Time-dependent studies of inclusive charm decays to multibody self-conjugate final states can be used to determine the indirect $CP$-violating observable $A_{\mathrm{\Gamma }}$ and the mixing observable $y_{CP}$, provided that the fractional $CP$-even content of the final state, $F_{+}$, is known. This approach can yield significantly improved sensitivity compared with the conventional method that relies on decays to $CP$ eigenstates. In particular, $D\to {\pi }^{+}{\pi }^{-}{\pi }^0$ appears to be an especially powerful channel, given its relatively large branching fraction and the high value of $F_{+}$ that has recently been measured at charm threshold.

The next-to-leading-order quantum chromodynamics (QCD) corrections for ${\chi }_{cJ}({{}^{3}P}_J^{[1]},{{}^{3}S}_1^{[8]})$ $P$-wave charmonium-inclusive production at $B$ factories are calculated utilizing the nonrelativistic QCD factorization formalism. Large next-to-leading-order corrections are found, especially for the ${{}^{3}P}_0^{[1]}$ and ${{}^{3}S}_1^{[8]}$ configurations. Numerical evaluation indicates that the total cross sections of ${\chi }_{cJ}$-inclusive production processes are of the order of 10 fb, which is accessible in the BELLE II (super-B) experiment.

We report improved measurements of the product branching fractions $\mathcal{B}(B^{+}\to {\overline{D}}^0{D}_{s0}^{*+}(2317))\times \mathcal{B}(D_{s0}^{*+}(2317)\to D_s^{+}{\pi }^0)=(8.0_{-1.2}^{+1.3}\pm 1.1\pm 0.4)\times 10^{-4}$ and $\mathcal{B}(B^0\to D^{-}{D}_{s0}^{*+}(2317))\times \mathcal{B}(D_{s0}^{*+}(2317)\to D_s^{+}{\pi }^0)=(10.2_{-1.2}^{+1.3}\pm 1.0\pm 0.4)\times 10^{-4}$, where the first errors are statistical, the second are systematic and the third are from $D$ and $D_s^{+}$ branching fractions. In addition, we report negative results from a search for hypothesized neutral (${\mathbf{z}}^0$) and doubly charged (${\mathbf{z}}^{++}$) isospin partners of the $D_{s0}^{*+}(2317)$ and provide upper limits on the product branching fractions $\mathcal{B}(B^0\to D^0{\mathbf{z}}^0)\times \mathcal{B}({\mathbf{z}}^0\to D_s^{+}{\pi }^{-})$ and $\mathcal{B}(B^{+}\to D^{-}{\mathbf{z}}^{++})\times \mathcal{B}({\mathbf{z}}^{++}\to D_s^{+}{\pi }^{+})$ that are more than an order of magnitude smaller than theoretical expectations for the hypotheses that the $D_{s0}^{*+}(2317)$ is a member of an isospin triplet. The analysis uses a $711{\mathrm{fb}}^{-1}$ data sample containing 772 million $B\overline{B}$-meson pairs collected at the $\mathrm{\Upsilon }(4S)$ resonance in the Belle detector at the KEKB collider.

The model of the self-interacting complex vector field is considered. It is shown that there are nontopological solitons in this model, and research into their properties is undertaken. The asymptotic dependences on a phase frequency are derived for the energy and the Noether charge of the soliton in the thick-wall regime. The asymptotic expressions are obtained for the energy density, the Noether charge density, and the phase frequency of the soliton in the thin-wall regime. The soliton solutions of the model field equations are obtained numerically. The dependences on the phase frequency are presented for the energy and the Noether charge of the soliton. The dependence of the soliton energy on the soliton Noether charge is obtained numerically. It follows from this dependence that the nontopological soliton is unstable to the decay in the free massive vector bosons in the thick-wall regime but is stable to this decay in the thin-wall regime.

We study a novel type of contribution to the partition function of the Maxwell system defined on a small compact manifold $\mathbb{M}$ such as a torus. These new terms cannot be described in terms of the physical propagating photons with two transverse polarizations. Rather, these novel contributions emerge as a result of tunneling events when transitions occur between topologically different but physically identical vacuum winding states. These new terms give an extra contribution to the Casimir pressure, yet to be measured. We argue that if the same system is considered in the background of a small external time-dependent magnetic field, then there will be emission of photons from the vacuum, similar to the dynamical Casimir effect (DCE) when real particles are radiated from the vacuum due to the time-dependent boundary conditions. The difference with conventional DCE is that the dynamics of the vacuum in our system is not related to the fluctuations of the conventional degrees of freedom, the virtual photons. Rather, the radiation in our case occurs as a result of tunneling events between topologically different but physically identical $|k⟩$ sectors in a time-dependent background. We comment on the relation of this novel effect to the well-known, experimentally observed, and theoretically understood phenomena of the persistent currents in normal metal rings. We also comment on possible cosmological applications of this effect.

We extend the Georgi-Glashow model of the ’t Hooft-Polyakov monopoles to include additional collective coordinates—“orientational isospin moduli.” The low-energy theory of these solitonic solutions can be interpreted as dyons with isospin.

The influence of an arbitrary spin orientation on the quadrupolar structure of an extended body moving in a Schwarzschild spacetime is investigated. The body dynamics is described by the Mathisson-Papapetrou-Dixon model, without any restriction on the motion or simplifying assumption on the associated spin vector and quadrupole tensor, generalizing previous works. The equations of motion are solved analytically in the limit of small values of the characteristic length scales associated with the spin and quadrupole variables with respect to the characteristic length of the background curvature. The solution provides all corrections to the circular geodesic on the equatorial plane taken as the reference trajectory due to both the dipolar and quadrupolar structures of the body as well as the conditions which the nonvanishing components of the quadrupole tensor must fulfill in order for the problem to be self-consistent.

We discuss area terms in entanglement entropy and show that a recent formula by Rosenhaus and Smolkin is equivalent to the term involving a correlator of traces of the stress tensor in the Adler-Zee formula for the renormalization of the Newton constant. We elaborate on how to fix the ambiguities in these formulas: Improving terms for the stress tensor of free fields, boundary terms in the modular Hamiltonian, and contact terms in the Euclidean correlation functions. We make computations for free fields and show how to apply these calculations to understand some results for interacting theories which have been studied in the literature. We also discuss an application to the F-theorem.

We study spherically symmetric solutions in scalar-torsion gravity theories in which a scalar field is coupled to torsion with a derivative coupling. We obtain the general field equations from which we extract a decoupled master equation, the solution of which leads to the specification of all other unknown functions. We first obtain an exact solution which represents a new wormholelike solution dressed with a regular scalar field. Then, we find large distance linearized spherically symmetric solutions in which the space asymptotically is anti–de Sitter.

We report the existence of unstable s-wave modes for black strings in Gauss-Bonnet theory (which is quadratic in the curvature) in seven dimensions. This theory admits analytic uniform black strings that are, in the transverse section, black holes of the same Gauss-Bonnet theory in six dimensions. All the components of the perturbation can be written in terms of a single component and its derivatives. For this, we find a master equation that admits bounded solutions provided the characteristic time of the exponential growth of the perturbation is related to the wave number along the extra direction, as in general relativity. It is known that these configurations suffer from a thermal instability; therefore, the results presented here provide evidence for the Gubser-Mitra conjecture in the context of Gauss-Bonnet theory. Because of the nontriviality of the curvature of the background, all of the components of the metric perturbation appear in the linearized equations. Similar to spherical black holes, the black strings should be obtained as the short-distance limit $r\ll {\alpha }^{1/2}$ of the black-string solution of Einstein-Gauss-Bonnet theory (which is not known analytically), where $\alpha$ is the Gauss-Bonnet coupling.

The explicit Robinson–Trautman solution with a minimally coupled free scalar field is derived and analyzed. It is shown that this solution contains curvature singularity, which is initially naked but later enveloped by the horizon. We use the quasilocal horizon definition and prove its existence in later retarded times using sub- and supersolution method combined with growth estimates. We show that the solution is generally of algebraic type II but reduces to type D in spherical symmetry.

In a previous paper [S. Q. Wu, Phys. Rev. D 83, 121502(R) (2011)], a new kind of metric ansatz was found to fairly describe all already-known black hole solutions in the ungauged Kaluza-Klein (KK) supergravity theories. That metric ansatz somewhat resembles the famous Kerr-Schild (KS) form, but it is different from the KS one in two distinct aspects. That is, apart from a global conformal factor, the metric ansatz can be written as a vacuum background spacetime plus a “perturbation” modification term, the latter of which is associated with a timelike geodesic vector field rather than a null geodesic congruence in the usual KS ansatz. Replacing the flat vacuum background metric by the (anti–)de Sitter [(A)dS] spacetime, the general rotating charged KK-(A)dS black hole solutions in all higher dimensions have been successfully constructed and put into a unified form. In this paper, we shall study this novel metric ansatz in detail, aiming at achieving some inspiration as to the construction of rotating charged AdS black holes with multiple charges in other gauged supergravity theories. We find that the traditional perturbation expansion method often successfully used in the KS form is no longer useful in our new ansatz, since here no good parameter can be chosen as a suitable perturbation indicator. In order to investigate the metric properties of the general KK-AdS solutions, in this paper we devise a new effective method, dubbed the background metric expansion method, which can be thought of as a generalization of the perturbation expansion method, to deal with the Lagrangian and all equations of motion. In addition to two previously known conditions, namely the timelike and geodesic properties of the vector, we get three additional constraints via contracting the Maxwell and Einstein equations once or twice with this timelike geodesic vector. In particular, we find that these are a simpler set of sufficient conditions to determine the vector and the dilaton scalar around the background metric, which is helpful in obtaining new exact solutions. With these five simpler equations in hand, we rederive the general rotating charged KK-(A)dS black hole solutions with spherical horizon topology and obtain new solutions with planar topology in all dimensions. It turns out that the overall calculations in finding the solution to the KK gauged supergravity can be reduced considerably, compared to the previous process, by directly solving all the field equations. It is then shown that the rotating charged KK-AdS black hole solutions can be further generalized by introducing one or two arbitrary constants, while the black hole solutions with the planar AdS background metric in all higher dimensions are newly obtained.

We present the extension of our cocal—Compact Object CALculator—code to compute general-relativistic initial data for binary compact-star systems. In particular, we construct quasiequilibrium initial data for equal-mass binaries with spins that are either aligned or antialigned with the orbital angular momentum. The Isenberg-Wilson-Mathews formalism is adopted and the constraint equations are solved using the representation formula with a suitable choice of a Green’s function. We validate the new code with solutions for equal-mass binaries and explore its capabilities for a wide range of compactnesses, from a white dwarf binary with compactness $\sim 10^{-4}$, up to a highly relativistic neutron-star binary with compactness $\sim 0.22$. We also present a comparison with corotating and irrotational quasiequilibrium sequences from the spectral code lorene [Taniguchi and Gourgoulhon, Phys. Rev. D 66, 104019 (2002)] and with different compactness, showing that the results from the two codes agree to a precision of the order of 0.05%. Finally, we present equilibria for spinning configurations with a nuclear-physics equation of state in a piecewise polytropic representation.

We propose a relativistic model of dark matter reproducing at once the concordance cosmological model $\mathrm{\Lambda }$-cold-dark-matter ($\mathrm{\Lambda }\text{−}\mathrm{CDM}$) at cosmological scales and the phenomenology of the modified Newtonian dynamics (MOND) at galactic scales. To achieve this we postulate a nonstandard form of dark matter, consisting of two different species of particles coupled to gravity via a bimetric extension of general relativity and linked together through an internal vector field (a “graviphoton”) generated by the mass of these particles. We prove that this dark matter behaves like ordinary cold dark matter at the level of first-order cosmological perturbation, while a pure cosmological constant plays the role of dark energy. The MOND equation emerges in the nonrelativistic limit through a mechanism of gravitational polarization of the dark matter medium in the gravitational field of ordinary matter. Finally we show that the model is viable in the Solar System as it predicts the same parametrized post-Newtonian parameters as general relativity.

The recent detection of a convective core in a main-sequence solar-type star is used here to test particular models of dark matter (DM) particles, those with masses and scattering cross sections in the range of interest for the DM interpretation of the positive results in several DM direct detection experiments. If DM particles do not effectively self annihilate after accumulating inside low-mass stars (e.g. in the asymmetric DM scenario) their conduction provides an efficient mechanism of energy transport in the stellar core. For main-sequence stars with masses between 1.1 and $1.3{\mathrm{M}}_{\odot }$, this mechanism may lead to the suppression of the inner convective region expected to be present in standard stellar evolution theory. The asteroseismic analysis of the acoustic oscillations of a star can prove the presence/absence of such a convective core, as it was demonstrated for the first time with the Kepler field main-sequence solarlike pulsator, KIC 2009505. Studying this star we found that the asymmetric DM interpretation of the results in the CoGeNT experiment is incompatible with the confirmed presence of a small convective core in KIC 2009505.

In extracting predictions from theories that describe a multiverse, we face the difficulty that we must assess probability distributions over possible observations prescribed not just by an underlying theory, but by a theory together with a conditionalization scheme that allows for (anthropic) selection effects. This means we usually need to compare distributions that are consistent with a broad range of possible observations with actual experimental data. One controversial means of making this comparison is by invoking the “principle of mediocrity”: that is, the principle that we are typical of the reference class implicit in the conjunction of the theory and the conditionalization scheme. In this paper, we quantitatively assess the principle of mediocrity in a range of cosmological settings, employing “xerographic distributions” to impose a variety of assumptions regarding typicality. We find that for a fixed theory, the assumption that we are typical gives rise to higher likelihoods for our observations. If, however, one allows both the underlying theory and the assumption of typicality to vary, then the assumption of typicality does not always provide the highest likelihoods. Interpreted from a Bayesian perspective, these results support the claim that when one has the freedom to consider different combinations of theories and xerographic distributions (or different “frameworks”), one should favor the framework that has the highest posterior probability; and then from this framework one can infer, in particular, how typical we are. In this way, the invocation of the principle of mediocrity is more questionable than has been recently claimed.

In Poulin and Serpico [Phys. Rev. Lett. 114, 091101 (2015)] we recently argued that when the energy of a photon injected in the primordial plasma falls below the pair-production threshold the universality of the nonthermal photon spectrum from the standard theory of electromagnetic cascades onto a photon background breaks down. We showed that this could reopen or widen the parameter space for an exotic solution to the “lithium problem.” Here we discuss another application, namely the impact that this has on nonthermal big bang nucleosynthesis constraints from ${}^4\mathrm{He}$, ${}^3\mathrm{He}$, and ${}^2\mathrm{H}$, using the parametric example of monochromatic photon injection of different energies. Typically, we find tighter bounds than those existing in the literature, up to more than 1 order of magnitude. As a consequence of the nonuniversality of the spectrum, the energy dependence of the photodissociation cross sections is important. We also compare the constraints obtained with current level and future reach of cosmic microwave background spectral distortion bounds.

We study the inflationary generation of helical cosmological magnetic fields in a higher-dimensional generalization of the electromagnetic theory. For this purpose, we also include a parity breaking piece to the electromagnetic action. The evolution of an extra-dimensional scale factor allows the breaking of conformal invariance of the effective electromagnetic action in $1+3$ dimensions required for such generation. Analytical solutions for the vector potential can be obtained in terms of Coulomb wave-functions for some special cases. We also present numerical solutions for the vector potential evolution in more general cases. In the presence of a higher-dimensional cosmological constant there exist solutions for the scale factors in which both normal and extra dimensional space either inflate or deflate simultaneously with the same rate. In such a scenario, with the number of extra dimensions $D=4$, a scale invariant spectrum of helical magnetic field is obtained. The net helicity arises, as one helical mode comes to dominate over the other at the superhorizon scales. A magnetic field strength of the order of ${10}^{-9}\mathrm{G}$ can be obtained for the inflationary scale $H\simeq 10^{-3}$ $M_{\text{pl}}$. Weaker fields will be generated for lower scales of inflation. Magnetic fields generated in this model respects the bounds on magnetic fields by Planck and $\gamma$-ray observations (i.e., ${10}^{-16}\mathrm{G}<B_{\text{obs}}<3.4\times {10}^{-9}\mathrm{G}$).

The fermion sign problem appearing in the mean-field approximation is considered, and the systematic computational scheme of the free energy is devised by using the Lefschetz-thimble method. We show that the Lefschetz-thimble method respects the reflection symmetry, which makes physical quantities manifestly real at any order of approximations using complex saddle points. The formula is demonstrated through the Airy integral as an example, and its application to the Polyakov-loop effective model of dense QCD is discussed in detail.

The inhomogeneous quark condensate, responsible for dynamical chiral symmetry breaking in cold nuclear matter, is studied by putting Skyrmions onto the face-centered cubic crystal and treating the Skyrmion matter as nuclear matter. By varying the crystal size, we explore the effect of density on the local structure of the quark-antiquark condensate. By endowing the light vector mesons $\rho$ and $\omega$ with hidden local symmetry and incorporating a scalar meson as a dilaton of spontaneously broken scale symmetry, we uncover the intricate interplay of heavy mesons in the local structure of the quark condensate in dense baryonic matter described in terms of Skyrmion crystal. It is found that the inhomogeneous quark density persists to as high a density as $\sim 4$ times nuclear matter density. The difference between the result from the present approach and that from the chiral density wave ansatz is also discussed.