Electroweak precision tests, expressed through the oblique parameters $S$, $T$, and $U$, impose stringent constraints on physics beyond the Standard Model. Gauge extensions of the Standard Model based on the $SU(3{)}_L\times U(1{)}_N$ symmetry predict a rich scalar and gauge spectrum that contribute to these parameters. Previous studies have shown that 3-3-1 gauge bosons give negligible contributions to the oblique parameters, while the contributions of the scalar sector to these parameters have received comparatively little attention. In particular, for the version of the $SU(3{)}_L\times U(1{)}_N$ model with right-handed neutrinos, the impact of the scalar sector on $S$, $T$, and $U$ has not yet been addressed. In this work, we fill this gap and address systematically the scalar contributions to the $S$, $T$, and $U$ within this version. As main result, we show that the parameter $T$ puts stringent constraints on the masses and energy scales associated to the spectrum of scalars of the model.

We have investigated the prospects of probing the five-dimensional $U(1{)}_{L_{\mu }-L_{\tau }}$ interactions in present and future muon dump experiments, namely, $\mathrm{NA}64_{\mu }$, ${\mathrm{M}}^3$, MuSIC, and a future muon beam dump experiment. These experiments are classified into two categories: the first two can probe processes where feebly interacting massive particles go into invisible channels, while the latter two can probe processes where these states decay into muon pairs. These two types of experiments are complementary in that they allow exploration of different parameter regions of a model. In our scenario, the presence of multiple massive gauge bosons as Kaluza-Klein (KK) particles leads to an enhancement in the signal events compared to the corresponding four-dimensional scenario. In particular, the decay process into muon pairs enables mass reconstruction of the parent particle, making it possible to directly demonstrate the existence of multiple KK particles in at least some parameter regions. This can provide clear evidence that the origin of the $U(1{)}_{L_{\mu }-L_{\tau }}$ interaction lies in five dimensions. Furthermore, the muon ($g-2$) value, which is now consistent with the Standard Model, can be used to exclude specific parameter regions for new particles interacting with muons. We also carefully discuss the nontrivial effects arising from nonzero kinetic mixing.

We investigate axion-photon conversion in stochastic magnetic fields, focusing on the evolution of the photon intensity and polarizations induced by conversion into axions. Assuming Gaussian magnetic fields characterized by the power spectra of their helical/nonhelical components, we express the expectation values and variances of the photon intensity and linear/circular polarizations after conversion in terms of these spectra. We find nontrivial dependencies of these statistical quantities on the characteristic magnetic-field correlation length, the propagation distance, and the axion mass. Moreover, we find that nontrivial polarizations emerge even if the photons are initially unpolarized, that the variances of these observables become suppressed in specific frequency regions, and that a peak structure arises in the expectation value of the circular polarization in the presence of statistically helical magnetic fields. We also point out consistency relations among these statistical quantities that hold independently of the specific forms of the magnetic-field power spectra.

The approaches to searching for axionlike signals based on pulsars include observations with pulsar timing arrays and pulsar polarization arrays. However, these methods are limited by observational uncertainties arising from multiple unknown and periodic physical effects, which substantially complicate subsequent data analysis. To mitigate these issues and improve data fidelity, we propose the artificial pulsar polarization arrays (APPA): a satellite network comprising multiple pulsed signal transmitters and a dedicated receiver satellite. To constrain the axion-photon coupling parameter $g_{a\gamma }$, we generate simulated observations using Monte Carlo methods and investigate the sensitivity of APPA using two complementary approaches: likelihood analysis and frequentist analysis. Simulations indicate that for the axion mass range of ${10}^{-22}–{10}^{-18}\mathrm{eV}$, APPA yields a tighter upper limit on $g_{a\gamma }$ [at the 95% Confidence Level (CL)] than conventional ground-based observations, while also achieving superior detection sensitivity. Moreover, a larger spatial distribution scale of the satellite network corresponds to a greater advantage in detecting axions with lighter masses.

We construct and analyse two-dimensional, current-carrying ring solutions, known as kinky vortons, in the ${\mathbb{Z}}_2$-symmetric global two-Higgs-doublet model (2HDM). We demonstrate the existence of multiple dynamically stable configurations that persist under nonaxially symmetric perturbations. These solutions are described with high accuracy by the thin string approximation and elastic string formalism, which correctly capture both their equilibrium radii and dynamical oscillation frequencies. Kinky vortons in the ${\mathbb{Z}}_2$-symmetric theory establish the viability of vorton solutions in a phenomenologically motivated extension of the Standard Model, and should provide a computationally tractable proxy for vortons in the $U(1)$-symmetric 2HDM. In addition, we identify a composite domain wall configuration in which localized condensates are supported on secondary domain walls existing on a ${\mathbb{Z}}_2$ wall, suggesting a mechanism by which kinky-vorton-like defects could arise in a three-dimensional setting.

We investigate the parameter space supporting large $CP$ violation (CPV) in the complex two-Higgs-doublet model with softly broken $Z_2$ symmetry, where the 125 GeV Higgs boson is identified as the lightest neutral Higgs boson $H_1$. Through a comprehensive global scan of type-I and type-II models under theoretical, collider, and eEDM constraints, we identify distinct structures that facilitate large CPV. In type-I, gauge-sector CPV is maximized when the 125 GeV Higgs boson is nearly degenerate with a second neutral scalar. For the ensemble of physically viable points, the predicted eEDM values typically exceed ${10}^{-31}e\mathrm{cm}$, placing the model largely within the sensitivity of next-generation experiments. Conversely, type-II models strongly suppress gauge-sector CPV while allowing for nearly maximal CPV in the Yukawa sector. Destructive interference among various contributions allows for $|d_e|$ values as low as $\mathcal{O}({10}^{-35})e\mathrm{cm}$, resulting in no phenomenologically relevant lower bound. Finally, we uncover the phenomenon of “hidden CPV” in the near-alignment limit, characterized by $CP$-violating mixing between the heavy neutral Higgs bosons governed by the angle ${\alpha }_3$. We demonstrate that this hidden CPV can be experimentally probed at future colliders via $CP$-violating Yukawa interactions of $H_2$ and $H_3$, as well as the robust $H_2\text{−}{H}_3\text{−}Z$ coupling.

Intersecting D-brane model building often suffer from the unstabilized open-string moduli, leading to the unwanted massless adjoint scalars. In our previous work [Phys. Rev. D 112, 055006 (2025)], this issue was resolved by employing the rigid D6-branes on the ${\mathbb{T}}^6/({\mathbb{Z}}_2\times {\mathbb{Z}}_2^{\prime })$ orientifold with discrete torsion, where fractional cycles eliminate all adjoint scalars. In this paper, we construct new three-family flux models in the type IIB setup on ${\mathbb{T}}^6/({\mathbb{Z}}_2\times {\mathbb{Z}}_2)$, T-dual to the type IIA rigid D6-brane construction with discrete torsion, by introducing the quantized background $G_3$ flux that stabilizes the closed-string complex structure moduli and axio-dilaton. The resulting Pati-Salam gauge symmetry can be spontaneously broken down to the Standard Model via a supersymmetry-preserving Higgs mechanism. All the consistency conditions, including $\mathcal{N}=1$ supersymmetry, RR tadpole cancellation, and K-theory constraints, are satisfied. We present the complete particle spectra for these models and discuss how exotic states dynamically decouple through strong dynamics in the hidden sector.

We report on a search for a gravitationally bound solar axion halo using data from the global network of optical magnetometers for exotic physics searches (GNOME), a worldwide array of magnetically shielded atomic magnetometers with sensitivity to exotic spin couplings. Motivated by recent theoretical work suggesting that self-interacting ultralight axions can be captured by the Sun’s gravitational field and thermalize into the ground state, we develop a signal model for the pseudomagnetic fields generated by axion-proton gradient couplings in such a halo. The analysis focuses on the fifth GNOME Science Run (69 days, 12 stations), employing a cross-correlation pipeline with time-shifted daily modulation templates to search for the global, direction-dependent, monochromatic signal expected from a solar axion halo. No statistically significant candidate signals are observed. We set 95% confidence-level upper limits on the amplitude of the axion-induced pseudomagnetic field over the frequency range $\approx 0.05–20\mathrm{Hz}$, translating to constraints on the linear and quadratic axion–proton couplings for halo densities predicted by gravitational capture models and for the maximum overdensities allowed by planetary ephemerides. In the quadratic coupling case, our limits surpass existing astrophysical bounds by over two orders of magnitude across much of the accessible parameter space.

We present a new determination of the $\overline{b}\overline{b}ud$ ($J^P=1^{+}$, $I=0$) tetraquark binding energy using lattice quantum chromodynamics (QCD) with domain-wall light quarks and a nonperturbatively tuned three-parameter anisotropic-clover “relativistic” action for the $b$ quarks. We also perform a direct comparison with a reanalysis of data generated in prior work using a lattice-nonrelativistic QCD (NRQCD) action for the $b$ quarks and otherwise identical parameters. Using the new data with relativistic $b$ quarks from seven different ensembles with multiple lattice spacings and pion masses, we perform combined chiral and continuum extrapolations and obtain $(m_{T_{bb}}-m_B-m_{B^{*}}{)}_{\mathrm{RHQ}}=(-76\pm 23)\mathrm{MeV}$. For the NRQCD data from five ensembles, we perform chiral-only extrapolations and obtain $(m_{T_{bb}}-m_B-m_{B^{*}}{)}_{\mathrm{NRQCD}}=(-74\pm 17\pm 10)\mathrm{MeV}$. The lower magnitude of the results obtained here, compared to the original analysis in [Phys. Rev. D 100, 014503 (2019)], is due to the use of the symmetric parts of the correlation matrices with local four-quark operators only.

We present a unified description of the low-lying $1P$- and $2S$-wave nucleon resonance within the framework of an extended Lee-Friedrichs scheme. By incorporating the coupled-channel dynamics between bare quark-model states and the $\pi N$, $\pi \mathrm{\Delta }$ and $\eta N$ meson-baryon continua, we examine the mass shifts and structural properties of these excited states. We demonstrate that when the model parameters are calibrated to match the $1P$-wave spectrum and their widths, the pole associated with the bare $2S$ state is naturally shifted downward to the mass region of physical Roper resonance–$N(1440)$, thereby offering a dynamical explanation for the long-standing level-inversion problem. An approximate analysis of compositeness and elementariness reveals that the Roper resonance contains a significant meson-baryon continuum states, consistent with the picture of a bare core heavily dressed by meson-baryon cloud. Simultaneously, the pole positions and properties of five $1P$-wave resonances–$N(1535)$, $N(1650)$, $N(1520)$, $N(1700)$ and $N(1675)$—are successfully reproduced. Our results highlight the essential role of coupled-channel effects in shaping the nucleon spectrum and provide a consistent microscopic insight into the interplay between internal quark degrees of freedom and external hadronic fields.

We investigate the $s$-wave $KN$ scattering up to next-to-leading order within a renormalizable framework of covariant chiral effective field theory. Using time-ordered perturbation theory, the scattering amplitude is obtained by treating the leading-order interaction nonperturbatively and including the higher-order corrections perturbatively via the subtractive renormalization. We demonstrate that the nonperturbative treatment is essential, at least at lowest order, in the SU(3) sector of $KN$ scattering. Our next-to-leading-order study achieves a good description of the empirical $s$-wave phase shifts in the isospin $I=1$ channel. An analysis of the effective range expansion yields a negative effective range, consistent with some partial wave analyses but opposite in sign to earlier phenomenological summaries. For the $I=0$ counterpart, the $KN$ interaction is found to be rather weak and exhibits large uncertainties. Further low-energy $KN$ scattering experiments and lattice QCD simulations are needed to better constrain both $s$-wave channels.

The shear-induced polarization plays a crucial role in understanding the local polarization of $\mathrm{\Lambda }$ and $\overline{\mathrm{\Lambda }}$ hyperons. A key puzzle is whether the shear-induced polarization is nondissipative or not. In this work, we analyzed the shear-induced polarization and the anomalous Hall effects using the entropy flow and H theorem introduced from quantum (chiral) kinetic theory. While the shear-induced polarization and the anomalous Hall effect do not directly contribute to the entropy production rate, the perturbations associated with the shear tensor lead to an increase in entropy, similar to the role of the shear tensor in classical kinetic theory. We also examined these effects within the framework of linear response theory using Zubarev’s approach. Our analysis based on Zubarev’s approach suggests that these effects may indeed possess a dissipative nature. These findings highlight the limitations of the current theoretical framework in fully characterizing the dissipative properties of these phenomena.

We investigate the spectrum of $T_{\mathrm{\Upsilon }\mathrm{\Upsilon }}$ tetraquark candidates within a coupled-channel framework. The analysis includes all $L\le 2$ combinations of $\mathrm{\Upsilon }(1S)$, $\mathrm{\Upsilon }(2S)$, ${\eta }_b(1S)$, and ${\eta }_b(2S)$ in the $J^P=0^{\pm },1^{\pm },2^{\pm }$ sectors. The meson-meson interaction is derived from an underlying constituent quark model through the resonating group method, and the properties of the states are obtained from poles of the scattering matrix. We find a rich spectrum of resonant, and virtual, states distributed between the ${\eta }_b(1S){\eta }_b(1S)$ and $\mathrm{\Upsilon }(2S)\mathrm{\Upsilon }(2S)$ thresholds. The pattern of poles exhibits approximate heavy-quark spin symmetry multiplets. Several states are dominated by a single channel and can be associated with threshold-driven structures, while higher-mass resonances show sizable mixing among channels involving radially excited bottomonia. The predicted widths range from tens to several hundred MeV. Branching ratios indicate that many states couple predominantly to final states with at least one excited bottomonium, whereas only a subset of the spectrum is expected to be visible in the ${\eta }_b(1S){\eta }_b(1S)$, ${\eta }_b(1S)\mathrm{\Upsilon }(1S)$ and $\mathrm{\Upsilon }(1S)\mathrm{\Upsilon }(1S)$ channels. These results provide quantitative guidance for experimental searches of fully heavy tetraquarks and offer a test of coupled-channel dynamics and heavy-quark spin symmetry in the $bb\overline{b}\overline{b}$ sector.

In this work, we employ both theoretical and data-driven methods to derive the QCD vacuum energy, utilizing the GMOR relation, the low-energy theorem, and the equation of state from lattice QCD. The QCD vacuum energy is determined to be between around $(163\mathrm{MeV}{)}^4$ and $(190\mathrm{MeV}{)}^4$. With the assumptions of complete deconfinement, vanishing gluon condensate, full chiral-symmetry restoration, and the validity of perturbative QCD at baryon chemical potentials of order of the proton mass, a very specific kind of quark nugget is found to be less stable than ordinary nuclei.

The determination of the Higgs boson trilinear self-coupling ${\lambda }_{3H}$ is a key goal of the LHC physics program. Its precise measurement will provide unique insight into the scalar potential and the mechanism of electroweak symmetry breaking. Higgs boson pair production in the $gg\to HH$ process, and particularly in the $HH\to b\overline{b}\gamma \gamma$ final state, offers direct sensitivity to ${\lambda }_{3H}$. We present the first implementation of the matrix element method (MEM) at next-to-leading order (NLO) for this process, which is publicly available. The MEM is a statistically optimal approach that maximizes information extraction from collision events. Extending it to NLO represents a major methodological challenge, which we address with a new formalism integrated into the momemta framework. Results with simulated pseudoexperiments demonstrate, in a proof-of-principle study, the strong discriminating power of the method and its ability to extract the coupling modifier ${\kappa }_{\lambda }={\lambda }_{3H}/{\lambda }_{3H}^{\mathrm{SM}}$ with high precision.

The paper is dedicated to the reanalysis of our previous long-term results, obtained in a fitting of all actual nucleon electromagnetic form factors data by the various modifications of the unitary and analytic model of nucleon electromagnetic structure, which led us to a prediction of the unacceptable inequality ${\sigma }_{\mathrm{tot}}(e^{+}{e}^{-}\to n\overline{n})>{\sigma }_{\mathrm{tot}}(e^{+}{e}^{-}\to p\overline{p})$. Finally, by means of the most accomplished version of the model in this paper, it is revealed that the numerical values of free parameters of the proton electromagnetic form factors determined in a fitting procedure of all existing experimental data do not reproduce the data on the total cross section ${\sigma }_{\mathrm{tot}}(e^{+}{e}^{-}\to p\overline{p})$, from which overwhelming majority of the proton form factors data with errors has been initially evaluated. On that account, in a repeated analysis all proton electromagnetic form factors data obtained from the total cross section ${\sigma }_{\mathrm{tot}}(e^{+}{e}^{-}\to p\overline{p})$ data have been excluded and a correction of the model parameters by a simultaneous fit of only the most reliable proton electromagnetic form factors in the spacelike and timelike regions, obtained by different methods, like polarization experiments and angular distribution measurements, has been carried out. The latter procedure got us finally into such forms of nucleon electromagnetic form factors that a theoretically predicted ${\sigma }_{\mathrm{tot}}(e^{+}{e}^{-}\to n\overline{n})$ behavior, despite of the small difference of the neutron and proton masses caused by the isotopic invariance violation, is found to be predominantly lower than the experimental ${\sigma }_{\mathrm{tot}}(e^{+}{e}^{-}\to p\overline{p})$ cross section, in consistency with a natural law of probabilities of the $e^{+}{e}^{-}\to h\overline{h}$ processes and also with recent measurements of ${\sigma }_{\mathrm{tot}}(e^{+}{e}^{-}\to n\overline{n})$.

The determination of the weak mixing angle, ${\sin }^2{\theta }_W$, at low momentum transfers remains a powerful test of the Standard Model and its potential new physics extensions. In this paper, we explore some physics opportunities at present and future reactor neutrino experiments through elastic neutrino-electron scattering ($\mathrm{E}\nu \mathrm{ES}$). We assess the expected sensitivity to the weak mixing angle considering the CLOUD, TAO, and DANSS experimental configurations. We find that both CLOUD and TAO may achieve a precision that surpasses the current global fit from reactor experiments, while DANSS alone is expected to surpass the benchmark precision set by TEXONO measurement of the weak mixing angle. Additionally, we derive projected upper limits for the nonstandard neutrino interactions, effective neutrino magnetic moment (${\mu }_{\nu }$) and translate these into constraints on the neutrino transition magnetic moments (${\mathrm{\Lambda }}_i$). Our results demonstrate the physics potential of the $\mathrm{E}\nu \mathrm{ES}$ channel at current and upcoming reactor-based neutrino experiments.

We investigate the modeling of weak boson number densities for leptons and hadrons in practical calculations in the Standard Model. In the framework of the Effective $W$ Approximation (EWA) and in the $R_{\xi }$ and axial gauges, we derive the unrenormalized, tree-level parton number densities for weak bosons from massless fermions at next-to-leading power in the collinear expansion. Corrections exhibit various pathologies and properties, including those conjectured but not proven, and parallel heavy quark factorization. We suppress pathologies through a new set of kinematical consistency conditions. When satisfied, shapes and normalizations of full matrix elements for many-leg processes can be well approximated by the EWA and fragmentation contributions at leading power, suggesting the onset of tree-level factorization. Findings also suggest that the EWA is testable at the LHC with $\mathcal{L}=450{\mathrm{fb}}^{-1}$ of same-sign $WW$ scattering data at $\sqrt{s}=13.6\mathrm{TeV}$.

We present a high-statistics measurement of muon antineutrino-induced charged-current neutral pion production on a hydrocarbon target using the NOvA near detector. The differential cross sections as functions of the momenta and angles of the outgoing pion and muon, the squared four-momentum transfer, and the invariant mass of the hadronic system at an average neutrino energy of 2 GeV are measured and compared with predictions from various neutrino interaction models. The results agree with the GENIE prediction but suggest that other models underestimate the cross section in the $\mathrm{\Delta }(1232)$ resonance region. These results represent the most precise measurement of antineutrino-induced neutral pion production to date.

We report first results from RadioAxion, an underground experiment searching for axion dark matter through periodic modulations of radioisotope decays. We monitor the $\alpha$ decay of ${}^{241}\mathrm{Am}$ via its 59.5 keV $\gamma$ line using a NaI detector installed at the Gran Sasso Laboratory, where cosmic-ray-induced systematics are strongly suppressed. We present the measured spectra and the corresponding time-series analysis. No evidence for a periodic modulation is observed. From these data, we derive constraints on the axion decay constant in the axion mass range from ${10}^{-21}$ to ${10}^{-9}\mathrm{eV}$.