We argue that a nonthermal leptogenesis occurs spontaneously, without direct couplings of the inflaton with right-handed neutrinos, in a wide class of high-scale inflation models such as the chaotic and hybrid inflation. It is only a finite vacuum expectation value of the inflaton, or more precisely, a linear term in the Kähler potential, that is a prerequisite for the spontaneous nonthermal leptogenesis. To exemplify how it works, we show that a chaotic inflation model in supergravity naturally produces a right amount of baryon asymmetry via the spontaneous nonthermal leptogenesis. We also discuss the gravitino production from the inflaton.

High resolution cosmological N-body simulations of four galaxy-scale dark matter halos are compared to corresponding N-body/hydrodynamical simulations containing dark matter, stars and gas. The simulations without baryons share features with others described in the literature in that the dark matter density slope continuously decreases towards the center, with a density ${\rho }_{\mathrm{DM}}\propto r^{-1.3\pm 0.2}$, at about 1% of the virial radius for our Milky Way sized galaxies. The central cusps in the simulations which also contain baryons steepen significantly, to ${\rho }_{\mathrm{DM}}\propto r^{-1.9\pm 0.2}$, with an indication of the inner logarithmic slope converging. Models of adiabatic contraction of dark matter halos due to the central buildup of stellar/gaseous galaxies are examined. The simplest and most commonly used model, by Blumenthal et al., is shown to overestimate the central dark matter density considerably. A modified model proposed by Gnedin et al. is tested and it is shown that, while it is a considerable improvement, it is not perfect. Moreover, it is found that the contraction parameters in their model not only depend on the orbital structure of the dark-matter–only halos but also on the stellar feedback prescription which is most relevant for the baryonic distribution. Implications for dark matter annihilation at the galactic center are discussed and it is found that, although our simulations show a considerable reduced dark matter halo contraction as compared to the Blumenthal et al. model, the fluxes from dark matter annihilation are still expected to be enhanced by at least a factor of a hundred, as compared to dark-matter–only halos. Finally, it is shown that, while dark-matter–only halos are typically prolate, the dark matter halos containing baryons are mildly oblate with minor-to-major axis ratios of $c/a=0.73\pm 0.11$, with their flattening aligned with the central baryonic disks.

We examine statistical isotropy of large scale anisotropies of the Internal Linear Combination (ILC) map, based on 3 yr WMAP data. Our study reveals no significant deviation from statistical isotropy on large angular scales of the 3 yr ILC map. Comparing statistical isotropy of the 3 yr ILC map and 1 yr ILC map, we find a significant improvement in the 3 yr ILC map which can be due to the gain model, improved ILC map processing, and foreground minimization.

We compute the leading order contribution to the four-point function of the primordial curvature perturbation in a class of single field models where the inflationary Lagrangian is a general function of the inflaton and its first derivative. This class of models includes string motivated inflationary models such as DBI inflation. We find that the trispectrum for some range of parameters could potentially be observed in future experiments. Moreover, the trispectrum can distinguish DBI inflation from other inflation models with large non-Gaussianities which typically have a similar bispectrum. We also derive a set of consistency conditions for $n$-point functions of the primordial curvature perturbation in single field inflation, generalizing Maldacena’s result for 3-point functions.

We consider Lorentz violation in supersymmetric extensions of the standard model. We perform a spurion analysis to show that, in the simplest natural constructions, the resulting supersymmetry-breaking masses are tiny. In the process, we argue that one of the strongest bounds on Lorentz violation in the photon Lagrangian, which comes from the absence of birefringence from distant astrophysical sources, does not apply when Lorentz violation is parametrized by a single vector.

In the framework of various statistical models as well as of mechanisms for color confinement, disorder parameters can be developed which are generally expressed as ratios of partition functions and whose numerical determination is usually challenging. We develop an efficient method for their computation and apply it to the study of dual superconductivity in 4D compact $U(1)$ gauge theory.

In this paper we use an exact method to impose unitarity on moduli of neutrino PMNS matrix recently determined, and show how one could obtain information on $CP$ nonconservation from a limited experimental information. One suggests a novel type of global fit by expressing all theoretical quantities in terms of convention independent parameters: the Jarlskog invariant $J$ and the moduli $|U_{\alpha i}|$, able to resolve the positivity problem of $|U_{e3}|$. In this way the fit will directly provide a value for $J$, and if it is different from zero it will prove the existence of $CP$ violation in the available experimental data. If the best-fit result, $|U_{e3}{|}^2<0$, from M. Maltoni et al., [New J. Phys. 6, 122 (2004)] is confirmed, it will imply a new physics in the leptonic sector.

We investigate the lepton flavor violating (LFV) rare decays in the supersymmetric minimal seesaw model in which the Frampton-Glashow-Yanagida ansatz is incorporated. The branching ratio of $\mu \to e\gamma$ is calculated in terms of the snowmass points and slopes (SPS). We find that the inverted mass hierarchy is disfavored by all SPS points. In addition, once the ratio of $\mathrm{BR}(\tau \to \mu \gamma )$ to $\mathrm{BR}(\mu \to e\gamma )$ is measured, one may distinguish the normal and inverted neutrino mass hierarchies, and confirm the masses of heavy right-handed Majorana neutrinos by means of the LFV processes and the thermal leptogenesis mechanism. It is worthwhile to stress that this conclusion is independent of the supersymmetric parameters.

We report the first observation of the decay $B^{+}\to {\overline{\Xi }}_c^0{\Lambda }_c^{+}$ with a significance of $8.7\sigma$ and evidence for the decay $B^0\to {\overline{\Xi }}_c^{-}{\Lambda }_c^{+}$ with a significance of $3.8\sigma$. The product $\mathcal{B}(B^{+}\to {\overline{\Xi }}_c^0{\Lambda }_c^{+})\times \mathcal{B}({\overline{\Xi }}_c^0\to {\overline{\Xi }}^{+}{\pi }^{-})$ is measured to be $({4.8}_{-0.9}^{+1.0}\pm 1.1\pm 1.2)\times {10}^{-5}$, and $\mathcal{B}(B^0\to {\overline{\Xi }}_c^{-}{\Lambda }_c^{+})\times \mathcal{B}({\overline{\Xi }}_c^{-}\to {\overline{\Xi }}^{+}{\pi }^{-}{\pi }^{-})$ is measured to be $({9.3}_{-2.8}^{+3.7}\pm 1.9\pm 2.4)\times {10}^{-5}$. The errors are statistical, systematic and the error of the ${\Lambda }_c^{+}\to p{K}^{-}{\pi }^{+}$ branching fraction, respectively. The decay $B^{+}\to {\overline{\Xi }}_c^0{\Lambda }_c^{+}$ is the first example of a two-body exclusive $B^{+}$ decay into two charmed baryons. The data used for this analysis was accumulated at the ${\rm Y}(4S)$ resonance, using the Belle detector at the $e^{+}{e}^{-}$ asymmetric-energy collider KEKB. The integrated luminosity of the data sample is equal to $357{\mathrm{fb}}^{-1}$, corresponding to $386\times {10}^6$ $B\overline{B}$ pairs.

We report measurements of $CP$ violation parameters in $B^0\to K_S^0{\pi }^0\gamma$ transitions based on a data sample of $535\times {10}^{6}B\overline{B}$ pairs collected with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. One neutral $B$ meson is fully reconstructed in the $B^0\to K_S^0{\pi }^0\gamma$ mode. The flavor of the accompanying $B$ meson is identified from its decay products. We obtain time-dependent and direct $CP$ violation parameters $\mathcal{S}$ and $\mathcal{A}$ for a $K_S^0{\pi }^0$ invariant mass up to $1.8\mathrm{GeV}/c^2$ as ${\mathcal{S}}_{K_S^0{\pi }^0\gamma }=-0.10\pm 0.31\pm 0.07$ and ${\mathcal{A}}_{K_S^0{\pi }^0\gamma }=-0.20\pm 0.20\pm 0.06$. For a $K_S^0{\pi }^0$ invariant mass near the $K^{*0}(892)$ resonance, we obtain ${\mathcal{S}}_{K^{*0}\gamma }=-{0.32}_{-0.33}^{+0.36}\pm 0.05$ and ${\mathcal{A}}_{K^{*0}\gamma }=-0.20\pm 0.24\pm 0.05$.

We study the possibility of forming the false vacuum bubble nucleated within the true vacuum background via the true-to-false vacuum phase transition in curved spacetime. We consider a semiclassical Euclidean bubble in the Einstein theory of gravity with a nonminimally coupled scalar field. In this paper we present the numerical computations as well as the approximate analytical computations. We mention the evolution of the false vacuum bubble after nucleation.

The variations of the apparent vertical direction of the gravity field were measured with horizontal gravimeters acting as tilt meters during the total solar eclipse in Turkey in March 29, 2006. Three separated locations within the path of totality were chosen for observations, two spaced apart along the center line, and one off the center line. No anomaly was observed at the furthest location from the center line. Aperiodic oscillations in tilt were recorded at the two locations on the center line. These may be related to the eclipse phenomenon. The average tilt amplitude deviation during the eclipse over all locations and in all directions was 150 nrad, which can be regarded as a mean upper limit for the eclipse related changes in the tilt.

We study the collider phenomenology of a littlest Higgs model with T parity. We first stress the important role of the T-odd $SU(2)$-doublet fermions (introduced to make the model T-parity invariant) in high energy scattering processes, such as $q\overline{q}\to W_H^{+}{W}_H^{-}$ where $W_H^{\pm }$ are the T-odd partners of $W$ bosons. Because the mass of the T-odd $SU(2)$-doublet fermions cannot be too heavy to be consistent with low energy data, they can be copiously produced at the CERN Large Hadron Collider (LHC). Therefore, we study the collider phenomenology of the model with emphasis on the contributions of the T-odd fermion to the production of the heavy T-parity partners (either bosons or fermions) of the usual particles at the LHC. The production cross sections and the decay branching ratios of the new heavy particles are classified and various experimental signatures are discussed.

We present skeleton-motivated evaluation of QCD observables. The approach can be applied in analytic versions of QCD in certain classes of renormalization schemes. We present two versions of analytic QCD which can be regarded as low-energy modifications of the “minimal” analytic QCD and which reproduce the measured value of the semihadronic $\tau$ decay ratio $r_{\tau }$. Further, we describe an approach of calculating the higher-order analytic couplings ${\mathcal{A}}_k$ $(k=2,3,\dots )$ on the basis of logarithmic derivatives of the analytic coupling ${\mathcal{A}}_1(Q^2)$. This approach can be applied in any version of analytic QCD. We adjust the free parameters of the aforementioned two analytic models in such a way that the skeleton-motivated evaluation reproduces the correct known values of $r_{\tau }$ and of the Bjorken polarized sum rule (BjPSR) $d_b(Q^2)$ at a given point (e.g., at $Q^2=2{\mathrm{GeV}}^2$). We then evaluate the low-energy behavior of the Adler function $d_v(Q^2)$ and the BjPSR $d_b(Q^2)$ in the aforementioned evaluation approach, in the three analytic versions of QCD. We compare with the results obtained in the minimal analytic QCD and with the evaluation approach of Milton et al. and Shirkov.

The branching ratio of $B^{-}\to h_c+K^{-}$ is re-evaluated in the PQCD approach. In this theoretical framework all the phenomenological parameters in the wave functions and Sudakov factor are priori fixed by fitting other experimental data, and in the whole numerical computations we do not introduce any new parameter. Our results are consistent with the upper bounds set by the BABAR and Belle measurements.

We measure the inclusive branching fractions of charm mesons into three mesons with large $s\overline{s}$ content, namely, the $\eta$, ${\eta }^{\prime }$ and $\varphi$. Data were accumulated with the CLEO-c detector. For $D^0$ and $D^{+}$ rates, we use $281{\mathrm{pb}}^{-1}$ taken on the $\psi (3770)$ resonance, and for $D_s^{+}$ rates, we use $195{\mathrm{pb}}^{-1}$ taken at 4170 MeV. We find that the production rates of these particles are larger in $D_s^{+}$ decays than in $D^0$ and $D^{+}$ decays. The $\varphi$ rate, in particular, is 15 times greater. These branching fractions can be used to measure $B_s$ yields either at the ${\rm Y}(5S)$ resonance or at hadron colliders.

Extrapolating the coupling strengths to very high energies, one finds that they do not converge to a single coupling constant, as expected in the simplest gauge theory of grand unification, the $SU(5)$ theory. We find that the coupling constants do converge, provided that two new intermediate energy scales are introduced, the energies where the group $SU(4)$, containing the color group, and the right-isospin gauge group are spontaneously broken down.

Using optimized perturbation theory, we evaluate the effective potential for the massless two-dimensional Gross-Neveu model at finite temperature and density containing corrections beyond the leading large-$N$ contribution. For large $N$, our results exactly reproduce the well-known $1/N$ leading order results for the critical temperature, chemical potential, and tricritical points. For finite $N$, our critical values are smaller than the ones predicted by the large-$N$ approximation and seem to observe Landau’s theorem for phase transitions in one space dimension. New analytical results are presented for the tricritical points that include $1/N$ corrections. The easiness with which the calculations and renormalization are carried out allied to the seemingly convergent optimized results displayed, in this particular application, show the robustness of this method and allows us to obtain neat analytical expressions for the critical as well as tricritical values beyond the results currently known.

The mean field (MF) approximation for the pion matter, being equivalent to the leading order chiral perturbation theory, involves no dynamical loops and, if self-consistent, produces finite renormalizations only. The weight factor of the Haar measure of the pion fields, entering the path integral, generates an effective Lagrangian $\delta {\mathcal{L}}_H$ which is generally singular in the continuum limit. There exists only one parametrization of the pion fields, for which the weight factor is equal to unity and $\delta {\mathcal{L}}_H=0$, respectively. This unique parametrization ensures self-consistency of the MF approximation. We use it to calculate thermal Green functions of the pion gas in the MF approximation as a power series over the density. The Borel transforms of thermal averages of a function $\mathcal{J}({\chi }^{\alpha }{\chi }^{\alpha })$ of the pion fields ${\chi }^{\alpha }$ with respect to the scalar pion density are found to be $\frac{2}{\sqrt{\pi }}\mathcal{J}(4t)$. The perturbation series over the scalar pion density for basic characteristics of the pion matter, such as the pion propagator, the pion optical potential, the scalar quark condensate $⟨\overline{q}q⟩$, the in-medium pion decay constant $\tilde{F}$, and the equation of state of pion matter, appear to be asymptotic ones. These series are summed up using the contour-improved Borel resummation method. The quark scalar condensate decreases smoothly until $T_{\max }\simeq 310\mathrm{MeV}$. The temperature $T_{\max }$ is the maximum temperature admissible for the thermalized nonlinear sigma model at zero pion chemical potentials. The estimate of $T_{\max }$ is above the chemical freeze-out temperature $T\simeq 170\mathrm{MeV}$ in relativistic heavy-ion collisions and above the phase transition to two-flavor quark matter $T_c\simeq 175\mathrm{MeV}$, predicted by lattice gauge theories.

Several ways of computing the radiative corrections to the heavy boson masses in Kaluza-Klein theory are discussed. It is argued that only an intrinsically higher dimensional approach embodies all the desired physical properties. This contradicts earlier results in the literature.