In this work, we study the decays ${\mathrm{\Lambda }}_c\to (\mathrm{\Lambda },n){\ell }^{+}{\nu }_{\ell }$ ($\ell =\mu$, $e$) within a model-independent framework. We calculate the helicity amplitudes for all possible four-fermion operators, including the interactions between different new physics (NP) operators. The form factors for the ${\mathrm{\Lambda }}_c\to (\mathrm{\Lambda },n)$ transitions are taken from lattice QCD calculations. We present detailed results for the branching fractions and other key observables. Although our results are generally consistent with previous studies, we find that the predicted central values for the branching fractions are approximately 10% larger than the experimental measurements. Additionally, we explore the potential impacts of NP, focusing particularly on the scenario in which NP particles couple exclusively to the muon. Using Wilson coefficients fitted from $D$ and $D_s$ meson decays, we examine NP effects in the ${\mathrm{\Lambda }}_c\to (\mathrm{\Lambda },n){\mu }^{+}{\nu }_{\mu }$ decay channels. It is found that although most potential contributions of NP are obscured by the uncertainties inherent in both theory and experiment, the right-handed scalar operator could suppress the branching fraction of ${\mathrm{\Lambda }}_c\to (\mathrm{\Lambda },n){\mu }^{+}{\nu }_{\mu }$ by up to 10%. We also highlight that the ratio of the forward-backward asymmetry in the ${\mathrm{\Lambda }}_c\to (\mathrm{\Lambda },n){\mu }^{+}{\nu }_{\mu }$ decay to that in the ${\mathrm{\Lambda }}_c\to (\mathrm{\Lambda },n)e^{+}{\nu }_e$ decay provides a novel probe for NP, as it is less sensitive to hadronic uncertainties and is largely unaffected by current NP operators. All of our results can be tested in ongoing experiments such as BESIII, Belle-II, and LHCb, as well as in future high-energy facilities like the Super Tau-Charm Factory (STCF) and the Circular Electron Positron Collider (CEPC).

We consider the nonplanar universal anomalous dimension of twist-two operators at four loops in $\mathcal{N}=4$ supersymmetric Yang-Mills theory and push its direct diagrammatic calculation through Lorentz spin $j=20$, one unit beyond the state of the art, so as to confirm the correctness of the general, all-$j$ result conjectured previously by us [Non-planar universal anomalous dimension of twist-two operators with general Lorentz spin at four loops in $\mathcal{N}=4$ SYM theory, Nucl. Phys. B968, 115429 (2021).] imposing certain constraints on its analytic form. Thanks to our new result, such constraints can be eliminated altogether. By the same token, this allows us to rederive, in a completely independent way, the nonplanar four-loop cusp anomalous dimension by taking the large-$j$ limit of the general result.

We present further applications of the formalism introduced by K. H. Akinori Tanaka and Akio Tomiya in [Deep Learning and Phyiscs (Springer, Switzerland, 2021)], which allows the embedding of a broad class of generalized Lemaître-Tolmann-Bondi (LTB) models into effective spherically symmetric spacetimes. We focus on regular black hole models, where a broad class of models can be considered, including for example loop quantum gravity (LQG)-inspired models as well as models with a regular center, e.g., of Bardeen and Hayward. For a certain class of regular black hole models, we can formulate a Birkhoff-like theorem in LTB coordinates. We further show that, depending on the properties of the polymerization functions characterizing such regular black hole models in this formalism, the uniqueness of the effective spherically symmetric vacuum solutions might not be given in general in Schwarzschild-like coordinates. Furthermore, we introduce a reconstruction algorithm that allows for a subclass of these models to construct from a given metric in Schwarzschild-like coordinates the corresponding effective spherically symmetric model, its dynamics as a $1+1$-dimensional field theory, as well as a corresponding covariant Lagrangian of extended mimetic gravity in four dimensions. Such a reconstruction allows us to obtain Lagrangians of extended mimetic gravity models for black holes with a regular center, e.g., the Bardeen and Hayward metric, as well as for effective LQG inspired models. Moreover, the reconstruction enables us to extend regular black hole models to general inhomogeneous dust collapse models. For the latter, within this formalism, we can investigate and explore various physical properties of the models such as the existence of weak shell-crossing singularities from a novel perspective.

In metric-affine gravity, both the gravitational and matter actions depend not just on the metric but also on the independent affine connection. Thus matter can be modeled as a hyperfluid, characterized by both the energy-momentum and hypermomentum tensors. The latter is defined as the variation of the matter action with respect to the connection and it encodes extra (micro)properties of particles. For a homogeneous and isotropic universe, it was recently shown that the generic cosmological hypermomentum possesses five degrees of freedom: one in dilation, two in shear, and two in spin part. The aim of the current work is to present the first systematic study of the implications of this perfect hyperfluid on the universe with Friedmann-Lemaître-Robertson-Walker metric. We adopt a simple model with non-Riemannian Einstein-Hilbert gravitational action plus arbitrary hyperfluid matter, and solve analytically the cosmological equations for single and multiple component hypermomentum contributions using different assumptions about the equation of state. It is remarkable, that in a number of cases the forms of the time evolution of the Hubble function and energy density still coincide with their general relativity counterparts, only the respective indexes ${\mathrm{w}}_{\mathrm{eff}}$ and ${\mathrm{w}}_{\rho }$ start to differ due to the hypermomentum corrections. The results and insights we obtained are very general and can assist in constructing interesting models to resolve the issues in standard cosmology.

Quantum evaporation of a black hole is conventionally studied semiclassically by assuming self-similarity of the black hole throughout the evaporation process. However, its validity was recently questioned, and the lifetime of a black hole is conjectured to be much extended by the memory burden effect. It gives rise to the possibility that the primordial black holes (PBHs) lighter than ${10}^{10}$ grams are the dark matter in the Universe. To probe such PBH dark matter, we study gravitational waves (GWs) induced by primordial curvature perturbations that produced the PBHs. We find ${\mathrm{\Omega }}_{\mathrm{GW}}(f_{\mathrm{peak}})h^2=7\times {10}^{-9}$ with the peak frequency $f_{\mathrm{peak}}=1\times {10}^3(M_{\mathrm{PBH}}/({10}^{10}\mathrm{g}){)}^{-1/2}\mathrm{Hz}$, and the induced GWs associated with the PBH dark matter whose initial mass is greater than about ${10}^7$ grams can be tested by future observations such as Cosmic Explorer. Furthermore, the scenario can be in principle confirmed by detecting another GW signal from the mergers of PBHs, which leads to high-frequency GWs with $f_{\mathrm{peak}}=2\times {10}^{27}(M_{\mathrm{PBH},\mathrm{ini}}/({10}^{10}\mathrm{g}){)}^{-1}\mathrm{Hz}$. On the other hand, the induced GW signals stronger than expected would contradict the dark matter abundance and exclude the memory burden effect.

We present a forecast of the pairwise kinematic Sunyaev-Zel’dovich (kSZ) measurement that will be achievable with the future CMB-S4 experiment. CMB-S4 is the next stage for ground-based cosmic microwave background experiments, with a planned wide-area survey that will observe approximately 50% of the sky. We construct a simulated sample of galaxy clusters that have been optically selected in a Legacy Survey of Space and Time–like survey and have spectroscopic redshifts. For this cluster sample, assuming the likelihood is Gaussian, we predict that CMB-S4 will reject the null hypothesis of zero pairwise kSZ signal at $36\sigma$. We estimate the effects of systematic uncertainties such as scatter in the mass-richness scaling relation and cluster miscentering. We find that these effects can reduce the signal-to-noise ratio of the CMB-S4 pairwise kSZ measurement by 20%. We explore the constraining power of the measured kSZ signal in combination with measurements of the galaxy clusters’ thermal SZ emission on two extensions to the standard cosmological model. The first extension allows the dark energy equation of state $w$ to vary. We find the CMB-S4 pairwise kSZ measurement yields a modest reduction in the uncertainty on $w$ by a factor of 1.36 over the Planck’s 2018 uncertainty. The second extension tests general relativity by varying the growth index $\gamma$. We find that CMB-S4’s pairwise kSZ measurement will yield a $28\sigma$ constraint on $\gamma$ and strongly constrain alternative theories of gravity.

Within the framework of general relativity, it can be shown that gravitational waves are radiated with the merger of massive compact objects. Such gravitational wave signals are observed on Earth on various detectors, in particular, on Laser Interferometer Gravitational Wave Observatory (LIGO) and Virgo. During the operation of these detectors, many events have been detected. Those events are associated with the merger of massive compact objects; however, the nature of some merging objects has not yet been reliably established. This work considers nontopological solitons of dark matter—Q-balls, as candidates for the role of massive compact objects. In this work, one of the simplest models of Q-balls, the mechanism of their birth during a phase transition in the early Universe and the mechanism of their mass gaining during the evolution of the Universe, which is based on their mutual merger, are considered. As a result, it is analyzed whether Q-balls of dark matter can grow to the mass gap masses and be candidates for the role of massive compact objects.

The exact sources of high-energy neutrinos detected by the IceCube neutrino observatory still remain a mystery. For the first time, this work explores the hypothesis that galaxy mergers may serve as sources for these high-energy neutrinos. Galaxy mergers can host very high-energy hadronic and photohadronic processes, which may produce very high-energy neutrinos. We perform an unbinned maximum-likelihood-ratio analysis utilizing the galaxy merger data from six catalogs and 10 years of public IceCube muon-track data to quantify any correlation between these mergers and neutrino events. First, we perform the single source search analysis, which reveals that none of the considered galaxy mergers exhibit a statistically significant correlation with high-energy neutrino events detected by IceCube. Furthermore, we conduct a stacking analysis with three different weighting schemes to understand if these galaxy mergers can contribute significantly to the diffuse flux of high-energy astrophysical neutrinos detected by IceCube. We find that upper limits (at 95% CL) of the all flavor high-energy neutrino flux, associated with galaxy mergers considered in this study, at 100 TeV with spectral index $\mathrm{\Gamma }=-2$ are $1.11\times {10}^{-18}$, $3.69\times {10}^{-19}$ and $1.02\times {10}^{-18}{\mathrm{GeV}}^{-1}{\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}{\mathrm{sr}}^{-1}$ for the three weighting schemes. This work shows that these selected galaxy mergers do not contribute significantly to the IceCube detected high energy neutrino flux. We hope that in the near future with more data, the search for neutrinos from galaxy mergers can either discover their neutrino production or impose more stringent constraints on the production mechanism of high-energy neutrinos within galaxy mergers.

A recent analysis on the properties of the XTE J1814-338 pulsar yielded a small radius value around $\sim 7\mathrm{km}$. Notably, this estimation is significantly lower compared to the currently inferred values for the radius of neutron stars (as they are derived from both theoretical calculations and corresponding observations). In this paper, we focus on the construction of hybrid equations of state (EOSs) for the possible reconciliation of the exotic XTE J1814-338 properties. Our analysis indicates that an equation of state involving a sufficiently strong phase transition could potentially lead to the explanation of the size and mass of such a compact object. By examining the sign of the $dM/d{P}_c$ slope, we found that stellar configurations compatible to XTE J1814-338 are only stable for a “stiff” low density phase. For a “soft” hadronic EOS selection the stability of the resulting configurations may not be satisfied in terms of the turning point criterion. However, a complementary analysis, for the radial oscillations of the aforementioned configurations, indicated their stability when a slow phase conversion is considered.

The polarized synchrotron data of the northern C-BASS survey show a surprisingly low linear polarization fraction, $⟨\mathrm{\Pi }⟩\simeq 3\%$, while the magnetic field polarization features coherent structures over rather large angular scales. The low polarization degree points to a strong dominance of the turbulent magnetic field—in agreement with the observation that the total synchrotron intensity is much larger than expected from the regular component in current models for the Galactic magnetic field (GMF). In contrast, studies of cosmic ray propagation employing these GMF models suggest that cosmic rays propagate anisotropically, which in turn suggests weak turbulent fields. As a solution to these contradicting requirements, we suggest that the GMF consists of three components with different levels of turbulence: a disk dominated by the turbulent field, a halo dominated by the regular field, plus an extended turbulent halo field.

In this paper we analyzed the exclusive photoproduction of ${\eta }_c\gamma$ pairs in the color glass condensate framework. We found that the cross section of this process is sensitive only to the forward dipole scattering amplitude, and thus could be used as a new tool for analysis of this fundamental nonperturbative object. Using the phenomenological parametrizations of this object, we estimated numerically the production cross section and counting rates in the kinematics of the ongoing and forthcoming experiments at LHC and future Electron Ion Collider. We found that the cross section is sufficiently large for dedicated experimental study. We also estimated the role of this process as a potential background to ${\eta }_c$ photoproduction, which is conventionally considered as a gateway for studies of odderons. We found that the contribution of ${\eta }_c\gamma$ (with undetected photon) is on par with expected contributions of odderons in the kinematics of small momentum transfer $|t|\lesssim 1{\mathrm{GeV}}^2$, though decreases rapidly at larger $|t|$. Finally, we also calculated the feeddown contribution (from radiative decays of other charmonia) and found that a sizable correction comes from $J/\psi \to {\eta }_c\gamma$ decays. This contribution remains pronounced even at relatively large $|t|$ and potentially can impose constraint on detectability of odderons via ${\eta }_c$ photoproduction.

Large-scale neutrino detectors currently under construction will have the unique ability to probe the annihilation of low-mass thermal-relic dark matter to neutrinos. This represents an essential test of the thermal freeze-out paradigm. This raises the question: what viable UV-complete models are there in which dark matter annihilates dominantly to neutrinos? We discuss models that fulfill these criteria, and are invariant under the Standard Model gauge group, for both scalar and fermionic dark matter. Specifically, we construct new models in which annihilation via the $s$-channel exchange of a scalar or pseudoscalar mediator achieves the correct relic density. In these models, dark matter is stabilized by an exact or a softly broken lepton-number symmetry. The parameter space of such models will be probed, almost entirely, by the combination of JUNO, Hyper-Kamiokande, and CMB-S4.

We study the consequences of new long-range forces between neutrinos on cosmic scales. If these forces are a few orders of magnitude stronger than gravity, they can induce perturbation instability in the nonrelativistic cosmic neutrino background in the late time universe. As a result, the cosmic neutrino background may form nonlinear bound states instead of free-streaming. The implications of the formation of nonlinear neutrino bound states include enhancing matter perturbations and triggering star formation. Based on existing measurements of the matter power spectrum and reionization history, we place new constraints on long-range forces between neutrinos with ranges lying in $1\mathrm{kpc}\lesssim m_{\varphi }^{-1}\lesssim 10\mathrm{Mpc}$.

A puzzling phenomenon, where the measured mass of the $\psi (4160)$ is pushed higher, presents a challenge to current theoretical models of hadron spectroscopy. This study suggests that the issue arises from analyses based on the outdated quenched charmonium spectrum. In the past two decades, the discovery of new hadronic states has emphasized the importance of the unquenched effect. Under the unquenched picture, six vector charmonium states—$\psi (4040)$, $\psi (4160)$, $\psi (4220)$, $\psi (4380)$, $\psi (4415)$, and $\psi (4500)$—are identified in the 4–4.5 GeV range, contrasting with the three states predicted in the quenched model. We reevaluate the resonance parameters of the $\psi (4160)$ using the dimuon invariant mass spectrum of $B^{+}\to K^{+}{\mu }^{+}{\mu }^{-}$ and unquenched charmonium spectroscopy. Our analysis indicates previous experimental overestimations for the mass of the $\psi (4160)$. This conclusion is supported by analyzing $e^{+}{e}^{-}\to D_s{\overline{D}}_s^{*}$, which finds the $\psi (4160)$ mass at $4145.76\pm 4.48\mathrm{MeV}$. Our findings have significant implications for both hadron spectroscopy and search for new physics signals by $R_K$.

The Indian Coherent Neutrino-nucleus Scattering Experiment (ICNSE) has been proposed at Bhabha Atomic Research Centre in India to measure the coherent elastic neutrino-nucleus scattering process using electron antineutrinos produced from reactors. Phenomenological studies are performed to find out the sensitivity of a sapphire detector for various fundamental physics parameters at an exposure of one year. Reactors of different core compositions, sizes, and thermal powers have been considered as sources of electron antineutrinos. The potential of the ICNSE to measure the weak mixing angle at a low energy regime has been extracted. Furthermore, the detector’s capability has been investigated for examining the electromagnetic properties of neutrinos, including their magnetic moment. Additionally, an exploration has been conducted on the detector’s sensitivity in restricting new interactions between neutrinos and electrons or nuclei, thereby constraining the parameter space related to light mediators. It is found that the ICNSE detector can put a stronger constraints on the scalar and vector mediators masses.

Motivated by recent LHCb measurements of $CP$ violation in ${\mathrm{\Lambda }}_b$ three body decays, we conduct an analysis of $CP$ asymmetry in three body decays of bottom baryons utilizing $U$-spin symmetry. We first develop a convenient representation that facilitates the incorporation of $U$-spin symmetry into our analysis. By integrating weak and strong phases into the derived amplitude, we obtain the $CP$ asymmetry and establish relationships between $CP$ asymmetries in $U$-spin related decay channels. With the help of experimental measurements, we provide numerical predictions for the $CP$ asymmetries for other decay channels, particularly ${\mathrm{\Xi }}_b^0\to \mathrm{\Lambda }{\pi }^{+}{\pi }^{-}$ under a specific scenario. Furthermore, we provide a quantity that can be used as a null test of the $\mathrm{SU}(3)$ symmetry and standard model. Deviations from zero would indicate potential new physics if they exceed the expected magnitude of $\mathrm{SU}(3)$ breaking effects. These results are valuable for $CP$ violation measurements in baryon decays, and can be tested in future experiments.

We determine generalized symmetries for 4D theories engineered via type II strings on nonsupersymmetric orbifold backgrounds ${\mathbb{R}}^{3,1}\times {\mathbb{R}}^6/\mathrm{\Gamma }$. Probe branes detect generalized symmetries via the adjacency matrix for fermionic degrees of freedom in an associated quiver gauge theory. In situations where the tachyons are sequestered away from the boundary $S^5/\mathrm{\Gamma }$, this exactly matches the result extracted from singular homology. In situations with an unsequestered tachyon which stretches out to the boundary, the presence of tachyonic pulses partitions up the space into several distinct sectors, and the net contribution again matches with the answer expected via quiver methods. For IIA backgrounds, the presence of a localized closed string tachyon leads to transitions in the spectrum of states, generalized symmetries, higher-group symmetries, as well as the level matrix of the associated symmetry topological field theory (SymTFT). For IIB backgrounds with a stack of spacetime filling probe D3-branes, the onset of a radiatively generated potential leads to similar considerations involving scale dependent transitions in the symmetries of the theory, including structures such as duality defects/interfaces.

We numerically construct a stable three-string junction of a Y shape in a flag manifold nonlinear sigma model on $SU(3)/U(1{)}^2$.

An investigation of the validity of the semiclassical approximation to quantum electrodynamics in $1+1$ dimensions is given. The criterion for validity used here involves the impact of quantum fluctuations introduced through a two-point function which emerges naturally when considering the stability of the backreaction equation to linear order perturbations, resulting in the linear response equation. Consideration is given to the case of a spatially homogeneous electric field generated by a classical source, coupled to a quantized massive spin $½$ field. Solutions to the linear response equation as well as the impact of quantum fluctuations introduced through the current density two-point correlation function are presented for two relevant electric field-to-mass parameter values $qE/m^2$, indicative of the strength of the backreaction process. Previous efforts utilized approximate solutions to the linear response equation that were expected to be valid for early times. A comparative analysis is given between the exact and approximate solutions in order to validate this conjecture.