We reconsider the inclusive production of isolated prompt photons in $pp$ collisions at the LHC energies in the framework of $k_T$-factorization approach. Our analysis is based on the $\mathcal{O}(\alpha {\alpha }_s)$ off-shell (depending on the transverse momenta of initial quarks and gluons) production amplitudes of $q^{*}{g}^{*}\to \gamma q$ and $q^{*}{\overline{q}}^{*}\to \gamma g$ partonic subprocesses and transverse momentum dependent (or unintegrated) quark and gluon densities in a proton, which are chosen in accordance with the Kimber-Martin-Ryskin prescription. We show that the subleading high-order $\mathcal{O}(\alpha {\alpha }_s^2)$ contributions, not covered by the noncollinear evolution of parton densities, are important to describe latest LHC data.

We present a method of solution of the Bartels-Kwiecinski-Praszalowicz (BKP) equation based on the numerical integration of iterated integrals in transverse momentum and rapidity space. As an application, our procedure, which makes use of Monte Carlo integration techniques, is applied to obtain the gluon Green function in the Odderon case at leading order. The same approach can be used for more complicated scenarios.

We compute the transport coefficients (drag and momentum diffusion) of the low-lying heavy baryons ${\mathrm{\Lambda }}_c$ and ${\mathrm{\Lambda }}_b$ in a medium of light mesons formed at the later stages of high-energy heavy-ion collisions. We employ the Fokker-Planck approach to obtain the transport coefficients from unitarized baryon-meson interactions based on effective field theories that respect chiral and heavy-quark symmetries. We provide the transport coefficients as a function of temperature and heavy-baryon momentum, and analyze the applicability of certain nonrelativistic estimates. Moreover we compare our outcome for the spatial diffusion coefficient to the one coming from the solution of the Boltzmann-Uehling-Uhlenbeck transport equation, and we find a very good agreement between both calculations. The transport coefficients for ${\mathrm{\Lambda }}_c$ and ${\mathrm{\Lambda }}_b$ in a thermal bath will be used in a subsequent publication as input in a Langevin evolution code for the generation and propagation of heavy particles in heavy-ion collisions at LHC and RHIC energies.

We present a treatment of the next-to-leading-order radiative corrections to unpolarized Møller and Bhabha scattering without resorting to ultrarelativistic approximations. We extend existing soft-photon radiative corrections with new hard-photon bremsstrahlung calculations so that the effect of photon emission is taken into account for any photon energy. This formulation is intended for application in the OLYMPUS experiment and the upcoming DarkLight experiment but is applicable to a broad range of experiments at energies where QED is a sufficient description.

We present a family of spherically symmetric Lorentzian wormholes in quadratic $F(R)$ gravity, with a thin shell of matter corresponding to the throat. At each side of the shell, the geometry has a different constant value of the curvature scalar $R$. The junction conditions determine the equation of state between the pressure and energy density at the throat, where a double layer is also located. We analyze the stability of the configurations under perturbations preserving the spherical symmetry. In particular, we study thin-shell wormholes with mass and charge. We find that there exist values of the parameters for which stable static solutions are possible.

We propose the modified version of the canonical energy which was introduced originally by Hollands and Wald. Our construction depends only on the Euler-Lagrange expression of the system and thus is independent of the ambiguity in the Lagrangian. After some comments on our construction, we briefly mention on the relevance of our construction to the boundary information metric in the context of the AdS/CFT correspondence. We also study the stability of three-dimensional hairy extremal black holes by using our construction.

The null energy condition can be violated stably in generalized Galileon theories, which gives rise to the possibilities of healthy nonsingular cosmologies. However, it has been reported that in many cases cosmological solutions are plagued with instabilities or have some pathologies somewhere in the whole history of the universe. Recently, this was shown to be generically true in a certain subclass of the Horndeski theory. In this short paper, we extend this no-go argument to the full Horndeski theory and show that nonsingular models (with flat spatial sections) in general suffer from either gradient instabilities or some kind of pathology in the tensor sector. This implies that one must go beyond the Horndeski theory to implement healthy nonsingular cosmologies.

Recently a new no-global-recollapse argument was given for some inhomogeneous and anisotropic cosmologies that utilizes surface deformation by the mean curvature flow. In this paper we discuss important properties of the mean curvature flow of spacelike surfaces in Lorentzian manifolds. We show that singularities may form during cosmic evolution, and the theorems forbidding the global recollapse lose their validity. The time evolution of the spatial scalar curvature that may kinematically prevent the recollapse is determined in normal coordinates, which shows the impact of inhomogeneities explicitly. Our analysis indicates a caveat in numerical solutions that give rise to inflation.

Recently we have proposed a novel method to probe primordial gravitational waves from upper bounds on the abundance of primordial black holes (PBHs). When the amplitude of primordial tensor perturbations generated in the early Universe is fairly large, they induce substantial scalar perturbations due to their second-order effects. If these induced scalar perturbations are too large when they reenter the horizon, then PBHs are overproduced, their abundance exceeding observational upper limits. That is, primordial tensor perturbations on superhorizon scales can be constrained from the absence of PBHs. In our recent paper we have only shown simple estimations of these new constraints, and hence in this paper, we present detailed derivations, solving the Einstein equations for scalar perturbations induced at second order in tensor perturbations. We also derive an approximate formula for the probability density function of induced density perturbations, necessary to relate the abundance of PBHs to the primordial tensor power spectrum, assuming primordial tensor perturbations follow Gaussian distributions. Our new upper bounds from PBHs are compared with other existing bounds obtained from big bang nucleosynthesis, cosmic microwave background, LIGO/Virgo and pulsar timing arrays.

We calculate the energy-differential rate for neutrino emission from electron-nucleus bremsstrahlung in stellar interiors taking into account the effects of electron screening and ionic correlations. We compare the energy-differential and the net rates, as well as the average ${\overline{\nu }}_e$ and ${\overline{\nu }}_x(x=\mu ,\tau )$ energies, for this process with those for $e^{\pm }$ pair annihilation, plasmon decay, and photoneutrino emission over a wide range of temperature and density. We also compare our updated energy loss rates for the above thermal neutrino emission processes with the fitting formulas widely used in stellar evolution models and determine the temperature and density domain in which each process dominates. We discuss the implications of our results for detection of ${\overline{\nu }}_e$ from massive stars during their presupernova evolution and find that pair annihilation makes the predominant contribution to the signal from the thermal emission processes.

We report on the first joint analysis of observational signatures from the electroweak baryogenesis in both gravitational wave (GW) detectors and particle colliders. With an effective extension of the Higgs sector in terms of the dimension-six operators, we derive a strong first-order phase transition associated with a sizable CP violation to realize a successful electroweak baryogenesis. We calculate the GW spectrum resulting from the bubble nucleation, plasma transportation, and magnetohydrodynamic turbulence of this process that occurred after the big bang and find that it yields GW signals testable with the Evolved Laser Interferometer Space Antenna, Deci-hertz Interferometer Gravitational Wave Observatory, and Big Bang Observer. We further identify collider signals from the same mechanism that are observable at the planning Circular Electron Positron Collider. Our analysis bridges astrophysics and cosmology with particle physics by providing significant motivation for searches for GW events peaking at the $(10^{-4},1)\mathrm{Hz}$ range, which are associated with signals at colliders, and highlights the possibility of an interdisciplinary observational window into baryogenesis. The technique applied in analyzing early Universe phase transitions may enlighten the study of phase transitions in applied science.

We construct a generic model of Majorana fermionic dark matter (DM). Starting with two Weyl spinor multiplets ${\eta }_{1,2}\sim (I,\mp Y)$ coupled to the Standard Model Higgs, six additional Weyl spinor multiplets with $(I\pm 1/2,\pm (Y\pm 1/2))$ are needed in general. It has 13 parameters in total, five mass parameters and eight Yukawa couplings. The DM sector of the minimal supersymmetric Standard Model is a special case of the model with $(I,Y)=(1/2,1/2)$. Therefore, this model can be viewed as an extension of the neutralino DM sector. We consider three typical cases: the neutralinolike, the reduced, and the extended cases. For each case, we survey the DM mass $m_{\chi }$ in the range of (1,2500) GeV by random sampling from the model parameter space and study the constraints from the observed DM relic density; the direct search of LUX, XENON100, and PICO experiments; and the indirect search of Fermi-LAT data. We investigate the interplay of these constraints and the differences among these cases. It is found that the direct detection of spin-independent DM scattering off nuclei and the indirect detection of DM annihilation to the $W^{+}{W}^{-}$ channel will be more sensitive to the DM searches in the near future. The allowed mass for finding $\tilde{H}$-, $\tilde{B}$-, $\tilde{W}$-, and non-neutralino-like DM particles and the predictions on $⟨\sigma (\chi \chi \to ZZ,ZH,t\overline{t})v⟩$ in the indirect search are given.

We present first predictions of the cross sections and differential distributions for the central exclusive reaction $pp\to pp{\pi }^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$ being studied at RHIC and LHC. The amplitudes for the processes are formulated in terms of the tensor Pomeron and tensor $f_{2\mathbb{R}}$ Reggeon exchanges with the vertices respecting the standard crossing and charge-conjugation relations of quantum field theory. The $\sigma \sigma$ and $\rho \rho$ contributions to the ${\pi }^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$ final state are considered, focusing on their specificities. The correct inclusion of the Pomeron spin structure seems crucial for the considered sequential mechanisms, in particular for the $\rho \rho$ contribution which is treated here for the first time. The mechanism considered gives a significant contribution to the $pp\to pp{\pi }^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$ reaction. We adjust parameters of our model to the CERN-ISR experimental data and present several predictions for the STAR, ALICE, ATLAS, and CMS experiments. A measurable cross section of order of a few $\mu \mathrm{b}$ is obtained, including the experimental cuts relevant for the LHC experiments. We show the influence of the experimental cuts on the integrated cross section and on various differential distributions.

A search for supersymmetry involving the pair production of gluinos decaying via third-generation squarks to the lightest neutralino (${\tilde{\chi }}_1^0$) is reported. It uses an LHC proton-proton data set at a center-of-mass energy $\sqrt{s}=13\mathrm{TeV}$ with an integrated luminosity of $3.2{\mathrm{fb}}^{-1}$ collected with the ATLAS detector in 2015. The signal is searched for in events containing several energetic jets, of which at least three must be identified as $b$ jets, large missing transverse momentum, and, potentially, isolated electrons or muons. Large-radius jets with a high mass are also used to identify highly boosted top quarks. No excess is found above the predicted background. For ${\tilde{\chi }}_1^0$ masses below approximately 700 GeV, gluino masses of less than 1.78 TeV and 1.76 TeV are excluded at the 95% C.L. in simplified models of the pair production of gluinos decaying via sbottom and stop, respectively. These results significantly extend the exclusion limits obtained with the $\sqrt{s}=8\mathrm{TeV}$ data set.

The code used in [Phys. Rev. D 92, 124012 (2015)] erroneously computed the enthalpy at the center of the neutron stars. Upon correcting this error, density oscillations in evolutions of rotating neutron stars are significantly reduced (from $\sim 20\%$ to $\sim 0.5\%$). Furthermore, it is possible to construct neutron stars with faster rotation rates.

It is established that physical observables in local quantum field theories should be invariant under invertible field redefinitions. It is then expected that this statement should be true for the entanglement entropy and moreover that, via the gauge/gravity correspondence, the recipe for computing entanglement entropy holographically should also be invariant under local field redefinitions in the gravity side. We use this fact to fix the recipe for computing holographic entanglement entropy (HEE) for $f(R,R_{\mu \nu })$ theories that could be mapped to Einstein gravity. An outcome of our prescription is that the surfaces that minimize the corresponding HEE functional for $f(R,R_{\mu \nu })$ theories always have a vanishing trace of extrinsic curvature and that the HEE may be evaluated using the Wald entropy functional. We show that similar results follow from the FPS and Dong HEE functionals, for Einstein manifold backgrounds in $f(R,R_{\mu \nu })$ theories.

We consider the Nekrasov-Shatashvili limit of the five-dimensional (5D) superconformal index and propose a novel prescription for selecting the finite contributions. Applying the latter to various examples of U(1) theories, we find that the 5D Nekrasov-Shatashvili index can be reproduced using recent techniques of Córdova and Shao, who related the 4D Schur index to the Bogomol’nyi-Prasad-Sommerfield (BPS) spectrum of the theory on the Coulomb branch. In this picture, the 5D instanton solitons are interpreted as additional flavor nodes in an associated 5D BPS quiver.

We study various supersymmetric renormalization group (RG) flows of $N=3$ Chern-Simons-Matter theory in three dimensions by using four-dimensional $N=3$ gauged supergravity coupled to eight vector multiplets with $SO(3)\times SU(3)$ gauge group. The ${\mathrm{AdS}}_4$ critical point preserving the full $SO(3)\times SU(3)$ provides a gravity dual of $N=3$ superconformal field theory with flavor symmetry $SU(3)$. We study the scalar potential and identify a new supersymmetric ${\mathrm{AdS}}_4$ critical point preserving the full $N=3$ supersymmetry and unbroken $SO(3)\times U(1)$ symmetry. An analytic RG flow solution interpolating between $SO(3)\times SU(3)$ and $SO(3)\times U(1)$ critical points is explicitly given. We then investigate possible RG flows from these ${\mathrm{AdS}}_4$ critical points to nonconformal field theories in the IR. All of the singularities appearing in the IR turn out to be physically acceptable. Furthermore, we look for supersymmetric solutions of the form ${\mathrm{AdS}}_2\times {\mathrm{\Sigma }}_2$ with ${\mathrm{\Sigma }}_2$ being a two-sphere or a two-dimensional hyperbolic space and find a number of ${\mathrm{AdS}}_2$ geometries preserving four supercharges with $SO(2)\times SO(2)\times SO(2)$ and $SO(2)\times SO(2)$ symmetries.