We present a detailed study of charmless two-body $B$ decays into final states involving two vector mesons ($VV$) or two axial-vector mesons ($AA$) or one vector and one axial-vector meson ($VA$), within the framework of QCD factorization, where $A$ is either a ${}^{3}P_1$ or ${}^{1}P_1$ axial-vector meson. The main results are as follows. (i) In the presence of next-to-leading-order nonfactorizable corrections, effective Wilson coefficients $a_i^h$ are helicity-dependent. For some penguin-dominated modes, the constructive (destructive) interference in the negative-helicity (longitudinal-helicity) amplitude of the $\overline{B}\to VV$ decay will render the former comparable to the latter and push up the transverse polarization. (ii) In QCD factorization, the transverse polarization fraction can be large for penguin-dominated charmless $VV$ modes by allowing for sizable penguin-annihilation contributions. (iii) Using the measured ${\overline{K}}^{*0}{\rho }^{-}$ channel as an input, we predict the branching ratios and polarization fractions for other $\overline{B}\to {\overline{K}}^{*}\rho$ decays. (iv) The smallness of the axial-vector decay constant of the ${}^{1}P_1$ axial-vector meson can be tested by measuring various $b_1\rho$ modes to see if $\Gamma ({\overline{B}}^0\to b_1^{-}{\rho }^{+})\ll \Gamma ({\overline{B}}^0\to b_1^{+}{\rho }^{-})$ and $\Gamma (B^{-}\to b_1^{-}{\rho }^0)\ll \Gamma (B^{-}\to b_1^0{\rho }^{-})$. (v) For the penguin-dominated modes $a_1{K}^{*}$ and $b_1{K}^{*}$, it is found that the former are dominated by transverse polarization amplitudes, whereas the latter are governed by longitudinal polarization states. (vi) The rates of $B\to K_1(1270)K^{*}$ and $K_1(1400)K^{*}$ are generally very small. The decay modes $K_1^{-}{K}^{*+}$ and $K_1^{+}{K}^{*-}$ are of particular interest as they are the only $AV$ modes which receive contributions solely from weak annihilation. (vii) For tree-dominated $B\to AA$ decays, the $a_1^{+}{a}_1^{-}$, $a_1^{-}{a}_1^0$, $a_1^{-}{b}_1^{+}$, $a_1^{-}{b}_1^0$, $b_1^{+}{\rho }^{-}$ and $b_1^0{\rho }^{-}$ modes have sizable branching ratios, of order $(20–40)\times {10}^{-6}$. (viii) There are many penguin-dominated $B\to AA$ decays within the reach of $B$ factories: $K_1(1270)(a_1,b_1^{\pm })$, $K_1(1400)(b_1,a_1^{\pm })$, $K_1(1270)(f_1(1285),f_1(1420))$ and $K_1(1400)(f_1(1420),h_1(1170))$.

We propose a measurement of the elastic $\pi \pi$ scattering phase-shift difference ${\delta }_0^0-{\delta }_0^2$ through the ${\Psi }^{\prime }\to J/\Psi {\pi }^{+}{\pi }^{-}$ process in the future high statistics BES-III experiment. The decay amplitude is constructed with seven Lorentz invariant form factors and is compared with their theoretical estimation. Based on a Monte Carlo study, it is found that the phase-shift difference can be indeed recovered and, hence, it is expected to be measured in the energy region between 350 and 550 MeV at future BES-III.

An unstable gravitino with lifetime longer than ${10}^{26}$ sec or so has been proposed as a possible dark matter candidate in supergravity models with R-parity breaking. We find a natural realization of this idea in the minimal supersymmetric left-right models, where left-right symmetry-breaking scale is in the few TeV range. It is known that in these models, R-parity must break in order to have parity breaking as required by low energy weak interactions. The sub-eV neutrino masses imply that R-parity breaking effects in this model must be highly suppressed. This in turn makes the gravitino lightest supersymmetric particle long-lived enough, so that it becomes the dark matter of the Universe. It also allows detectable displaced vertices at the LHC from next-to-lightest supersymmetry particle decays. We present a detailed analysis of the model and some aspects of its rich phenomenology.

Topological charge changing transitions can induce chirality in the quark-gluon plasma by the axial anomaly. We study the equilibrium response of the quark-gluon plasma in such a situation to an external magnetic field. To mimic the effect of the topological charge changing transitions we will introduce a chiral chemical potential. We will show that an electromagnetic current is generated along the magnetic field. This is the chiral magnetic effect. We compute the magnitude of this current as a function of magnetic field, chirality, temperature, and baryon chemical potential.

This paper is devoted to consideration of the hard exclusive processes $e^{+}{e}^{-}\to VP$, where $V=\rho$, $\varphi$; $P=\eta$, ${\eta }^{\prime }$. Experimental measurement of the cross section of the process $e^{+}{e}^{-}\to \varphi \eta$ at the BABAR Collaboration at large center of mass energy $\sqrt{s}=10.6\mathrm{GeV}$ and some low energy experimental data $\sqrt{s}\sim 2–4\mathrm{GeV}$ give us the possibility to study the cross section in the broad energy region. As a result, we have determined the asymptotic behavior of the cross section of $e^{+}{e}^{-}\to \varphi \eta$ in the limit $s\to \infty$, which is in agreement with perturbative QCD prediction. Assuming that the same asymptotic behavior is valid for the other processes under consideration and using low energy experimental data, we have predicted the cross sections of these processes at energies $\sqrt{s}=3.67$, 10.6 GeV. In addition, we have calculated the cross sections of these processes at the same energies within perturbative QCD. Our results are in agreement with available experimental data.

We examine the spatial density within extended objects of the momentum component $p^{+}$, and find relativistically exact connections to Fourier transforms of gravitational form factors. We apply these results to obtain semiempirical momentum density distributions within nucleons, and similar distributions for spin-1 objects based on theoretical results from the AdS/QCD correspondence. We find that the momentum density in the transverse plane is more compact than the charge density.

We reconsider the question of the excitation rate of a particle detector in the quantum flux due to an accelerated mirror in a noncommutative space-time [R. Casadio et al., Phys. Rev. D 73, 044019 (2006)] and show that, contrary to the result in the paper indicating an increased value compared to that in the usual space, the excitation rate is smaller and vanishes at infinite times.

An effective theory based on wave optics is used to describe indeterminacy of position in holographic spacetime with a UV cutoff at the Planck scale. Wave functions describing spacetime positions are modeled as complex disturbances of quasimonochromatic radiation. It is shown that the product of standard deviations of two position wave functions in the plane of a holographic light sheet is equal to the product of their normal separation and the Planck length. For macroscopically separated positions the transverse uncertainty is much larger than the Planck length, and is predicted to be observable as a “holographic noise” in relative position with a distinctive shear spatial character, and an absolutely normalized frequency spectrum with no parameters once the fundamental wavelength is fixed from the theory of gravitational thermodynamics. The spectrum of holographic noise is estimated for the GEO600 interferometric gravitational-wave detector and is shown to approximately account for currently unexplained noise between about 300 and 1400 Hz. In a holographic world, this result directly and precisely measures the fundamental minimum interval of time.

The analog of the Cachazo-Svrček-Witten rules for scattering amplitudes with massive quarks is derived following an approach previously employed for amplitudes with massive scalars. A prescription for the external wave functions is given that leads to a one-to-one relation between fields in the action and spin states of massive quarks. Several examples for the application of the rules are given and the structure of some all-multiplicity amplitudes with a pair of massive quarks is discussed. The rules make supersymmetric relations to amplitudes with massive scalars manifest at the level of the action. The formalism is extended to several quark flavors with different masses.

Five-dimensional theories manifesting spontaneous brane generation are discussed in a gravitational context. Without gravity, the IR dynamics of the brane fluctuation below the brane tension scale is described by an effective theory for the Nambu-Goldstone modes. When gravity is properly taken into account, the long-distance dynamics changes. The spontaneous breaking of local translational invariance triggers the formation of massive representations via the Higgs mechanism and induces the appearance of new mass scales in the IR. These scales can in principle depend on other fundamental parameters besides the brane tension and the Planck mass. In noncompact extra dimensions the massive states are found to be scalar bound states. We obtain explicit expressions for their propagator and show that their masses depend on the brane width. We present an exactly solvable model which captures the main features of the gravitational system.

Particles propagating in de Sitter spacetime can be described by the topological BF $\mathsf{S}\mathsf{O}(4,1)$ theory coupled to point charges. Gravitational interaction between them can be introduced by adding to the action a symmetry breaking term, which reduces the local gauge symmetry down to $\mathsf{S}\mathsf{O}(3,1)$, and which can be treated as a perturbation. In this paper we focus solely on topological interactions which correspond to zeroth order in this perturbative expansion. We show that in this approximation the system is effectively described by the $\mathsf{S}\mathsf{O}(4,1)$ Chern-Simons theory coupled to particles and living on the three-dimensional boundary of spacetime. Then, using Alekseev-Malkin construction we find the effective theory of particles kinematics. We show that the particles action contains standard kinetic terms and the deformation shows up in the presence of interaction terms. The strength of the interactions is proportional to deformation parameter, identified with Planck mass scale.

We present an extension of the velocity-dependent one-scale model for cosmic string evolution, which is suitable for describing the evolution of local and global monopole networks. We discuss the key dynamical features that need to be accounted for, in particular, the fact that the driving force is due to the other monopoles (rather than being due to local curvature as in the case of extended objects) and new forms of energy-loss terms due to monopole-antimonopole capture and annihilation. For the case of local monopoles we recover and generalize the results of Preskill, suggesting that the scaling law for the monopole correlation length is very sensitive to the annihilation rate. On the other hand, for global monopoles the long-range forces generically lead to linear scaling (just like in the case of local cosmic strings). In this case we also find good qualitative agreement between our results and the numerical simulations of Bennett and Rhie and Yamaguchi, although future high-resolution simulations will be needed for quantitative comparisons.

Recently, stellar collapse involving black-hole formation from massive stars is suggested to emit enormous fluxes of neutrinos on par with ordinary core-collapse supernovae. We investigate their detectability for the currently operating neutrino detector, SuperKamiokande. Neutrino oscillation is also taken into account for the evaluation. We find that the event number is larger than or comparable to that of supernova neutrinos and, hence, black-hole formation is also a candidate for neutrino astronomy. Moreover, we find that the event number depends dominantly on the equation of state used in the computations of the black-hole formation. This fact implies that the detection of neutrinos emitted from the black hole progenitors is very valuable to probe the properties of the equation of state for hot and/or dense matter.

Observations of the cosmic microwave background (CMB) provide increasingly accurate information about the structure of the Universe at the recombination epoch. Most of this information is encoded in the angular power spectrum of the CMB. The aim of this work is to propose a versatile and powerful method for spectral estimation on the sphere which can easily deal with nonstationary uncorrelated noise and multiple experiments with various specifications. In this paper, we use needlets (wavelets) on the sphere to construct natural and efficient spectral estimators for partially observed and beamed CMB with nonstationary noise. In the case of a single experiment, we compare this method with pseudo-$C_{\ell }$ methods. The performance of the needlet spectral estimators (NSE) compares very favorably to the best pseudo-$C_{\ell }$ estimators, over the whole multipole range. On simulations with a simple model ($\mathrm{CMB}+\mathrm{\text{uncorrelated noise}}$ with known variance per $\mathrm{\text{pixel}}+\mathrm{\text{mask}}$), they perform uniformly better. Their distinctive ability to aggregate many different experiments, to control the propagation of errors, and to produce a single wideband error bar is highlighted. The needlet spectral estimator is a powerful, tunable tool which is very well suited to the angular power spectrum estimation of spherical data such as incomplete and noisy CMB maps.

Superhorizon perturbations induce large-scale temperature anisotropies in the cosmic microwave background (CMB) via the Grishchuk-Zel’dovich effect. We analyze the CMB temperature anisotropies generated by a single-mode adiabatic superhorizon perturbation. We show that an adiabatic superhorizon perturbation in a $\Lambda \mathrm{CDM}$ universe does not generate a CMB temperature dipole, and we derive constraints to the amplitude and wavelength of a superhorizon potential perturbation from measurements of the CMB quadrupole and octupole. We also consider constraints to a superhorizon fluctuation in the curvaton field, which was recently proposed as a source of the hemispherical power asymmetry in the CMB.

Froggatt, Nielsen et al. [C. D. Froggatt, L. V. Laperashvili, R. B. Nevzorov, H. B. Nielsen, and C. R. Das, arXiv:0804.4506; C. D. Froggatt, H. B. Nielsen, and L. V. Laperashvili, Int. J. Mod. Phys. A 20, 1268 (2005); C. D. Froggatt and H. B. Nielsen, Surv. High Energy Phys. 18, 55 (2003).] suggested that the Higgs boson exchange between top quarks produces enough attraction to generate their multiple bound states. Furthermore they claimed that the system of 6 top and 6 antitop quarks is bound so strongly that the binding energy nearly compensates the masses of $t$ quarks, making it very light. We calculated the energy of such states more accurately, variationally and by self-consistent mean-field approximation, and found that these states are weakly bound for a massless Higgs boson and unbound taking into account its mass.

The successful description of current data provided by the standard model includes fundamental fermions that are color-singlets and electroweak-nonsinglets, but no fermions that are electroweak-singlets and color-nonsinglets. In an effort to understand the absence of such fermions, we construct and study gedanken models that do contain electroweak-singlet chiral quark fields. These models exhibit several distinctive properties, including the absence of any neutral lepton and the fact that both the $(uud)$ and $(ddu)$ nucleons are electrically charged. We also explore how such models could arise as low-energy limits of grand unified theories and, in this more restrictive context, we show that they exhibit further exotic properties.

We report an upper limit on the flux of relativistic monopoles based on the nonobservation of in-ice showers by the Radio Ice Cherenkov Experiment (RICE) at the South Pole. We obtain a 95% C.L. limit of order ${10}^{-18}({\mathrm{cm}}^2\mathrm{s}\mathrm{sr}{)}^{-1}$ for intermediate-mass monopoles of ${10}^7\le \gamma \le {10}^{12}$ at the anticipated energy $E_{\mathrm{tot}}={10}^{16}\mathrm{GeV}$. This bound is over an order of magnitude stronger than all previously published experimental limits for this range of boost parameters $\gamma$ and exceeds 2 orders of magnitude improvement over most of the range. We review the physics of radio detection, describe a Monte Carlo simulation including continuous and stochastic energy losses, and compare to previous experimental limits.

The minimal supergravity (mSUGRA) parameter space corresponding to light sleptons well within the reach of LHC and relatively light squarks and gluinos (mass $\le 1\mathrm{TeV}$) has three regions consistent with the Wilkinson Microwave Anisotropy Probe data on dark matter relic density and direct mass bounds from LEP 2. Each region can lead to distinct leptonic signatures from squark-gluino events during the early LHC experiments (integrated luminosity $\sim 10{\mathrm{fb}}^{-1}$ or even smaller) due to the distinct features of the 2-body leptonic decay modes of the electroweak gauginos, produced in squark-gluino decay cascades, in each region. In the much studied stau-LSP coannihilation region with a vanishing common trilinear coupling ($A_0$) at the grand unified theory scale, a large fraction of the final states contains electrons and/or muons and $e\mathrm{\text{−}}\mu \mathrm{\text{−}}\tau$ universality holds to a good approximation. In the not so well-studied scenarios with nonvanishing $A_0$ both lightest supersymmetric particle (LSP) pair annihilation and stau-LSP coannihilation could contribute significantly to the dark matter relic density for even smaller squark-gluino masses. Our simulations using Pythia indicate that the corresponding signatures are final states rich in $\tau$-leptons while final states with electrons and muons are suppressed leading to a violation of lepton universality. These features may be observed to a lesser extent even in the modified parameter space (with nonzero $A_0$) where the coannihilation process dominates. We also show that the generic $m\mathrm{\text{−}}\mathrm{\text{leptons}}+n\mathrm{\text{−}}\mathrm{\text{jets}}+{\mathrm{E̸}}_T$ signatures without flavor tagging can also discriminate among the three scenarios. However, the signals become more informative if the $\tau$ and $b$-jet tagging facilities at the LHC experiments are utilized.

We perform a Faddeev calculation for the three-meson system $\varphi K\overline{K}$, taking the interaction between two pseudoscalar mesons and between a vector and a pseudoscalar meson from the chiral unitary approach. We obtain a neat resonance peak around a total mass of 2150 MeV and an invariant mass for the $K\overline{K}$ system around 970 MeV, very close to the $f_0(980)$ mass. The state appears in $I=0$ and qualifies as a $\varphi f_0(980)$ resonance. We enlarge the space of states including $\varphi \pi \pi$, since $\pi \pi$ and $K\overline{K}$ build up the $f_0(980)$, and find moderate changes that serve to quantify theoretical uncertainties. No state is seen in $I=1$. This finding provides a natural explanation for the recent state found at BABAR and BES, the $X(2175)$, which decays into $\varphi f_0(980)$.