The two-loop contributions to the chiral vortical conductivity are considered. The Kubo formula together with the anomalous Ward identity of the axial vector current suggest that there may be a nonzero correction to the coefficient of the $T^2$ term of the conductivity.

In the commented paper it is claimed that there is provided a model-independent determination of the quantity $B_0(m_d-m_u)$ based on the analysis of the decay of eta to three neutral pions that takes the strong-interaction correction as an unknown parameter. In the following we show that the two constraints presented there as independent equations are in fact two approximations of a single constraint connecting together $B_0(m_d-m_u)$ with the strong-interaction correction to the $\eta \to 3{\pi }^0$ decay amplitude. Thus, without some additional information on the latter (such as its correct value at least at one kinematic point) it does not lead to any determination of $B_0(m_d-m_u)$, and the numerical values presented there should not be taken seriously. We have also found that the numerical result for the studied quantity obtained in the commented paper is just an accidental number stemming from some numerical errors that had occurred in the computations presented there.

We compute, for top quark pair production at the Tevatron and the Large Hadron Collider, the collider-independent forward-backward asymmetries defined by [Aguilar-Saavedra and Juste, Phys. Rev. Lett. 109, 211804 (2012).] in the standard model at next-to-leading order in QCD, including also electromagnetic and weak corrections.

We have measured the energy dependence of the liquid xenon (LXe) scintillation yield of electrons with energies between 2.1 and 120.2 keV, using the Compton coincidence technique. A LXe scintillation detector with a very high light detection efficiency was irradiated with ${}^{137}\mathrm{Cs}$ $\gamma$ rays, and the energy of the Compton-scattered $\gamma$ rays was measured with a high-purity germanium detector placed at different scattering angles. The excellent energy resolution of the high-purity germanium detector allows the selection of events with Compton electrons of known energy in the LXe detector. We find that the scintillation yield initially increases as the electron energy decreases from 120 to about 60 keV but then decreases by about 30% from 60 to 2 keV. The scintillation yield was also measured with conversion electrons from the 32.1 and 9.4 keV transitions of the ${}^{83m}\mathrm{Kr}$ isomer, used as an internal calibration source. We find that the scintillation yield of the 32.1 keV transition is compatible with that obtained from the Compton coincidence measurement. On the other hand, the yield for the 9.4 keV transition is much higher than that measured for a Compton electron of the same energy. We interpret the enhancement in the scintillation yield as due to the enhanced recombination rate in the presence of Xe ions left from the 32.1 keV transition, which precedes the 9.4 keV one by 220 ns, on average.

We explicitly construct two classes of the BPS solutions in the Aharony-Bergman-Jafferis-Maldacena action—the funnel type solutions and the ’t Hooft-Polyakov type solutions—and study their physical properties as the M2–M5 bound state. Furthermore, we give a one-to-one correspondence between the solutions of the BPS equation and the ones of an extended Nahm equation which includes the Nahm equation. This enables us to construct infinitely many conserved quantities from the Lax form of the Nahm equation.

We show from the action integral that in the special environment of a flux tube, ${\mathrm{QCD}}_4$ in ($3+1$) dimensional space-time can be approximately compactified into ${\mathrm{QCD}}_2$ in ($1+1$) dimensional space-time. In such a process, we find out how the coupling constant $g_{2D}$ in ${\mathrm{QCD}}_2$ is related to the coupling constant $g_{4D}$ in ${\mathrm{QCD}}_4$. We show how the quark and the gluon in ${\mathrm{QCD}}_2$ acquire contributions to their masses arising from their confinement within the tube and how all these quantities depend on the excitation of the partons in the transverse degrees of freedom. The compactification facilitates the investigation of some dynamical problems in ${\mathrm{QCD}}_4$ in the simpler dynamics of ${\mathrm{QCD}}_2$ where the variation of the gluon fields leads to a bound state.

We discuss the usage of measurements of the stability of nature’s fundamental constants coming from comparisons between atomic clocks as a means to constrain coupled variations of these constants in a broad class of unification scenarios. After introducing the phenomenology of these models, we provide updated constraints based on a global analysis of the latest experimental results. We obtain null results for the proton-to-electron mass ratio $\dot{\mu }/\mu =(0.68\pm 5.79)\times {10}^{-16}{\mathrm{yr}}^{-1}$ and for the gyromagnetic factor ${\dot{g}}_p/g_p=(-0.72\pm 0.89)\times {10}^{-16}{\mathrm{yr}}^{-1}$ (both of these being at the 95% confidence level). These results are compatible with theoretical expectations on unification scenarios, but much freedom exists due to the presence of a degeneracy direction in the relevant parameter space.

Starting from kinetic theory, we obtain a nonlinear dissipative formalism describing the nonequilibrium evolution of scalar colored particles coupled self-consistently to non-Abelian classical gauge fields. The link between the one-particle distribution function of the kinetic description and the variables of the effective theory is determined by extremizing the entropy production. This method does not rely on the usual gradient expansion in fluid dynamic variables, and therefore the resulting effective theory can handle situations where these gradients (and hence the momentum-space anisotropies) are expected to be large. The formalism presented here, being computationally less demanding than kinetic theory, may be useful as a simplified model of the dynamics of color fields during the early stages of heavy ion collisions and in phenomena related to parton energy loss.

We explore perturbations about a Friedmann-Robertson-Walker background with a nonvanishing cosmological Chern-Simons scalar field in Chern-Simons gravity. At large momenta one of the two circularly polarized tensor modes becomes ghostlike. We argue that nevertheless the theory does not exhibit classical runaway solutions, except possibly in the relativistic nonlinear regime. However, the ghost modes cause the vacuum state to be quantum mechanically unstable, with a decay rate that is naively infinite. The decay rate can be made finite only if one interprets the theory as an effective quantum field theory valid up to some momentum cutoff $\Lambda$, which violates Lorentz invariance. By demanding that the energy density in photons created by vacuum decay over the lifetime of the Universe not violate observational bounds, we derive strong constraints on the two dimensional parameter space of the theory, consisting of the cutoff $\Lambda$ and the Chern-Simons mass.

We construct the conserved charge of generic gravity theories built on arbitrary contractions of the Riemann tensor (but not on its derivatives) for asymptotically (anti)–de Sitter spacetimes. Our construction is a generalization of the Abbott-Deser-Tekin charges of linear and quadratic gravity theories in cosmological backgrounds. As an explicit example we find the energy and angular momentum of the Banados-Teitelboim-Zanelli black hole in the ($2+1$)-dimensional Born-Infeld gravity.

Continuing work initiated in an earlier publication [T. Ichita, K. Yamada, and H. Asada, Phys. Rev. D 83, 084026 (2011)], we reexamine the post-Newtonian effects on Lagrange’s equilateral triangular solution for the three-body problem. For three finite masses, it is found that a triangular configuration satisfies the post-Newtonian equation of motion in general relativity if and only if it has the relativistic corrections to each side length. This post-Newtonian configuration for three finite masses is not always equilateral, and it recovers previous results for the restricted three-body problem when one mass goes to zero. For the same masses and angular velocity, the post-Newtonian triangular configuration is always smaller than the Newtonian one.

We study the Brans-Dicke theory of gravity in Riemann-Cartan space-times and obtain general torsion solutions, which are completely determined by the Brans-Dicke scalar field $\Phi$, in the false- vacuum-energy–dominated epoch. The substitution of the torsion solutions back to our action gives the original Brans-Dicke action with $\Phi$-dependent Brans-Dicke parameter $\omega (\Phi )$. The evolution of $\omega (\Phi )$ during the inflation is studied and it is found that $\omega$ approaches infinity at the end of inflation. This may solve the $\omega$-problem in the extended inflation model.

We show how scaling arguments may be used to generate templates for the tidal stresses around saddles for a vast class of modified Newtonian dynamics theories detached from their obligations as dark matter alternatives. Such theories are to be seen simply as alternative theories of gravity with a preferred acceleration scale, and could be tested in the Solar System by extending the LISA Pathfinder mission. The constraints thus obtained may then be combined, if one wishes, with requirements arising from astrophysical and cosmological applications, but a clear separation of the issues is achieved. The central technical content of this paper is the derivation of a scaling prescription allowing complex numerical work to be bypassed in the generation of templates. We find that LISA Pathfinder could constrain very tightly the acceleration $a_0$ and the free parameter $\kappa$ present in these theories. As an application of our technique we also produce predictions for the Moon saddle (for which a similar scaling argument is applicable) with the result that we recommend that it should be included in orbit design.

Coleman tunneling in a general scalar potential with two nondegenerate minima is known to have an approximation in terms of a piecewise linear triangular-shaped potential with sharp “kinks” at the place of the local minima. This approximate potential has a regime where the existence of the bounce solution needs the scalar field to “wait” for some amount of Euclidean time at one of the kinks. We discuss under which conditions a kink approximation of locally smooth “cap” regions provides a good estimate for the bounce action.

We derive explicit expressions for the multidetector $\mathcal{F}$-statistic metric applied to short-duration nonprecessing inspiral signals. This is required for template bank production associated with coherent searches for short-duration nonprecessing inspiral signals in gravitational-wave data from a network of detectors. We compare the metric’s performance with explicit overlap calculations for all relevant dimensions of parameter space and find the metric accurately predicts the loss of detection statistic above overlaps of 95%. We also show the effect that neglecting the variations of the detector response functions has on the metric.

We propose a simple way to improve the sensitivity of laser gravitational-wave detectors and other high-precision laser interferometric position meters by means of reduction of the number of reflective coating layers of the core optics mirrors. This effects in the proportional decrease of the coating thermal noise, the most notorious among the interferometer’s technical noise sources. The price for this is increased quantum noise, as well as high requirements for the pump laser power and, therefore, power at the beam splitter, the power-recycling mirror, and the arm cavities’ input mirror substrates. However, as far as these processes depend differently on the coating thickness, we demonstrate that a certain trade-off is possible. In the particular case of large-scale laser gravitational-wave detectors, this trade-off yields a 20–30% gain (for diverse gravitational-wave signal types and interferometer configurations), provided that increased laser power (comparable with that planned for the third-generation gravitational-wave detectors) becomes available, and that it will be possible to mitigate the increased thermal effects caused by absorption in the beam splitter and input mirrors.

In the minimal universal extra dimension model, the second Kaluza-Klein gluon $g^{(2)}$ has loop-induced vertices with the standard model quarks, mediated by the first Kaluza-Klein modes of the quark and the gluon/Higgs boson. With a top quark pair, this vertex is enhanced by the cooperation of strong coupling of a gluon and a large Yukawa coupling of a top quark, leading to substantial branching ratio of $\mathrm{BR}(g^{(2)}\to t\overline{t})\approx 7\%–8\%$. As the $g^{(2)}$ coupling with two gluons appears via dimension-6 operators, the process $q\overline{q}\to g^{(2)}\to t\overline{t}$ is very efficient to probe the minimal universal extra dimension model. The recent Tevatron data on the search for the $t\overline{t}$ resonance at $\sqrt{s}=1.96\mathrm{TeV}$ with an integrated luminosity of $8.7{\mathrm{fb}}^{-1}$ are shown to give the direct bound on the $g^{(2)}$ mass above 800 GeV. The implication and future prospect at the LHC are discussed also.

In the Standard Model, no dim-5 $\Delta B\ne 0$ operators exist, so that Planck-scale-induced proton decay amplitudes are suppressed by at least $1/M_{P\ell }^2$. If the Standard Model is augmented by a light, color-nonsinglet boson, then $O(1/M_{P\ell })$ proton-decay amplitudes are possible. These always conserve $B+L$, so that the dominant decay modes are $p\to {\Pi }^{+}\nu$ and $p\to {\Pi }^{+}{\Pi }^{+}{\ell }^{-}$, where ${\Pi }^{+}={\pi }^{+}$ or $K^{+}$.

We derive dispersive representations for the anomalous process $\gamma \pi \to \pi \pi$ with the $\pi \pi$ $P$-wave phase shift as input. We investigate how in this framework the chiral anomaly can be extracted from a cross-section measurement using all data up to 1 GeV, and discuss the importance of a precise representation of the $\gamma \pi \to \pi \pi$ amplitude for the hadronic light-by-light contribution to the anomalous magnetic moment of the muon.