We investigate the attainable maximum energy of particles accelerated in the core-collapse supernova remnant (SNR) shock propagating in the free wind region with the Parker-spiral magnetic field, current sheet, and the wind termination shock (WTS) by using test particle simulations. This work focuses on Wolf-Rayet stars as progenitors. The magnetic field amplification in the free wind region (shock upstream region) is not considered in this work. Test particle simulations show that particles escaped from the core-collapse SNR reach and move along the WTS, and eventually return to the SNR shock from the poles or equator of the WTS. The particle attainable energy can be boosted by this cyclic motion between the SNR shock and WTS and can be larger than the particle energy that is limited by escape from the SNR shock. The particle energy limited by the cyclic motion between the SNR shock and WTS is about 10–100 TeV. Thus, the core-collapse SNR without upstream magnetic field amplification can be the origin of the break around 10 TeV of the energy spectrum of observed cosmic ray protons and helium.

Recent studies have proposed using a geocentric muon spin force to account for the $(g-2{)}_{\mu }$ anomaly, with the long-range force mediator being a light axionlike particle. The mediator exhibits a $CP$-violating scalar coupling to nucleons and a normal derivative coupling to muons. Due to the weak symmetry, this axion inevitably couples to neutrinos, providing potential impact on neutrino oscillations. By utilizing neutrino data from BOREXINO, IceCube DeepCore, Super-Kamiokande, and SNO, we have identified that both atmospheric and solar neutrino data can impose stringent constraints on the long-range muon spin force model and the $(g-2{)}_{\mu }$ parameter space. With optimized data analysis techniques and the potential from future experiments, such as JUNO, Hyper-Kamiokande, $\mathrm{SNO}+$, and IceCube PINGU, there exists a promising opportunity to achieve even greater sensitivities. Indeed, neutrino oscillations offer a robust and distinctive cross-check for the model, offering stringent constraints on the $(g-2{)}_{\mu }$ parameter space.

We study the continuous phase transition and thermodynamic observables in the three-dimensional Euclidean $SU(2)$ principal chiral field model with the triad tensor renormalization group and the anisotropic tensor renormalization group methods. Using these methods, we find results that are consistent with previous Monte Carlo estimates and the predicted renormalization group scaling of the magnetization close to criticality. These results bring us one step closer to studying finite-density quantum chromodynamics in four dimensions using tensor network methods.

The 4D compact U(1) gauge theory has a well-established phase transition between a confining and a Coulomb phase. In this paper, we revisit this model using state-of-the-art Monte Carlo simulations on anisotropic lattices. We map out the coupling-temperature phase diagram, and determine the location of the tricritical point, $T/K_0\simeq 0.19$, below which the first-order transition is observed. We find the critical exponents of the high-temperature second-order transition to be compatible with those of the 3-dimensional $O(2)$ model. Our results at higher temperatures can be compared with literature results and are consistent with them. Surprisingly, below $T/K_0\simeq 0.05$ we find strong indications of a second tricritical point where the first-order transition becomes continuous. These results suggest an unexpected second-order phase transition extending down to zero temperature, contrary to the prevailing consensus. If confirmed, these findings reopen the question of the detailed characterization of the transition including a suitable field theory description.

Within the framework of transverse momentum dependent factorization in combination with nonrelativistic quantum chromodynamics (QCD), we study charmonium and bottomonium production in hadronic collisions. We focus on quarkonium states with even charge conjugation, for which the color-singlet production mechanism is expected to be also dominant in the small transverse momentum region, $q_T^2\ll 4M_{c,b}^2$. It is shown that the distributions of linearly polarized gluons inside unpolarized, longitudinally, and transversely polarized protons contribute to the cross sections for scalar and pseudoscalar quarkonia in a very distinctive, parity-dependent way, whereas their effects on higher angular momentum states are strongly suppressed. We derive analytical expressions for single and double spin asymmetries, which would allow for the direct extraction of the gluon transverse momentum dependent distributions, mirroring the phenomenological studies of the Drell-Yan processes aimed at the extraction of their quark counterparts. By adopting Gaussian models for the gluon transverse momentum dependent distributions, which fulfill without saturating everywhere their positivity bounds, we provide numerical predictions for the transverse single-spin asymmetries. These observables could be measured at LHCSpin, the fixed target experiment planned at the LHC.

In this work we present a calculation of exotic charmonium production in ultraperipheral collisions, in which the exotic state is explicitly treated as a meson molecule. Our formalism is general, but we focus on the lightest possible exotic charmonium state: a $D^{+}{D}^{-}$ molecular bound state. It was proposed some time ago, and it has been an object of experimental searches. Here we study the production of the open charm pair in the process $\gamma \gamma \to D^{+}{D}^{-}$. Then we use a prescription to project the free pair $|D^{+}{D}^{-}⟩$ onto a bound state at the amplitude level and compute the cross section of the process $\gamma \gamma \to B$ (where $B$ is the bound state). Finally, we convolute this last cross section with the equivalent photon distributions coming from the projectile and target in an ultraperipheral collision and find the $AA\to AAB$ cross section, which, for $Pb-Pb$ collisions at $\sqrt{s_{NN}}=5.02\mathrm{TeV}$, is of the order of $3\mathrm{\mu }\mathrm{b}$.

We consider an arbitrary deformation of the Gaussian matrix model parametrized by Miwa variables $z_a$. One can look at it as a mixture of the Gaussian and logarithmic (Selberg) potentials, which are both superintegrable. The mixture is not, still one can find an explicit expression for an arbitrary Schur average as a linear transform of a finite degree polynomial made from the values of skew Schur functions at the Gaussian locus $p_k={\delta }_{k,2}$. This linear operation includes multiplication with an exponential $e^{z_a^2/2}$ and a kind of Borel transform of the resulting product, which we call multiple and enhanced. The existence of such remarkable formulas appears intimately related to the theory of auxiliary $K$-polynomials, which appeared in bilinear superintegrable correlators at the Gaussian point (strict superintegrability). We also consider in great detail the generating function of correlators $⟨(\mathrm{Tr}X{)}^k⟩$ in this model, and discuss its integrable determinant representation. At last, we describe deformation of all results to the Gaussian $\beta$-ensemble.

We study even-parity black hole perturbations in minimal theory of bigravity. We consider the Schwarzschild solution written in the spatially flat coordinates in the self-accelerating branch as the background solution. We clarify the gauge transformations for the $\ell =0$, 1, and $\ge 2$ modes with $\ell$ being the angular multipole moments under the joint foliation-preserving diffeomorphism transformation. Requiring that the asymptotic regions in the physical and fiducial sectors share the same Minkowski vacua, the solution to the $\ell =0$ perturbations can be absorbed by a redefinition of the Schwarzschild background. In order to analyze the $\ell =1$ and $\ge 2$ modes, for simplicity we focus on the effectively massless case, where the constant parameter measuring the ratio of the proper times between the two sectors is set to unity and the effective mass terms in the equations of motion vanish. We also find that as a particular solution all the $\ell =1$ perturbations vanish by imposing their regularity at spatial infinity. For each of the $\ell \ge 2$ modes, in the effectively massless case, we highlight the existence of the expected two propagating modes and four instantaneous modes.

Gravitational wave physics can probe theories that extend beyond general relativity. Motivated by recent attention on the Kalb-Ramond field as a dark matter candidate, in this work, we study a parity violating dimension four operator which couples the dual Riemann curvature to the 2-form field. After mapping the equations of motion for the right- and left-handed gravitational wave amplitudes to the novel parametrization recently presented in Jenks et al. [Phys. Rev. D 108, 044023 (2023)], we discuss various constraints on the model parameters in light of the coincident electromagnetic/gravitational wave signal of GW170817 and the GWTC-3 dataset.

In this work, we study the gravitational backreaction (i.e., the “self-force”) of a point mass moving around a nonrotating, compact star on a circular orbit. We find that the additional self-force, comparing with the case with a point mass orbiting around a Schwarzschild black hole, can be well characterized by a universal frequency-dependent function multiplied by the (dynamical) tidal deformability of the compact star. This finding provides the foundation for building the waveform model for an extreme mass-ratio inspiral system around a starlike black hole mimicker, which is relevant for testing general relativity and exotic compact objects with space-borne gravitational-wave detectors.

The Event Horizon Telescope (EHT) Collaboration observed ring images called the shadows of M87* and Sagittarius A* (Sgr A*), which are supermassive objects in M87 and our galaxy, respectively, and their general relativistic magnetohydrodynamic simulations of black holes imply that the observed rings are formed by the gravitational lensing of synchrotron radiations from a hot plasma near outside of supermassive black holes. The EHT Collaboration gave constrains on the electrical or alternative charges of M87* and Sgr A* under an assumption that the radius of the observed ring should be proportional to the changing rates of photon spheres by the charges. Since the validness of this assumption is not sure, it is worth to checking the same constraints under another assumption. In this paper, we consider the changing rates of not only the photon spheres but also lensing rings in a simple model and we test whether aforementioned constraint is robust. We conclude that the EHT Collaboration’s constraints based on the changing rates of the photon spheres can be relaxed compared to that based on the changing rate of the lensing rings while we do not claim that the observed rings are formed by the photon spheres and the lensing rings in our simple model. We concentrate on Reissner-Nordström black hole spacetimes in this paper, but our result implies the relaxation of the bound of the charge parameters on other black hole spacetimes.

We study observational signatures of nonsingular ultracompact objects regularized by nonlinear electrodynamics. The phenomenon of birefringence causes photons of different polarizations to propagate with respect to two distinct metrics, which manifests itself in the appearance of additional light rings surrounding the ultracompact object. We analyze the observational consequences of this result and illustrate our findings based on three regular black hole models commonly considered in the literature. We find that nonsingular horizonless ultracompact objects sourced by nonlinear electrodynamics possess an odd number of light rings and discuss the viability of this model as an effective description of their properties. In addition, we compare the phase velocities of polarized light rays propagating in nonsingular geometries sourced by nonlinear electrodynamics to the corresponding phase velocity in the Schwarzschild spacetime and demonstrate that regularizing the singularity by means of a theory that does not adhere to the Maxwell weak-field limit may lead to the emergence of acausal regions.

Convolutional neural networks (CNNs) have recently been applied to cosmological fields—weak lensing mass maps and Galaxy maps. However, cosmological maps differ in several ways from the vast majority of images that CNNs have been tested on: they are stochastic, typically low signal-to-noise per pixel, and with correlations on all scales. Further, the cosmology goal is a regression problem aimed at inferring posteriors on parameters that must be unbiased. We explore simple CNN architectures and present a novel approach of regularization and data augmentation to improve its performance for lensing mass maps. We find robust improvement by using a mixture of pooling and shuffling of the pixels in the deep layers. The random permutation regularizes the network in the low signal-to-noise regime and effectively augments the existing data. We use simulation-based inference to show that the model outperforms CNN designs in the literature. Including systematic uncertainties such as intrinsic alignments, we find a 30% improvement over unoptimized CNNs and power spectrum in the constraints of the $S_8$ parameter for simulated Stage-III surveys. We explore various statistical errors corresponding to next-generation surveys and find comparable improvements. We expect that our approach will have applications to other cosmological fields as well, such as Galaxy maps or 21-cm maps.

The unified models of astrophysical sources to account for ultrahigh-energy cosmic rays (UHECRs) and high-energy cosmic neutrinos with energies greater than 100 TeV have been discussed. Based on model-independent arguments, we argue that if the photomeson production is the dominant mechanism, the most probable candidate sources are x-ray transient objects, allowing for the semitransparency for the photomeson production. We develop a generic model of high-energy neutrino emitters accompanied by x-ray emission, and present how multimessenger observations can place significant constraints on the source parameters that characterize the common sources of neutrinos and UHECRs, such as the cosmic-ray loading factor. The requirements of UHECR acceleration, escape, and energetics further constrain the magnetic field and the bulk Lorentz factor of the sources. The resulting bounds provide diagnoses of the unified models, which demonstrates the importance of current and future x-ray facilities such as MAXI and Einstein Probe.

We present the results from a search for gravitational-wave transients associated with core-collapse supernovae observed optically within 30 Mpc during the third observing run of Advanced LIGO and Advanced Virgo. No gravitational wave associated with a core-collapse supernova has been identified. We then report the detection efficiency for a variety of possible gravitational-wave emissions. For neutrino-driven explosions, the distance at which we reach 50% detection efficiency is up to 8.9 kpc, while more energetic magnetorotationally driven explosions are detectable at larger distances. The distance reaches for selected models of the black hole formation, and quantum chromodynamics phase transition are also provided. We then constrain the core-collapse supernova engine across a wide frequency range from 50 Hz to 2 kHz. The upper limits on gravitational-wave energy and luminosity emission are at low frequencies down to ${10}^{-4}{M}_{\odot }{c}^2$ and $6\times {10}^{-4}{M}_{\odot }{c}^2/\mathrm{s}$, respectively. The upper limits on the proto-neutron star ellipticity are down to 3 at high frequencies. Finally, by combining the results obtained with the data from the first and second observing runs of LIGO and Virgo, we improve the constraints of the parameter spaces of the extreme emission models. Specifically, the proto-neutron star ellipticities for the long-lasting bar mode model are down to 1 for long emission (1 s) at high frequency.

Ascribed as $\rho \rho$ and $K^{*}{\overline{K}}^{*}$ molecular states, respectively, isoscalar $f_0(1500)$ and $f_0(1710)$ states are expected to have isovector partners, potentially identified as $a_0(1450)$ and $a_0(1710)$. The predicted dominant decay modes for these two $a_0$ resonances are $a_0(1450)\to \omega \pi \pi$ and $a_0(1710)\to \omega \pi \pi ,\varphi \pi \pi$. We estimate cross sections for two-photon production of these four resonances within hadronic molecular picture, and demonstrate that SuperKEKB’s luminosity is sufficient for their observation and more precise parameter measurements.

Parton distribution functions play a pivotal role in hadron collider phenomenology. They are nonperturbative quantities extracted from fits to available data, and their scale dependence is dictated by the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations. In this article, we discuss machine-assisted strategies to efficiently compute parton distribution functions (PDFs) explicitly incorporating the scale dependence. Analytical approximations to the PDFs as functions of $x$ and $Q^2$, including up to next-to-leading-order effects in quantum chromodynamics, are obtained. The methodology is tested by reproducing the herapdf2.0 set and implementing the analytical expressions in benchmarking codes. It is found that the computational time cost of evaluating the distributions is reduced by $\sim 50\%$, while the precision of the simulations stays well under control.

Recently, several normalizing flow-based deep generative models have been proposed to accelerate the simulation of calorimeter showers. Using caloflow as an example, we show that these models can simultaneously perform unsupervised anomaly detection with no additional training cost. As a demonstration, we consider electromagnetic showers initiated by one (background) or multiple (signal) photons. The caloflow model is designed to generate single-photon showers, but it also provides access to the shower likelihood. We use this likelihood as an anomaly score and study the showers tagged as being unlikely. As expected, the tagger struggles when the signal photons are nearly collinear but is otherwise effective. This approach is complementary to a supervised classifier trained on only specific signal models using the same low-level calorimeter inputs. While the supervised classifier is also highly effective at unseen signal models, the unsupervised method is more sensitive in certain regions, and, thus, we expect that the ultimate performance will require a combination of these approaches.

Protvino to ORCA (oscillation research with cosmics in the abyss) (P2O) is an upcoming neutrino oscillation experiment with a very long baseline of 2595 km. Because of the substantial baseline, this experiment provides a unique opportunity to study the Earth matter effects over very large distances. This makes it a suitable experiment to investigate the environmental decoherence in neutrino oscillations, where the neutrino system could interact with a stochastic environment and lead to a loss in the coherence of neutrino states. In this work, we consider an open quantum system framework to simulate the neutrino oscillations in the P2O experiment and obtain bounds on the decoherence parameters in different phenomenological models. Here, we also consider that the decoherence parameter $\mathrm{\Gamma }$ depends on neutrino energy $E_{\nu }$ as ${\mathrm{\Gamma }}_{jk}(E_{\nu })={\mathrm{\Gamma }}_0(\frac{E_{\nu }}{E_0}{)}^n$. Furthermore, assuming the presence of decoherence in nature, we study the effect of it on the determination of neutrino mass hierarchy and $CP$ violation at the P2O experiment.

In one-component dark matter (DM) scenarios is commonly assumed that a scalar weakly interacting massive particle must either be part of an $SU(2{)}_L$ multiplet with zero hypercharge or have suppressed vector interactions with the $Z$-gauge boson to circumvent stringent direct detection (DD) bounds. In this work, we demonstrate that multicomponent scenarios with a dark scalar doublet exhibiting vectorlike interactions with the $Z$ boson are also compatible with bounds arising from DD searches. Specifically, we consider a simple extension of the Standard Model wherein the dark sector comprises a doublet and a complex singlet $\varphi$, both charged under a $Z_6$ symmetry. We find that semi-annihilation processes drastically reduce the relic abundance of the neutral component of the doublet, $H^0$, sufficiently attenuating the effects of its large $Z$-mediated elastic scattering cross-section with nucleons to satisfy the DD constraints. Although the contribution of $H^0$ to the total relic abundance is nearly negligible, with $\varphi$ dominating, both dark matter components are expected to be detectable in ongoing and future DD experiments. The viability of the model is tested against several theoretical and experimental constraints, resulting in a parameter space featuring a nondegenerate mass spectrum at the electroweak scale.