We show that a variant of the Gross-Neveu Yukawa model with disorder provides a real, nonsupersymmetric generalization of the Sachdev–Ye Kitaev (SYK) model to three dimensions. The model contains $M$ real scalar fields and $N$ Dirac (or Majorana) fermions, interacting via a Yukawa interaction with a local Gaussian random coupling in three dimensions. In the limit where $M$ and $N$ are both large, and the ratio $M/N$ is held fixed, the model defines a line of infrared fixed points parametrized by $M/N$, reducing to the Gross-Neveu vector model when $M/N=0$. When $M/N$ is nonzero, the model is dominated by melonic diagrams and gives rise to SYK-like physics. We compute the spectrum of single-trace operators in the theory, and find that it is real for all values of $M/N$.

Radiation-reaction forces originating from the emission of gravitational waves (GWs) bring binaries to close proximity and are, thus, responsible for virtually all the mergers that we can observe in GW interferometers. We show that there exists a supplementary radiation-reaction force between two binaries interacting gravitationally, changing, in particular, the decay rate of the semimajor axis under the emission of GWs. This new binary-binary force is in some settings of the same order of magnitude as the usual 2.5PN force for an isolated binary and presents some striking features such as a dependence on retarded time even in the post-Newtonian regime where all velocities are arbitrarily small. Using effective field theory tools, we provide the expression of the force in generic configurations and show that it interpolates between several intuitive results in different limits. In particular, our formula generalizes the standard post-Newtonian estimates for radiation-reaction forces in $N$-body systems which are valid only in the limit where the GW wavelength goes to infinity.

Propagation of a localized wave function of a massive scalar field is investigated in its rest frame. The complete orthogonal Hermite-Gauss basis is presented, and the Gouy phase and Rayleigh scale notions are adapted. The leading and subleading gravitational corrections to a localized quantum wave function propagating in a generally curved spacetime geometry are calculated within the Fermi coordinates around the timelike geodesic of its rest frame, and cross-talk coefficients among the modes are derived. It is observed that spherically symmetric modes propagate along the geodesic. However, nonspherical modes are found to experience a mode-dependent residual quantum force at the subleading order. It is shown that the residual force does not generate an escape velocity for in-falling wave functions but leads to a mode-dependent deflection angle for the scattered ones.

We consider the influence of the higher-order correction to the gravitational action inspired by the Goroff-Sagnotti term upon the Kiselev black hole with $\tilde{\omega }=-2/3$ and contrast the thus obtained results with the analogous results obtained for the Schwarzschild–de Sitter black hole. Expressing the perturbed solution in terms of the exact radius of the event horizon and the radius of the cosmological horizon of the unperturbed black hole we calculate corrections to the line element, to the cosmological horizon, and to the surface gravity. It is shown that although in both cases the lukewarm configuration does not exist classically (the equality of the surface gravities is possible only for the merged horizons), the sixth-order term removes the degeneracy of the classical solution and simultaneously shifts the degenerate horizon to a new place in the space of parameters. The lukewarm configuration is characterized by the value of the parameters that classically characterize the extremal solution. It is shown that the Karlhede scalar still may serve as the detector of the event and the cosmological horizon. Finally, we study the complex frequencies of the low-lying fundamental modes of the quasinormal oscillations and argue that they are the best candidates (at least theoretically) to distinguish between different black hole configurations.

We investigate the photon-axionlike particle (ALP) oscillation effects on TeV gamma-ray spectral irregularities from the uncertain redshift active galactic nuclei (AGN) VER $\mathrm{J}0521+211$. The gamma-ray spectra are measured by Fermi-LAT and VERITAS with the three flux states in 2013 and 2014. We set the combined constraints on the ALP parameter ($m_a,g_{a\gamma }$) space with these states and test the extragalactic background light (EBL) absorption effect on ALP constraints with the redshift limit scenarios $z_0\sim \mathcal{O}(0.1-0.3)$. The 99% C.L. photon-ALP combined constraints set by VER $\mathrm{J}0521+211$ are roughly at $g_{a\gamma }\gtrsim 2.0\times {10}^{-11}{\mathrm{GeV}}^{-1}$ for $1.0\times {10}^{-9}\mathrm{eV}\lesssim m_a\lesssim 1.0\times {10}^{-7}\mathrm{eV}$. We find no clear connection between the redshift limit scenarios and the photon-ALP constraints. Both the underestimated and overestimated redshifts can affect the constraint results.

The dark matter abundance plays a crucial role in the determination of the valid parameter space of models both in the case of a discovery of dark matter and in the context of exclusion limits. Reliable theoretical predictions of the dark matter relic density require technically demanding precision calculations, which were so far limited in their automation due to challenges in the treatment of infrared divergences appearing in higher order calculations. In particular, massive initial states need to be considered in early Universe computations, so that the known dipole subtraction methods could not be directly exploited. We therefore provide a full generalization of the dipole subtraction method by Catani and Seymour to supersymmetric (SUSY) QCD with massive initial states. All dipole splitting functions and their integrated counterparts are given explicitly for four different dimensional schemes. To showcase their application, we apply our results to dark matter (co)annihilation processes in the context of the minimal supersymmetric Standard Model. We also demonstrate the accuracy of the dipole method by comparing our numerical results with those obtained with the phase space slicing method. Our analytical results will facilitate future automation of dark matter abundance calculations at next-to-leading order for both SUSY and non-SUSY models.

We present the first theoretical prediction of the partial decay width of the process $J/\psi \to \gamma {\eta }_1$, where ${\eta }_1$ is the lightest flavor singlet $1^{-+}$ hybrid meson. Our $N_f=2$ lattice QCD calculation at $m_{\pi }\approx 350\mathrm{MeV}$ results in the ${\eta }_1$ mass $m_{{\eta }_1}=2.23(4)\mathrm{GeV}$ and the related electromagnetic form factors $M_1(0)=-4.73(74)\mathrm{MeV}$, $E_2(0)=1.18(22)\mathrm{MeV}$, which give $\mathrm{\Gamma }(J/\psi \to \gamma {\eta }_1)=2.04(61)\mathrm{eV}$. These form factors can be applied to the physical $N_f=3$ case, where there should be two hybrid mass eigenstates ${\eta }_1^{(l)}$ and ${\eta }_1^{(h)}$ due to the singlet-octet mixing. It is shown that the ratio of the branching fractions $\mathrm{Br}(J/\psi \to \gamma {\eta }_1^{(l,h)}\to \gamma \eta {\eta }^{\prime })$ is inversely proportional to the ratio of the total widths of ${\eta }_1^{(l,h)}$. Given our results and the mixing angle derived by a previous lattice study, whether ${\eta }_1(1855)$ is assigned to be ${\eta }_1^{(1)}$ or ${\eta }_1^{(h)}$, the observed branching fraction $J/\psi \to {\eta }_1(1855)\to \gamma \eta {\eta }^{\prime }$ implies a very large coupling of the octet ${\eta }_1$ to $\eta {\eta }^{\prime }$. This should be investigated in future studies.

We make a theoretical study of the three-body system composed of ${\overline{K}}^{*}{\overline{B}}^{*}{\overline{B}}^{*}$ and ${\overline{K}}^{*}\overline{B}{\overline{B}}^{*}$ to look for possible bound states, which could be associated to mesonic resonances of very exotic nature, containing open strange and double-bottom flavors. The three-body interaction is evaluated by using the fixed center approach to the Faddeev equations where the ${\overline{B}}^{*}{\overline{B}}^{*}$ or $\overline{B}{\overline{B}}^{*}$ is bound forming an $I(J^P)=0(1^{+})$ state, as it was found in previous works, and the third particle, the ${\overline{K}}^{*}$, of much smaller mass, interacts with the components of the cluster. We obtain bound states for all the channels considered: spin $J=0$, 1, and 2, all of them with isospin $I=1/2$ and negative parity.

We study the hadronic molecular states with the quark content $bc\overline{s}\overline{q}$ by investigating the interactions of the ${\overline{B}}_{s}D$, $\overline{B}{D}_s$, ${\overline{B}}_s^{*}D$, ${\overline{B}}^{*}{D}_s$, ${\overline{B}}_s{D}^{*}$, $\overline{B}{D}_s^{*}$, ${\overline{B}}_s^{*}{D}^{*}$, and ${\overline{B}}^{*}{D}_s^{*}$ systems. By solving the Bethe-Salpeter equation within the extended local hidden gauge formalism, we find altogether six poles qualifying as possible hadronic molecular states: one pole of $J^P=0^{+}$ below the ${\overline{B}}_{s}D\text{−}\overline{B}{D}_s$ threshold, one pole of $J^P=1^{+}$ below the ${\overline{B}}_s^{*}D\text{−}{\overline{B}}^{*}{D}_s$ threshold, one pole of $J^P=1^{+}$ below the ${\overline{B}}_s{D}^{*}\text{−}\overline{B}{D}_s^{*}$ threshold, and three poles of $J^P=0^{+}/1^{+}/2^{+}$ below the ${\overline{B}}_s^{*}{D}^{*}\text{−}{\overline{B}}^{*}{D}_s^{*}$ threshold. Their binding energies are calculated to be about 10–20 MeV with the cutoff momentum $q_{\max }=600\mathrm{MeV}$. Similarly, we study the hadronic molecular states with $bs\overline{c}\overline{q}$ by investigating the interactions of the $\overline{B}{\overline{D}}_s$, ${\overline{B}}_c\overline{K}$, ${\overline{B}}^{*}{\overline{D}}_s$, ${\overline{B}}_c^{*}\overline{K}$, $\overline{B}{\overline{D}}_s^{*}$, ${\overline{B}}_c{\overline{K}}^{*}$, ${\overline{B}}^{*}{\overline{D}}_s^{*}$, ${\overline{B}}_c^{*}{\overline{K}}^{*}$ systems, and the states with $bq\overline{c}\overline{s}$ by investigating the interactions of the ${\overline{B}}_s\overline{D}$, ${\overline{B}}_{c}K$, ${\overline{B}}_s^{*}\overline{D}$, ${\overline{B}}_c^{*}K$, ${\overline{B}}_s{\overline{D}}^{*}$, ${\overline{B}}_c{K}^{*}$, ${\overline{B}}_s^{*}{\overline{D}}^{*}$, ${\overline{B}}_c^{*}{K}^{*}$ systems. However, no deeply bound poles are found in these systems.

We investigate the nature of the complex retarded potential of a heavy quarkonium moving in a hot and dense static deconfined nuclear medium. The well-known concept of the retarded potential in electrodynamics is extended to the context of the heavy-quark by modifying the static vacuum Cornell potential through Lorentz transformation to the static frame of the medium. The resulting potential in the vacuum is further corrected to incorporate the screening effect offered by the thermal medium. To do so, the retarded Cornell potential is modified by the dielectric function of the static quark-gluon plasma (QGP) medium. We present the numerical results for the real and imaginary parts of the potential along with the analytical expression of the potential approximated by a small velocity limit. Finally, we present the thermal width of quarkonia in the QGP medium derived using the imaginary part of the potential and study its dependence on velocity and temperature.

Gradient jet tomography in high-energy heavy-ion collisions utilizes the asymmetric transverse momentum broadening of a propagating parton in an inhomogeneous medium. Such broadening is studied within a path-integral description of the evolution of the Wigner distribution for a propagating parton in medium. Going beyond the eikonal approximation of multiple scattering, the evolution operator in the transverse direction can be expressed as the functional integration over all classical trajectories of a massive particle with the light-cone momentum $\omega$ as its mass. With a dipole approximation of the Wilson line correlation function, evolution with the light-cone time $t$ is determined by the jet transport coefficient $\widehat{q}$ that can vary with space and time. In a uniform medium with a constant ${\widehat{q}}_0$, the analytical solution to the Wigner distribution becomes a typical drifted Gaussian in both transverse momentum and coordinate with the diffusion width $\sqrt{{\widehat{q}}_{0}t}$ and $\sqrt{{\widehat{q}}_0{t}^3/3{\omega }^2}$, respectively. In the case of a simple Gaussian-like transverse inhomogeneity with a spatial width $\sigma$ on top of a uniform medium, the final asymmetrical momentum distribution can be calculated semianalytically. The transverse asymmetry defined for jet gradient tomography that characterizes the asymmetrical distribution is found to linearly correlate with the initial transverse position of the propagating parton within the domain of the inhomogeneity. It decreases with the parton energy $\omega$, increases with the propagation time initially and saturates when the diffusion distance is much larger than the size of the inhomogeneity or $t^3\gg 3{\omega }^2{\sigma }^2/{\widehat{q}}_0$. The transverse momentum broadening due to the inhomogeneity also saturates at late times in contrast to the continued increase with time if the drifted diffusion in space is ignored.

We present a phenomenological model for the $\gamma \gamma \to {\pi }^{+}{\pi }^{-}{\pi }^0$ reaction by including the production mechanism of the $a_2(1320)$ resonance, as well as the contributions from the $\sigma /f_0(500){\pi }^0$ and $f_2(1270){\pi }^0$ production channels. Furthermore, the $\gamma \gamma \to {\rho }^{\pm }{\pi }^{\mp }\to {\pi }^{+}{\pi }^{-}{\pi }^0$ channel, which is essential for a description in the low-energy region, is investigated carefully by introducing the complete set of gauge invariant and Lorentz-covariant tensors for the $\gamma \gamma \to {\rho }^{\pm }{\pi }^{\mp }$ subprocess. The full amplitude is constructed to yield a correct high-energy Regge behavior. Within our model, we achieve a very reasonable description of ARGUS and L3 data of the total cross section, as well as of the ${\pi }^{\pm }{\pi }^0$ and ${\pi }^{+}{\pi }^{-}$ invariant mass distributions. We also predict the invariant mass distributions in the $\gamma \gamma$ center-of-mass energy range from 0.8 to 2.0 GeV, which will be studied by the forthcoming data of the BESIII Collaboration.

Pion production on nuclei constitutes a significant part of the total cross section in experiments involving few-GeV neutrinos. Combined analyses of data on deuterium and heavier nuclei points to tensions between the bubble-chamber data and the data of the $\mathrm{MINER}\nu \mathrm{A}$ experiment, which are often ascribed to unspecified nuclear effects. In experimental analysis use is made of approximate treatments of nuclear dynamics, usually in a Fermi gas approach with classical treatments of the reaction mechanism, and fits are often performed by simply rescaling cross sections. To understand the origin of these tensions, check the validity of approximations, and to further advance the description of neutrino pion production on nuclei, a microscopic quantum mechanical framework is needed to compute nuclear matrix elements. We use the local approximation to the relativistic distorted wave impulse approximation to calculate the nuclear matrix elements. We include the distortion of wave functions of the final-state nucleon in a real energy-dependent potential. We compare results with and without distortion. To perform this comparison under conditions relevant to neutrino experiments, we compute cross sections for the $\mathrm{MINER}\nu \mathrm{A}$ and T2K charged-pion production datasets. The inclusion of nucleon distortion leads to a reduction of the cross section up to 10%, but to no significant change in shape of the flux-averaged cross sections. Results with and without distortion compare favorably to experimental data, with the exception of the low-$Q^2$ $\mathrm{MINER}\nu \mathrm{A}$ ${\pi }^{+}$ data. We point out that hydrogen target data from BEBC is also overpredicted at low $Q^2$, and the data-model discrepancy is similar in shape and magnitude as what is found in comparison to $\mathrm{MINER}\nu \mathrm{A}$ data. Including nucleon distortion alone cannot explain the overprediction of low-$Q^2$ cross sections measured by $\mathrm{MINER}\nu \mathrm{A}$. The similar overprediction of BEBC data on hydrogen means that it is impossible to ascribe this discrepancy solely to a nuclear effect. Axial form factors might not be constrained in a satisfactory way by the Argonne and Brookhaven National Laboratories (ANL/BNL) data alone. Axial couplings and their $Q^2$ dependence should ideally be derived from more precise data on hydrogen and deuterium. Nuclear matrix elements should be tested with e.g., electron scattering data for which nucleon level physics is better constrained.

We report the results of a new global QCD analysis including deep-inelastic scattering data off ${}^1\mathrm{H}$, ${}^2\mathrm{H}$, ${}^3\mathrm{H}$, and ${}^3\mathrm{He}$ targets. Nuclear corrections are treated in terms of a nuclear convolution approach with off-shell bound nucleons. The off-shell (OS) corrections responsible for the modification of the structure functions (SFs) of bound nucleons are constrained in a global fit along with the proton parton distribution functions (PDFs) and the higher-twist (HT) terms. We investigate the proton-neutron difference for the OS correction and discuss our predictions for the SF ratio $F_2^n/F_2^p$ and the corresponding PDF ratio $d/u$ in the proton, as well as their correlations with the underlying treatment of the HT terms and of the OS corrections. In particular, we find that the recent MARATHON data are consistent with equal relative OS corrections for both the proton and the neutron.

We consider the motion of a massive particle in a static, weakly curved spacetime where the gravitational field is taken to be quantized. We find that Newton’s law of free fall is modified by quantum-gravitational corrections, in addition to the known special-relativistic and post-Newtonian modifications. The quantum-gravitational corrections take the form of stochastic noise in the particle trajectory, where the statistical properties of the noise depend on the quantum state of the gravitational field.

Conformal symmetry can be spontaneously broken due to the presence of a defect or other background, which gives a symmetry-breaking vacuum expectation value (VEV) to some scalar operators. We study the effective field theory of fluctuations around these backgrounds, showing that it organizes as an expansion in powers of the inverse of the VEV, and computing some of the leading corrections. We focus on the case of spacelike defects in a four-dimensional Lorentzian theory relevant to the pseudoconformal universe scenario, although the conclusions extend to other kinds of defects and to the breaking of conformal symmetry to Poincaré symmetry.

Unitarity is the fundamental property of the S-matrix, while its usage for a scattering of unstable particles has been subtle as unstable particles do not appear in the asymptotic states. Defining unstable-particle amplitudes as residues of a higher-point amplitude at an appropriate complex pole, we find unitarity equations for the 2-to-2 unstable-particle amplitudes from unitarity and analyticity of stable-particle scattering amplitudes. The unstable-particle unitarity equations take a form analogous to those of the stable-particle amplitudes when the in and out states are chosen to be complex-conjugate positions. In particular, as in the optical theorem, we find a positivity constraint on a discontinuity of the amplitudes in a positive region of the momentum transfer variable.

The gravitational spin connection appears in gravity as a non-Abelian gauge field for the Lorentz group $SO(3,1)$, which is noncompact. The action for general relativity is linear in the field strength associated to the spin connection, and its equation of motion corresponds to the standard metricity constraint. Consequently, the zero-torsion spin connection is never realized as an independent degree of freedom and is determined by the vierbein field. In this work, we take a different perspective and consider a pure Yang-Mills theory for the spin connection coupled to Dirac fermions, resulting in the former being a dynamical field. After discussing various approaches towards managing the pathologies associated with noncompact gauge theories, we compute the tree-level amplitude for fermion scattering via a spin connection exchange. In contrast to integrating out torsion in the presence of fermions, the model induces a chiral four-Fermi like term that involves a right-right current interaction, which is not present in the Standard Model.

We present a new family of charged $C$ metrics in $\mathcal{N}=2$ gauged supergravity in four dimensions. The double Wick rotation of the $C$ metric allows us to bring our solution into a different family of the $C$ metrics previously found by Lü and Vázquez-Poritz. In the case of zero acceleration limit, our solution with vanishing charges reduces to the scalar haired black holes in anti–de Sitter space with regular horizons. Nevertheless, it turns out that each family of neutral solutions fails to veil the curvature singularity by the event horizon, showing that neither of them represents the accelerated black holes with a scalar hair. Physical solutions without visible curvature singularities are obtained only in the case of nonvanishing charges. Causal structures of the solution are spelled out in detail. We also present conditions under which the solution preserves supersymmetry.

Far away observers can, in principle, bound from below the dimensionless maximum-density parameter $\mathrm{\Lambda }\equiv 4\pi R^2{\rho }_{\max }$ of a compact star by measuring the gravitational redshift factor $z\equiv {\nu }_{\mathrm{e}}/{\nu }_{\infty }-1$ of photons that were emitted from the surface of the star: $\mathrm{\Lambda }\ge \frac{3}{2}[1-(1+z{)}^{-2}]$ (here $R$ is the radius of the star and $\{{\nu }_{\mathrm{e}},{\nu }_{\infty }\}$ are, respectively, the frequency of the emitted light as measured at the location of the emission and by asymptotic observers). However, if photons that were created somewhere inside the star can make their way out and reach the asymptotic observers, then the measured redshift parameter $z$ may not determine uniquely the surface properties of the star, thus making the above bound unreliable. In the present compact paper, we prove that in these cases, in which the creation depth of a detected photon is not known to the far away observers, the empirically measured redshift parameter can still be used to set a (weaker) lower bound on the dimensionless density parameter of the observed star: $\mathrm{\Lambda }\ge \frac{3}{2}[1-(1+z{)}^{-2/3}]$.