Given that gamma rays with energies larger than TeV are severely absorbed by background radiation fields, for many extragalactic sources, the GeV–TeV gamma-ray observations are the messengers that are closest in energy to the TeV–PeV neutrinos observed by IceCube. Investigating whether there is a correlation between the gamma-ray and neutrino observations can help us identify high-energy neutrino sources and determine which sources are the main contributors to the all-sky diffuse neutrino flux of IceCube. In previous work, we have already studied the possible gamma-neutrino correlations by analyzing 10 years of IceCube public muon-track data. In this work, we further investigate such correlations by employing the IceCube $p$-value sky map of the scan for point sources. We examine the spatial associations of hot spots in the neutrino sky map with various gamma-ray source samples: the third Fermi-LAT catalog of high-energy sources (3FHL), LAT 14-year source catalog, the fourth catalog of active galactic nuclei, and subsets of these samples. Among all the samples, the 3FHL sample shows a possible correlation with the neutrino hot spots with a pretrial $p$ value of $9.0\times {10}^{-5}$ ($\sim 3.9\sigma$), corresponding to a posttrial significance of $\sim 1.7\sigma$. However, this is found to be caused by three already known neutrino sources or source candidates: NGC 1068, TXS $0506+056$, and PKS $1424+240$.

We present a comprehensive polarization analysis for the process $e^{+}{e}^{-}\to J/\psi \to$ baryon-antibaryon pairs $B_1{\overline{B}}_2$. All possible helicity amplitudes for $e^{+}{e}^{-}\to J/\psi$ and $J/\psi \to B_1{\overline{B}}_2$ are provided, along with their transformation properties under parity and $CP$ operations. Taking full account of beam polarization, we analyze the polarization of the $J/\psi$ produced in $e^{+}{e}^{-}$ annihilation and show that all eight independent polarization components can be nonzero. By introducing a polarization transfer matrix, we propose a novel method to compute the polarization transfer in the decay $J/\psi \to B_1{\overline{B}}_2$. Considering both hadronic and radiative baryon decay models, we derive the joint angular distribution of the final-state particles. Focusing on the process $J/\psi \to \mathrm{\Lambda }{\overline{\mathrm{\Sigma }}}^0$, we provide statistical uncertainty estimates for probing $CP$ violation in associated production of different baryons. This work establishes a complete framework for studying the parity and $CP$ violations present in baryon productions and decays within the helicity formalism.

We consider a neutrinophilic $U(1)$ extension of the Standard Model (SM) under which only a second Higgs doublet and SM singlet scalars and fermions are charged. The new gauge boson $Z^{\prime }$ couples to the SM minimally, generated by $Z-Z^{\prime }$ mixing. As the $Z^{\prime }$ is very weakly coupled, it can mostly be produced through the decay of the scalars from the second Higgs doublet at the Large Hadron Collider (LHC). We discuss the scalar sector of the model in detail and consider decay modes such as $(H^{\pm }\to W^{\pm }{Z}^{\prime },h_2\to VV,(V=W^{\pm },Z,Z^{\prime }),A_2\to h_1{Z}^{\prime }(Z))$ that lead to multilepton signals at the LHC from the pair production of the scalars. We analyze the signal with a representative value of the $Z^{\prime }$ mass to show the discovery potential of the two-Higgs doublet model scalars at the LHC.

We investigate the discovery potential of multi-TeV muon colliders for a heavy dark $Z$ boson ($Z_{\mathrm{D}}$) with a mass above 1 TeV, via the associated production process ${\mu }^{+}{\mu }^{-}\to Z_{\mathrm{D}}\gamma$. This process enables precise reconstruction of $M_{Z_{\mathrm{D}}}$ through the photon recoil mass ($m_{\mathrm{recoil}}$). Focusing on the $Z_{\mathrm{D}}\to jjX$ and $Z_{\mathrm{D}}\to e^{+}{e}^{-}$ decay modes, we present strategies to achieve high sensitivity to the kinetic mixing parameter $ϵ$ at 3, 6, and 10 TeV muon colliders with integrated luminosities of 1, 4, and $10{\mathrm{ab}}^{-1}$, respectively, assuming that $Z_{\mathrm{D}}$ decays exclusively into Standard Model particles. We apply mass-dependent cuts on $m_{\mathrm{recoil}}$ and $m_{ee}$ to account for the energy-dependent detector response. For heavier $M_{Z_{\mathrm{D}}}$, the associated photon becomes less energetic, leading to better photon energy resolution and enabling more stringent $m_{\mathrm{recoil}}$ cuts. Conversely, for lighter $M_{Z_{\mathrm{D}}}$, the lower-energy electron pair from $Z_{\mathrm{D}}\to e^{+}{e}^{-}$ allows tighter invariant mass ($m_{ee}$) cuts. By combining these complementary $m_{\mathrm{recoil}}$- and $m_{ee}$-based selections across both the $jjX$ and $e^{+}{e}^{-}$ channels, we achieve sensitivity to $ϵ$ down to $\mathcal{O}({10}^{-3})$ as $M_{Z_{\mathrm{D}}}$ approaches $\sqrt{s}$, substantially surpassing the projected reach of a 100 TeV proton-proton collider. Even if $Z_{\mathrm{D}}$ decays into dark-sector particles, the recoil mass method remains effective, highlighting muon colliders as powerful facilities for exploring heavy dark sectors.

With the aim of looking for signatures of deconfinement, the poles and the spectral function of the Landau-gauge gluon propagator are investigated at one loop, vanishing spatial momentum, and finite temperature within the framework of the screened massive expansion of pure Yang-Mills theory and of full QCD. When computed using both temperature-independent parameters optimized by principles of gauge invariance and temperature-dependent parameters obtained by fitting lattice data at zero Matsubara frequency, the propagator is found to have a pair of complex-conjugate poles in its squared complexified frequency variable throughout the considered temperature interval, ranging from $T=0$ to temperatures $T>T_c$ of interest to quark-gluon plasma phenomenology. The spectral function is found to violate positivity and not to develop sharp peaks over said temperature interval. In full QCD, a simple model is used for mass generation in the infrared quark sector; the dependence of our results on the quark masses is discussed.

For the $N$-point energy correlator in the collinear limit, the largest projected angle $R$ in the large $N$ limit can be viewed as the radius of the jet that encompasses all the collinear core particles, while contributions from soft gluons to the radius are suppressed. We relate the $N$-point energy correlator in the large $N$ limit to the moments of the fragmentation functions to a jet, and, using previous work, we compare the difference between jets initiated by heavy quarks and light quarks. This comparison demonstrates the dead-cone effect.

The characteristics of the hadron-to-quark first-order phase transition differ depending on whether charge neutrality is locally or globally fulfilled. In $\beta$-equilibrated matter, these two possibilities correspond to the Maxwell and Gibbs constructions. Recently, we presented a new framework in which a continuously varying parameter allows one to describe a first-order phase transition in intermediate scenarios to the two extremes of fully local and fully global charge neutrality. In this work, we extend the previous framework to finite temperatures and out-of-$\beta$ equilibrium conditions, making it available for simulations of core-collapse supernovae and binary neutron star mergers. We investigate its impact on key thermodynamic quantities across a range of baryon densities, temperatures, and electron fractions. We find that when matter is not in $\beta$ equilibrium, the pressure in the mixed phase is not constant even for the case of fully local charge neutrality. Moreover, we compute the thermal index using three different approaches, demonstrating that the finite-temperature extension of an equation of state using a constant thermal index can be ill defined when applied to the mixed phase.

We investigate the structural modifications of heavy quarkonia in the presence of strong magnetic fields using a constituent quark model. By incorporating the effects of spin mixing and quark Landau levels, we employ a nonrelativistic Hamiltonian that captures the essential features of quark dynamics in a magnetic field. The two-body Schrödinger equation is solved using the cylindrical Gaussian expansion method, which respects the cylindrical symmetry induced by a magnetic field. We extract the corresponding light-front wave function (LFWF) densities and analyze their transverse and longitudinal structures, revealing characteristic features such as transverse momentum broadening. While the longitudinal structure is only slightly modified within the nonrelativistic Hamiltonian, we discuss some corrections that can significantly affect its longitudinal structure. Furthermore, we discuss the structure modifications of excited states and find notable changes in the LFWF densities, and state reshuffling near avoided crossings. These results demonstrate the sensitivity of hadron structure to external magnetic fields and help bridge our understanding to relativistic approaches.

The competition between bulk color superconductivity and the localized screening of a heavy quark impurity, analogous to the Kondo effect, leads to a rich spectrum of phenomena in dense quark matter. We investigate this competition at the edge of a superconducting quark bulk, where both the superconducting gap and the Kondo scale are dynamically generated in a tractable toy model. Utilizing the exact Bethe Ansatz method, we elucidate the resulting boundary physics. We identify distinct regimes characterized by either multiparticle Kondo screening or an unscreened local moment. Crucially, we also uncover a novel intermediate phase featuring impurity screening through a single-particle bound state formed within the superconducting gap. The toy model presented in this work highlights the complex interplay between dynamically generated bulk properties and boundary impurities in extreme quantum chromodynamics environments, offering potential insights into phenomena occurring in heavy-ion collisions and compact stars.

Polar materials with optical phonons in the meV range are excellent candidates for both dark matter direct detection via dark photon-mediated scattering and light dark matter absorption. In this study, we propose, for the first time, the metal halide perovskites ${\mathrm{MAPbI}}_3$, ${\mathrm{MAPbCl}}_3$, and ${\mathrm{CsPbI}}_3$ for these purposes. Our findings reveal that ${\mathrm{CsPbI}}_3$ is the best material, significantly improving exclusion limits compared to other polar materials. For scattering, ${\mathrm{CsPbI}}_3$ can probe dark matter masses down to the keV range. For absorption, it enhances sensitivity to detect dark photon masses below $\sim 10\mathrm{meV}$. The only material that has so far been investigated and that could provide competitive bounds is CsI, which, however, demonstrates lower stability as device platform compared to ${\mathrm{CsPbI}}_3$. Moreover, CsI is isotropic while the anisotropic structure of ${\mathrm{CsPbI}}_3$ enables daily modulation analysis, showing that a significant percentage of daily modulation exceeding 1% is achievable for dark matter masses below 40 keV.

We identify new families of duality-invariant theories of electrodynamics. We achieve this in two different ways. On the one hand, we present an algorithm to construct a one-parameter family of exactly duality-invariant theories from a single seed duality-invariant theory. If the seed theory is causal, the theories constructed from this method will also be causal when the parameter is non-negative. On the other hand, we find two additional novel families of duality-invariant theories which include a nonzero term independent of the electromagnetic field. The first of them generalizes Bialynicki-Birula electrodynamics, while the second family of theories features a well-defined Maxwell limit as the term independent of the gauge field strength is sent to zero.

Dispersion relations are nonperturbative formulas that relate the ultraviolet and infrared behavior of an observable with wide-ranging applications applications in linear response theory, quantum field theory scattering amplitudes, and conformal correlators. We derive a position-space dispersion relation for scalar four-point mixed correlation functions in an arbitrary conformal field theory. This formula expresses the correlator in terms of its integrated double-discontinuity times a kinematic kernel. The kernel is analytically computed, and expressed in a remarkably simple form as a two-variable Appell function. The dispersion kernel is found by solving a coupled partial differential equation that the kernel obeys. Numerical checks of the dispersion relation are successfully performed for generalized free field correlators. Finally, we show that our position-space dispersion relation is equivalent to a Cauchy-type dispersion relation of the Mellin amplitude of the correlator.

We present results from a high-resolution interstellar turbulence simulation and show that it closely reproduces recent Planck measurements. Our model captures the scaling of $EE$ and $BB$ spectra and the $EE/BB$ ratio in the inertial range. The probability density function of the dust polarization fraction is also consistent with observations. The $TE$ cross-correlation is in broad agreement with the Planck sky. This simulation provides new insights into the physical origins of the observed $E/B$ asymmetry and positive $TE$ signal, facilitating the development of advanced Galactic dust emission models for current and future cosmic microwave background experiments.

Identifying the origin of high-energy hadronic jets (jet tagging) has been a critical benchmark problem for machine learning in particle physics. Jets are ubiquitous at colliders and are complex objects that serve as prototypical examples of collections of particles to be categorized. Over the last decade, machine learning-based classifiers have replaced classical observables as the state of the art in jet tagging. Increasingly complex machine learning models are leading to increasingly more effective tagger performance. Our goal is to address the question of convergence—are we getting close to the fundamental limit on jet tagging or is there still potential for computational, statistical, and physical insights for further improvements? We address this question using state-of-the-art generative models to create a realistic, synthetic dataset with a known jet tagging optimum. Various state-of-the-art taggers are deployed on this dataset, showing that there is a significant gap between their performance and the optimum. Our dataset and software are made public to provide a benchmark task for future developments in jet tagging and other areas of particle physics.

Both General Relativity and the Standard Model of particle physics are not UV complete. General Relativity is perturbatively nonrenormalizable, while the Standard Model features Landau poles, where couplings are predicted to diverge at finite energies, e.g., in the Abelian gauge sector. Asymptotically safe quantum gravity may resolve both of these issues at the same time. In this paper, we assess the systematic uncertainties associated with this scenario, in particular with the gravitationally induced UV-completion of the Abelian gauge sector. Specifically, we study the dependence of this qualitative feature, namely the existence of a UV-complete gauge sector, on unphysical choices like the gauge, and the regulator function. Intriguingly, in some scenarios, we find simultaneous points of minimal sensitivity relative to both the regulator and gauge parameters, which allow for a UV completion. This provides further indications that the simultaneous UV-completion of quantum gravity and matter via an asymptotically safe fixed point is a robust physical feature, and that physical quantities, like scaling exponents, can become independent of unphysical choices.

This paper explores the application of Newton-Cartan geometry to the kinetic theory of gases that includes nonrelativistic gravitational effects and the principle of general covariance. Starting with an introduction to the basics of Newton-Cartan geometry, we examine the motion of point particles within this framework, leading to a detailed analysis of kinetic theory and the derivation of conservation equations. The equilibrium distribution function is explored, and the example of a rotating gas in a gravitational field is discussed. Further, we develop covariant hydrodynamic equations and extend our analysis through a gradient expansion approach to assess first-order constitutive relations for rotating gases. Finally, we address the frame-dependence paradox, presenting a novel resolution that addresses apparent discrepancies. Our construction resolves a 50-year-old debate about the frame-indifferent formulation of kinetic theory. The resolution is presented in a modern, symmetry-based approach.

The homotopy Lie or $L_{\infty }$ algebra encoding Yang-Mills theory is the tensor product of a color Lie algebra with the kinematic $C_{\infty }$ algebra. We derive this $C_{\infty }$ algebra, via homotopy transfer, from a strict operator algebra of a worldline theory, realized as an associative star product algebra. This gives a homotopy transfer interpretation to worldline vertex operators introduced in previous work.

We use the physics-informed renormalization group (PIRG) for the construction of gauge invariant renormalization group flows. The respective effective action is a sum of a gauge invariant quantum part and the classical gauge fixing part which arranges for invertibility of the gauge field two-point function. Thus, the BRST transformations simply accommodate the gauge consistency of the gauge fixing sector, while the quantum part of the effective action is gauge and BRST invariant. We apply this physics-informed approach to Yang-Mills theory and gravity and show how the flowing gauge fields arrange for full gauge invariance. We also embed the background field approximation to the functional renormalization group (fRG) in an exact gauge invariant PIRG flow. This allows us to discuss the dynamics of the correction terms, and the nontrivial ultraviolet or infrared relevant terms are elucidated within a one-loop approximation. The background field approximation of the latter is known for violating one-loop universality for specific regulators, and we show how the present setup reinstates universality in a constructive way. Finally, we discuss the landscape of fRG flows in gauge theories through the lens of the novel PIRG approach as well as potential applications.

We have studied an $SO(4)$ gauged $O(5)$ Skyrmion on ${\mathrm{I}\mathrm{R}}^4$, which can be seen as a static soliton in $4+1$ dimensions. This is a sequel of the known $SO(D)$ gauged $O(D+1)$ Skyrmions on ${\mathrm{I}\mathrm{R}}^D$ in $D=2$ and in $D=3$, which are likewise localized to an absolute scale and topologically stable, their energies being bounded below by the winding number. In the absence of an analytic proof of existence, some such solutions are constructed numerically. Two families of solutions are found, of which only one possesses a gauge decoupling limit. The curvatures of both of these solutions decay as $r^{-3}$, a property they share with the Yang-Mills instantons on ${\mathrm{I}\mathrm{R}}^4$.

Momentum space entanglement of four fermion field theory is calculated from the Wilsonian effective action pertubatively using replica trick, local terms in low energy effective action are proved to be nonrelevant pertubatively, and nonlocal terms are the only source of entanglement between different momentum modes. The final result can be represented by a set of basketball Feynman diagrams with new Feynman rules proposed to interpret them.