We investigate the dynamics of $U(1)$ gauged $Q$-balls using fully three-dimensional numerical simulations. We consider two different scenarios: first, the classical stability of gauged $Q$-balls with respect to generic three-dimensional perturbations, and second, the behavior of gauged $Q$-balls during head-on and off-axis collisions at relativistic velocities. With regard to stability, we find that there exist gauged $Q$-ball configurations which are classically stable in both logarithmic and polynomial scalar field models. With regard to relativistic collisions, we find that the dynamics can depend on many different parameters such as the collision velocity, relative phase, relative charge, and impact parameter of the colliding $Q$-balls.

A number of new tetraquark candidate states containing from one to four charm or anticharm quarks have been observed recently. Many of these new states have been discovered at the LHC. The production of these states via intrinsic charm in the proton is investigated. The tetraquark masses obtained in this approach, while dependent on the internal transverse momenta of the partons in the state, are shown to agree well with the measured masses. These calculations can provide some insight into the nature of the tetraquark candidates, whether as a bound meson pair or as a looser configuration of four individual partons. The kinematic distributions of these states as a function of rapidity and transverse momentum are also studied. The possible cross sections for these states are finally considered, with a comparison to the $X(3872)$ $p_T$ distributions from $p+p$ collisions at $\sqrt{s}=13\mathrm{TeV}$.

The off-shell pion electromagnetic form factors are explored with corresponding off-shell light-front wave functions modeled by constituent quark and antiquark. We apply the Mandelstam approach for the microscopic computation of the form factors relating the model parameters with the pion decay constant and charge radius. Analyzing the existing data on the cross sections for the Sullivan process, ${}^1\mathrm{H}(e,e^{\prime },{\pi }^{+})n$ [H. P. Blok et al. (Jefferson Lab $F_{\pi }$ Collaboration), Charged pion form factor between $Q^2=0.60$, and $2.45{\mathrm{GeV}}^2$. I. Measurements of the cross section for the ${}^1\mathrm{H}(e,e^{\prime }{\pi }^{+})n$ reaction, Phys. Rev. C 78, 045202 (2008).], we extract the off-shell pion form factor using the relation derived from the generalized Ward-Takahashi identity for the pion electromagnetic current. They are compared with our previous results [H.-M. Choi et al., Pion off-shell electromagnetic form factors: Data extraction and model analysis, Phys. Rev. D 100, 116020 (2019).] from exactly solvable manifestly covariant model of a ($3+1$)-dimensional fermion field theory. We find that the adopted constituent quark model reproduces the extracted off-shell form factor $F_1(Q^2,t)$ from the experimental data within a few percent difference and matches well with our previous theoretical simulation which exhibits a variation of about 10% for the extracted off-shell pion form factor $g(Q^2,t)$. We also identify the pion valence parton distribution function (PDF) and transverse momentum distribution (TMD) in terms of the light-front wave function and discuss their off-shell properties.

In this work, we systematically study the radiative decays of singly heavy baryons, a crucial aspect of their spectroscopic behavior. To enhance the accuracy of our calculations, we utilize numerical spatial wave functions for the singly heavy baryons obtained through the Gaussian expansion method, which also yields their mass spectrum. As hadron spectroscopy enters an era of high precision, we believe our study of the radiative decays of singly heavy baryons will provide valuable insights for further exploration of these particles.

Recent studies have demonstrated that the tau produced in charged current neutrino deeply inelastic interactions at the GeV-TeV neutrino energy range is not fully polarized. In this paper we investigate the impact of the tau polarization on the pions generated in its decay. In particular, we consider tau neutrino-tungsten interactions at the LHC energies and estimate the associated pion momentum, energy, and angular distributions. The contribution of the $F_5$ is also investigated. Our results indicate that the pion properties are sensitive to the tau polarization state as well as to the magnitude of $F_5$.

Neutrino trident production of dilepton pairs is well recognized as a sensitive probe of both electroweak physics and physics beyond the Standard Model. Although a rare process, it could be significantly boosted by such new physics, and it also allows the electroweak theory to be tested in a new regime. We demonstrate that the forward neutrino physics program at the Large Hadron Collider offers a promising opportunity to measure for the first time, dimuon neutrino tridents with a statistical significance exceeding $5\sigma$, improving on the previous claims at the $\sim 3\sigma$ level by the CHARM-II and CCFR collaborations while accounting for additional backgrounds later identified by the NuTeV collaboration. We present predictions for various proposed experiments and outline a specific experimental strategy to identify the signal and mitigate backgrounds, based on “reverse tracking” dimuon pairs in the $\mathrm{FASER}\nu 2$ detector. We also discuss prospects for constraining beyond Standard Model contributions to neutrino trident rates at high energies.

We measure the absolute branching fractions of semileptonic $D_s^{+}$ decays via the $e^{+}{e}^{-}\to D_s^{*+}{D}_s^{*-}$ process using $e^{+}{e}^{-}$ collision data corresponding to an integrated luminosity of $10.64{\mathrm{fb}}^{-1}$ collected by the BESIII detector at center-of-mass energies between 4.237 and 4.699 GeV. The branching fractions are $\mathcal{B}(D_s^{+}\to \eta e^{+}{\nu }_e)=(2.35\pm {0.11}_{\mathrm{stat}}\pm {0.10}_{\mathrm{syst}})\%$, $\mathcal{B}(D_s^{+}\to {\eta }^{\prime }{e}^{+}{\nu }_e)=(0.82\pm {0.09}_{\mathrm{stat}}\pm {0.04}_{\mathrm{syst}})\%$, $\mathcal{B}(D_s^{+}\to \varphi e^{+}{\nu }_e)=(2.21\pm {0.16}_{\mathrm{stat}}\pm {0.11}_{\mathrm{syst}})\%$, $\mathcal{B}(D_s^{+}\to f_0(980)e^{+}{\nu }_e,f_0(980)\to {\pi }^{+}{\pi }^{-})=(0.15\pm {0.02}_{\mathrm{stat}}\pm {0.01}_{\mathrm{syst}})\%$, $\mathcal{B}(D_s^{+}\to K^0{e}^{+}{\nu }_e)=(0.24\pm 0.04_{\mathrm{stat}}\pm 0.01_{\mathrm{syst}})\%$, and $\mathcal{B}(D_s^{+}\to K^{*0}{e}^{+}{\nu }_e)=(0.19\pm 0.03_{\mathrm{stat}}\pm 0.01_{\mathrm{syst}})\%$. These results are consistent with those measured via the $e^{+}{e}^{-}\to D_s^{*\pm }{D}_s^{\mp }$ process by BESIII and CLEO. Using two-parameter series expansion, the hadronic transition form factors of $D_s^{+}\to \eta e^{+}{\nu }_e$, $D_s^{+}\to {\eta }^{\prime }{e}^{+}{\nu }_e$, and $D_s^{+}\to K^0{e}^{+}{\nu }_e$ are determined to be $f_{+}^{\eta }(0)=0.442\pm 0.022_{\mathrm{stat}}\pm 0.017_{\mathrm{syst}}$, $f_{+}^{{\eta }^{\prime }}(0)=0.557\pm 0.062_{\mathrm{stat}}\pm 0.024_{\mathrm{syst}}$, and $f_{+}^{K^0}(0)=0.677\pm 0.098_{\mathrm{stat}}\pm 0.023_{\mathrm{syst}}$.

I propose a generalization of the Liouville action which corresponds to the Nambu-Goto string like the usual Liouville action corresponds to the Polyakov string. The two differ by higher-derivative terms which are negligible classically but revive quantumly. An equivalence with the four-derivative action suggests that the Nambu-Goto string in four dimensions can be described by the (4,3) minimal model analogously to the critical Ising model on a dynamical lattice. While critical indices are the same as in the usual Liouville theory, the domain of applicability becomes broader.

Conformal field theory in a Minkowski setting is discussed in an embedding space approach, paying special attention to causality constraints for four-point amplitudes. The physics of dilatation and Lorentz boost is emphasized in specifying the noncompact maximal Abelian subgroup of $SO(d,2)$. Reduction of a conformal field theory four-point amplitudes as functions of cross ratios is shown to be equivalent to enforcing $H$ bi-invariance, i.e., $F(hg{h}^{\prime })=F(g)$, with $g\in SO(d,2)$ and $H$ an appropriate subgroup. Causality is imposed by introducing appropriate semigroups. Causal zonal spherical functions are constructed, making contact with Minkowski conformal blocks introduced previously.

We construct and explore the complex structures of boson stars, drawing inspiration from similar configurations of nontopological solitons in Minkowski space. These “molecular states” of boson stars have a multipolar structure and both positive and negative Noether charges within one star, and the opposite charges swap with time. Thanks to the gravitational attraction, they exist even in the case of a free scalar field. We also explore the effects of scalar self-interactions on these complex structures. We propose to use Galactic-scale charge-swapping boson stars as a potential solution to the problem of the observed anisotropic distribution of satellite galaxies.

In this work, we analyze the observational properties of static, spherically symmetric boson stars with fourth and sixth-order self-interactions, using the Julia-based general-relativistic radiative transfer code skylight. We assume the boson stars are surrounded by an optically thick, geometrically thin accretion disk. We use the Novikov-Thorne model to compute the energy flux, introducing a physically based accretion model around these boson star configurations. Additionally, we calculate the relativistic broadening of emission lines, incorporating a lamppost corona model where the relativistic effects arising from the boson star spacetime have been taken into consideration. Our results show distinct observational features between quartic-potential boson stars and Schwarzschild black holes, owing to the presence of stable circular orbits at all radii around the former. On the other hand, compact solitonic boson stars, which possess an innermost stable circular orbit, have observational features closely similar to black holes. This similarity emphasizes their potential as black-hole mimickers. However, the compact boson stars, lacking an event horizon, have complex light ring structures that produce potentially observable differences from black holes with future generations of experiments.

We study the linear response of four dimensional magnetized black holes and regular topological stars arising from dimensional compactification of Einstein-Maxwell theory in five dimensions. We consider both radial and nonradial perturbations and study the stability of these solutions, both in the frequency and in the time domain. Due to the presence of magnetic fluxes in the background, axial (i.e., odd-parity) gravitational perturbations are coupled to polar (i.e., even-parity) electromagnetic perturbations (type I sector) whereas polar gravitational and scalar perturbations are coupled to axial electromagnetic ones (type II sector). We provide a comprehensive analytical and numerical study of the radial perturbations and of the type I sector, finding no evidence of linear instabilities (besides the already known Gregory-Laflamme instability of black strings occurring only in a certain range of the parameters), even despite the fact that the effective potential for radial perturbations of topological stars is negative and divergent near the inner boundary. Ultracompact topological stars exhibit long-lived trapped modes that give rise to echoes in the time-domain response. Their prompt response is very similar to that of the corresponding black hole with comparable charge-to-mass ratio. This provides a concrete realization of ultracompact objects arising from a well-defined theory. The numerical analysis of the type II sector will appear in a companion paper.

Primordial black holes (PBHs) as an all-dark matter (DM) hypothesis has recently been demotivated by the prediction that these objects would source an excessive rate of fast radio bursts (FRBs). However, these predictions were based on several simplifying assumptions to which this rate is highly sensitive. In this article, we improve previous estimates of this rate arising from the capture of PBHs by neutron stars (NSs), aiming to revitalise this theory. We more accurately compute the velocity distribution functions of PBHs and NSs and also consider an enhancement in the NS and DM density profiles at galactic centers due to the presence of a central supermassive black hole. We find that previous estimates of the rate of FRBs sourced by the capture of PBHs by NSs were 3 orders of magnitude too large, concluding that the PBHs as all DM hypothesis remains a viable theory and that the observed FRB rate can only be entirely explained when considering a central, sufficiently spiky PBH density profile.

We examine the power spectrum $P_n$ of the $n$th harmonic for Garfinkle-Vachaspati cosmic strings, which correspond to planar rectangular loops. While these loop trajectories are self-intersecting, a slightly perturbed non-self-intersecting form of these trajectories has been suggested as a generic end state of cosmic string loop fragmentation. We find that $P_n$ scales as $n^{-2}\ln n$, rather than the expected $n^{-2}$ for kink-kink collisions. This result is demonstrated analytically for even $n$ in square loops and numerically for all other cases. At lowest order, the effect of loop decays is to further enhance $P_n$ at large $n$ relative to its value at small $n$. The consequences for relic stochastic background radiation along with the caveats pertaining to our results are discussed.

As galaxy redshift surveys expand to larger areas on the sky, effects coming from the curved nature of the sky become important, introducing wide-angle (WA) corrections to the power spectrum multipoles at large galaxy-pair separations. These corrections particularly impact the measurement of physical effects that are predominantly detected on large scales, such the local primordial non-Gaussianities. In this paper, we examine the validity of the perturbative approach to modeling WA effects in the power spectrum multipoles for upcoming surveys by comparing to measurements on simulated galaxy catalogs using the Yamamoto estimator. We show that on the scales $k\lesssim 2\pi /\chi$, where $\chi$ is the comoving distance to the galaxies, the estimated power spectrum monopole differs by up to 5% from the second-order perturbative result, with similar absolute deviations for higher multipoles. To enable precision comparison, we pioneer an improved treatment of the $\mu$-leakage effects in the Yamamoto estimator. Additionally, we devise a solution to include $f_{\mathrm{NL}}$ in the perturbative WA calculations, avoiding divergences in the original framework through the integral constraint. This allows us to conclude that WA effects can mimic a $f_{\mathrm{NL}}\sim 5$ signal in the lowest SPHEREx redshift bin. We recommend using nonperturbative methods to model large scale power spectrum multipoles for $f_{\mathrm{NL}}$ measurements. A companion paper, Wen et al. 2024, addresses this by introducing a new nonperturbative method going through the spherical Fourier-Bessel basis.

The three-dimensional galaxy power spectrum is a powerful probe of primordial non-Gaussianity and additional general relativistic effects, which become important on large scales. At the same time, wide-angle (WA) effects due to differing lines-of-sight on the curved sky also become important with large angular separation. In this work, we accurately model WA and Doppler effects using the spherical Fourier-Bessel (SFB) formalism, before transforming the result into the commonly used power spectrum multipoles (PSM). This mapping from the SFB power spectrum to PSM represents a new way to nonperturbatively model WA and general relativistic effects present in the PSM, which we validate with log-normal mocks. Moreover, for the first time, we can compute the analytical PSM Gaussian covariance on large scales, exactly including WA-induced mode-couplings, without resorting to any plane-parallel approximations.

Scaling relations with the bag constant parameter are investigated for strange quark matter (SQM) stars in the presence of gravitationally strong magnetic fields minimally coupled with matter, considering both massless and massive strange quark scenarios. Assuming a simple model for such coupling under the approximation of spherical symmetry, a phenomenological scaling formula for the maximum mass of stars is derived as a function of the surface magnetic field and the strange quark mass. This formula is applicable for all formally admissible values of the free parameters, and strict scaling with the bag constant is retained only for a vanishing strange quark mass. As a by-product of this study, the mathematical structure of the equation of state for the relativistic SQM model with a massive strange quark is revisited without approximations. It is observed that the contribution of the electron term to the energy density cannot be neglected in the theoretical limit of large strange quark masses. Consequently, the maximum mass of SQM stars increases with sufficiently large strange quark mass, contrasting with the behavior observed for low strange quark masses.

We present the results of the charge ratio ($R$) and polarization ($P_0^{\mu }$) measurements using decay electron events collected between September 2008 and June 2022 with the Super-Kamiokande detector. Because of its underground location and long operation, we are able to perform high-precision measurements by accumulating cosmic-ray muons. We measured the muon charge ratio to be $R=1.32\pm 0.02(\mathrm{stat}+\mathrm{syst})$ at $E_{\mu }\cos {\theta }_{\text{Zenith}}={0.7}_{-0.2}^{+0.3}\mathrm{TeV}$, where $E_{\mu }$ is the muon energy and ${\theta }_{\text{Zenith}}$ is the zenith angle of incoming cosmic-ray muons. This result is consistent with the Honda flux model while indicating a tension with the $\pi K$ model of $1.9\sigma$. We also measured the muon polarization at the production location to be $P_0^{\mu }=0.52\pm 0.02(\mathrm{stat}+\mathrm{syst})$ at the muon momentum of ${0.9}_{-0.1}^{+0.6}\mathrm{TeV}/c$ at the surface of the mountain; this also suggests a tension with the Honda flux model of $1.5\sigma$. This is the most precise measurement ever to experimentally determine the cosmic-ray muon polarization near $1\mathrm{TeV}/c$. These measurement results are useful to improve atmospheric neutrino simulations.

Double-heavy hadrons can decay into pairs of heavy hadrons through transitions from confining Born-Oppenheimer potentials to heavy-hadron-pair potentials with the same Born-Oppenheimer quantum numbers. The states of the double-heavy hadron are constrained by a Born-Oppenheimer exclusion principle from the identical heavy quarks. The states of a pair of identical heavy hadrons are constrained by exclusion principles from identical particles. The transitions are also constrained by conservation of angular momentum and parity. From these constraints, we derive model-independent selection rules for decays of double-heavy hadrons into pairs of heavy hadrons. The coupling potentials are expressed as sums of products of Born-Oppenheimer transition amplitudes and angular-momentum coefficients. If there is a single dominant Born-Oppenheimer transition amplitude, it factors out of the coupling potentials between double-heavy hadrons in the same Born-Oppenheimer multiplet and pairs of heavy hadrons in specific heavy-quark-spin-symmetry multiplets and out of the corresponding partial decay rates. As examples, we discuss the Born-Oppenheimer potentials and multiplets for conventional double-heavy baryons and for double-heavy tetraquark mesons. We also discuss the relative partial decay rates for conventional double-heavy baryons into pairs of heavy hadrons.

Recent results indicate that charm quarks are intrinsic components of the proton wave function, and that the charm and anticharm distributions for a given value of the Bjorken-$x$ variable can be different. In this paper, we will investigate the impact of this asymmetric intrinsic charm on the production of $D^0$ and ${\overline{D}}^0$ mesons for fixed target $p+{}^{20}\mathrm{Ne}$ collisions at the LHCb. In our calculations, we include the contribution of the gluon-gluon fusion, gluon-charm and recombination processes and assume distinct models for the treatment of the intrinsic charm component. We demonstrate that the presence of an intrinsic charm improves the description of the current data for the rapidity and transverse momentum distributions of $D$ mesons. However, such models are not able to describe the LHCb data for the $D^0\text{−}{\overline{D}}^0$ asymmetry at large transverse momentum, which point out that the description of the intrinsic charm needs to be improved and/or new effects should be taken into account in the production of heavy mesons at forward rapidities in fixed-target collisions.