We study $s$-wave bound states of a hadron and a light pseudoscalar meson induced by the Weinberg-Tomozawa (WT) interaction in the flavor SU(3) symmetric limit. The WT interaction is a driving force to generate quasibound states dynamically in the chiral unitary approaches. The strength and sign of the WT interaction are determined only by the group theoretical structure of the target hadrons, and we present a general expression of the strengths for the flavor SU(3) case. We show that, for the channels which are more exotic than the target, the interaction is repulsive in most cases, and the strength of the attractive interaction is universal for any possible target states. We demonstrate that the attractive coupling is not strong enough to generate an exotic state from the physically known masses of target hadrons. In addition, we also find a nontrivial $N_c$ dependence of the coupling strengths. We show that the channels which are attractive at $N_c=3$ change into repulsive ones for large $N_c$, and, therefore, no attractive interaction exists in exotic channels in the large-$N_c$ limit.

We consider a nonsupersymmetric extension of the standard model with a family symmetry based on $D_6\times Z_2\times Z_2$, where one of $Z_2$’s is exactly conserved. This $Z_2$ forbids the tree-level neutrino masses and simultaneously ensures the stability of cold dark matter candidates. From the assumption that cold dark matter is fermionic we can single out the $D_6$ singlet right-handed neutrino as the best cold dark matter candidate. We find that an inert charged Higgs with a mass between 300 and 750 GeV decays mostly into an electron (or a positron) with a large missing energy, where the missing energy is carried away by the cold dark matter candidate. This will be a clean signal at LHC.

We report a measurement of the inclusive electron energy spectrum for charmed semileptonic decays of $B$ mesons in a $140{\mathrm{fb}}^{-1}$ data sample collected at the ${\rm Y}(4S)$ resonance with the Belle detector at the KEKB asymmetric energy $e^{+}{e}^{-}$ collider. We determine the first four moments of the electron energy spectrum for threshold values of the electron energy between 0.4 and 2.0 GeV. In addition, we provide values of the partial branching fraction (zeroth moment) for the same electron threshold energies, and independent measurements of the $B^{+}$ and $B^0$ partial branching fractions at 0.4 GeV and 0.6 GeV electron threshold energies. We measure the independent $B^{+}$ and $B^0$ partial branching fractions with electron threshold energies of 0.4 GeV to be $\Delta \mathcal{B}(B^{+}\to X_{c}e\nu )=(10.79\pm 0.25(\mathrm{stat}.)\pm 0.27(\mathrm{sys}.))\%$ and $\Delta \mathcal{B}(B^0\to X_{c}e\nu )=(10.08\pm 0.30(\mathrm{stat}.)\pm 0.22(\mathrm{sys}.))\%$. Full correlations between all measurements are evaluated.

The Higgs potential of 2HDM keeps its generic form under the group of transformation $GL(2,C)$, which is larger than the usually considered reparametrization group $SU(2)$. This reparametrization symmetry induces the Minkowski space structure in the orbit space of 2HDM. Exploiting this property, we present a geometric analysis of the number and properties of stationary points of the most general 2HDM potential. In particular, we prove that charge-breaking and neutral vacua never coexist in 2HDM and establish conditions when the most general explicitly $CP$-conserving Higgs potential has spontaneously $CP$-violating minima. We also define the prototypical model of a given 2HDM, which has six free parameters less than the original one but still contains all the essential physics. Our analysis avoids manipulation with high-order algebraic equations.

A set of new, precise data have recently been made available by the NA49 Collaboration for charged pion production in proton-proton and proton-Carbon reactions at 158 GeV. The current paper compares this new data to five currently available arithmetic parameterizations. Although a precise fit is not expected, two of the parameterizations do not work very well but the other three are able to provide a moderately good, but not precise fit to the proton-proton data. The best two of these three parameterizations are scaled to the proton-Carbon data and again provide a moderately good, but not precise fit.

Minor errors are corrected in several equations. The corrections do not change the conclusions, but for completeness the conclusions are restated more explicitly.

We study the Casimir contribution to the bag energy coming from gluon field fluctuations, within the context of the stochastic vacuum model of pure QCD. After formulating the problem in terms of the generating functional of field strength cumulants, we argue that the resulting predictions about the Casimir energy are compatible with the phenomenologically required bag energy term.

We examine factorization in the connected prescription of Yang-Mills amplitudes. The multiparticle pole is interpreted as coming from representing delta functions as meromorphic functions. However, a naive evaluation does not give a correct result. We give a simple prescription for the integration contour which does give the correct result. We verify this prescription for a family of gauge-fixing conditions.

We discuss the covariant formulation of the dynamics of particles with Abelian and non-Abelian gauge charges in external fields. Using this formulation we develop an algorithm for the construction of constants of motion, which makes use of a generalization of the concept of Killing vectors and tensors in differential geometry. We apply the formalism to the motion of classical charges in Abelian and non-Abelian monopole fields.

We calculate the greybody factors for scalar, vector and graviton fields in the background of an exact black hole localized on a tensional 3-brane in a world with two large extra dimensions. Finite brane tension modifies the standard results for the case with of a black hole on a brane with negligible tension. For a black hole of a fixed mass, the power carried away into the bulk diminishes as the tension increases, because the effective Planck constant, and therefore entropy of a fixed mass black hole, increase. In this limit, the semiclassical description of black hole decay becomes more reliable.

We study the phase space of the spherically symmetric solutions of the system obtained from the dimensional reduction of the six-dimensional Einstein-Gauss-Bonnet action with a cosmological constant. We show that all the physical solutions have anti-de Sitter asymptotic behavior.

We calculate the total flux of Hawking radiation from Kerr-(anti)de Sitter black holes by using gravitational anomaly method developed in [S. P. Robinson and F. Wilczek, Phys. Rev. Lett. 95, 011303 (2005)]. We consider the general Kerr-(anti)de Sitter black holes in arbitrary $D$ dimensions with the maximal number $[D/2]$ of independent rotating parameters. We find that the physics near the horizon can be described by an infinite collection of ($1+1$)-dimensional quantum fields coupled to a set of gauge fields with charges proportional to the azimuthal angular momentums $m_i$. With the requirement of anomaly cancellation and regularity at the horizon, the Hawking radiation is determined.

The contributions of supersymmetric particles in the isospin symmetry violation in $B\to K^{*}\gamma$ decay mode are investigated. The model parameters are adopted from minimal Supergravity with minimal flavor violation. A complete scan of the mSUGRA parameter space has been performed, using the next to leading supersymmetric contributions to the relevant Wilson coefficients. The results are compared to recent experimental data in order to obtain constraints on the parameter space. We point out that isospin asymmetry can prove to be an interesting observable and imposes severe restrictions on the allowed parameter space, in particular, for large values of $\tan \beta$. The constraints obtained with isospin asymmetry also appear as more restricting than the ones from the branching ratio of $B\to X_s\gamma$.

We calculate the eigenvalue distribution of the Faddeev-Popov operator in Coulomb gauge QCD using quenched SU(3) lattice simulation. In the confinement phase, the density of the low-lying eigenvalues increases with lattice volume, and the confinement criterion is satisfied. Moreover, even in the deconfinement phase, the behavior of the FP eigenvalue density is qualitatively the same as in the confinement phase. This is consistent with the fact that the color-Coulomb potential is not screened in the deconfined phase.

We calculate the cross section of charm photoproduction at HERA collider in the framework of the $k_T$-factorization QCD approach. Our analysis covers the inclusive charm production as well as charm and associated jet production processes. Both photon-gluon and gluon-gluon fusion mechanisms are taken into account. The unintegrated gluon densities in a proton and in a photon obtained from the full Ciafaloni-Catani-Fiorani-Marchesini (CCFM), from unified Balitsky-Fadin-Kuraev-Lipatov–Dokshitzer-Gribov-Lipatov-Altarelli-Parizi evolution equations as well as from the Kimber-Martin-Ryskin prescription are used. Our theoretical results are compared with the recent experimental data taken by the H1 and ZEUS collaborations at HERA. Special attention is put on the specific angular correlations which can provide unique information about noncollinear gluon evolution dynamics.

Dirac leptogenesis (or Dirac neutrinogenesis), in which neutrinos are purely Dirac particles, is an interesting alternative to the standard leptogenesis scenario. In its supersymmetric version, the modified form of the superpotential required for successful baryogenesis contributes new, generically nonflavor-diagonal terms to the slepton and sneutrino mass matrices. In this work, we examine how current experimental bounds on flavor-changing effects in the lepton sector (and particularly the bound on $\mu \to e\gamma$) constrain Dirac leptogenesis and we find that it is capable of succeeding with superpartner masses as low as $\sim 100\mathrm{GeV}$. For such light scalars and electroweakinos, upcoming experiments such as MEG are generically expected to observe signals of lepton flavor violation.

We consider an action for an Abelian gauge field for which the density is given by a power of the Maxwell Lagrangian. In $d$ spacetime dimensions this action is shown to enjoy conformal invariance if the power is chosen as $d/4$. We take advantage of this conformal invariance to derive black hole solutions electrically charged with a purely radial electric field. Since we are considering a power of the Maxwell density, the black hole solutions exist only for dimensions which are multiples of four. The expression for the electric field does not depend on the dimension and corresponds to the four-dimensional Reissner-Nordström field. Using the Hamiltonian action we identify the mass and the electric charge of these black hole solutions.

This is a study of the phenomenology of the neutralino dark matter in the so called deflected anomaly mediation scenario. This scheme is obtained from the minimal anomaly-mediated scenario by introducing a gauge-mediated sector with $N_f$ messenger fields. Unlike the former scheme the latter has no tachyons. We find that the neutralino is still the LSP in a wide region of the parameter space: it is essentially a pure bino in the scenario with $N_f=1$ while it can also be a pure Higgsino for $N_f>1$. This is very different from the naive anomaly-mediated scenario which predicts a wino like neutralino. Moreover we do not find any tachyonic scalars in this scheme. After computing the relic density (considering all the possible coannihilations) we find that there are regions in the parameter space with values compatible with the latest WMAP results with no need to consider moduli fields that decay in the early universe.