\,(k_*/10^4\,{\rm Mpc}^{-1})^2$ for $k_*<10^4\,{\rm Mpc}^{-1}$ at 95\% confidence.

Femtoscopic measurements of two-pion Bose--Einstein correlations have established that particle-emitting sources in heavy-ion collisions are well described by Lévy $\alpha$-stable distributions, motivating systematic studies across a wide range of collision energies. In this work, we present a three-dimensional femtoscopic analysis of pion pairs in Au+Au collisions simulated with the UrQMD model for collision energies $\sqrt{s_{NN}}=3$--$27\,\mathrm{GeV}$, taking the RHIC BES-II range of collider and fixed target experiment energies for reference. Using Lévy-type source parameterisations, we extract the pair multiplicity parameter $\lambda^{*}$ (related to the correlation strength $\lambda$), Lévy index $\alpha$, and three-dimensional radii $R_\mathrm{out}$, $R_\mathrm{side}$, and $R_\mathrm{long}$. We investigate their dependence on the transverse mass ($m_T$) and collision energy, along with derived quantities such as the radius difference $R_{\mathrm{diff}}^2=R_{\mathrm{out}}^2-R_\mathrm{side}^2$ and the ratio $R_\mathrm{out}/R_\mathrm{side}$. We find that $R_\mathrm{out,side,long}$ all decrease with increasing $m_T$ and increase with collision energy, consistent with collective expansion, $R_\mathrm{long}$ showing the strongest and $R_\mathrm{side}$ the weakest energy dependence. The Lévy index $\alpha$ decreases with collision energy, with a larger $m_T$-dependence towards higher energies. The $\lambda^{*}$ parameter is consistent with a constant close to unity in the absence of pions from long-lived resonances. These results provide a baseline for future comparisons with experimental measurements from the STAR Collaboration, contributing to constraints on the QCD phase diagram.

Radio detection of extensive air showers enables near-continuous observation and precise measurements of the shower geometry and the depth of shower maximum, $X_{\rm max}$. Beyond $X_{\rm max}$, the longitudinal shower development follows a Universal Shower Profile (USP), whose shape parameters contain information on primary mass composition and hadronic interaction models. While previous studies have focused on event-by-event reconstruction of profile parameters, in this work we investigate the reconstruction of the average USP using radio interferometric techniques. Using Monte Carlo simulations, we reconstruct the average longitudinal profile directly from radio data and extract the Gaisser-Hillas shape parameters $(R,L)$. We find that the radio-derived average profiles provide enhanced separation between primary masses and hadronic interaction models compared to that obtained from fluorescence-equivalent longitudinal profiles. These results demonstrate that radio interferometry can access higher-order information on the longitudinal shower development and that the use of the average USP significantly improves the sensitivity to composition and hadronic interaction studies at ultra-high energies.

In this work, we study the effects of accretion on the primordial black hole (PBH) reheating scenario. PBHs could form from primordial fluctuations. If they have the right mass and abundance, they could dominate the Universe and complete the reheating entirely through Hawking radiation. We find accretion effects on the BH can not only increase the BH mass, but also prolong such early matter domination. The consequence of the accretion is further investigated using isocurvature induced gravitational waves (GWs), which are generated right after the sudden evaporation of the BHs from the oscillation of the gravitational potential. Big Bang nucleosynthesis limits on the energy density of the GWs put important constraints on the PBH domination scenario. Inclusion of accretion shifts such constraints significantly towards smaller formation mass and smaller initial abundance. Furthermore, the PBH could undergo mergers leading to extended mass functions. We find similar shifts in the allowed parameters with the inclusion of accretion for the merger constraint. We find the constraints from isocurvature GWs typically stronger than the constraints from mergers.

We show that for a CFT$_D$ on a flat open solid torus, the two point function in the Weyl frame is exactly paired with a finite geodesic lying entirely in the AdS$_{D+1}$ bulk interior. This relation is exact and requires neither large $N$, strong coupling, nor heavy operators. The standard boundary-anchored relation is a singular limit of the exact pair. For the free scalar, a mode expansion along $S^1$ generates an infinite tower of effective masses on $H_{D-1}$, whose intricate propagators resum exactly to the same simple higher-dimensional geodesic expression. Together with another exact pair between disjoint entanglement entropy and entanglement wedge cross-section found on the same open solid torus, this result points toward a broader exact-pair program in AdS/CFT.

We investigate the propagation of fronts in an inhomogeneous medium within the framework of the $\phi^4$ model. The inhomogeneity is modeled either as an interface separating regions with different dissipation or as a finite layer with modified dissipation. The propagating front is described in two ways: as a kink solution in an effectively unbounded domain, and as a half-kink in a finite system. The half-kink represents the decay of the unstable state $\phi=0$ toward the true vacuum. We show that while the effective description based on the kink provides accurate results, applying a similar approach to the half-kink leads to significant deviations from the predictions of the field model. We then demonstrate that a consistent description does exist and propose a modified effective model which reproduces the field-theory results over a relatively broad range of parameters.

A systematic study of chiral effects is presented using an Effective Field Theory framework. By integrating out a massive Dirac fermion at finite temperature in presence of vector and axial background fields, the currents and their anomalies are computed from the path-integral. Chiral effects previously considered separately naturally arise in a unified computation, including new mass corrections. The link between each anomalous transport effect and the anomalies is clearly established, beyond the identification of their coefficients. In particular, we can appreciate how these effects are sourced by the anomalous nature of the theory even in configurations where the anomaly itself vanishes. The consistent and covariant anomalies are both encapsulated in master formulae for the currents which result from a careful treatment of the regularisation. It is finally found that, at finite temperature, the physical currents cannot be inferred simply from the Chern-Simons terms whose divergence reproduce the chiral anomalies.

We study the Sudakov form factor and the four-point scattering amplitude on the Coulomb branch of planar $\mathcal{N}=4$ SYM as functions of the Coulomb-branch parameters and kinematic invariants. This setup provides a controlled probe of the interpolation between on- and off-shell regimes of infrared-sensitive quantities in gauge theories. We identify a novel scaling limit in which both observables exhibit double-logarithmic behavior governed by a walking anomalous dimension. As the mass scales are varied, this walking anomalous dimension interpolates between the cusp anomalous dimension of the on-shell regime and the octagon anomalous dimension of the off-shell regime. Based on the explicit two-loop result and the expected all-order structure, we propose an all-loop form for the walking anomalous dimension both for the form factor and for the four-point scattering amplitude. These all-loop expressions depend on new, presently unknown functions of the 't Hooft coupling.

In Effective Field Theory, we describe $\mu\leftrightarrow e$ flavour changing transitions using an operator basis motivated by experimental observables. In a six-dimensional subspace probed by $\mu \to e \gamma$, $\mu \to 3e$ and $\mu\to e$ conversion on nuclei, we derive constraints on the New Physics scale from past and future experiments, illustrating the complementarity of the processes in an intuitive way. We also recall that a precise determination of the scalar quark currents in the nucleon will be required to distinguish scalar $\mu\to e$ interactions on u-quarks from those on d-quarks.

We propose using highly excited cyclotron states of a trapped electron to detect meV axion and dark photon dark matter, marking a significant improvement over our previous proposal and demonstration [Phys. Rev. Lett. 129, 261801]. When the axion mass matches the cyclotron frequency $\omega_c$, the cyclotron state is resonantly excited, with a transition probability proportional to its initial quantum number, $n_c$. The sensitivity is enhanced by taking $n_c \sim 10^6 \left( \frac{0.1~\text{meV}}{\omega_c} \right)^2$. By optimizing key experimental parameters, we minimize the required averaging time for cyclotron detection to $t_{\text{ave}} \sim 10^{-6} $ seconds, permitting detection of such a highly excited state before its decay. An open-endcap trap design enables the external photon signal to be directed into the trap, rendering our background-free detector compatible with large focusing cavities, such as the BREAD proposal, while capitalizing on their strong magnetic fields. Furthermore, the axion conversion rate can be coherently enhanced by incorporating layers of dielectrics with alternating refractive indices within the cavity. Collectively, these optimizations enable us to probe the QCD axion parameter space from 0.1 meV to 2.3 meV (25-560 GHz), covering a substantial portion of the predicted post-inflationary QCD axion mass range. This sensitivity corresponds to probing the kinetic mixing parameter of the dark photon down to $\epsilon \approx 2 \times 10^{-16}$.

It is demonstrated how a set of particle representations, familiar from the Standard Model, collectively form a superalgebra. Those representations mirroring the internal behaviour of the Standard Model's gauge bosons, and three generations of fermions, are each included in this algebra, with exception only to those irreps involving the top quark. This superalgebra is isomorphic to the Euclidean Jordan algebra of $16\times 16$ hermitian matrices, $H_{16}(\mathbb{C}),$ and is generated by division algebras. The division algebraic substructure enables a natural factorization between internal and spacetime symmetries. It also allows for the definition of a $\mathbb{Z}_2^5$ grading on the algebra. Those internal symmetries respecting this substructure are found to be $\mathfrak{su}(3)_C \oplus \mathfrak{su}(2)_L \oplus \mathfrak{u}(1)_Y,$ in addition to four iterations of $\mathfrak{u}(1)$. For spatial symmetries, one finds multiple copies of $\mathfrak{so}(3)$. Given its Jordan algebraic foundation, and its apparent non-relativistic character, the model may supply a bridge between particle physics and quantum computing. We close by describing current research directions. This includes (1) detailing how this construction fits into the larger picture of Bott Periodic Particle Physics, first introduced in [1], [2], [3], and (2) detailing how the origin of this Peirce decomposition may be grounded in the unsung algebra $\mathbb{R} \oplus \mathbb{C} \oplus \mathbb{H} \oplus \mathbb{O}$.

One of the forthcoming major challenges in particle physics is the experimental determination of the Higgs trilinear self-coupling. While efforts have largely focused on on-shell double- and single-Higgs production in proton-proton collisions, off-shell Higgs production has also been proposed as a valuable complementary probe. In this article, we design a hybrid neural simulation-based inference (NSBI) approach to construct a likelihood of the Higgs signal incorporating modifications from the Standard Model effective field theory (SMEFT), relevant background processes, and quantum interference effects. It leverages the training efficiency of matrix-element-enhanced techniques, which are vital for robust SMEFT applications, while also incorporating the practical advantages of classification-based methods for effective background estimates. We demonstrate that our NSBI approach achieves sensitivity close to the theoretical optimum and provide expected constraints for the high-luminosity upgrade of the Large Hadron Collider. While we primarily concentrate on the Higgs trilinear self-coupling, we also consider constraints on other SMEFT operators that affect off-shell Higgs production.

The Standard Model of particle physics is derived from first principles from the free Dirac Lagrangian in 8-dimensional spacetime. Motivated by second quantization arguments, we embed the 4-dimensional Clifford algebra of the Dirac Lagrangian into the Clifford algebra of 8-dimensional spacetime. We show this process carries a natural redundancy described by the SM gauge group and an additional $U(1)_{B-L}$ symmetry. All known fermionic particle representations, with additional right handed neutrinos, arise as Dirac spinors transforming under this symmetry. Four particle families are predicted with mixing intrinsically restricted to the first three, while avoiding common challenges related to a fourth family. The strong force arises from Spin(8) triality, with chirality emerging as the property of rotations left invariant by this automorphism. The symmetry group acts internally and externally, via right and left multiplications on Dirac spinors, respectively. The external counterpart results in a $U(3)_F$ family interaction and a $U(2)_L$ symmetry acting on spinor indexes whose gauging yields a 4-dimensional left-handed spin connection. The proposed breaking of $U(3)_F$ results in a hierarchy governed by a generalized Koide formula, with mass scales displaying a modular nature. Internal and external transformations carry a direct algebraic interpretation in 8-dimensional spacetime while avoiding the Coleman-Mandula theorem. Weak interactions are encoded in the Clifford algebra of the observed 4-dimensional spacetime, while strong interactions live in the Clifford algebra of the four extra dimensions. The theory is anomaly free and devoid of proton decay.

The origin of the three fermion generations and their highly hierarchical mass spectra remains one of the most profound puzzles in particle physics. We show that the complexified exceptional Jordan algebra $J_{3}(\mathbb{O}_{\mathbb{C}})$, the natural mathematical framework for the exceptional Lie group $E_{6}$, provides a unified explanation for both. The three generations arise from the three off-diagonal Peirce slots of $J_{3}(\mathbb{O}_{\mathbb{C}})$, each carrying an isomorphic $Cl(6,\mathbb C)$ minimal-ideal fiber and permuted cyclically by triality $S_3\subset\mathrm{Out}(\mathrm{Spin}(8))$; pre-breaking, the three families are identical by symmetry. After triality breaking the residual $SU(3)_F$ flavor symmetry organises the three generations of each family as a $\mathrm{Sym}^{3}(\mathbf{3})$ multiplet, the minimal $S_3$-symmetric degree-3 arena consistent with the cubic structure of the Jordan determinant and the unique $E_6$-invariant Yukawa. The mass-ratio formula follows from a one-line diagonal-action theorem: when $\langle X\rangle$ is Jordan-diagonalised to $\mathrm{diag}(a,b,c)$, the induced action $X^{\odot 3}$ on the $\mathrm{Sym}^{3}(\mathbf{3})$ monomial basis is diagonal with eigenvalues $a^pb^qc^r$, so a fermion identified with the weight state $|p,q,r\rangle$ has $\sqrt m\propto a^pb^qc^r$ and adjacent generations related by an edge move have $\sqrt m$-ratios that depend only on the edge type ($c/a$, $b/a$, $c/b$). We refer to this as $\textit{edge universality}$; it is monomial arithmetic, not a Clebsch-Gordan cancellation. The universal Jordan eigenvalue spectrum $(q-\delta, q, q+\delta)$ with $\delta^{2}=3/8$ is fixed by the cubic on the coassociative slice of $J_3(\mathbb O_\mathbb C)$. [abstract truncated]

We study ultralight scalar fields with quadratic couplings to Standard-Model fermions and derive strong constraints from white-dwarf mass-radius data. Such couplings source scalar profiles inside compact stars, shift fermion masses, and can produce a new ground state of matter. We analyze couplings to electrons and to nucleons, incorporating composition and finite-temperature effects in white dwarf structure and equations of state. We identify two robust observables: (i) forbidden gaps - ranges of radii with no stable configurations - and (ii) characteristic shape distortions that drive white dwarf masses toward the Chandrasekhar limit (electron couplings) or shift the maximum mass (nucleon couplings). Confronting these predictions with precise measurements for Sirius B and Procyon B, together with the global white dwarf population, excludes large regions of unexplored parameter space and extends earlier QCD-axion-specific bounds to a broader class of scalar theories. Our stellar constraints rely only on sourcing and do not assume the scalar constitutes dark matter; where mass reductions are small, precision laboratory searches remain competitive. White-dwarf astrophysics thus provides a powerful, largely assumption-minimal probe of ultralight, quadratically coupled scalars.

We present a comprehensive analysis of the discovery reach and exclusion limits for an ultraheavy diquark scalar (7-9.5 TeV) decaying into a pair of vectorlike quarks (1.5-2 TeV) at the HL-LHC. Building on an improved signal selection efficiency achieved using Machine Learning techniques, we extend our previous six-jet final-state study by providing a complete likelihood-based statistical treatment of this search topology. The analysis incorporates theoretical and systematic uncertainties through nuisance parameters within the likelihood framework, enabling a consistent statistical interpretation. The mass regions of interest were determined through scans of the local $p$-values, $CL_s$, and the upper limits on the model-dependent signal strength $\mu$. The results indicate a promising sensitivity to ultraheavy diquark scalars within the explored mass range, suggesting that the HL-LHC could either discover or set stringent exclusion limits on such particles.

We investigate how the interference of the SM with ten four-light quark operators in the SMEFT can be constrained thanks to multijet and $Z$, $W$, $\gamma$ VBF production in association with jets. The differential distributions for each process are generated at LO for different jet multiplicities, that are then merged and showered. We check which observables provide better bounds on the Wilson coefficients, and what directions in the ten-dimensional coefficient space they are able to probe. We discuss the relevance of the quadratic contributions with respect to the linear terms and use them to assess the validity of the EFT approach.

Motivated by the enigmatic vector charmonium-like states, we investigate the strong decay behaviors of four kinds of vector tetraquark states, which are possible candidates for the $Y(4660)$, within the framework of three-point QCD sum rules based on rigorous quark-hadron duality. We take into account the vacuum condensates up to dimension 5 on the QCD side, and obtain the hadronic coupling constants therefore the partial decay widths of those states. The predicted total width $61.5\pm7.3\,\rm{MeV}$ is in excellent agreement with the experimental data for the $Y(4660)$, which supports its interpretation as a $[sc][\bar{s}\bar{c}]$ tetraquark state with the $J^{PC}=1^{--}$.

We study the phenomenology of a sub-GeV $L_\mu-L_\tau$ gauge boson. We find discrepancies with existing literature in sensitivity projections for the upcoming SHiP experiment and in the treatment of supernovae cooling constraints. We present a quantitative analysis of different production modes in beam dumps and compare our results to previous work. In the context of supernovae, we re-evaluate the standard supernova cooling bounds from SN1987A and analyze additional supernova-based probes: diffusive cooling, constraints from the existence of low-energy supernovae, and the absence of a high-energy neutrino signal from SN1987A.

Wave-like dark matter composed of spin-1 particles, known as dark photons, is theorized to form clumps called "vector solitons". These solitons are compact astrophysical objects that exhibit coherent oscillations and a high concentration relative to the local dark matter density. A significant portion of dark matter in galactic halos today may consist of these solitons. This study explores how photons can be produced from these vector solitons by the influence of external electromagnetic fields or charge densities, via a dimension-6 dark photon-photon coupling and a kinetic mixing, respectively. We further explore the astrophysical implications of these phenomena, highlighting a novel avenue for dark matter discovery that our research provides.

The Higgs self-couplings remain only weakly constrained by current Large Hadron Collider (LHC) measurements, leaving ample room for physics beyond the Standard Model that could modify the structure of the Higgs potential. Multi-Higgs production processes provide a particularly sensitive probe of deviations in both the Higgs trilinear and quartic self-couplings. In this note, we summarize the current status of next-to-leading-order electroweak (EW) corrections to double-Higgs production computed within the Standard Model Effective Field Theory and Higgs Effective Field Theory frameworks, emphasizing how these calculations introduce sensitivity to the Higgs self-couplings beyond what is accessible at leading order. We discuss the key conceptual and technical differences between the two effective field theory approaches, including their treatment of higher-dimensional operators, renormalization procedures, and the structure of EW~two-loop amplitudes. Despite these differences, both approaches yield broadly consistent constraints, illustrating the complementarity of double- and triple-Higgs measurements. With the high-luminosity LHC and future high-energy colliders on the horizon, these developments and further advances provide an essential foundation for extracting increasingly precise information on the dynamics of EW symmetry breaking.

We propose a mechanism for baryogenesis in which the baryon asymmetry is generated as an equilibrium response of weak sphalerons in a region where electroweak sphaleron transitions remain unsuppressed, $h/T\lesssim 1$. A nonzero equilibrium baryon density arises in the presence of an approximately conserved global charge, carried either by new states with nonzero hypercharge, or by Standard Model fields themselves. The required global charge asymmetry is generated during a phase transition that changes the strength of electroweak symmetry breaking, but need not coincide with the final electroweak phase transition. In particular, the mechanism can operate during an inverse electroweak phase transition, where baryon number is produced behind the advancing wall, in contrast to conventional electroweak baryogenesis. Because baryon production is decoupled from a direct first-order electroweak phase transition, the scenario can be realized at parametrically higher temperatures than standard electroweak baryogenesis, thereby weakening current experimental constraints. This framework provides a qualitatively distinct route to electroweak baryogenesis, with different parametric dependence, phase-transition dynamics, and phenomenological signatures.

A virtual production of heavy axion-like particles (ALPs) via light-by-light scattering in pp, pPb and Pb collisions at the future 100 TeV collider FCC-hh is studied. Both differential and total cross sections are calculated. The 95\% C.L. exclusion limits, as well as $3\sigma$ and $5\sigma$ discovery limits on an ALP coupling constant versus ALP mass $m_a$ are given, using integrated luminosities of 30 ab$^{-1}$, 27 pb$^{-1}$ and 110 nb$^{-1}$. Our results are compared with the current LHC bounds. The strongest limit on the ALP coupling is obtained if $m_a \simeq 250$ GeV for the PbPb collisions, and if $m_a \simeq 1$ TeV for pp or pPb collisions. This suggests that the FCC-hh has a great physics potential of searching for the heavy ALPs.

We investigate the dynamics of a cosmological first-order phase transition (FOPT) and the associated stochastic gravitational wave background (SGWB) in a hidden strongly coupled sector described by an extended Nambu--Jona-Lasinio (NJL) model with $N_f = 3$ fermion flavors. The model incorporates a CP-violating six-fermion 't Hooft interaction, an explicit chiral symmetry breaking mass term, and chirally symmetric eight-fermion operators that stabilize the vacuum. We perform a multi-field analysis of the tunneling dynamics, going beyond conventional single-field approximations. The interplay between explicit symmetry breaking and CP violation induces a vacuum misalignment, resulting in a curved tunneling path and a spatially varying CP-violating background across the bubble wall. Through a comprehensive scan of the multi-dimensional parameter space, we find a parameter regime where the conventionally rapid transition rate of the NJL framework is drastically reduced to $\beta/H \sim \mathcal{O}(10^2)$. Consequently, the gravitational wave (GW) production is significantly enhanced, with the predicted SGWB peak amplitudes successfully reaching the detection sensitivity of the proposed $\mu$Ares observatory. Furthermore, our analysis reveals that the macroscopic thermodynamic properties governing the SGWB are predominantly determined by the radial profile of the effective potential, rendering the resulting GW signatures remarkably insensitive to the CP-violating topological vacuum angle. Finally, the explicit symmetry breaking mass introduces a crucial energy bias between competing vacua, triggering the prompt collapse of transient domain wall configurations and thereby ensuring the cosmological viability of the model.

The discovery of the Higgs boson by the ATLAS and CMS experiments concluded a glorious century of experimental particle physics discoveries, from Rutherford's discovery of the nucleus in 1911, through the discoveries of quarks and leptons from the 1950s to the 1970s, to the discoveries of the weak vector bosons in the 1980s. It cemented the Standard Model of particle physics as providing the viable parameterisation of all sub-atomic observables up to the TeV scale and possibly up to the GUT and Planck scales. The experimental determination of the Higgs properties and parameters will shed light on these fundamental theories. A particularly pertaining question from the point of view of String Phenomenology is whether the Higgs boson is a fundamental or composite particle. The fermionic Z2xZ2 orbifolds provide bench mark models to explore how the parameters of the Standard Model can arise from a theory of quantum gravity, as well as for physics Beyond the Standard Model. Observation that the Higgs is composite will nullify much of the work that have gone into heterotic string model building over the past 40 years and will indicate the relevance of other classes of string vacua or possibly other approaches to quantum gravity. An ideal facility in the near future to investigate this question is a hadron collider at 50-60 TeV that utilises contemporary magnet technology and can be built in 10-15 years from decision.

Under certain conditions, the production of a Higgs boson in association with a top-anti-top pair at hadron colliders can be described via a factorisation theorem using perturbative fragmentation functions. The latter describe the nearly collinear emission of a Higgs boson from a top-quark and reproduce the leading mass dependence of the exact next-to-leading-order (NLO) calculation. Although the NLO fragmentation functions have been calculated a few years ago, it has not been possible up to now to demonstrate the applicability of the approximation in a realistic setup. At NLO, we analyse two different ways of treating the top-quark mass, called the zero-mass-top-quark (ZMTQ) and the hybrid prescription. We show that the method yields reliable results at LHC center-of-mass (cms) energies in the hybrid prescription. In the ZMTQ prescription, the results at LHC cms energies are only reliable in the quark-anti-quark channel, but become viable for the full $pp \rightarrow t\bar{t}H$ process at a 100 TeV hadron collider. In addition, we discuss some subtleties and complications arising when extending the formalism to next-to-next-to-leading-order (NNLO) and beyond.

A comprehensive study of the phase structure of the two-flavor quark-meson-diquark model is presented within the nonperturbative functional renormalization group framework. The influence of mesonic fluctuations beyond the mean-field approximation is investigated, and two-point functions of the diquark fields are computed at finite real-time frequencies. Renormalization group consistency of the effective potential is ensured in order to avoid cutoff artifacts. Substantial modifications of the phase structure are found once mesonic fluctuations are included, and for sufficiently strong diquark couplings the dynamics become dominated by diquark condensation. These effects are elucidated through an analysis of the diquark pole mass and the Silver-Blaze property.

In this paper, we presented an approximate analytical treatment of the Coulomb plus logarithmic potential using perturbation theory to investigate the mass spectra of bottomonium and charmonium mesons for the low-order quantum states. The derived energy equation, to first-order corrections, was employed to model the free potential parameters through fitting to experimental data of the Particle Data Group. The proposed potential successfully reproduces asymptotic freedom at short distances through one-gluon exchange interactions and quark confinement at large distances, which are the essential features of the strong interactions in Quantum chromodynamics theory. The calculated bottomonium masses exhibited excellent agreement with experimental values, yielding an absolute percentage average deviation (APAD) of 0.24%, which improves upon several previously reported theoretical results. Similarly, the vector and pseudoscalar charmonium masses were obtained with an APAD of 1.65%, demonstrating improved and comparable accuracy relative to existing competing theoretical calculations. Although our results were limited to first-order corrections to the energy spectra within the perturbation theory, the reliability of the approximation was validated by comparison with exact numerical solutions obtained using the matrix Numerov method. The small percentage errors obtained confirm the effectiveness of the phenomenological potential and perturbation approximation in describing quarkonia systems. The results suggest that the approach can be reliably extended to higher excited states.

Upcoming experiments need improved simulations of neutrino scattering. This work uses the popular GENIE event generator to test a variety of neutrino interaction models against recent MicroBooNE measurements of pionless charged-current interactions. The GENIE code can easily interchange model components, including nucleon form factor parameterizations, quasielastic cross-section calculations, treatments of the nuclear ground state and hadronic final-state interactions. Leveraging this software capability in comparisons with MicroBooNE data, the performance of some of GENIE's most theoretically sophisticated model components is evaluated and contrasted with more empirically-driven alternatives.

A recently proposed superconducting linear collider with energy recovery (ERLC) and multiple beam reuse employs twin RF structures to eliminate parasitic collisions in the linacs. Such a collider can operate in either pulsed or continuous-wave (CW) mode, achieving a luminosity of ${\cal O}(10^{36})$ cm$^{-2}$s$^{-1}$ at $2E_0$ = 250--500 GeV. This paper demonstrates that in pulsed mode, the ERLC luminosity is independent of the accelerating gradient for a fixed total power, enabling operation at the highest available gradients. A similar independence holds for the CW mode when the available power significantly exceeds the operational threshold. The luminosity scales with the cavity quality factor as $L\propto Q_0^{1/2}$. We also present, for the first time, a study of a twin $e^-e^-$ ERLC and estimate its performance. This configuration is simpler than the $e^+e^-$ version as it eliminates the need for beam recirculation; electrons can be generated anew for each cycle. In this case, the luminosity scales as $L\propto Q_0^{1/4}$. Furthermore, the use of traveling-wave (TW) RF structures allows for higher gradients and reduced thermal loading. We show that an ERLC with $G$ = 40 MeV/m can operate in CW mode, reaching luminosities of $L_{e^+e^-}$= (1-2.5)$\times 10^{36}$ and $L_{e^-e^-}$= (3-7)$\times 10^{36}$ cm$^{-2}$s$^{-1}$ at $2E_0$ = 250 and 500 GeV, respectively, with a total power consumption of 150-300 MW. These results position the ERLC as a highly promising candidate for a future Higgs factory.

The accelerated expansion of the Universe is well established by geometric probes, yet its physical origin remains poorly understood. Most constraints on dark energy arise from background observables -- supernovae, baryon acoustic oscillations, and the cosmic microwave background -- which mainly test the homogeneous expansion history. To move beyond this limitation, we examine how kinetic Sunyaev--Zel'dovich (kSZ) tomography, combined with galaxy clustering, can probe perturbative effects of dark energy and improve constraints on its background parameters. Using a Fisher-matrix analysis of the joint power spectra for LSST- and CMB-S4-like surveys, we quantify the additional information kSZ tomography contributes to dark-energy inference. Including kSZ data tightens constraints on $w_0$ by 15 % and on $w_a$ by 32 %, with parameter degeneracies distinct from those of geometric probes. We also assess the detectability of dark-energy perturbations through a two-parameter model, finding that for canonical sound speed ($c_s=1$) the effects are sub-percent and confined to horizon scales, while smaller sound speeds shift them to accessible $k$-ranges. Near-term kSZ measurements will primarily serve to test the consistency between background and perturbative signals, while future low-noise, high-resolution surveys may begin to uncover the microphysical properties of dark energy.

We investigate two different definitions of a scalar field effective potential in quantum field theory in de Sitter spacetime: the standard textbook definition, and the constraint effective potential proposed by O'Raifeartaigh et al. in 1986. While these definitions are equivalent in Minkowski spacetime, they differ significantly in de Sitter. We demonstrate this by computing them both explicitly at one-loop order in perturbation theory. It is well known that the perturbative expansion of the standard effective potential fails converge for light fields. In contrast, the constraint effective potential does not suffer from this infrared problem, and it can therefore be computed using perturbation theory. We discuss the physical interpretation of the two effective potentials. In particular, we provide evidence supporting an earlier conjecture that the constraint effective potential is the correct one to use in the stochastic Starobinsky-Yokoyama theory.

The light-shining-through-a-wall experiment ALPS II at DESY in Hamburg searched for axions and similar lightweight particles in its first science campaign from February to May 2024. No evidence for the existence of such particles was found. For pseudoscalar bosons like the axion, with masses below about 0.1 meV, we achieved a limit for the di-photon coupling strength of 1.5e-9 1/GeV at a 95% confidence level. This is more than a factor of 20 improvement compared to all previous similar experiments. We also provide limits on photon interactions for scalar, vector and tensor bosons. An achievement of this first science campaign is the demonstration of stable operation and robust calibration of the complex experiment. Currently, the optical system of ALPS II is being upgraded aiming for another two orders of magnitude sensitivity increase.

A detection method for high-frequency gravitational waves using two-dimensional ion crystals is investigated. Gravitational waves can resonantly excite the drumhead modes of the ion crystal, particularly the parity-odd modes. In the optical dipole force protocol, entanglement between the drumhead modes and the collective spins transfers the excitation of the drumhead modes to the rotation of the total spin. Furthermore, gravitational wave detection beyond the standard quantum limit becomes possible as a squeezed spin state is generated through this entanglement. The sensitivity gets better with a larger ions crystals as well as a larger number of the ions. Future realization of large ion crystals can significantly improve the sensitivity to gravitational waves in the 10 kHz to 10 MHz region.

The trace anomaly of dense matter, $\Delta \equiv 1/3 - P/\varepsilon$, defined through the ratio $w \equiv P/\varepsilon$ of pressure $P$ to energy density $\varepsilon$, quantifies deviations from conformal symmetry and provides a dimensionless measure of the stiffness of the equation of state (EOS) relevant for both neutron stars and heavy-ion collisions. While $\Delta(\varepsilon)$ has recently been inferred from neutron star observations, we report the first Bayesian extraction of the trace anomaly from collective flow observables in intermediate-energy heavy-ion collisions. By employing transport-model simulations that explicitly decouple the cold matter mean-field potential from thermal effects, we directly constrain the EOS of cold dense matter. Remarkably, the trace anomaly inferred from laboratory flow data agrees quantitatively, within $68\%$ credible intervals, with independent astrophysical posterior bands. This nontrivial agreement demonstrates that heavy-ion collisions and neutron star observations probe the same macroscopic properties in a mutually consistent way, establishing the dense-matter trace anomaly as a composition-insensitive macroscopic bridge observable across widely different physical environments.

We present the first systematic study of the radiative decays of charmed mesons using $2+1$-flavor clover fermion gauge ensembles generated by the CLQCD collaboration. One of the ensembles is at the physical pion mass, and one has a fine lattice spacing $a\sim 0.05 ~\text{fm}$. We determine the coupling constants to be $g_{D^{\ast+} D^+ \gamma} = -0.204(22)$ GeV$^{-1}$, $g_{D^{\ast0} D^0 \gamma} = 1.73(37)$ GeV$^{-1}$, and $g_{D_s^{\ast+} D_s^+ \gamma} =-0.120(14)$ GeV$^{-1}$, respectively. Compared with previous studies, our results demonstrate significant improvements in precision. In particular, we carefully estimate the systematic uncertainty arising from matrix element fits, momentum transfer extrapolations, and chiral and continuum limit extrapolations, which are included in the reported total uncertainties. These couplings yield the following predictions of decay widths: $\Gamma_{D^{\ast+} \rightarrow D^+ \gamma} = 0.253(55)$ keV, $\Gamma_{D^{\ast0} \rightarrow D^0 \gamma} = 18.2(7.8)$ keV, and $\Gamma_{D_s^{\ast+}\rightarrow D_s^+ \gamma} = 0.094(22)$ keV. This work establishes first-principles results of the charmed meson radiative transitions and provides inputs for understanding the structure and properties of heavy-light mesons.

We perform a stability analysis of the homogeneous ground state of nuclear matter against inhomogeneous perturbations of the pion condensate. In $\beta$-equilibrium, restricting the baryon species to nucleons only, we observe no instability; however, at high densities, the pseudoscalar density-density correlations assume a moat regime, i.e. a damped oscillatory patterned spatial correlation, which in momentum space appears as a non-zero global minimum for some finite three-momentum. When hyperons are permitted to appear, this minimum can cross down to negative values, which configures an instability towards an inhomogeneous pion condensate which ultimately will affect the equation of state.

We study the scalar perturbations of asymptotically flat extremal Reissner-Nordström black holes via the quantum Seiberg-Witten geometry of $\mathcal{N}=2$ SU(2) gauge theory with $N_f=2$ flavors. The radial master equation, governed by a double confluent Heun equation, is exactly mapped to the quantum Seiberg-Witten curve, providing an exact quantization condition derived from the non-perturbative Nekrasov-Shatashvili free energy. Analytically, this exact dictionary unveils precise gauge-theoretic interpretations for critical physical thresholds, demonstrating that the superradiance and mass decoupling limits naturally reduce the master equation to the Whittaker equation and the reduced doubly confluent Heun equation (the latter corresponds to the SW geometry of the $\mathcal{N}=2$ SU(2) gauge theory with $N_f=1$), respectively. At the strict extremal limit, the coalescence of horizons induces a topological singularity that complicates the spectral analysis. By accommodating this irregular singularity, our geometric framework resolves the singularity coalescence and enables the extraction of the discrete global quasinormal mode. As our main contribution, we provide the first non-perturbative evaluation of the quasinormal modes spectrum for simultaneously charged and massive scalar fields directly at strict extremity. Furthermore, our analytical results reproduce numerical benchmarks for both neutral and charged massless probes, and naturally capture quasi-resonance behaviors.

We aim to clarify the experimentally observed near-degeneracy and decay patterns of the isospin, $I=1$, hidden-bottom tetraquarks $Z_b(10610)$ and $Z_b(10650)$ with quantum numbers $J^{P}=1^{+}$.We refer to them as $Z_b$ and $Z_b^{'}$, respectively. In particular, we find first evidence that the suppression of the decay of $Z_b^{'}$ to $B\bar{B^*}$ can be understood in the context of the Born-Oppenheimer Effective Field Theory (BOEFT). BOEFT enables writing both $Z_b$ and $Z_b^{'}$ as superpositions of $Z_1$ and $Z_2$ tetraquark configurations. This decomposition naturally relates the decay patterns of $Z_b$ and $Z_b^{'}$ to the degeneracy of the light degrees of freedom associated with $Z_1$ and $Z_2$ tetraquarks, {\it i.e.,} $1^{--}$and $0^{-+}$ adjoint mesons, respectively. By calculating the adjoint meson correlators within the framework of lattice QCD, we get good indications that these adjoint mesons are degenerate.