We calculate chirally enhanced corrections to the muon’s electric and magnetic dipole moments in two-Higgs-doublet models extended by vector-like leptons, and we explore a sharp correlation between $h\to {\mu }^{+}{\mu }^{-}$ and the muon’s dipole moments in these models. Among many detailed predictions, for a model with new leptons with the same quantum numbers as standard model leptons, we find that $0.38\lesssim \tan \beta \lesssim 21$ necessarily requires a muon electric dipole moment to be observed at near-future experiments, assuming $h\to {\mu }^{+}{\mu }^{-}$ is measured within 1% of the standard model prediction for the current central value of the measured muon magnetic moment. In all studied models, the predicted values of the electric dipole moment can reach up to current experimental limits. Moreover, we show that in some models there can be two sources of chiral enhancement, parametrizing the correlation between $h\to {\mu }^{+}{\mu }^{-}$ and the dipole moments by a complex number. This leads to sign-preferred predictions for the electric dipole moment.

The effective action of the $SU(N)$ Polyakov-loop model in the strong coupling region and in the static limit for the quark determinant can be mapped onto the Ising model in any dimensions, with the Ising variables attached on the links of the lattice. We use this reformulation to study the finite temperature $SU(2)$ lattice gauge theory at finite baryon density.

In this paper, we examine a modification of the Kazakov-Migdal (KM) model with gauge group $U(N_c)$, where the adjoint scalar fields in the conventional KM model are replaced by $N_f$ fundamental scalar fields (FKM model). After tuning the coupling constants and eliminating the fundamental scalar fields, the partition function of this model is expressed as an integral of a graph zeta function weighted by unitary matrices. The FKM model on cycle graphs at large $N_c$ exhibits the Gross-Witten-Wadia (GWW) phase transition only when $N_f>N_c$. In the large $N_c$ limit, we evaluate the free energy of the model on a general graph in two distinct parameter regimes and demonstrate that the FKM model generally consists of multiple phases. The effective action of the FKM model reduces to the standard Wilson action by taking an appropriate scaling limit when the graph consists of plaquettes (fundamental cycles) of the same size, as in the square lattice case. We show that, for the FKM model on such a graph, the third-order GWW phase transition universally occurs in this scaling limit.

Recent open quantum system studies showed that quarkonium time evolution inside the quark-gluon plasma is determined by transport coefficients that are defined in terms of a gauge invariant correlator of two chromoelectric field operators connected by an adjoint Wilson line. We study the Euclidean version of the correlator for quarkonium evolution and discuss the extraction of the transport coefficients from this Euclidean correlator, highlighting its difference from other problems that also require reconstructing a spectral function, such as the calculation of the heavy quark diffusion coefficient. Along the way, we explain why the transport coefficient ${\gamma }_{\mathrm{adj}}$ differs from ${\gamma }_{\text{fund}}$ at finite temperature at $\mathcal{O}(g^4)$, in spite of the fact that their corresponding spectral functions differ only by a temperature-independent term at the same order. We then discuss how to evaluate the Euclidean correlator via lattice QCD methods, with a focus on reducing the uncertainty caused by infrared renormalons in determining the renormalization factor nonperturbatively.

The generating functional ${\mathcal{W}}^E[J_{\mathcal{O}}]$ of Euclidean correlators of twist-2 operators in $\mathrm{SU}(N)$ Yang-Mills theory admits the ’t Hooft large-$N$ expansion: ${\mathcal{W}}^E[J_{\mathcal{O}}]={\mathcal{W}}_{\text{sphere}}^E[J_{\mathcal{O}}]+{\mathcal{W}}_{\text{torus}}^E[J_{\mathcal{O}}]+\cdots$. Nonperturbatively, ${\mathcal{W}}_{\text{sphere}}^E[J_{\mathcal{O}}]$ is a sum of tree diagrams involving glueball propagators and vertices, while ${\mathcal{W}}_{\text{torus}}^E[J_{\mathcal{O}}]$ is a sum of glueball one-loop diagrams. Moreover, it has been predicted that ${\mathcal{W}}_{\text{torus}}^E[J_{\mathcal{O}}]$ should admit the structure of the logarithm of a functional determinant summing glueball one-loop diagrams. We work out in a closed form the ultraviolet (UV) asymptotics of ${\mathcal{W}}_{\text{sphere}}^E[J_{\mathcal{O}},\lambda ]\sim {\mathcal{W}}_{\text{asym sphere}}^E[J_{\mathcal{O}},\lambda ]$ and ${\mathcal{W}}_{\text{torus}}^E[J_{\mathcal{O}},\lambda ]\sim {\mathcal{W}}_{\text{asym torus}}^E[J_{\mathcal{O}},\lambda ]$ in the coordinate representation as all the coordinates of the correlators are uniformly rescaled by a factor $\lambda \to 0$. The calculation is performed in two steps. First, extending our previous work, we compute—directly from its functional-integral definition as a Gaussian integral—the generating functional of the conformal correlators ${\mathcal{W}}_{\mathrm{conf}}[J_{\mathcal{O}}]={\mathcal{W}}_{\text{conf sphere}}[J_{\mathcal{O}}]+{\mathcal{W}}_{\text{conf torus}}[J_{\mathcal{O}}]$ to the lowest perturbative order of all the twist-2 operators with maximal spin along the $p_{+}$ direction, in both Minkowskian and—by analytical continuation—Euclidean spacetimes. Thus, we provide a purely perturbative explanation as to why ${\mathcal{W}}_{\mathrm{conf}}[J_{\mathcal{O}}]$ has the structure of the logarithm of a functional determinant. Second, by means of a careful choice of the renormalization scheme that reduces the mixing of the above operators to the multiplicatively renormalizable case to all orders of perturbation theory, we lift the generating functional of the Euclidean conformal correlators ${\mathcal{W}}_{\mathrm{conf}}^E[J_{\mathcal{O}}]$ to the generating functional of the renormalization-group improved correlators ${\mathcal{W}}_{\mathrm{asym}}^E[J_{\mathcal{O}},\lambda ]={\mathcal{W}}_{\text{asym sphere}}^E[J_{\mathcal{O}},\lambda ]+{\mathcal{W}}_{\text{asym torus}}^E[J_{\mathcal{O}},\lambda ]$ that inherits the very same structure of the logarithm of a functional determinant. Remarkably, we verify the above prediction that ${\mathcal{W}}_{\text{asym torus}}^E[J_{\mathcal{O}},\lambda ]$—being asymptotic in the UV to ${\mathcal{W}}_{\text{torus}}^E[J_{\mathcal{O}},\lambda ]$—admits the structure of the logarithm of a functional determinant as well. Hence, the computation above sets strong UV asymptotic constraints on the nonperturbative solution of large-$N$ Yang-Mills theory, and it may be a pivotal guide for the search of such a solution.

Recently, the next-to-next-to-leading order (NNLO) electroweak corrections with fermion loops to the Higgsstrahling process were computed. Here we present numerical results for polarized electron/positron beams, as well as for two input parameter schemes known as the $\alpha (0)$ and $G_{\mu }$ schemes. The size of the NNLO corrections strongly depends on the beam polarization, leading to an increase of the $ZH$ cross section by 0.76% for $e_{\mathrm{L}}^{+}{e}_{\mathrm{R}}^{-}$ beams, and a decrease of 0.04% for $e_{\mathrm{R}}^{+}{e}_{\mathrm{L}}^{-}$ beams. Furthermore, inclusion of the NNLO corrections is found to significantly reduce the discrepancy between the results in the $\alpha (0)$ and $G_{\mu }$ schemes. Using the remaining difference, together with other methods, the theory uncertainty from missing bosonic electroweak corrections is estimated to be less than 0.3%.

We investigate the neutral-current neutrino-nucleon deep inelastic scattering with particular emphasis on short-range correlation (SRC) and the European Muon Collaboration (EMC) effect, as well as their impact on the weak-mixing angle ${\sin }^2{\theta }_W$ determination. The ratios of relevant structure functions are presented where the nuclei are chosen as carbon, iron, and lead. One kind of universal modification function is proposed which would provide a nontrivial test of SRC universality on the platform of neutrino-nucleon deep inelastic scattering. In addition, we study the impact of “SRC-driven” nuclear effects on the extraction of ${\sin }^2{\theta }_W$ which is naturally associated with the renowned NuTeV anomaly. The results indicate that these effects may account for a substantial fraction of the NuTeV anomaly and considerably affect the value of extracted ${\sin }^2{\theta }_W$.

A search is presented for a heavy resonance $Y$ decaying into a Standard Model Higgs boson $H$ and a new particle $X$ in a fully hadronic final state. The full Large Hadron Collider run 2 dataset of proton-proton collisions at $\sqrt{s}=13\mathrm{TeV}$ collected by the ATLAS detector from 2015 to 2018 is used and corresponds to an integrated luminosity of $139{\mathrm{fb}}^{-1}$. The search targets the high $Y$-mass region, where the $H$ and $X$ have a significant Lorentz boost in the laboratory frame. A novel application of anomaly detection is used to define a general signal region, where events are selected solely because of their incompatibility with a learned background-only model. It is constructed using a jet-level tagger for signal-model-independent selection of the boosted $X$ particle, representing the first application of fully unsupervised machine learning to an ATLAS analysis. Two additional signal regions are implemented to target a benchmark $X$ decay into two quarks, covering topologies where the $X$ is reconstructed as either a single large-radius jet or two small-radius jets. The analysis selects Higgs boson decays into $b\overline{b}$, and a dedicated neural-network-based tagger provides sensitivity to the boosted heavy-flavor topology. No significant excess of data over the expected background is observed, and the results are presented as upper limits on the production cross section $\sigma (pp\to Y\to XH\to q\overline{q}b\overline{b}$) for signals with $m_Y$ between 1.5 and 6 TeV and $m_X$ between 65 and 3000 GeV.

The mass difference between the ${\mathrm{\Omega }}_b^{-}$ and ${\mathrm{\Xi }}_b^{-}$ baryons is measured using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of $9{\mathrm{fb}}^{-1}$, and is found to be $m({\mathrm{\Omega }}_b^{-})-m({\mathrm{\Xi }}_b^{-})=248.54\pm 0.51(\mathrm{stat})\pm 0.38(\mathrm{syst})\mathrm{MeV}/c^2$. The mass of the ${\mathrm{\Omega }}_b^{-}$ baryon is measured to be $m({\mathrm{\Omega }}_b^{-})=6045.9\pm 0.5(\mathrm{stat})\pm 0.6(\mathrm{syst})\mathrm{MeV}/c^2$. This is the most precise determination of the ${\mathrm{\Omega }}_b^{-}$ mass to date. In addition, the production rate of ${\mathrm{\Omega }}_b^{-}$ baryons relative to that of ${\mathrm{\Xi }}_b^{-}$ baryons is measured for the first time in $pp$ collisions, using an LHCb dataset collected at a center-of-mass energy of 13 TeV and corresponding to an integrated luminosity of $6{\mathrm{fb}}^{-1}$. Reconstructing beauty baryons in the kinematic region $2<\eta <6$ and $p_T<20\mathrm{GeV}/c$ with their decays to a $J/\psi$ meson and a hyperon, the ratio $\frac{f_{{\mathrm{\Omega }}_b^{-}}}{f_{{\mathrm{\Xi }}_b^{-}}}\times \frac{\mathcal{B}({\mathrm{\Omega }}_b^{-}\to J/\psi {\mathrm{\Omega }}^{-})}{\mathcal{B}({\mathrm{\Xi }}_b^{-}\to J/\psi {\mathrm{\Xi }}^{-})}=0.120\pm 0.008(\mathrm{stat})\pm 0.008(\mathrm{syst})$, is obtained, where $f_{{\mathrm{\Omega }}_b^{-}}$ and $f_{{\mathrm{\Xi }}_b^{-}}$ are the fragmentation fractions of $b$ quarks into ${\mathrm{\Omega }}_b^{-}$ and ${\mathrm{\Xi }}_b^{-}$ baryons, respectively, and $\mathcal{B}$ represents the branching fractions of their respective decays.

We construct new solutions of a $U(1)$ gauged Skyrme-Maxwell model of topological degrees $Q\le 5$, which represent skyrmions coupled to magnetic fluxes. It is found that, generically, in the strong coupling limit, coupling to the magnetic field results in transformation of the configuration to the toroidally shaped skyrmions bounded to the local magnetic flux.

In November 2022, the China Space Station (CSS) was equipped with a cold atomic microwave clock and a Sr optical lattice clock with stabilities of $5\times {10}^{-14}/\sqrt{\tau }$ and $2\times {10}^{-15}/\sqrt{\tau }$ (where $\tau$ is the integration time in seconds), respectively, which provides an excellent opportunity to test gravitational redshift (GRS) with higher accuracy than previous results. Based on high-precision frequency links between the China Space Station and a ground station, we formulated a model and provided simulation experiments to test GRS. Simulation results suggest that this method could test the GRS at the accuracy level of $5\times {10}^{-7}$, more than 2 orders in magnitude higher than the result of the experiment of a hydrogen clock on board a flying rocket more than 40 years ago.

Hořava gravity has been proposed as a renormalizable quantum gravity without the ghost problem through anisotropic scaling dimensions which break Lorentz symmetry in UV. In the Hamiltonian formalism, due to the Lorentz-violating terms, the constraint structure looks quite different from that of general relativity (GR) but we have recently found that “there exists the case where we can recover the same number of degrees of freedom as in GR”, in a rather general setup. In this paper, we study its Lagrangian perspectives and examine the full diffeomorphism (Diff) symmetry and its associated conservation laws in Hořava gravity. Surprisingly, we find that the full Diff symmetry in the action can also be recovered when a certain condition, called “supercondition,” which superselects the Lorentz-symmetric sector in Hořava gravity, is satisfied. This indicates that the broken Lorentz symmetry, known as “foliation-preserving” Diff, is just an apparent symmetry of the Hořava gravity action and rather its “full action symmetry can be as large as the Diff in GR.” The supercondition exactly corresponds to the tertiary constraint in Hamiltonian formalism which is the second-class constraint and provides a nontrivial realization of the Lorentz symmetry otherwise being absent apparently. From the recovered Lorentz symmetry in the action, we obtain the conservation laws with the Noether currents as in covariant theories. The general formula for the conserved Noether charges reproduces the mass of four-dimensional static black holes with an arbitrary cosmological constant in Hořava gravity, and is independent of ambiguities associated with the choice of asymptotic boundaries. We also discuss several challenging problems, including its implications to Hamiltonian formalism, black hole thermodynamics, radiations from colliding black holes.

If two particles move toward a black hole and collide in the vicinity of the horizon, under certain conditions, their energy $E_{\mathrm{c}.\mathrm{m}.}$ in the center of mass frame can grow unbounded. This is the Bañados-Silk-West (BSW) effect. Usually, this effect is considered for extremal horizons and geodesic (or electrogedesic) trajectories. We study this effect in a more general context, when both geometric and dynamic factors are taken into account. We consider generic axially symmetric rotating black holes. The near-horizon behavior of metric coefficients is determined by three numbers $p$, $q$, $k$ that appear in the Taylor expansions for different types of a horizon. This includes nonextremal, extremal, and ultraextremal horizons. We also give general classification of possible trajectories that include so-called usual, subcritical, critical, and ultracritical ones depending on the near-horizon behavior of the radial component of the four-velocity. We assume that particles move not freely but under the action of some unspecified force. We find when the finiteness of a force and the BSW effect are compatible with each other. The BSW effect implies that one of two particles has fine-tuned parameters. We show that such a particle always requires an infinite proper time for reaching the horizon. Otherwise, either a force becomes infinite, or a horizon fails to be regular. This realizes the so-called principle of kinematic censorship that forbids literally infinite $E_{\mathrm{c}.\mathrm{m}.}$ in any act of collision. The obtained general results are illustrated for the Kerr-Newman-(anti-)de Sitter metric used as an example. The description of diversity of trajectories suggested in our work can be of use also in other contexts, beyond the BSW effect. In particular, we find the relation between a force and the type of a trajectory.

We investigate the joint effect of cosmological phase transitions, thermal light dark matter, and lepton asymmetry on big bang nucleosynthesis and the cosmic microwave background. We find that all of them can modify the predictions of the effective number of neutrino species and primordial nucleosynthesis. In turn, we observe that (i) cosmological observations can exclude slow and strong phase transitions with strength even smaller than $\mathcal{O}({10}^{-3}–{10}^{-2})$; (ii) a much larger portion of the dark matter mass region is excluded when the phase transition temperature is closer to 1 MeV; and (iii) the magnitude of the nonvanishing neutrino lepton asymmetry is limited to be around $\mathcal{O}({10}^{-2}–{10}^{-1})$ depending on the phase transition strength. These phase transitions can produce stochastic gravitational wave background to be probed by pulsar timing array experiments.

In this paper we study the production of primordial black holes (PBHs) from inflation in order to explain the dark matter (DM) in the Universe. The evaluation of the fractional PBHs abundance to DM is sensitive to the value of the threshold ${\delta }_{\mathrm{c}}$ and the exact value of ${\delta }_{\mathrm{c}}$ is sensitive to the specific shape of the cosmological fluctuations. Different mechanisms producing PBHs lead to different thresholds and hence to different fractional abundances of PBHs. In this study, we examine various classes of inflationary models proposed in the existing literature to elucidate the formation of PBHs and we evaluate numerically the associated threshold values. Having evaluated the thresholds we compute the abundances of PBHs to DM using the Press-Schecter approach and the peak theory. Given the influence of different power spectra on the thresholds, we investigate whether these inflationary models can successfully account for a significant fraction of DM. Moreover, we provide suggested values for the critical threshold. By examining the interplay between inflationary models, threshold values, and PBH abundances, our study aims to shed light on the viability of PBHs as a candidate for DM and contributes to the ongoing discussion regarding the nature of DM in the Universe.

We develop a precise analytic description of oscillons—long-lived quasiperiodic field lumps—in scalar field theories with nearly quadratic potentials, e.g., the monodromy potential. Such oscillons are essentially nonperturbative due to large amplitudes, and they achieve extreme longevities. Our method is based on a consistent expansion in the anharmonicity of the potential at strong fields, which is made accurate by introducing a field-dependent “running mass.” At every order, we compute effective action for the oscillon profile and other parameters. Comparison with explicit numerical simulations in ($3+1$)-dimensional monodromy model shows that our method is significantly more precise than other analytic approaches.

Recent multidimensional (multi-D) core-collapse supernova (CCSN) simulations characterize gravitational waves (GWs) and neutrino signals, offering insight into universal properties of CCSN independent of progenitor. Neutrino analysis in real observations, however, will be complicated due to the ambiguity of self-induced neutrino flavor conversion (NFC), which poses an obstacle to extracting detailed physical information. In this paper, we propose a novel approach to place a constraint on NFC from observed quantities of GWs and neutrinos based on correlation analysis from recent, detailed multi-D CCSN simulations. The proposed method can be used even in cases with low significance or no detection of GWs. We also discuss how we can utilize electromagnetic observations to complement the proposed method. Although our proposed method has uncertainties associated with CCSN modeling, the present result will serve as a base for more detailed studies. Reducing the systematic errors involved in CCSN models is a key to success in this multimessenger analysis that needs to be done in collaboration with different theoretical groups.

As first proposed by Gruzinov, a charged particle moving in strong electromagnetic fields can enter an equilibrium state where the power input from the electric field is balanced by radiative losses. When this occurs, the particle moves at nearly light speed along special directions called the principal null directions (PNDs) of the electromagnetic field. This equilibrium is “Aristotelian” in that the particle velocity, rather than acceleration, is determined by the local electromagnetic field. In Paper I of this series, we analytically derived the complete formula for the particle velocity at leading order in its deviation from the PND, starting from the fundamental Landau-Lifshitz (LL) equation governing charged particle motion, and demonstrated agreement with numerical solutions of the LL equation. We also identified five necessary conditions on the field configuration for the equilibrium to occur. In this paper we study the entry into equilibrium using a similar combination of analytical and numerical techniques. We simplify the necessary conditions and provide strong numerical evidence that they are also sufficient for equilibrium to occur. Based on exact and approximate solutions to the LL equation, we identify key timescales and properties of entry into equilibrium and show quantitative agreement with numerical simulations. Part of this analysis shows analytically that the equilibrium is linearly stable and identifies the presence of oscillations during entry, which may have distinctive radiative signatures. Our results provide a solid foundation for using the Aristotelian approximation when modeling relativistic plasmas with strong electromagnetic fields.

Previous studies from the astrophysics and laser physics communities have identified an interesting phenomenon wherein ultrarelativistic charged particles experiencing strong radiation reaction tend to move along special directions fixed by the local electromagnetic field. In the relativity literature these are known as the “principal null directions” (PNDs) of the Maxwell field. A particle in this regime has “Aristotelian” dynamics in the sense that its velocity (rather than acceleration) is determined by the local field. We study this Aristotelian equilibrium in detail, starting from the Landau-Lifshitz equation describing charged particle motion including radiation reaction. Using a Frenet-Serret frame adapted to the PNDs, we derive the Lorentz factor describing motion along the local PND, together with drift velocities reflecting slower passage from one PND to another. We derive conditions on the field configuration that are necessary for such an equilibrium to occur. We demonstrate agreement of our analytic formulas with full numerical solutions of the Landau-Lifshitz equation in the appropriate regime.

Positivity bounds on scattering amplitudes provide a necessary condition for a low-energy effective field theory to have a consistent ultraviolet completion. Their extension to gravity theories has been studied in the past years aiming at application to the swampland program, showing that positivity bounds hold at least approximately even in the presence of gravity. A theoretical issue in this context is how much negativity is allowed for a given scattering process. We show that this issue is relevant to physics within the scope of ongoing experiments, especially in the context of dark sector physics. A detailed analysis of dark photon scenarios is provided as an illustrative example. Our results do not merely show the phenomenological importance of the theoretical study of gravitational positivity bounds but also open up an exciting possibility of exploring the nature of quantum gravity via an experimental search of the dark sector.