Recent experiments of photon-nucleon and meson-nucleon scatterings have accumulated a lot of data for various meson production processes. One of the purposes of those experiments is to search for the missing resonances which were not discovered until now but whose existence was predicted by hadron models. The analyses of the data requires the development of dynamical coupled-channel models. Since several missing resonances are expected to have spin higher than $3/2$, we need to include higher-spin resonances in dynamical coupled-channel models, which enable us to determine the couplings of effective Lagrangians of higher-spin baryons with pseudoscalar mesons or vector mesons. However, hadron models, such as quark models, give predictions only of the decay amplitudes of such baryons. Here we demonstrate the formalism of high-spin resonances and construct the relation between the coupling constants of effective Lagrangians and the partial decay widths that can be predicted by hadron models. This allows us to compare the coupling constants to the hadron model predictions not only in magnitude but in sign as well.

Using $(27.12\pm 0.14)\times {10}^8$ $\psi (3686)$ events collected with the BESIII detector operating at the BEPCII collider, we have observed the decay $\psi (3686)\to {\mathrm{\Sigma }}^0{\overline{\mathrm{\Sigma }}}^0\varphi$ for the first time with a statistical significance of $7.6\sigma$. Its branching fraction is measured to be $(2.64\pm 0.32_{\mathrm{stat}}\pm 0.12_{\mathrm{sys}})\times {10}^{-6}$, where the first uncertainty is statistical and the second is systematic. The result is consistent with the previous measurement of its isospin partner process $\psi (3686)\to {\mathrm{\Sigma }}^{+}{\overline{\mathrm{\Sigma }}}^{-}\varphi$, aligning with the naive expectation of isospin symmetry. In addition, we search for potential intermediate states in the ${\mathrm{\Sigma }}^0\varphi$ (${\overline{\mathrm{\Sigma }}}^0\varphi$) invariant mass distribution and a possible threshold enhancement in the ${\mathrm{\Sigma }}^0{\overline{\mathrm{\Sigma }}}^0$ system, but no conclusive evidence of them is observed.

Minimal dark matter is an attractive candidate for dark matter because it is stabilized without the need to impose additional symmetries. It is known that the $SU(2{)}_L$ quintuplet fermion can serve as a minimal dark matter candidate, with its mass predicted to be around 14 TeV, based on the thermal production mechanism. In this work, we embed the quintuplet dark matter within nonsupersymmetric $SU(5)$ grand unified theories. We find that two pairs of colored sextet fermions are required at the $\mathcal{O}(1–10)\mathrm{TeV}$ scale to achieve gauge coupling unification, with the unification scale near the reduced Planck scale. These colored sextet fermions become metastable because their interactions are suppressed by the unification scale. Our model can be tested through comprehensive searches for colored sextet fermions in collider experiments, as well as through indirect and direct detection methods for minimal dark matter. Once the minimal dark matter scenario has been experimentally confirmed, it will have implications for modifying string theories.

Evidences of vortical effects have been recently found by experiments in heavy ion collisions, instigating new insights into the phase diagram of quantum chromodynamics (QCD). Considering the effect of rotations, lattice QCD data shows that the temperatures for deconfinement and chiral symmetry restoration should increase with real angular velocity, and the dominant effects are related to gluonic degrees of freedom. These findings could be essential for quark models in rotating systems that lack gluonic interactions, which predicts the decreasing of the chiral temperature transition with the angular velocity. To address this issue properly, in this work we apply the two-flavor Nambu–Jona-Lasinio model to explore the phase diagram in a rotating rigid cylinder with constant angular velocity in the mean field approximation. To circumvent the absence of gluons, we propose the application of an effective coupling dependent of the angular velocity, fitted to match the pseudocritical temperature of chiral phase transition in the model through lattice QCD data. Our results indicate that the running coupling induces the enhancement of the chiral condensate as a function of angular velocity, strengthening the breaking of chiral symmetry, an effect previously dubbed as chiral vortical catalysis. For the chiral susceptibility we observe stronger fluctuations around the transition temperature when we consider the running coupling. The phase diagram is affected by these findings shifting the critical end point (CEP) to higher temperatures and chemical potentials.

The temperature-dependent mass of the heavy neutrino can lead to the second leptogenesis occurring below the electroweak scale, potentially explaining the large discrepancy between baryon and lepton asymmetries. We investigate this scenario further, exploring the intricate interplay of the weak interaction processes within this framework. It includes notable shifts in the dominant decay channels of heavy neutrinos around the electroweak symmetry breaking, along with the resonance behavior of the scattering processes near the $W/Z$ mass. The $CP$ asymmetry can also vary over cosmic history due to the temperature-dependent mass, allowing the $B-L$ asymmetry generation to be amplified in the late epoch. These findings elucidate how such alterations in the dynamics of second leptogenesis contribute to addressing the observed discrepancies in baryon-lepton asymmetry.

We study spontaneous symmetry breaking in quantum field theories with fermionic order parameters and construct, for the first time in the literature, the constraint effective potential for it. The Grassmann-valued constraint we encounter is handled using its large-volume expansion, corresponding to a saddle-point approximation. We test the method in the chiral Gross-Neveu model and demonstrate its consistency with the standard approach. The machinery we developed opens up a new avenue to investigate the spontaneous symmetry breaking and restoration in field theories, in particular for the chiral symmetry breaking in the strong interactions.

We study the deflection of light rays in a cold, nonmagnetized plasma using the worldline framework. Starting from Synge’s Hamiltonian formalism, we construct a position-space action and use it perturbatively to calculate light bending angles. In the homogeneous case, the action reduces to that of a massive particle, allowing us to extract the bending angle of light in the presence of the medium using a well-known analogy. For the inhomogeneous case, we consider a power law model and construct Feynman rules in time to compute the purely plasma-induced corrections to the bending angle at next-to-leading-order.

The Weinberg compositeness criterion dictates that a pure shallow bound state is characterized by a large scattering length $a_0\gg \mathcal{O}(1/\beta )$ and a positive effective range $r_0$ that naturally scales to the size of $\mathcal{O}(1/\beta )$, where $1/\beta$ signifies the interaction range. In constructing the contact-range effective field theory (EFT) up to the next-to-leading order to describe the pentaquarks $P_c(4312)$, $P_c(4440)$, and $P_c(4457)$ observed by the LHCb collaboration in 2019, we match the effective range $r_0$ at single-channel situation for these pentaquarks with the low-energy couplings within the EFT framework. Three different schemes are used to connect the couplings with the effective range. We find positive effective ranges $r_0$ of the natural size of $\mathcal{O}(1/\beta )$ for the spin configurations $J^P={\frac{3}{2}}^{-}$ for $P_c(4440)$ and $J^P={\frac{1}{2}}^{-}$ for $P_c(4457)$ within the molecular ${\overline{D}}^{*}{\mathrm{\Sigma }}_c$ description. Additionally, predictions from the power counting for low-energy couplings or Wilsonian coefficients suggest that, under heavy quark spin symmetry, the broad $P_c(4380)$ resonance, discovered by the LHCb collaboration in 2015, when considered as part of the single-channel ${\overline{D}}^{(*)}{\mathrm{\Sigma }}_c^{(*)}$ molecular system alongside $P_c(4312)$, $P_c(4440)$, and $P_c(4457)$, has a mass of approximately $4376\mathrm{MeV}$.

In this study, we investigate the $CP$-averaged branching fractions and direct $CP$ asymmetries in the quasi-two-body decays $B\to P(f_0(980)\to )(K^{+}{K}^{-},{\pi }^{+}{\pi }^{-})$ within the framework of the perturbative QCD approach, where $P$ denotes light pseudoscalar mesons ($\pi$,$K$). The timelike form factor $F_S(\omega )$, characterizing final-state interactions between collinear particles in the resonant region, is modeled through the revised relativistic Breit-Wigner formalism for the $S$-wave $f_0(980)$ resonance. Within the Gegenbauer moments of the $S$-wave two-meson distribution amplitudes constrained by current data, we predict the branching fractions of $B\to P(f_0(980)\to )(K^{+}{K}^{-},{\pi }^{+}{\pi }^{-})$ to lie in the range of ${10}^{-8}$ to ${10}^{-6}$. Our calculations reveal that our theoretical results for some decay modes exhibit satisfactory agreement with existing measurements from the BABAR and Belle collaborations. Furthermore, we extract the corresponding branching fractions of $B\to P{f}_0(980)$ decays from the quasi-two-body counterparts $B\to P(f_0(980)\to ){\pi }^{+}{\pi }^{-}$ rather than $B\to P(f_0(980)\to )K^{+}{K}^{-}$. All predictions are awaiting experimental verification in current and upcoming collider experiments.

Using a sample of $\sim {10}^{10}J/\psi$ events collected by the BESIII detector at the BEPCII collider, a partial-wave analysis of the decay $\gamma \gamma \varphi$ is performed to investigate the intermediate resonances in $J/\psi \to \gamma R$, $R\to \gamma \varphi$. Resonances including $f_1(1285)$, $\eta (1405)$, $f_1(1420)$, $f_1(1510)$, $f_2(1525)$, $X(1835)$, $f_2(1950)$, $f_2(2010)$, $f_0(2200)$, and ${\eta }_c$ have been detected with statistical significance greater than $5\sigma$. The product branching fractions $\mathcal{B}(J/\psi \to \gamma R,R\to \gamma \varphi )$ are reported, and the resonance parameters of $\eta (1405)$ and $X(1835)$ have been precisely determined. It seems likely that $\eta (1405)$ and $X(1835)$ act as the first—and second—excited states of ${\eta }^{\prime }$, respectively. The observation of ${\eta }_c\to \gamma \varphi$ holds great significance for the in depth study of charmonium properties. No evidence of $\eta (1295)$, ${\eta }_1(1855)$ or X(2370) is found. The measured upper limits of relevant branching fraction products do not conflict with theoretical expectations for X(2370) as a pseudoscalar glueball and ${\eta }_1(1855)$ as a hybrid state.

We uncover new nonsupersymmetric boundary conditions in 10- and 11-dimensional supergravity whereby spacetime ends on a smeared distribution of D- and M-branes, respectively. For example, we find a solution of type IIB supergravity where the ${\mathrm{AdS}}_5\times {\mathbb{S}}^5$ vacuum ends on an $SO(6)$-invariant distribution of D3-branes. These distributions give a stringy completion of simple models of tensionful end-of-the-world branes considered previously in the literature. However, we find that our solutions are all unstable to the fragmentation of the end-of-the-world brane into its constituents.

The leading quantum-gravitational correction to the black hole entropy is known to be a universal logarithmic term. In this study, we investigate the logarithmic corrections for the black holes in the STU supergravity models, which are a bosonic truncation into a specific class of $U(1{)}^2$-charged Einstein-Maxwell-dilaton theory. We demonstrate how the entire Kerr-Newman-AdS and Kerr-Newman family of black holes can be recovered within the gauged and ungauged STU supergravity models as special embedding choices in 4D. Logarithmic corrections are computed using two distinct Euclidean quantum gravity setups for extremal and nonextremal limits of all embedded rotating, static, charged, and neutral black holes. Our calculations employ the on-shell heat kernel method based Seeley-DeWitt expansion computations. Notably, all the ${\mathrm{AdS}}_4$ results exhibit a confirmed nontopological nature as compared to the flat counterparts, offering a natural and more comprehensive “infrared window into the microstates” of black holes.

We recently studied spin precession in various stationary and axisymmetric spacetimes and applied it to the case of neutrinos propagating in those spacetimes. In this paper, the study of spin precession is extended to the case of a spinning particle propagating within the spacetime of a time-dependent gravitational plane wave. First, the angular velocity of spin precession of a particle propagating in a geodesic along an arbitrary direction relative to the gravitational wave is derived. Our general result is then used to derive the helicity flip probability for neutrinos freely propagating along such an arbitrary direction within the gravitational wave.

We compute the physical running of a general higher derivative scalar coupled to a nondynamical metric and of higher derivative Weyl invariant gravity with a dynamical metric in four dimensions. In both cases, we find that the physical running differs from the $\mu$-running of dimensional regularization because of infrared divergences which are present in amplitudes also at large momenta, differently from what happens in standard two derivative theories. We use the higher derivative scalar as a toy-model to elaborate on the properties of the conformal limit in relation to the trace anomaly. The physical running of higher derivative Weyl gravity, while different from the $\mu$-running, remains asymptotically free, suggesting that the model is a viable completion of Einstein’s gravity, at least from the point of view of its renormalization group properties.

In recent work by Lynch, Cohen, Hadad, and Kaminer (LCHK), a modified model of the Unruh-DeWitt two-level quantum detector, coupled to a semiclassical four-vector current, has been proposed to examine the radiation emitted by high energy positrons channeled into silicon crystal samples. Inspired by their ideas, we analyze theoretical aspects of such a model, its internal consistency, and ignore all questions related to experiments. The two-potential correlation functions for the quantized electromagnetic field in a vacuum state and the corresponding detector radiation power (DRP), considered in proper time formalism, are used as the basis for investigating the radiation observed at an accelerating point detector. The quantum detector is assumed to be moving through an electromagnetic vacuum along a classical hyperbolic trajectory with a constant proper acceleration. The DRP is obtained for three possible cases. First, the DRP is found in a Lorentz-invariant manner. It contains both transverse and nonphysical longitudinal polarization modes and is a divergent quantity. Second, the radiation power holds only physical transverse modes, but it is nonrelativistic and also depends on the detector proper time, which contradicts the fact that there is no preferred time for hyperbolic detector motion. Third, in the particular case considered by LCHK, for zero detector proper time when its velocity in the lab inertial system is zero, the radiation power with transverse modes shows some signs of thermality that could be associated with a detector acceleration but different from the Bose-Einstein statistics expected for the photon field. If the detector energy gap is zero then, in complete contradiction with what LCHK claim, there is no radiation and no “thermalized Larmor formula.” Based on our analysis we do not believe that the LCHK’s model can be used to support the idea about thermal effects of uniform acceleration.

We examine the physical implications of the centrifugal and gravitational electromotive forces on magnetic reconnection in a Kerr black hole background. We find that both forces increase the reconnection rate, though the underlying mechanisms differ substantially. The gravitational force leads to a separation of charge density, breaking the quasineutrality of the plasma. In contrast, the centrifugal electromotive force affects the electric current by reducing the effective length of the current sheet. This reduction arises from the non-Euclidean spatial geometry observed by a locally comoving observer with respect to the rotating sheet. This phenomenon amplifies both the transport of charged carriers and the thermal-inertia effect within the current sheet, irrespective of the presence of a black hole.

We present a new non-BPS solution describing an asymptotically flat, stationary, biaxisymmetric capped black hole in the bosonic sector of five-dimensional minimal supergravity. This solution describes a spherical black hole, while the exterior region of the horizon exhibits a nontrivial topology of $[{\mathbb{R}}^4\#\mathbb{C}{\mathbb{P}}^2]\backslash {\mathbb{B}}^4$ on a time slice. This solution extends our previously constructed three-parameter solution to a more general four-parameter solution. To derive this solution, we utilize a combination of the Ehlers and Harrison transformations and then impose appropriate boundary conditions on the solution’s parameters. It can be shown that the resultant solution is free from curvature, conical, Dirac-Misner string and orbifold singularities, as well as closed timelike curves on and outside the horizon. Characterized by four independent conserved charges—mass, two angular momenta, and electric charge—this solution reveals two distinct branches: a small bubble branch and a large bubble branch, distinguished by nonconserved local quantities such as magnetic flux or magnetic potential. This shows the nonuniqueness for spherical black holes, even among capped black holes. For equivalent sets of conserved charges, we find that the large/small bubble branch can have larger/smaller entropy than the Cvetič-Youm black hole.

In this paper we follow an effective theory approach to study the nonrelativistic limit of a self-gravitating and self-interacting massive vector field. Our effective theory is characterized by three parameters: the field’s mass $m_0$ and the self-interaction constants ${\lambda }_n$ and ${\lambda }_s$. For definiteness, we focus on a systematic study of the equilibrium configurations, commonly referred to as Proca stars when they have finite energy. We identify two different types of Proca stars, depending on the specific sector of the effective theory that we are exploring. In the generic sector, defined by ${\lambda }_s\ne 0$, all equilibrium configurations are stationary states described by wave functions that evolve harmonically in time. However, in the symmetry-enhanced sector, for which ${\lambda }_s=0$, there exist multifrequency states whose wave functions oscillate with two or three distinct frequencies in addition to the stationary states. We determine the conditions under which a ground state configuration with fixed particle number exists. When these conditions are met, we prove that the lowest energy is reached by a stationary spherically symmetric configuration of constant polarization that is linear or circular depending on the sign of ${\lambda }_s$. We numerically construct some illustrative examples of spherical stationary and multifrequency solutions, analyze their properties, and compare them with our analytical predictions. Unlike stationary states and other soliton configurations, which form a discrete set in the solution space associated with fixed particle number, the symmetry-enhanced sector exhibits a continuum of solutions with multifrequency states connecting stationary states of constant polarization.

We study the gravitational perturbations of black holes in quadratic gravity, in which the Einstein-Hilbert term is supplemented by quadratic terms in the curvature tensor. In this class of theories, the Schwarzschild solution can coexist with modified black hole solutions, and both families are radially stable in a wide region of the parameter space. Here we study nonradial perturbations of both families of static, spherically symmetric black holes, computing the quasinormal modes with axial parity and finding strong numerical evidence for the stability of these solutions under axial perturbations. The perturbation equations describe the propagation of a massless and a massive spin-two fields. We show that the Schwarzschild solution admits the same quasinormal modes as in general relativity, together with new classes of modes corresponding to the massive spin-two degrees of freedom. The spectrum of the modified black hole solution has the same structure, but all modes are different from those of general relativity. We argue that both classes of modes can be excited in physical processes, suggesting that a characteristic signature of this theory is the presence of massive spin-two modes in the gravitational ringdown, even when the stationary solution is the same as in general relativity.

Primordial black holes could potentially form during a first-order cosmological phase transition due to a buildup of particles which are predominantly reflected from the advancing bubble walls. After discussing the general mechanism, we examine the criteria that need to be satisfied for a black hole to form. We then set out the Boltzmann equation that describes the evolution of the relevant phase space distribution function, carefully describing our treatment of the Liouville operator and the collision term. Assuming a spherical false-vacuum pocket of sufficient size and a constant wall velocity, we find that black holes can form in a range of different scenarios.