We analyze the rho meson unpolarized and polarized transverse momentum dependent parton distribution functions (TMDPDFs) in the instanton liquid model (ILM). The corresponding TMDs in ILM are approximated by a constituent quark beam function in the leading Fock state multiplied by a rapidity-dependent factor resulting from the staple-shaped Wilson lines, for fixed longitudinal momentum, transverse separation, and rapidity. At the resolution of the ILM, all of the rho meson TMDs are symmetric in parton $x$ for fixed transverse momentum, and Gaussian-like in the transverse momentum for fixed parton $x$. The latter is a direct consequence of the profiling of the quark zero modes in the ILM. The evolved TMDs at higher rapidity using the Collins-Soper kernel, and higher resolution using the renormalization group, show substantial skewness towards low parton $x$.

The chiral quark-soliton model applied to baryons with one heavy quark predicts new exotic states belonging to three $\overline{\mathbf{15}}$ SU(3) multiplets. Here, we extend previous analysis of charm exotica to the case of beauty. All model parameters are fixed from the charm sector and from the nonexotic $b$-baryons. We present predictions for masses of beautiful exotica and discuss the decay widths, which are either very small or relatively large.

We report measurements of the ratios of branching fractions $\mathcal{R}(D^{(*)+})=\mathcal{B}({\overline{B}}^0\to D^{(*)+}{\tau }^{-}{\overline{\nu }}_{\tau })/\mathcal{B}({\overline{B}}^0\to D^{(*)+}{\ell }^{-}{\overline{\nu }}_{\ell })$, where $\ell$ denotes either an electron or a muon. These ratios test the universality of the charged-current weak interaction. The results are based on a $365{\mathrm{fb}}^{-1}$ data sample collected with the Belle II detector at the SuperKEKB $e^{+}{e}^{-}$ collider, which operates at a center-of-mass energy corresponding to the $\mathrm{\Upsilon }(4S)$ resonance, just above the threshold for $B\overline{B}$ production. Signal candidates are reconstructed by selecting events in which the companion $B$ meson from the $\mathrm{\Upsilon }(4S)\to B\overline{B}$ decay is identified in semileptonic modes. The $\tau$ lepton is reconstructed via its leptonic decays. We obtain $\mathcal{R}(D^{+})={0.418}_{-0.073}^{+0.075}{(\mathrm{stat})}_{-0.056}^{+0.049}(\mathrm{syst})$ and $\mathcal{R}(D^{*+})={0.306}_{-0.033}^{+0.035}{(\mathrm{stat})}_{-0.018}^{+0.016}(\mathrm{syst})$, which are consistent with world average values. Accounting for the correlation between them, these values differ from the Standard Model expectation by a collective significance of 1.7 standard deviations.

We describe the implementation of a model for charged-current quasielastic (CCQE) neutrino-nucleus scattering in the NEUT Monte Carlo event generator. This model employs relativistic momentum distributions obtained from mean-field theory and relativistic distorted waves to describe the initial and final nucleon states. Final state interactions, both elastic and inelastic, are modeled by combining distorted waves with NEUT’s intranuclear cascade, offering a more accurate representation of the interactions experienced by scattered nucleons. The model and its implementation in NEUT are described in detail and benchmarked against ${\nu }_{\mu }\text{−}{}^{12}\mathrm{C}$ scattering cross section measurements from T2K and $\mathrm{MINER}\nu \mathrm{A}$, as well as ${\nu }_{\mu }\text{−}{}^{40}\mathrm{Ar}$ measurements from MicroBooNE. The results, including transverse kinematic imbalance variables and scattered nucleon kinematics, show improved ${\chi }^2$ values compared to other CCQE models in NEUT. Furthermore, the model consistently predicts lower cross sections in CCQE-dominated regions, indicating the potential for further refinement, such as incorporating two-body currents or the use of more advanced nucleon axial form factors consistent with lattice QCD calculations.

We propose the first method for water Cherenkov detectors to constrain GeV-scale dark matter (DM) below the solar evaporation mass. While previous efforts have highlighted the Sun and Earth as DM capture targets, we demonstrate that Jupiter is a viable target. Jupiter’s unique characteristics, such as its lower core temperature and significant gravitational potential, allow it to capture and retain light DM more effectively than the Sun, particularly in the mass range below 4 GeV where direct detection sensitivity diminishes. Our calculations provide the first sensitivity estimates to GeV-scale annihilating DM within Jupiter, predicting Hyper-K can reach spin dependent cross sections as low as ${\sigma }_{p\chi }^{\mathrm{SD}}=2\times {10}^{-35}{\mathrm{cm}}^2$ for DM masses below 2 GeV. This surpasses current solar limits and direct detection results. We additionally provide estimates for Super-K ORCA, and the IceCube-Upgrade, showing that these experiments could provide complimentary bounds to direct detection experiments.

The recent observation of the ultrahigh-energy neutrino event KM3-230213A by the KM3NeT experiment offers a compelling avenue to explore physics beyond the Standard Model (SM). In this paper, we explore a simplest possibility that this event originates from the decay of a super-heavy dark matter (SHDM). We consider a minimal scenario where the SHDM decays to neutrino and SM Higgs. We derive constraints on the DM lifetime as a function of DM mass, ensuring consistency with IceCube, Auger upper limits, and the observed KM3-230213A event, along with the gamma-ray constraints. We find that KM3-230213A gives stringent constraint on the DM mass ranging from $1.5\times {10}^8\mathrm{GeV}$ to $5.2\times {10}^9\mathrm{GeV}$ with lifetime in the range: $1.42\times {10}^{30}\mathrm{s}$ to $5.4\times {10}^{29}\mathrm{s}$. Remarkably, in our SHDM scenario, the apparent tension between the KM3NeT observation and the nonobservation of this event by IceCube and Auger can be reduced to below $1.2\sigma$. Our results are applicable to any neutrinophilic SHDM models while evading gamma-ray constraints.

Current and most upcoming neutrino detectors can only reach a dark matter annihilation cross section to neutrinos larger than the standard freeze-out value, but they open intriguing detection avenues for nonstandard dark matter paradigms. An important corollary of these nonstandard scenarios is relic dark matter annihilation after neutrino decoupling, which was previously overlooked in constraining MeV-scale dark matter. However, by combining the contributions from entropy injection during neutrino decoupling and from nonthermal neutrino energy release after decoupling, we derive significant constraints on the annihilation cross section to neutrinos, which in some mass regimes become stronger than the current bounds. Furthermore, we find that the lower bounds on dark matter masses become inconclusive under the recent data releases from the Dark Energy Spectroscopic Instrument, South Pole Telescope 3G, and Atacama Cosmology Telescope collaborations. These bounds determine the extent to which upcoming neutrino detectors will probe dark matter annihilation into neutrinos.

This study investigates the gravitational dynamics of a spherically symmetric black hole embedded within a dark matter halo, focusing on the impact of the dark matter halo on timelike particle geodesics. We analyze key orbital parameters, including marginally bound orbits, innermost stable circular orbits, and periodic orbits, demonstrating how the dark matter halo alters their energy and angular momentum compared to an isolated black hole. Furthermore, we calculate the gravitational waveforms emitted by these periodic orbits, providing potential observational signatures for such systems. Our results demonstrate a clear correlation between the gravitational waveforms emitted by a small object orbiting a supermassive black hole and the object’s zoom-whirl orbital behavior. Higher zoom numbers correspond to more complex waveform substructures. The presence of a dark matter halo significantly impacts these waveforms. We have conducted a detailed analysis of the frequency spectra of the gravitational waveforms arising from these periodic orbits and evaluated their potential detectability. This research contributes to a deeper understanding of the interplay between black holes and dark matter halos, offering insights into their complex gravitational interactions.

In our previous paper [Keeler et al., From Navier-Stokes to Maxwell via Einstein, J. High Energy Phys. 08 (2020) 147.] we discussed type-D and type-N fluid-dual spacetimes and provided their associated single copies in the context of the Weyl double copy. In this work we extend our analysis to more general fluids thereby requiring the application of the double-copy picture to type-II spacetimes. By combining our previous type-D and type-N fluids via their associated stream functions we construct an example of a viable type-II double copy. We show that the gravity duals of these fluids perturbatively satisfy Einstein’s equations. We use a near-horizon expansion to identify the type-II double copy for the fluid-dual spacetimes. We show a Maxwell spinor ansatz containing a heterogeneous bispinor component is necessary to provide a viable type-II double copy at the lowest order.

Electrically and magnetically charged (a.k.a. dyonic) black holes with scalar hair have recently been constructed for a sextic scalar field potential. Here, we reinvestigate this model, but with a bounded scalar field potential of exponential form. We demonstrate that qualitative differences appear. First, we present scalar clouds on (dyonic) Reissner-Nordström black holes as well as (dyonically) charged clouds on Schwarzschild black holes, respectively. We then extend our results to the fully backreacted case and put the focus on the comparison of the electrically charged black holes with their dyonic counterparts.

We study cosmic strings in the complex symmetron model, a scalar-tensor theory with a spontaneously broken local $U(1)$ symmetry in low matter density regions. Using numerical simulations, we show that these strings preferentially attach to matter halos, leading to the stabilization of string loops. While the requirement for screening of fifth-force interactions in the solar-system limits observable signatures in theories with universal coupling to matter, analogous topological defects in the dark sector may still influence cosmic structure formation, offering a novel avenue to constrain dark-sector interactions.

We investigate the properties of the static neutron stars and strangeness-mixed stars, based on the equations of state derived from a pion mean-field approach. Using the empirical data on the pion-nucleus scattering and bulk properties of nuclear matter, we have already fixed all of the parameters in a previous work, where the nucleons and hyperons were shown to be modified in various nuclear media. In the current work, we first examine the energy and pressure inside a neutron star. We show that the central densities in various neutron stars vary within the range of $(3–4){\rho }_0$, where ${\rho }_0$ is the normal nuclear matter density. The mass-radius relations are obtained and discussed. As the slope parameter for neutron matter increases, the radii of the neutron stars increase with their masses fixed. We also study the strangeness-mixed stars or the hyperon stars using the same sets of parameters. As the strangeness content of strange matter increases, the binding energy per nucleon is saturated and the corresponding equation of state becomes softened. Consequently, the central densities of the strangeness-mixed stars increase. Assuming that recently observed neutron stars are the strangeness-mixed ones, we find that the central densities increase.

In this paper, we consider a secular orbital evolution of a supermassive binary black hole (SBBH) with unequal masses $M_p$ and $M_s<M_p$ immersed in a central part of a nonspherical nuclear star cluster (NSC). When the mass of NSC enclosed inside the orbit becomes smaller than $M_s$, dynamical friction becomes inefficient. The subsequent orbital evolution of SBBH is largely governed by perturbing tidal potential of NSC arising from its nonsphericity. When the perturbing potential is mainly determined by quadrupole harmonics with azimuthal number $|m|=2$, the corresponding secular dynamics of the SBBH does not conserve any components of the angular momentum and can lead, for this reason, to the formation of highly eccentric orbits. Then such orbits can experience an efficient circularization due to emission of gravitational waves (GWs). In this paper, we consider this situation in some detail. We study analytically the secular evolution taking into account the important effect of Einstein apsidal precession and estimate the largest possible value of $e$, which can be obtained. We confirm and extend our analytic results by solving numerically the secular equations. These results are used to estimate a possibility of fast orbital circularization through emission of gravitation waves on a highly eccentric orbit, with a circularization timescale of the order of the orbital period. We find that our mechanism could result in such events on a timescale of the order of or smaller than a few Gyr. It is stressed that for particular values of the model parameters, such events may sometimes be distinguished from the ones expected in more standard scenarios, since in our case, the eccentricity may remain substantial all the way down to the final merger. It is also noted that our results can be applied to other astrophysical settings, e.g., to study the orbital evolution of a binary star or a proto planetary system inside a massive deformed gas cloud.

Gravitational-wave (GW) approximants are essential for gravitational-wave astronomy, allowing the coverage of the binary black hole parameter space for inference or match filtering without costly numerical relativity (NR) simulations but generally trading some accuracy for computational efficiency. To reduce this trade-off, NR surrogate models can be constructed using interpolation within NR waveform space. We present a two-stage training approach for neural network-based NR surrogate models. We initially train four models on waveforms generated from four different GW approximants and then fine-tune these models on NR data. We show that despite the median mismatches of the pretrained models with NR ranging over two orders of magnitude, the fine-tuned models all reach median mismatches of order ${10}^{-5}$, on par with top-performing NR surrogates. The dual-stage artificial neural surrogate (DANSur3dq8) models also offer rapid waveform generation, with millions of waveforms being generated in under 20 ms on a GPU. Implemented in the bilby framework, we show DANSur3dq8 can be used for parameter estimation tasks.

We present comprehensive calculations of the electromagnetic form factors, including the charge, magnetic-dipole, electric-quadrupole, and magnetic-octupole form factors, of the ${\mathrm{\Omega }}^{-}$ in the spacelike region using the quark-diquark approach, incorporating the effect of the meson cloud. The obtained magnetic moment is in agreement with the experimental measurement, and the electromagnetic radii are comparable with other model calculations. It is found that the meson cloud effect remains almost unchanged as the energy becomes high, and this feature implies that the meson cloud should be considered in all the energy regions. Moreover, the asymptotic relations allow us to extend the electromagnetic form factors from the spacelike region to the timelike region, and then the effective form factor is almost identical with the data from CLEO and BESIII. Finally, polarization properties of the final state ${\mathrm{\Omega }}^{-}$ in the $e^{+}{e}^{-}\to {\mathrm{\Omega }}^{-}{\overline{\mathrm{\Omega }}}^{+}$ process with the unpolarized initial states are also investigated.

Motivated by the recent LHCb measurements of the ratios between the branching ratios (BRs), $R_{{\chi }_{c2}/J/\psi }\equiv \mathrm{BR}(B_c^{+}\to {\chi }_{c2}{\pi }^{+})/\mathrm{BR}(B_c^{+}\to J/\psi {\pi }^{+})$ and $R_{{\chi }_{c1}/{\chi }_{c2}}\equiv \mathrm{BR}(B_c^{+}\to {\chi }_{c1}{\pi }^{+})/\mathrm{BR}(B_c^{+}\to {\chi }_{c2}{\pi }^{+})$, we analyze the decays $B_c^{+}\to {\chi }_{cJ}(P,V{)}^{+}$ in the improved perturbative QCD (iPQCD) formalism, where ${\chi }_{cJ}$ denotes the $p$-wave charmonia with $J=0$, 1, 2, and $P(V)$ denotes the pseudoscalars $\pi$ and $K$ (the vectors $\rho$ and $K^{*}$). Our results $R_{{\chi }_{c2}/J/\psi }=0.32\pm 0.05$ and $R_{{\chi }_{c1}/{\chi }_{c2}}=0.11\pm 0.01$ at leading order in the strong coupling ${\alpha }_s$ agree well with the data within uncertainties. The result $R_{{\chi }_{c0}/J/\psi }\equiv \mathrm{BR}(B_c^{+}\to {\chi }_{c0}{\pi }^{+})/\mathrm{BR}(B_c^{+}\to J/\psi {\pi }^{+})=0.17\pm 0.02$ is lower than ${1.41}_{-0.45}^{+0.50}$ inferred by the $B_c^{+}\to {\chi }_{c0}{\pi }^{+}$ measurement. The large longitudinal polarization fractions imply that these components dominate the $B_c^{+}\to {\chi }_{c1,c2}{\rho }^{+}$ BRs. A peculiar constructive (destructive) interference between the twist-2 and twist-3 contributions is identified in the $B_c^{+}\to {\chi }_{c1}{\rho }^{+}$ ($B_c^{+}\to {\chi }_{c1}{\pi }^{+}$) mode, but not in the corresponding ones with ${\chi }_{c0,c2}$ mesons. Inputting the BRs of the strong decays ${\chi }_{c0,c2}\to {\pi }^{+}{\pi }^{-}/K^{+}{K}^{-}$ and ${\chi }_{cJ}\to {\pi }^{+}{\pi }^{-}({\pi }^{+}{\pi }^{-}/K^{+}{K}^{-})$ reported by the BESIII Collaboration, we obtain those of $B_c^{+}\to {\chi }_{cJ}(\rho ,\pi {)}^{+}$ followed by secondary decay chains under the narrow-width approximation. All the above iPQCD predictions can be confronted by more precise experiments in the future to deepen our understanding of QCD dynamics in $B_c\to {\chi }_{cJ}$ transitions.

In the minimal gauged $\mathrm{B}-\mathrm{L}$ extension of the Standard Model, we demonstrate that PeV-scale dark matter (DM) and the baryon asymmetry of the Universe (BAU) can be simultaneously explained through the three right-handed neutrinos (RHNs) present in the theory. The DM candidate undergoes rare decay into light neutrinos, providing an explanation for the observed IceCube events, while the other two RHNs generate the BAU via leptogenesis. The breaking of gauge symmetry gives rise to detectable gravitational waves (GWs) from decaying cosmic strings (CS), making this framework testable at several future GW detectors—despite being beyond the reach of conventional collider experiments due to the extremely weak gauge coupling. The symmetry-breaking scale establishes a connection between particle masses, couplings, and the GW spectrum, offering a unified and predictive scenario.

It is known that single-field freeze-in dark matter barely leaves footprints in dark matter direct detection and collider experiments. This situation can be altered in the two-field context. In this work we propose a two-field freeze-in dark matter model through the Higgs portal. The observed dark matter relic abundance is obtained by a decay of scalar mediator thermalized in the early Universe. While there is a lack of direct dark matter signals, the scalar mediator is in the reach of High Luminosity LHC either through the vector boson fusion or mono-Z channels. Within the allowed scalar mass window of 10–50 GeV, we use improved cuts to derive both $2\sigma$ exclusion and $5\sigma$ discovery limits, depending on the value of Higgs portal coupling. If verified, this scalar mediator signal allows us to infer the freeze-in dark matter.

We study the impact of a nonuniform magnetic background field on the chiral magnetic effect (CME) in equilibrium QCD using lattice simulations with $2+1$ flavors of dynamical staggered quarks at the physical point. We show that in the presence of a nonuniform magnetic field the CME manifests itself via a localized electromagnetic current density along the direction of the field, which integrates to zero over the full volume. Our primary observable is the leading-order coefficient of the current in a chiral chemical potential expansion, which we compute for various lattice spacings and extrapolate to the continuum limit. Our findings demonstrate that, even though the global spatial average of the CME conductivity vanishes in equilibrium, steady currents still exist locally. Thus, spatially modulated magnetic fields provide a possible way of generating a nontrivial CME signal in equilibrium.

We develop an extended framework for the hybrid Monte Carlo (HMC) algorithm in lattice gauge theory by embedding the $SU(N)$ group into the space of general complex matrices, $M_N(\mathbb{C})$. Auxiliary directions will be completely factorized in the path integral, and the embedding does not alter the expectation values of the original theory. We perform the molecular dynamics updates by using the matrix elements of $W\in M_N(\mathbb{C})$ as the dynamical variables without group theoretic constraints. The framework enables us to introduce nonseparable Hamiltonians for the HMC in lattice gauge theory exactly, whose immediate application includes the Riemannian manifold HMC.