We investigate the multipole structure of nucleon tensor form factors within the chiral quark-soliton model based on the $1/N_c$ expansion. Extending the previous leading-order analysis [N.-Y. Ghim et al., Phys. Rev. D 111, 074024 (2025)], we include the rotational $1/N_c$ corrections. These corrections provide the leading nonvanishing contributions to the flavor components that are absent at leading order, thereby completing the flavor decomposition of the tensor multipole form factors at the present order. We numerically evaluate the isoscalar tensor charge, the isovector anomalous tensor magnetic moment, and the isoscalar tensor quadrupole moment, obtaining $g_T^{u+d}=0.81$, ${\kappa }_T^{u-d}=1.97$, and $E_T^{u+d}(0)=5.98$, respectively. The isoscalar tensor charge and quadrupole moment are mainly governed by the valence-quark contribution, whereas the isovector anomalous tensor magnetic moment receives a sizable Dirac-sea contribution. We also examine the momentum-transfer dependence of the corresponding form factors. They decrease monotonically with increasing $-t$. In particular, the isovector anomalous tensor magnetic form factor shows a pronounced falloff in the small-$|t|$ region, reflecting the importance of the Dirac sea in the tensor dipole structure.

In this manuscript, we analyze the elastic $pp$ and $p\overline{p}$ cross section in the color glass condensate framework, treating them as a dilute-dense system, and derive the phenomenological constraints (upper bounds) on the odderon-mediated part of the dipole scattering amplitude $\mathcal{O}(Y,\mathit{r},\mathit{b})$. For our analysis, we used the experimental data available from TOTEM-D0 and ISR Collaborations and constructed a combination of the cross sections which is directly proportional to the odderon-mediated part of the amplitude. This allows one to suppress possible uncertainties associated with charge-parity even part of the amplitude. We analyze two phenomenological parametrizations of odderons and demonstrate that, after minor adjustments to the global normalization, they can describe the experimental data reasonably well, although due to large experimental uncertainties the odderon amplitude remains loosely constrained.

In this work, we further develop the application of the topological diagram approach (TDA) to charmed baryon weak decays ${\mathcal{B}}_c\to \mathcal{B}V$ with a vector meson in the final state. By incorporating the Körner-Pati-Woo theorem, we show that only five independent sets of TDA parameters are required. Relations among different decay channels arising from isospin, U-spin, and V-spin symmetries are explicitly derived within the TDA framework. Partial wave contributions and form factors associated with different topological diagrams are extracted from global fits to the experimental data. It is found that the form factors $A_2$ and $B_2$ induced from the tensor interaction of the vector meson with octet baryons are comparable in magnitude to $A_1$ and $B_1$, implying the importance of the tensor coupling in ${\mathcal{B}}_c\to \mathcal{B}V$ decays. Branching fractions for all ${\mathcal{B}}_c\to \mathcal{B}V$ channels are predicted, and most measured modes are found to be in good agreement with current data. More physical observables, including up-down asymmetries, longitudinal polarizations as well as observables in the subsequent decays are also predicted. Our results provide a systematic framework for understanding charmed baryon weak decays with vector mesons and can be further tested with future experiments.

The mass spectra of charged pions (${\pi }_{\pm }$) and kaons ($K_{\pm }$) at finite magnetic field, temperature, and quark chemical potential are investigated in frame of a three-flavor Nambu–Jona–Lasinio model. Based on the analytical formula, we observe that different behavior between charged mesons and neutral mesons is induced by the isospin symmetry breaking in magnetic field, and different behavior between ${\pi }_{\pm }$ and $K_{\pm }$ mesons comes from different mass of constituent $u/d$ and $s$ quarks. With vanishing temperature and quark chemical potential, the mass of charged pions $m_{{\pi }_{+}}=m_{{\pi }_{-}}$ and charged kaons $m_{K_{+}}=m_{K_{-}}$ increase monotonically with magnetic field ($eB<40m_{\pi }^2$). With fixed magnetic field and vanishing quark chemical potential, $m_{{\pi }_{+}}=m_{{\pi }_{-}}$ and $m_{K_{+}}=m_{K_{-}}$ show nonmonotonic behavior with increasing temperature, and several mass jumps at finite temperature caused by the discrete Landau level of constituent quarks. With fixed magnetic field and vanishing temperature, $m_{{\pi }_{+}}=m_{{\pi }_{-}}$ and $m_{K_{+}}=m_{K_{-}}$ remain constant at low-quark chemical potential, and then their mass jumps occur caused by the mass jump of constituent quarks. After that, $m_{{\pi }_{+}}\simeq m_{{\pi }_{-}}$ decreases with quark chemical potential, but $m_{K_{+}}$ ($m_{K_{-}}$) first increases and then decreases (decreases monotonically) with quark chemical potential, with apparent mass deviation $m_{K_{+}}\ne m_{K_{-}}$. Furthermore, we consider the inverse magnetic catalysis (IMC) effect on meson mass spectra by using a magnetic field dependent coupling parameter $G(eB)$ in four-fermion interaction term ${\mathcal{L}}_4$ or a magnetic field dependent coupling parameter $K(eB)$ in six-fermion interaction term ${\mathcal{L}}_6$. Including IMC effect does not lead to qualitative modification for the mass spectra at finite magnetic field, temperature, and quark chemical potential.

We develop a general formalism for computing physical observables within the background field approach, based on representing propagators of the Feynman diagrams in the background fields as path-ordered exponents. This representation allows systematic expansion of the background fields onto arbitrary linear piecewise contours in coordinate space, yielding gauge-covariant QCD operators to any required order of the expansion. We apply this formalism to deeply inelastic scattering dijet production and derive a general form of the cross section in terms of (anti)quark propagators in the background fields, valid in arbitrary kinematics. To demonstrate the versatility of our approach, we consider two kinematic limits. In the back-to-back limit, the expansion contour reduces to that of transverse momentum dependent operators. In this limit we recover the known leading-power results. In the small-$x$ regime, defined by the high-energy power counting for boosted background fields, the expansion contour assumes a staplelike shape. We find that, at the leading eikonal order, the transverse component of the background field $B_i$, though parametrically suppressed relative to the light-cone component, contributes nontrivially through the field-strength tensor $F_{-i}$ and the transverse gauge links. Setting $B_i=0$ recovers the standard color glass condensate result. We also demonstrate matching between the eikonal and back-to-back expansions, providing a quantitative dictionary between these two distinct kinematic regimes.

Coherent elastic neutrino-nucleus scattering ($\mathrm{CE}\nu \mathrm{NS}$) is predominantly governed by vector neutral-current interactions, with subleading contributions arising from the axial current in nuclei with nonzero ground-state spin. Experimentally, the extraction of axial-current contributions has been so far of little interest, mainly because of the challenges its measurement entails. In this work, we investigate the relative size of the vector and axial components for target materials currently employed by the neutrino and dark matter experimental communities. We identify fluorine-based compounds as the most promising targets for probing the axial-current event rate. Among them, octafluoropropane (${\mathrm{C}}_3{\mathrm{F}}_8$) emerges as a particularly suitable candidate, given its widespread use in spin-dependent dark matter searches and its relevance for upcoming dedicated $\mathrm{CE}\nu \mathrm{NS}$ experiments. Considering both pion decay-at-rest and reactor neutrino fluxes, we show that such measurements can allow an indirect determination of the axial coupling at the $\sim 10\%$ level, depending on flux uncertainties and detector thresholds. We further emphasize that measurements of the axial current will allow one to probe spin-dependent new physics scenarios through $\mathrm{CE}\nu \mathrm{NS}$.

We study the nonperturbative and higher-order perturbative corrections on the electromagnetic ($F_{1p,2p}^{\gamma }$) and electromagnetic-weak interference ($F_{1p,2p,3p}^{\gamma Z}$) structure functions and their impact on the parity-violating electron asymmetry in the deep inelastic scattering of longitudinally polarized electron off an unpolarized proton target. The numerical results for them are presented by including the perturbative corrections beyond the leading order up to the next-next-to-leading-order and nonperturbative QCD corrections due to the target-mass corrections and the higher-twist (HT: twist-4) effects. We also present the numerical results for the electron beam spin asymmetry $A_{PV}^{(e)}(x,Q^2)$ corresponding to the JLab energies of 6 GeV, 12 GeV, and 22 GeV and discuss the feasibility of determining the $d/u$ quark distribution ratio. The results obtained in this work may be useful for the analysis of future measurements at the Electron Ion Collider (EIC) in the USA, and the Electron ion collider in China (EicC) aimed at studying parity-violating effects in the deep inelastic scattering of polarized electrons from unpolarized proton targets.

We report a comprehensive measurement of the environmental $\gamma$-ray flux in Hall C of the Gran Sasso National Laboratory. A spatial mapping of the radiation was carried out using a high-purity germanium detector mounted on a movable cart and deployed at eight locations within the hall. The detector response function and full-energy-peak efficiencies were determined through Geant4 simulations validated with calibrated $\gamma$-ray sources, with particular attention devoted to the efficiency modeling and associated systematic uncertainties. In the energy range of 57–2800 keV, the average $\gamma$-ray flux is measured to be ($0.46\pm 0.06_{\mathrm{stat}}\pm 0.03_{\mathrm{syst}}$) ${\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}$. The radon level was monitored for about a month using a radon detector mounted on the same cart, and a clear correlation is observed between the environmental $\gamma$-ray rate and the ambient radon concentration, consistent with the short-lived daughters of ${}^{222}\mathrm{Rn}$. This result represents the first high-precision and efficiency-corrected mapping of the $\gamma$-ray flux in Hall C, substantially improving its radiological characterization and providing key input for future rare-event experiments operating in this hall.

We analytically sum the leading bubble diagrams that contribute to the elastic scattering amplitude of a kink and a meson in the ${\varphi }^4$ double-well model. We find a single peak, corresponding to the unstable kink state in which the shape mode is excited twice. The peak has the usual Breit-Wigner form, and its imaginary part agrees with the shape mode decay rate found by Manton and Merabet.

In this work, we construct a static and spherically symmetric black hole solution sourced by a nonlinear scalar-vector sector within the framework of the minimal geometric deformation (MGD) approach. Starting from a scalar-vector gravity theory in which the vector field is described by nonlinear electrodynamics, the gravitational field equations are integrated to obtain a non-Schwarzschild geometry. We show that the resulting family of solutions naturally splits into two black hole branches with distinct physical properties. While one branch satisfies the odd- and even-parity stability criteria, it violates the weak energy condition outside the event horizon. Conversely, the complementary branch exhibits a more satisfactory effective matter sector, admitting a real scalar-field reconstruction and a regular nonlinear electromagnetic coupling, although it does not satisfy the odd-parity stability criterion. The causal structure and stability properties of both black hole branches are analyzed and compared, whereas the matter reconstruction, geodesic motion and thermodynamic properties are investigated for the branch exhibiting the most satisfactory effective matter sector. These results reveal the rich structure of the MGD solution space and illustrate the interplay between dynamical stability, energy conditions and causal structure.

We investigate the superhorizon behavior of scalar hair sourced by black holes in de Sitter spacetime in the linearly coupled shift-symmetric scalar-Gauss-Bonnet theory. Working in the test-field regime, we show that this hair exhibits both temporal and spatial growth on superhorizon scales. This growth is not a special consequence of the black hole, but instead follows from the dynamics of a minimally coupled massless scalar field in expanding de Sitter spacetime. Moreover, it is not even specific to black holes, but also arises for a point scalar charge in de Sitter, indicating that a scalarized black hole acts effectively as a localized subhorizon source of scalar perturbations. Backreaction, when important, first arises on subhorizon scales and does not by itself eliminate the superhorizon profile. The time-dependent scalar hair also carries a steady outward energy flux, which frames the test-field regime as a transient, and helps explain the difficulties encountered in attempts to construct self-consistent static solutions.

We compute the abundance of cosmological gravitational waves produced during the evolution of an ultralight vector (spin-1) dark matter field. A homogeneous background vector field breaks spatial isotropy, requiring a Bianchi I geometry and inducing a mixing between the scalar, vector, and tensor perturbation sectors. We derive the perturbation equations in this background and show that, as a consequence of this mixing, scalar perturbations act as a source of tensor modes, generating a stochastic gravitational wave background. The production and cosmological evolution of these gravitational waves are implemented in class.vfdm, a modified version of class, from which we obtain the present-day spectrum.

In the recent preprint by Heinesen and Clifton [arXiv:2604.07244v1], the authors introduce a novel combination of redshift, distance, and expansion rate observables for constraining cosmic backreaction observationally. The current work presents a first application of the method, in principle yielding the first direct constraints on the total cosmic backreaction in our Universe over a significant redshift range. However, we find that current data are not yet sufficient to place tight constraints on backreaction. Thus, neither vanishing nor significant backreaction can be ruled out with the presented constraints. Nonetheless, the results suggest that forthcoming survey data will enable enlightening constraints on cosmic backreaction using this method.

Detecting gravitational waves above 100 kHz would constitute a major discovery, as any observable signal would have to arise from new physics within the late universe. Although many technologies have been identified to explore this high-frequency regime, the known landscape of promising sources remains extremely sparse. In this work, we aim to rectify this issue by providing model-independent arguments that highlight the most interesting parts of theory space, while remaining agnostic of the specific signal mechanism. For example, energy-conservation implies that gravitational waves detectable by future experiments well above a MHz would most likely have to originate from within the Solar System. Based on these arguments, we also constrain the physical properties of such sources.

We study dark matter coupled to the Standard Model via electroweak scale right-handed neutrinos in a type-I seesaw framework. We consider a minimal dark sector containing a fermion $\chi$ and a complex scalar $\varphi$ whose only connection to the Standard Model is through renormalizable Yukawa interactions with right-handed Majorana neutrinos, thus realizing a neutrino portal after seesaw mixing. We discuss three representative realizations of electroweak right-handed neutrinos arising from the type-I seesaw mechanism, spanning small, tiny, and ultraweak couplings to the Standard Model sector, so that the dark particles can either undergo secluded freeze-out or be produced via freeze-in. Instead of merely estimating the order of magnitude of the seesaw couplings, we use the particle swarm optimization algorithm to obtain viable seesaw parameter sets consistent with neutrino data and other constraints, and then compute the coupled evolution of the dark particles and right-handed neutrinos, reproducing the observed dark matter relic abundance in representative benchmark scenarios. For freeze-out, dark matter depletion is controlled by coupled dark sector dynamics, requiring a full Boltzmann treatment for a reliable relic abundance. For freeze-in, internal dark interactions also alter the relic density: treating hidden particles as independent components with late decays added afterward can misestimate the abundance by 30% or even 95%, depending on the interaction structure. Electroweak right-handed neutrino portal dark matter thus provides a robust and predictive framework that tightly connects neutrino physics, heavy neutral lepton phenomenology, and the cosmological dark matter relic density, offering a well-motivated benchmark for complementary collider, neutrino, and cosmological probes at the high energy frontier.

The Belle II measurement of the branching fraction for $B^{+}\to K^{+}\nu \overline{\nu }$ shows a $2.7\sigma$ excess over the Standard Model prediction and motivates new-physics explanations such as axionlike particles, Higgs-like scalars, or beyond Standard Model gauge bosons. A two-body decay $B^{+}\to K^{+}X$ with an invisible $X$ provides a natural candidate explanation. This work provides a comprehensive test of this hypothesis using Belle II’s public model-agnostic likelihood. Posterior distributions are derived for the resonance mass $m_X$ and the branching fraction, and a modified frequentist upper-limit mass scan is performed. The data favor a resonance with mass $m_X={2.1}_{-0.1}^{+0.2}\mathrm{GeV}$ and the product $\mathcal{B}(B^{+}\to K^{+}X)·{\mathcal{P}}_{X,\mathrm{inv}}={9.2}_{-3.4}^{+1.8}\times {10}^{-6}$, where ${\mathcal{P}}_{X,\mathrm{inv}}$ is the probability that $X$ (and its decay products) are undetected. Bayes’s factors indicate a very strong preference for the Standard Model plus resonance over the Standard Model-only hypothesis. A frequentist likelihood-ratio test favors the Standard Model plus resonance hypothesis by $3.0\sigma$. A light invisible resonance plus the Standard Model therefore provides a compelling description of the Belle II data.

We show that the direction of renormalization in effective field theory is constrained by fundamental principles in the infrared—unitarity, analyticity, and Lorentz invariance. Our theorem, in the spirit of the $a$ theorem in conformal field theory, determines the sign of the one-loop running of couplings in the forward limit, when one inserts two operators whose mass dimensions are identical and even. The theorem holds for a broad class of effective field theories with arbitrary ultraviolet completions. The constraint directly applies to linear positivity bounds derived using tree-level amplitudes in the infrared, providing a criterion for whether renormalization effects can preserve the positivity bounds or lead to their apparent violation. We discuss the phenomenological implications of our theorem in chiral perturbation theory and the Standard Model effective field theory, where our theorem is particularly constraining for the running at dimension eight. We provide several examples and show various extensions and applications even at dimension six.

We investigate the spreading of entanglement, and entanglement memory effects, in two-dimensional conformal field theory (CFT) propagating on evaporating black hole backgrounds. Memory effects leading to late-time spikes in mutual information for widely separated intervals are well known in CFTs admitting a quasiparticle description. In this work we examine the effect of black hole scrambling on late time mutual information spikes for disjoint intervals in free fermion CFT prepared in a thermofield double state. Late-time entanglement revival is driven by island-induced purification of modes in the union of the intervals. We show across two distinct 2D gravity models, Jackiw-Teitelboim (JT) gravity and the Russo-Susskind-Thorlacius (RST) model, that parametrically dialing up black hole scrambling time smooths out and suppresses entanglement spikes until they disappear at a critical scale, interpolating between free quasiparticle and maximal scrambling pictures. At the critical point, the interval lengths are exponential in black hole scrambling time. We further find a very closely related effect manifest as an entanglement dip for a single interval in a single-sided evaporating RST black hole.

We study the motion of a charged test particle in the spacetime with a spherically symmetric black hole which is immersed in a monopole magnetic field. We show that the radial motion of the charged test particle is governed by completely the same equation as that in the case of no magnetic field. This result implies that the black hole will acquire the electric charge if it is surrounded by the collisionless plasma composed of protons and electrons which obey the Maxwell velocity distribution. The drastically different situation from no magnetic field case appears in the angular motions of charged test particles due to the magnetic field. The trajectory of a charged test particle around the black hole in the magnetic field of the order of 10 Gauss near the event horizon is confined on a very thin cone as long as the specific angular momentum of the particle is not much larger than the gravitational radius of the black hole times the speed of light. This result leads to a possibility that a plasma lump can hover over the black hole and is very hot, in the monopole magnetic field.

We present a local seed-to-Kerr-Schild route to Birkhoff rigidity in four-dimensional spherical vacuum gravity. On the two-dimensional orbit space, the areal radius $r$ determines a scalar $F≔-(\nabla r{)}^2$, and the reduced vacuum equations imply $F(r)=1-2M/r$. We show that the normalized one-forms $dr/F$ and $(*dr)/F$ are closed, so that the null combinations $F^{-1}(dr\pm *dr)$ are exact null seed forms. Integrating these yields local Eddington-Finkelstein coordinates in which the metric takes the Kerr-Schild form over a flat background. We then prove the corresponding uniqueness statement in the stationary optical sector: spherical symmetry forces the inverse optical seed $\mathcal{R}$ to equal $\pm r$, equivalently the optical seed $\rho$ to equal $\mp 1/r$, and the resulting seed data reconstruct the Schwarzschild family. Thus, Birkhoff rigidity is paired with a spherical converse theorem in the stationary optical framework: Schwarzschild is the unique spherically symmetric stationary vacuum Kerr-Schild geometry generated by a nowhere-vanishing optical seed.