We calculate the $J/\psi$ mass, leptonic width and radiative decay rate to $\gamma {\eta }_c$ from lattice QCD including $u$, $d$ and $s$ quarks in the sea for the first time. We use the highly improved staggered quark formalism and nonperturbatively normalized vector currents for the leptonic and radiative decay rates. Our results are: $M_{J/\psi }-M_{{\eta }_c}=116.5(3.2)\mathrm{MeV}$; $\Gamma (J/\psi \to e^{+}{e}^{-})=5.48(16)\mathrm{keV}$; $\Gamma (J/\psi \to \gamma {\eta }_c)=2.49(19)\mathrm{keV}$. The first two are in good agreement with experiment, with $\Gamma (J/\psi \to e^{+}{e}^{-})$ providing a test of a decay matrix element in QCD, independent of Cabibbo-Kobayashi-Maskawa uncertainties, to 2%. At the same time results for the time moments of the correlation function can be compared to values from the charm contribution to $\sigma (e^{+}{e}^{-}\to \mathrm{\text{hadrons}})$, giving a 1.5% test of QCD. Our results show that an improved experimental error would enable a similarly strong test from $\Gamma (J/\psi \to \gamma {\eta }_c)$.

Recently realization of TeV scale inverse seesaw mechanism in supersymmetric $SO(10)$ framework has led to a number of experimentally verifiable predictions including low-mass $W_R^{\pm }$ and $Z^{\prime }$ gauge bosons and nonunitarity effects. Using nonsupersymmetric $SO(10)$ grand unified theory, we show how a TeV scale inverse seesaw mechanism for neutrino masses is implemented with a low-mass $Z^{\prime }$ boson accessible to Large Hadron Collider. We derive renormalization group equations for fermion masses and mixings in the presence of the intermediate symmetries of the model and extract the Dirac neutrino mass matrix at the TeV scale from successful grand unified theory-scale parametrization of fermion masses. We estimate leptonic nonunitarity effects measurable at neutrino factories and lepton flavor violating decays expected to be probed in the near future. While our prediction on the nonunitarity matrix element ${\eta }_{\mu \tau }$ for degenerate right-handed neutrinos is similar to the supersymmetric $SO(10)$ case, we find new predictions with significantly enhanced value of its phase ${\delta }_{\mu \tau }\simeq {10}^{-4}–{10}^{-2}$ when partial degeneracy among these neutrino masses is adequately taken into account by a constraint relation that emerges naturally in this approach. Other predictions on branching ratios and $CP$-violating parameters are discussed. An important distinguishing characteristic as another test of the minimal model is that the threshold corrected two-loop prediction of the proton lifetime with maximum value $({\tau }_p{)}_{\max }\simeq {10}^{35}\mathrm{yrs}$. is accessible to ongoing search experiments for the decay $p\to e^{+}{\pi }^0$ in the near future. Simple model extensions with longer proton lifetime predictions are also discussed.

Motivated by recent observations of nonzero ${\theta }_{13}$ from the Daya Bay and RENO experiments, we propose a renormalizable neutrino model with $A_4$ discrete symmetry accounting for deviations from the tri-bimaximal mixing pattern of the neutrino mixing matrix indicated by neutrino oscillation data. In the model, the light neutrino masses can be generated by radiative corrections, and we show how the light neutrino mass matrix can be diagonalized by the Pontecorvo-Maki-Nakagawa-Sakata mixing matrix whose entries are determined by the current neutrino data, including the Daya Bay result. We show that the origin of the deviations from the tri-bimaximal mixing is nondegeneracy of the neutrino Yukawa coupling constants, and unremovable $CP$ phases in the neutrino Yukawa matrix give rise to both low energy $CP$ violation measurable from neutrino oscillation and high energy $CP$ violation.

Inspired by a new relation ${\theta }_{13}^{\mathrm{PMNS}}={\theta }_C/\sqrt{2}$ observed from the relatively large ${\theta }_{13}^{\mathrm{PMNS}}$, we find that the combination of this relation with the quark-lepton complementarity and the self-complementarity results in correlations of the lepton mixing angles with the quark mixing angles. We find that the three mixing angles in the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix are all related to the Wolfenstein parameter $\lambda$ in the quark mixing, so they are also correlated. Consequently, the PMNS matrix can be parameterized by $\lambda$, A, and a Dirac $CP$-violating phase $\delta$. Such parametrizations for the PMNS matrix have the same explicitly hierarchical structure as the Wolfenstein parametrization for the Cabibbo-Kobayashi-Maskawa matrix in the quark mixing, and the bimaximal mixing pattern is deduced at the leading order. We also discuss implications of these phenomenological relations in parametrizations.

The top quark is the heaviest known elementary particle, with a mass about 40 times larger than the mass of its isospin partner, the bottom quark. It decays almost 100% of the time to a $W$ boson and a bottom quark. Using top-antitop pairs at the Tevatron proton-antiproton collider, the CDF and D0 Collaborations have measured the top quark’s mass in different final states for integrated luminosities of up to $5.8{\mathrm{fb}}^{-1}$. This paper reports on a combination of these measurements that results in a more precise value of the mass than any individual decay channel can provide. It describes the treatment of the systematic uncertainties and their correlations. The mass value determined is $173.18\pm 0.56(\mathrm{stat})\pm 0.75(\mathrm{syst})\mathrm{GeV}$ or $173.18\pm 0.94\mathrm{GeV}$, which has a precision of $\pm 0.54\%$, making this the most precise determination of the top-quark mass.

This work presents a new inclusive search for supersymmetry (SUSY) by the ATLAS experiment at the LHC in proton-proton collisions at a center-of-mass energy $\sqrt{s}=7\mathrm{TeV}$ in final states with jets, missing transverse momentum and one or more isolated electrons and/or muons. The search is based on data from the full 2011 data-taking period, corresponding to an integrated luminosity of $4.7{\mathrm{fb}}^{-1}$. Single-lepton and multilepton channels are treated together in one analysis. An increase in sensitivity is obtained by simultaneously fitting the number of events in statistically independent signal regions, and the shapes of distributions within those regions. A dedicated signal region is introduced to be sensitive to decay cascades of SUSY particles with small mass differences (“compressed SUSY”). Background uncertainties are constrained by fitting to the jet-multiplicity distribution in background control regions. Observations are consistent with Standard Model expectations, and limits are set or extended on a number of SUSY models.

The inclusive production rate of neutral pions in the rapidity range greater than $y=8.9$ has been measured by the Large Hadron Collider forward (LHCf) experiment during $\sqrt{s}=7\mathrm{TeV}$ proton-proton collision operation in early 2010. This paper presents the transverse momentum spectra of the neutral pions. The spectra from two independent LHCf detectors are consistent with each other and serve as a cross-check of the data. The transverse momentum spectra are also compared with the predictions of several hadronic interaction models that are often used for high-energy particle physics and for modeling ultrahigh-energy cosmic ray showers.

Neutrino speed experiments could be viewed not only as tests of Lorentz invariance but also as measurements of limiting propagation speed for all standard model species below certain depth where no direct metrological information is available. The latter option, hypothetically caused by some chameleon-type background, is tested by the neutrino speed experiments. We show that complementary constraints on the same class of models can be obtained with experiments testing clock universality in deep underground/underwater experiments. By considering the explicit QED model with particle-universal modification of propagation speed by a depth-dependent tensor background, we show that, in general, one should expect shifts of the clock frequencies and clock nonuniversality. Such effects can be larger than predicted by general relativity and can be tested by comparison of the narrow transitions in atomic clocks, which for a generic model could deliver a superior accuracy compared to the neutrino speed experiments.

In this paper two things are done. First, it is pointed out the existence of exact asymptotically flat, spherically symmetric black holes when a self-interacting, minimally coupled scalar field is the source of the Einstein equations in four dimensions. The scalar field potential is recently found to be compatible with the hairy generalization of the Plebanski-Demianski solution of general relativity. This paper describes the spherically symmetric solutions that smoothly connect the Schwarzschild black hole with its hairy counterpart. The geometry and scalar field are everywhere regular except at the usual Schwarzschild-like singularity inside the black hole. The scalar field energy momentum tensor satisfies the null-energy condition in the static region of spacetime. The first law holds when the parameters of the scalar field potential are fixed under thermodynamical variation. Second, it is shown that an extra, dimensionless parameter, present in the hairy solution, allows to modify the gravitational field of a spherically symmetric black hole in a remarkable way. When the dimensionless parameter is increased, the scalar field generates a flat gravitational potential that, however, asymptotically matches the Schwarzschild gravitational field. Finally, it is shown that a positive cosmological constant can render the scalar field potential convex if the parameters are within a specific rank.

We study conformal coupling of dark spinor fields to gravity and calculate the energy density and the pressure of the spinor in Friedmann-Robertson-Walker spacetime. We consider the renormalizable potential of the spinor field. In the cases where the field is proportional to some power of the cosmic scale factor $a(t)$, we determine the Hubble parameter as a function of the scale factor and find analytic solutions for $a(t)$ when the spinor field matter dilutes as the Universe expands. We discuss the possibility that both matter- and dark energy-dominated eras of our Universe can be described by the dark spinor.

There is a well-known, intuitive geometric correspondence between high-frequency quasinormal modes of Schwarzschild black holes and null geodesics that reside on the light ring (often called spherical photon orbits): the real part of the mode’s frequency relates to the geodesic’s orbital frequency, and the imaginary part of the frequency corresponds to the Lyapunov exponent of the orbit. For slowly rotating black holes, the quasinormal mode’s real frequency is a linear combination of the orbit’s precessional and orbital frequencies, but the correspondence is otherwise unchanged. In this paper, we find a relationship between the quasinormal-mode frequencies of Kerr black holes of arbitrary (astrophysical) spins and general spherical photon orbits, which is analogous to the relationship for slowly rotating holes. To derive this result, we first use the Wentzel-Kramers-Brillouin approximation to compute accurate algebraic expressions for large-$l$ quasinormal-mode frequencies. Comparing our Wentzel-Kramers-Brillouin calculation to the leading-order, geometric-optics approximation to scalar-wave propagation in the Kerr spacetime, we then draw a correspondence between the real parts of the parameters of a quasinormal mode and the conserved quantities of spherical photon orbits. At next-to-leading order in this comparison, we relate the imaginary parts of the quasinormal-mode parameters to coefficients that modify the amplitude of the scalar wave. With this correspondence, we find a geometric interpretation of two features of the quasinormal-mode spectrum of Kerr black holes: First, for Kerr holes rotating near the maximal rate, a large number of modes have nearly zero damping; we connect this characteristic to the fact that a large number of spherical photon orbits approach the horizon in this limit. Second, for black holes of any spins, the frequencies of specific sets of modes are degenerate; we find that this feature arises when the spherical photon orbits corresponding to these modes form closed (as opposed to ergodically winding) curves.

We investigate the effect of a cosmological constant on the gravothermal catastrophe in the Newtonian limit. A negative cosmological constant acts as a thermodynamic “destabilizer”. The Antonov radius gets smaller and the instability occurs, not only for negative but also for positive energy values. A positive cosmological constant acts as a “stabilizer” of the system, which, in this case, exhibits a novel “reentrant behavior”. In addition to the Antonov radius we find a second critical radius, where an “inverse Antonov transition” occurs; a series of local entropy maxima is restored.

We show that higher spin systems specific to cosmological spaces are subject to the same problems as models with Poincaré limits. In particular, we analyze partially massless (PM) spin 2 and find that both its gravitational coupling and nonlinear extensions suffer from the usual background- and self-coupling difficulties: Consistent free field propagation does not extend beyond background Einstein geometries. Then (using conformal, Weyl, gravity, which contains relative ghost PM and graviton excitations) we find that avoiding graviton ghosts restricts Weyl-generated PM self-couplings to the usual, leading, safe, Noether current cubic ones.

We consider the quantization of scalar fields in spacetimes such that, by means of a suitable scaling of the field by a time dependent function, the field equation can be regarded as that of a field with a time dependent mass propagating in an auxiliary ultrastatic static background. For Klein-Gordon fields, it is well known that there exist an infinite number of nonequivalent Fock representations of the canonical commutation relations and, therefore, of inequivalent quantum theories. A context in which this kind of ambiguities arises and prevents the derivation of robust results is, e.g., in the quantum analysis of cosmological perturbations. In these situations, typically, a suitable scaling of the field by a time dependent function leads to a description in an auxiliary static background, though the nonstationarity still shows up in a time dependent mass. For such a field description, and assuming the compactness of the spatial sections, we recently proved in three or less spatial dimensions that the criteria of a natural implementation of the spatial symmetries and of a unitary time evolution are able to select a unique class of unitarily equivalent vacua, and hence of Fock representations. In this work, we succeed to extend our uniqueness result to the consideration of all possible field descriptions that can be reached by a time dependent canonical transformation which, in particular, involves a scaling of the field by a function of time. These kinds of canonical transformations modify the dynamics of the system and introduce a further ambiguity in its quantum description, exceeding the choice of a Fock representation. Remarkably, for any compact spatial manifold in less than four dimensions, we show that our criteria eliminate any possible nontrivial scaling of the field other than that leading to the description in an auxiliary static background. Besides, we show that either no time dependent redefinition of the field momentum is allowed or, if this may happen—something which is typically the case only for one-dimensional spatial manifolds—the redefinition does not introduce any Fock representation that cannot be obtained by a unitary transformation.

We present analytical solutions of the geodesic equations of test particles and light in the five-dimensional singly spinning black ring spacetime for special cases, since it does not appear possible to separate the Hamilton-Jacobi equation for singly spinning black rings in general. Based on the study of the polynomials in the equations of motion we characterize the motion of test particles and light and discuss the associated orbits.

Cocal is a code for computing equilibriums or quasiequilibrium initial data of single or binary compact objects based on finite difference methods. We present the results of supplementary convergence tests of cocal code using time symmetric binary black hole data (Brill-Lindquist solution). Then, we compare the initial data of binary black holes on the conformally flat spatial slice obtained from cocal and KADATH, where KADATH is a library for solving a wide class of problems in theoretical physics including relativistic compact objects with spectral methods. Data calculated from the two codes converge nicely towards each other, for close as well as largely separated circular orbits of binary black holes. Finally, as an example, a sequence of equal mass binary black hole initial data with corotating spins is calculated and compared with data in the literature.

We investigate a cosmological scenario with three interacting components that includes dark matter, dark energy, and radiation in the spatially flat Friedmann-Robertson-Walker universe. We introduce a 3-dimensional internal space, the interaction vector $\mathbf{Q}=(Q_x,Q_m,Q_r)$ satisfying the constraint plane $Q_x+Q_m+Q_r=0$, the barotropic index vector $\mathit{\gamma }=({\gamma }_x,{\gamma }_m,{\gamma }_r)$ and select a transversal interaction vector ${\mathbf{Q}}_{\mathbf{t}}$ in a sense that ${\mathbf{Q}}_{\mathbf{t}}·\mathit{\gamma }=0$. We exactly solve the source equation for a linear ${\mathbf{Q}}_{\mathbf{t}}$, that depends on the total energy density and its derivatives up to third order, and find all the component energy densities. We obtain a large set of interactions for which the source equation admits a power law solution and show its asymptotic stability by constructing the Lyapunov function. We apply the ${\chi }^2$ method to the observational Hubble data for constraining the cosmic parameters, and analyze the amount of dark energy in the radiation era for the above linear ${\mathbf{Q}}_{\mathbf{t}}$. It turns to be that our model fulfills the severe bound of ${\Omega }_x(z\simeq 1100)<0.1$ and is consistent with the future constraints achievable by Planck and CMBPol experiments.

Shadows of multi-black holes have structures distinct from the mere superposition of the shadow of a single black hole: the eyebrow-like structures outside the main shadows and the deformation of the shadows. We present analytic estimates of these structures using the static multi-black hole solution (Majumdar-Papapetrou solution). We show that the width of the eyebrow is related to the distance between the black holes and that the shadows are deformed into ellipses due to the presence of the second black holes. These results are helpful to understand qualitatively the features of the shadows of colliding black holes. We also present the shadows of colliding or coalescing black holes in the Kastor-Traschen solution.

Fluctuations in the local Newtonian gravitational field present a limit to high precision measurements, including searches for gravitational waves using laser interferometers. In this work, we present a model of this perturbing gravitational field and evaluate schemes to mitigate the effect by estimating and subtracting it from the interferometer data stream. Information about the Newtonian noise is obtained from simulated seismic data. The method is tested on causal as well as acausal implementations of noise subtraction. In both cases it is demonstrated that broadband mitigation factors close to 10 can be achieved removing Newtonian noise as a dominant noise contribution. The resulting improvement in the detector sensitivity will substantially enhance the detection rate of gravitational radiation from cosmological sources.