In a model in which leptons, quarks, and the recently introduced hyperquarks are built up from two fundamental spin-$\frac{1}{2}$ preons, the standard model weak gauge bosons emerge as preon bound states. In addition, the model predicts a host of new composite gauge bosons, in particular, those responsible for hyperquark and proton decay. Their presence entails a left-right symmetric extension of the standard model weak interactions and a scheme for a partial and grand unification of nongravitational interactions based on, respectively, the effective gauge groups $\mathrm{SU}(6{)}_P$ and $\mathrm{SU}(9{)}_G$. This leads to a prediction of the Weinberg angle at low energies in good agreement with experiment. Furthermore, using evolution equations for the effective coupling strengths, we calculate the partial and grand unification scales, the hyperquark mass scale, as well as the mass and decay rate of the lightest hyperhadron.

We present a detailed analysis of the neutrino-induced muon signals coming from neutralino pair annihilations inside the Sun and the Earth with particular emphasis for light neutralinos. The theoretical model considered is an effective minimal supersymmetric extension of the standard model without gaugino-mass unification, which allows neutralinos of light masses (below 50 GeV). The muon events are divided into through-going and stopping muons, using the geometry of the Super-Kamiokande detector. In the evaluation of the signals, we take into account the relevant hadronic and astrophysics uncertainties and include neutrino oscillation and propagation properties in a consistent way. We derive the ranges of neutralino masses which could be explored at neutrino telescopes with a low muon-energy threshold (around 1 GeV) depending on the category of events and on the values of the various astrophysics and particle-physics parameters. A final analysis is focused on the upward muon fluxes which could be generated by those neutralino configurations which are able to explain the annual modulation data of the DAMA/LIBRA experiment. We show how combining these data with measurements at neutrino telescopes could help in pinning down the features of the dark matter particle and in restraining the ranges of the many quantities (of astrophysics and particle-physics origins) which enter in the evaluations and still suffer from large uncertainties.

We present the first detailed, large-scale study of the minimal supersymmetric standard model (MSSM) at the $\sqrt{s}=500\mathrm{GeV}$ International Linear Collider (ILC), including full standard model backgrounds and detector simulation. This is the first realistic study of the capabilities of the ILC examining the physics of many distinct points in MSSM parameter space which are not linked to a particular supersymmetry (SUSY) breaking mechanism. Specifically, we investigate 242 points in the MSSM parameter space, which we term models, that correspond to the 162 pairs of models that were found by Arkani-Hamed et al. to give indistinguishable signatures at the LHC. We first determine whether the production of the various SUSY particles is visible above the standard model background for each of these parameter space points, and then make a detailed comparison of their various signatures. Assuming an integrated luminosity of $500{\mathrm{fb}}^{-1}$ with 80% electron beam polarization, we find that only 82 out of 242 models lead to visible signatures of some kind with a significance $\ge 5$ and that only 57 (63) out of the 162 model pairs are distinguishable at $5(3)\sigma$. Our analysis includes PYTHIA and CompHEP SUSY signal generation, full matrix element SM backgrounds for all $2\to 2$, $2\to 4$ and $2\to 6$ processes, ILC-specific initial state radiation and beamstrahlung generated via WHIZARD/GuineaPig, and employs the fast SiD detector simulation org.lcsim. If SUSY is light, the ILC will do a good job at examining its details.

It is demonstrated that the light Higgs boson scenario, in which the lightest Higgs mass is less than the LEP bound, $m_h>114.4\mathrm{GeV}$, is consistent with the supersymmetric seesaw model. With the assumptions of the universal right-handed neutrino mass and the hierarchical mass spectrum of the ordinary neutrinos, the bounds for the right-handed neutrino mass are investigated in terms of lepton flavor violating charged lepton decays. We also discuss the effect of the modification of renormalization group equations by the right-handed neutrinos on the $b\to s\gamma$ process and the relic abundance of dark matter in the light Higgs boson scenario.

A multichannel calculation of excited $J^{PC}=1^{--}\varphi$ states is carried out within a generalization of the resonance-spectrum expansion, which may shed light on the classification of the $\varphi (2170)$ resonance, discovered by BABAR and originally denoted $X(2175)$. In this framework, a complete spectrum of bare $s\overline{s}$ states is coupled to those Okubo-Zweig-Iizuka–allowed decay channels that should be most relevant for the considered energy range. The included $S$- and $P$-wave two-meson channels comprise the lowest pseudoscalar, vector, scalar, and axial-vector mesons, while in the $q\overline{q}$ sector both the ${}^{3}S_1$ and ${}^{3}D_1$ states are coupled. The only two free parameters are tuned so as to reproduce mass and width of the $\varphi (1020)$, but come out reasonably close to previously used values. Among the model’s $T$-matrix poles, there are good candidates for observed resonances, as well as other ones that should exist according to the quark model. Besides the expected resonances as unitarized confinement states, a dynamical resonance pole is found at $(2186-i246)\mathrm{MeV}$. The huge width makes its interpretation as the $\varphi (2170)$ somewhat dubious, but further improvements of the model may change this conclusion.

In deep-inelastic processes the heavy flavor Wilson coefficients factorize for $Q^2\gg m^2$ into the light-flavor Wilson coefficients of the corresponding process and the massive operator matrix elements (OMEs). We calculate the $O({\alpha }_s^2)$ and $O({\alpha }_s^3)$ massive OME for the flavor nonsinglet transversity distribution. At $O({\alpha }_s^2)$ the OME is obtained for general values of the Mellin variable $N$, while at $O({\alpha }_s^3)$ the moments $N=1$ to 13 are computed. The terms $\propto T_F$ of the 3-loop transversity anomalous dimension are obtained and results in the literature are confirmed. We discuss the relation of these contributions to the Soffer bound for transversity.

The proton-air cross section in the energy range 1–100 TeV has been measured by the ARGO-YBJ cosmic ray experiment. The analysis is based on the primary cosmic ray flux attenuation for different atmospheric depths (i.e. zenith angles) and exploits the detector capabilities of selecting the shower development stage by means of hit multiplicity, density and lateral profile measurements at ground. The effects of shower fluctuations, the contribution of heavier primaries and the uncertainties of the hadronic interaction models, have been taken into account. The results have been used to estimate the total proton-proton cross section at center-of-mass energies between 70 and 500 GeV, where no accelerator data are currently available.

Solar and KamLAND data are in slight tension when interpreted in the standard two-flavor oscillations framework and this may be alleviated allowing for a nonzero value of the mixing angle ${\theta }_{13}$. Here we show that, likewise, nonstandard flavor-changing interactions (FCI), possibly intervening in the propagation of solar neutrinos, are equally able to alleviate this tension and therefore constitute a potential source of confusion in the determination of ${\theta }_{13}$. By performing a full three-flavor analysis of solar and KamLAND data in presence of FCI we provide a quantitative description of the degeneracy existing between ${\theta }_{13}$ and the vectorial coupling ${ϵ}_{e\tau }^{dV}$ characterizing the nonstandard transitions between ${\nu }_e$ and ${\nu }_{\tau }$ in the forward scattering process with $d$-type quarks. We find that couplings with magnitude ${ϵ}_{e\tau }^{dV}\sim 10\%$, compatible with the existing bounds, can mimic the nonzero values of ${\theta }_{13}$ indicated by the latest analyses.

We report measurements of the exclusive cross section for $e^{+}{e}^{-}\to D^0{D}^{*-}{\pi }^{+}$ as a function of center-of-mass energy from the $D^0{D}^{*-}{\pi }^{+}$ threshold to 5.2 GeV with initial-state radiation. No evidence is found for $Y(4260)\to D^0{D}^{*-}{\pi }^{+}$ decays. The analysis is based on a data sample collected with the Belle detector at or near a center-of-mass energy of 10.58 GeV with an integrated luminosity of $695{\mathrm{fb}}^{-1}$ at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider.

In a recent paper [2] it was shown in examples that the covariant retarded Green’s functions in certain gauges for electromagnetism and linearized gravity can be used to reproduce field configurations correctly in spite of the spacelike nature of past infinity in de Sitter spacetime. In this paper we extend the work of Ref. [2] concerning the electromagnetic field and show that the covariant retarded Green’s function with an arbitrary value of the gauge parameter reproduces the electromagnetic field from two opposite charges at antipodal points of de Sitter spacetime.

For the baby Skyrme model with a specific potential, compacton solutions, i.e., configurations with a compact support and parabolic approach to the vacuum, are derived. Specifically, in the nontopological sector, we find spinning $Q$-balls and $Q$-shells, as well as peakons. Moreover, we obtain compact baby skyrmions with nontrivial topological charge. All these solutions may form stable multisoliton configurations provided they are sufficiently separated.

The recently proposed renormalization scheme based on the definition of field operators as operator valued distributions acting on specific test functions is shown to be very convenient in explicit calculations of physical observables within the framework of light-front dynamics. We first recall the main properties of this procedure based on identities relating the test functions to their Taylor remainder of any order expressed in terms of Lagrange’s formulas, hence the name given to this scheme. We thus show how it naturally applies to the calculation of state vectors of physical systems in the covariant formulation of light-front dynamics. As an example, we consider the case of the Yukawa model in the simple two-body Fock state truncation.

By using a quasistationary approach, we consider the mass evolution of Schwarzschild black holes in the presence of a nonminimally coupled cosmological scalar field. The mass evolution equation is analytically solved for generic coupling, revealing a qualitatively distinct behavior from the minimal coupling case. In particular, for black hole masses smaller than a certain critical value, the accretion of the scalar field can lead to mass decreasing even if no phantom energy is involved. The physical validity of the adopted quasistationary approach and some implications of our result for the evolution of primordial and astrophysical black holes are discussed. More precisely, we argue that black hole observational data could be used to place constraints on the nonminimally coupled energy content of the Universe.

We consider curvature corrections to static, axisymmetric Dirac-Nambu-Goto membranes embedded into a spherically symmetric black hole spacetime with arbitrary number of dimensions. Since the next to leading order corrections in the effective brane action are quadratic in the brane thickness $\ell$, we adopt a linear perturbation approach in ${\ell }^2$. The perturbations are general in the sense that they are not restricted to the Rindler zone nor to the near-critical solutions of the unperturbed system. As a result, an unexpected asymmetry in the perturbed system is found. In configurations, where the brane does not cross the black hole horizon, the perturbative approach does not lead to regular solutions if the number of the brane’s spacetime dimensions $D>3$. This condition, however, does not hold for the horizon crossing solutions. Consequently we argue that the presented perturbative approach breaks down for subcritical type solutions near the axis of the system for $D>3$. Nevertheless, we can discuss topology-changing phase transitions in cases when $D=2$ or 3, i.e. when the brane is a one-dimensional string or a two-dimensional sheet, respectively. For the general case, a different, nonperturbative approach should be sought. Based on the energy properties of those branes that are quasistatically evolved from the equatorial configuration, we illustrate the results of the phase transition in the case of a $D=3$ brane. It is found that small thickness perturbations do not modify the order of the transition, i.e. it remains first order just as in the case of vanishing thickness.

We study generalized Misner-Sharp energy in $f(R)$ gravity in a spherically symmetric space-time. We find that unlike the cases of Einstein gravity and Gauss-Bonnet gravity, the existence of the generalized Misner-Sharp energy depends on a constraint condition in the $f(R)$ gravity. When the constraint condition is satisfied, one can define a generalized Misner-Sharp energy, but it cannot always be written in an explicit quasilocal form. However, such a form can be obtained in a Friedmann-Robertson-Walker universe and for static spherically symmetric solutions with constant scalar curvature. In the Friedmann-Robertson-Walker universe, the generalized Misner-Sharp energy is nothing but the total matter energy inside a sphere with radius $r$, which acts as the boundary of a finite region under consideration. The case of scalar-tensor gravity is also briefly discussed.

Precise measurements of the microwave background anisotropy have confirmed the inflationary picture of approximately scale invariant, Gaussian primordial adiabatic density perturbations. However, there are some anomalies that suggest a small violation of rotational and/or translational invariance in the mechanism that generates the primordial density fluctuations. Motivated by this we study the two-point correlation of a massless scalar (the inflaton) when the stress tensor contains the energy density from an infinitely long straight cosmic string in addition to a cosmological constant.

We study the production of sterile neutrinos in the region $T\sim M_W$ in an extension beyond the standard model with the seesaw mass matrix originating in Yukawa couplings to Higgs-like scalars with masses and vev’s of the order of the electroweak scale. Sterile neutrinos are produced by the decay of scalars and standard model vector bosons. We obtain the index of refraction, dispersion relations, mixing angles in the medium and production rates including those for right-handed sterile neutrinos, from the standard model and beyond the standard model self-energies. For $1\lesssim M_W/T\lesssim 3$ we find narrow MSW resonances with $k\lesssim T$ for both left- and right-handed neutrinos even in absence of a lepton asymmetry in the (active) neutrino sector, as well as very low energy ($k/T\ll |\xi |$) narrow MSW resonances in the presence of a lepton asymmetry consistent with the bounds from Wilkinson Microwave Anisotropy Probe and Big Bang Nucleosynthesis. For small vacuum mixing angle, consistent with observational bounds, the absorptive part of the self-energies lead to a strong damping regime very near the resonances resulting in the exact degeneracy of the propagating modes with a concomitant breakdown of adiabaticity. We argue that cosmological expansion sweeps through the resonances, resonant and nonresonant sterile neutrino production results in a highly nonthermal distribution function enhanced at small momentum $k<T$, with potentially important consequences for their free-streaming length and transfer function at small scales.

The rise in the energy spectrum of the positron ratio, observed by the PAMELA satellite above 10 GeV, and other cosmic-ray measurements, have been interpreted as a possible signature of dark matter annihilation in the Galaxy. However, the large number of free parameters, and the large astrophysical uncertainties, make it difficult to draw conclusive statements about the viability of this scenario. Here, we perform a multiwavelength, multimessenger analysis, that combines in a consistent way the constraints arising from different astrophysical observations. We show that if standard assumptions are made for the distribution of dark matter (we build models on the recent Via Lactea II and Aquarius simulations) and the propagation of cosmic rays, current dark matter models cannot explain the observed positron flux without exceeding the observed fluxes of antiprotons or gamma-ray and radio photons. To visualize the multimessenger constraints, we introduce “star plots,” a graphical method that shows in the same plot theoretical predictions and observational constraints for different messengers and wavelengths.

We identify a variety of coannihilation scenarios in a supersymmetric $SU(4{)}_c\times SU(2{)}_L\times SU(2{)}_R$ model with discrete left-right symmetry. Nonuniversal gaugino masses, compatible with the gauge symmetry, play an essential role in realizing gluino and bino-wino coannihilation regions that are consistent with the WMAP dark matter constraints. We also explore regions of the parameter space in which the little hierarchy problem is partially resolved. We present several phenomenologically interesting benchmark points and the associated sparticle and Higgs mass spectra.

We perform a systematic study of the effects of the type-I seesaw mechanism on the dark matter abundance in the constrained minimal supersymmetric standard model (CMSSM) which includes three right-handed neutrinos (the $\nu \mathrm{CMSSM}$). For large values of $m_0$, $m_{1/2}$, we exploit the effects of large neutrino Yukawa couplings on the renormalization group evolution of the up-type Higgs. In particular, we show that the focus point scale can greatly exceed the electroweak scale resulting in the absence of a focus point region for which the relic density of neutralinos is within the range determined by WMAP. We also discuss the effects of the right-handed neutrinos on the so-called funnel region, where the relic density is controlled by $s$-channel annihilations through a heavy Higgs. For small values of $m_0$, $m_{1/2}$, we discuss the possibility of sneutrino coannihilation regions with an emphasis on the suppression of the left-handed slepton doublet masses due to the neutrino Yukawa coupling. We consider two types of toy models consistent with either the normal or inverted hierarchy of neutrino masses.