Quasinormal modes provide valuable information about the structure of spacetime outside a black hole. There is also a conjectured relationship between the highly damped quasinormal modes and the semiclassical spectrum of the horizon area/entropy. In this paper, we show that for spacetimes characterized by more than one scale, the “infinitely damped” modes in principle probe the structure of spacetime outside the horizon at the shortest length scales. We demonstrate this with the calculation of the highly damped quasinormal modes of the nonsingular, single-horizon, quantum corrected black hole derived in [A. Peltola and G. Kunstatter, Phys. Rev. D 79, 061501 (2009); ].

The Pomeransky-Sen’kov solution is well known to describe an asymptotically flat doubly rotating black ring in five dimensions, whose self-gravity is exactly balanced by the centrifugal force arising from the rotation in the ring direction. In this paper, we generalize this solution to the unbalanced case, in which there is in general a conical singularity in the space-time. Unlike a previous form of this solution presented in the literature, our form is much more compact. We describe in detail how this solution can be derived using the inverse-scattering method, and study its various properties. In particular, we show how various known limits can be recovered as special cases of this solution.

We show that Schwarzschild geometry remains as a vacuum solution for those four-dimensional $f(T)$ gravitational theories behaving as ultraviolet deformations of general relativity. In the gentler context of three-dimensional gravity, we also find that the infrared-deformed $f(T)$ gravities, like the ones used to describe the late cosmic speed up of the Universe, have as the circularly symmetric vacuum solution a Deser-de Sitter or a Bañados, Teitelboim and Zanelli-like spacetime with an effective cosmological constant depending on the infrared scale present in the function $f(T)$.

Collider signatures of the $SO(5)\times U(1)$ gauge-Higgs unification model in the Randall-Sundrum warped space are explored. Gauge couplings of quarks and leptons receive small corrections from the fifth dimension whose effects are tested by the precision data. It is found that the forward-backward asymmetries in $e^{+}{e}^{-}$ collisions on the $Z$ pole are well explained in a wide range of the warp factor $z_L$, but the model is consistent with the branching fractions of $Z$ decay only for large $z_L\gtrsim {10}^{15}$. Kaluza-Klein (KK) spectra of gauge bosons, quarks, and leptons as well as gauge and Higgs couplings of low-lying KK excited states are determined. Right-handed quarks and leptons have larger couplings to the KK gauge bosons than left-handed ones. Production rates of Higgs bosons and KK states at the Tevatron, LHC, and International Linear Collider are evaluated. The first KK $Z$ has a mass 1130 GeV with a width 422 GeV for $z_L={10}^{15}$. The current limit on the $Z^{\prime }$ production at the Tevatron and LHC indicates $z_L>{10}^{15}$. A large effect of parity violation appears in the difference between the rapidity distributions of $e^{+}$ and $e^{-}$ in the decay of the first KK $Z$. The first KK gauge bosons decay into light and heavy quarks evenly.

We introduce dressed Wilson loops as a novel confinement observable. It consists of closed planar loops of arbitrary geometry but fixed area, and its expectation values decay with the latter. The construction of dressed Wilson loops is based on chiral condensates in response to magnetic and electric fields, thus linking different physical concepts. We present results for generalized condensates and dressed Wilson loops on dynamical lattice configurations and confirm the agreement with conventional Wilson loops in the limit of large probe mass. We comment on the renormalization of dressed Wilson loops.

A study of three-pseudoscalar $\pi K\overline{K}$ and $\pi \pi \eta$ coupled system is made by solving the Faddeev equations within an approach based on unitary chiral dynamics. A resonance with total isospin one and spin-parity $J^{\pi }=0^{-}$ is found with mass $\sim 1400\mathrm{MeV}$ when the $K\overline{K}$ system gets reorganized as the $f_0(980)$. This resonance is identified with the $\pi (1300)$ listed by the Particle Data Group. Further, the two-body amplitude which describes the interaction between a $\pi$ and the $f_0(980)$ is extracted from the study of the $\pi K\overline{K}$ and $\pi \pi \eta$ system and is then employed to study the $f_0(980)\pi \pi$ system. As a result, a scalar resonance is found near 1790 MeV which drives the two $f_0(980)\pi$ systems to resonate as the $\pi (1300)$ while the invariant mass of the two pions falls in the mass region of the scalar $\sigma (600)$. These findings support the existence of a new $f_0$ resonance near 1790 MeV, as found by the BES and Crystal Barrel collaborations. Our results show that this $f_0(1790)$ is definitely distinct to $f_0(1710)$, the latter of which seems to possess a glueball structure dominantly.

Within the nonrelativistic quantum chromodynamics (NRQCD) factorization formalism, we compute the relativistic corrections to the exclusive decays of bottomonia with even charge conjugation parity into $S$-wave charmonium pairs at leading order in the strong coupling constant. Relativistic corrections are resummed for a class of color-singlet contributions to all orders in the charm-quark velocity $v_c$ in the charmonium rest frame. Almost every process that we consider in this work has negative relativistic corrections ranging from $-20$ to $-35\%$. Among the various processes, the relativistic corrections of the next-to-leading order in $v_c$ to the decay rate for ${\chi }_{b2}\to {\eta }_c(mS)+{\eta }_c(nS)$ with $m$, $n=1$ or 2 are very large. In every case, the resummation of the relativistic corrections enhances the rate in comparison with the next-to-leading-order results. We compare our results with available predictions based on the NRQCD factorization formalism. The NRQCD predictions are significantly smaller than those based on the light-cone formalism by 1 or 2 orders of magnitude.

We explore scenarios where top quarks may be produced singly in association with missing energy, a very distinctive signature, which, in analogy with monojets, we dub monotops. We find that monotops can be produced in a variety of modes, typically characterized by baryon number-violating or flavorchanging neutral interactions. We build a simplified model that encompasses all the possible (tree-level) production mechanisms and study the LHC sensitiveness to a few representative scenarios by considering fully hadronic top decays. We find that constraints on such exotic models can already be set with $1\mathrm{f}{\mathrm{b}}^{-1}$ of integrated luminosity collected at $\sqrt{s}=7\mathrm{TeV}$.

We perform the first search for lepton-number-violating $B^{+}\to D^{-}{\ell }^{+}{\ell }^{\prime +}$ decays, where $\ell$ and ${\ell }^{\prime }$ stand for $e$ or $\mu$, using $772\times {10}^6$ $B\overline{B}$ pairs accumulated at the ${\rm Y}(4S)$ resonance with the Belle detector at the KEKB $e^{+}{e}^{-}$ collider. No evidence for these decays has been found. Assuming uniform three-body phase space distributions for the $D^{-}{\ell }^{+}{\ell }^{\prime +}$ decays, we set the following upper limits on the branching fractions at 90% confidence level: $\mathcal{B}(B^{+}\to D^{-}{e}^{+}{e}^{+})<2.6\times {10}^{-6}$, $\mathcal{B}(B^{+}\to D^{-}{e}^{+}{\mu }^{+})<1.8\times {10}^{-6}$ and $\mathcal{B}(B^{+}\to D^{-}{\mu }^{+}{\mu }^{+})<1.1\times {10}^{-6}$.

In this brief report we compare the predictions of a recent next-to-next-to-leading order hard-thermal-loop perturbation theory (HTLpt) calculation of the QCD trace anomaly to available lattice data. We focus on the trace anomaly scaled by $T^2$ in two cases: $N_f=0$ and $N_f=3$. When using the canonical value of $\mu =2\pi T$ for the renormalization scale, we find that for Yang-Mills theory ($N_f=0$) agreement between HTLpt and lattice data for the $T^2$-scaled trace anomaly begins at temperatures on the order of $8T_c$, while when including quarks ($N_f=3$) agreement begins already at temperatures above $2T_c$. In both cases we find that at very high temperatures the $T^2$-scaled trace anomaly increases with temperature in accordance with the predictions of HTLpt.

Scalar QED is studied with higher order derivatives for the scalar-field kinetic energy. A local potential is generated for the gauge field due to the covariant derivatives and the vacuum with nonvanishing expectation value for the scalar field, and the vector potential is constructed in the leading-order saddle-point expansion. This vacuum breaks the global gauge and Lorentz symmetry spontaneously. The unitarity of time evolution is assured in the physical, positive norm subspace, and the linearized equations of motion are calculated. The Goldstone theorem always keeps the radiation field massless. A particular model is constructed where the full set of standard Maxwell equations is recovered on the tree level, thereby relegating the effects of broken Lorentz symmetry to the level of radiative corrections.

We examine the time evolution of the five-dimensional Einstein field equations subjected to a flat, anisotropic Robertson-Walker metric, where the 3D and higher-dimensional scale factors are allowed to dynamically evolve at different rates. By adopting equations of state relating the 3D and higher-dimensional pressures to the density, we obtain an exact expression relating the higher-dimensional scale factor to a function of the 3D scale factor. This relation allows us to write the Friedmann-Robertson-Walker field equations exclusively in terms of the 3D scale factor, thus yielding a set of 4D effective Friedmann-Robertson-Walker field equations. We examine the effective field equations in the general case and obtain an exact expression relating a function of the 3D scale factor to the time. This expression involves a hypergeometric function and cannot, in general, be inverted to yield an analytical expression for the 3D scale factor as a function of time. When the hypergeometric function is expanded for small and large arguments, we obtain a generalized treatment of the dynamical compactification scenario of Mohammedi [Phys. Rev. D 65, 104018 (2002)] and the 5D vacuum solution of Chodos and Detweiler [Phys. Rev. D 21, 2167 (1980)], respectively. By expanding the hypergeometric function near a branch point, we obtain the perturbative solution for the 3D scale factor in the small time regime. This solution exhibits accelerated expansion, which, remarkably, is independent of the value of the 4D equation of state parameter $w$. This early-time epoch of accelerated expansion arises naturally out of the anisotropic evolution of 5D spacetime when the pressure in the extra dimension is negative and offers a possible alternative to scalar field inflationary theory.

We consider an evaporating Schwarzschild black hole in a framework in which the spectral dimension of spacetime varies continuously from four at large distances to a number smaller than three at small distances, as suggested by various approaches to quantum gravity. We demonstrate that the evaporation stops when the horizon radius reaches a scale at which spacetime becomes effectively three-dimensional, and argue that an observer remaining outside the horizon cannot probe the properties of the black hole at smaller scales. This result is universal in the sense that it does not depend on the details of the effective dimension as a function of the diffusion time. Observers falling into the black hole can resolve smaller scales, as can external observers in the presence of a cosmological constant. Even in these cases, though, we obtain an absolute bound $D\ge 2$ on the effective dimension that can be seen in any such attempt to measure the properties of the black hole.

Building on the recently computed next-to-next-to-leading order (NNLO) post-Newtonian spin-orbit Hamiltonian for spinning binaries [J. Hartung and J. Steinhoff, arXiv:1104.3079.] we improve the effective-one-body description of the dynamics of two spinning black holes by including NNLO effects in the spin-orbit interaction. The calculation that is presented extends to NNLO the next-to-leading order spin-orbit Hamiltonian computed in [T. Damour, P. Jaranowski, and G. Schaefer, Phys. Rev. D 78, 024009 (2008).]. The present effective-one-body Hamiltonian reproduces the spin-orbit coupling through NNLO in the test-particle limit case. In addition, in the case of spins parallel or antiparallel to the orbital angular momentum, when circular orbits exist, we find that the inclusion of NNLO spin-orbit terms moderates the effect of the next-to-leading order spin-orbit coupling.

We show that the geometry of cutoffs on eternal inflation strongly constrains predictions for the time scales of vacuum domination, curvature domination, and observation. We consider three measure proposals: the causal patch, the fat geodesic, and the apparent horizon cutoff, which is introduced here for the first time. We impose neither anthropic requirements nor restrictions on landscape vacua. For vacua with positive cosmological constant, all three measures predict the double coincidence that most observers live at the onset of vacuum domination and just before the onset of curvature domination. The hierarchy between the Planck scale and the cosmological constant is related to the number of vacua in the landscape. These results require only mild assumptions about the distribution of vacua (somewhat stronger assumptions are required by the fat geodesic measure). At this level of generality, none of the three measures are successful for vacua with negative cosmological constant. Their applicability in this regime is ruled out unless much stronger anthropic requirements are imposed.

In the presence of Lorentz violation, the motion of a charged particle in a magnetic field is distorted. By measuring the eccentricities of particles’ elliptical orbits and studying how those eccentricities vary with the absolute orientation of the laboratory, it is possible to constrain the Lorentz-violating $c_{JK}$ parameters. For each observed species, this method can provide constraints on four linear combinations of coefficients for which, in some species, there are presently no two-sided bounds.

We investigate the charm quark system using the relativistic heavy quark action on $2+1$ flavor PACS-CS configurations previously generated on ${32}^3\times 64$ lattice. The dynamical up, down, and strange quark masses are set to the physical values by using the technique of reweighting to shift the quark-hopping parameters from the values employed in the configuration generation. At the physical point, the lattice spacing equals $a^{-1}=2.194(10)\mathrm{GeV}$ and the spatial extent $L=2.88(1)\mathrm{fm}$. The charm quark mass is determined by the spin-averaged mass of the $1S$ charmonium state, from which we obtain $m_{\mathrm{charm}}^{\overline{\mathrm{MS}}}(\mu =m_{\mathrm{charm}}^{\overline{\mathrm{MS}}})=1.260(1)(6)(35)\mathrm{GeV}$, where the errors are due to our statistics, scale determination and renormalization factor. An additional systematic error from the heavy quark is of order ${\alpha }_s^{2}f(m_{Q}a)(a{\Lambda }_{\mathrm{QCD}})$, $f(m_{Q}a)(a{\Lambda }_{\mathrm{QCD}}{)}^2$, which are estimated to be a percent level if the factor $f(m_{Q}a)$ analytic in $m_{Q}a$ is of order unity. Our results for the charmed and charmed-strange meson decay constants are $f_D=226(6)(1)(5)\mathrm{MeV}$, $f_{D_s}=257(2)(1)(5)\mathrm{MeV}$, again up to the heavy quark errors of order ${\alpha }_s^{2}f(m_{Q}a)(a{\Lambda }_{\mathrm{QCD}})$, $f(m_{Q}a)(a{\Lambda }_{\mathrm{QCD}}{)}^2$. Combined with the CLEO values for the leptonic decay widths, these values yield $|V_{cd}|=0.205(6)(1)(5)(9)$, $|V_{cs}|=1.00(1)(1)(3)(3)$, where the last error is because of the experimental uncertainty of the decay widths.

We study finite-volume effects on the masses of the ground-state octet baryons using covariant baryon chiral perturbation theory (ChPT) up to next-to-leading order by analyzing the latest $n_f=2+1$ lattice quantum chromodynamics (LQCD) results from the NPLQCD Collaboration. Contributions of virtual decuplet baryons are taken into account using the consistent coupling scheme. We compare our results with those obtained from heavy baryon ChPT and show that, although both approaches can describe well the lattice data, the underlying physics is different: In heavy baryon ChPT, virtual decuplet baryons play a more important role than they do in covariant ChPT. This is because the virtual octet-baryon contributions to finite-volume corrections are larger in covariant ChPT than in heavy baryon ChPT, while the contributions of intermediate decuplet baryons are smaller, because of relativistic effects. We observe that for the octet-baryon masses, at fixed $m_{\pi }L$ ($\gg 1$) finite-volume corrections decrease as $m_{\pi }$ approaches its physical value, provided that the strange quark mass is at or close to its physical value, as in most lattice quantum chromodynamics setups.

We interpret the spectrum of meson states recently obtained in nonperturbative lattice QCD calculations in terms of constituent quark-antiquark bound states and states, called “hybrids”, in which the $q\overline{q}$ pair is supplemented by an excitation of the gluonic field. We identify a lightest supermultiplet of hybrid mesons with $J^{PC}=(0,1,2{)}^{-+},1^{--}$ built from a gluonic excitation of chromomagnetic character coupled to $q\overline{q}$ in an $S$-wave. The next lightest hybrids are suggested to be quark orbital excitations with the same gluonic excitation, while the next distinct gluonic excitation is significantly heavier. Existing models of gluonic excitations are compared to these findings and possible phenomenological consequences explored.

Many models of physics beyond the standard model yield exotic Higgs decays. Some of these, particularly those in which the Higgs decays to light quarks or gluons, can be very difficult to discover experimentally. Here we introduce a new set of jet substructure techniques designed to search for such a Higgs when its dominant decay is into gluons via light, uncolored resonances. We study this scenario in both $V+h$ and $t\overline{t}+h$ production channels, and find both channels lead to discovery at the LHC with $\gtrsim 5\sigma$ at $\mathcal{L}\sim 100{\mathrm{fb}}^{-1}$.