We report a measurement of time-integrated $CP$-violation asymmetries in the resonant substructure of the three-body decay $D^0\to K_S^0{\pi }^{+}{\pi }^{-}$ using CDF II data corresponding to $6.0{\mathrm{fb}}^{-1}$ of integrated luminosity from Tevatron $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$. The charm mesons used in this analysis come from $D^{*+}(2010)\to D^0{\pi }^{+}$ and $D^{*-}(2010)\to {\overline{D}}^0{\pi }^{-}$, where the production flavor of the charm meson is determined by the charge of the accompanying pion. We apply a Dalitz-amplitude analysis for the description of the dynamic decay structure and use two complementary approaches, namely, a full Dalitz-plot fit employing the isobar model for the contributing resonances and a model-independent bin-by-bin comparison of the $D^0$ and ${\overline{D}}^0$ Dalitz plots. We find no $CP$-violation effects and measure an asymmetry of $A_{CP}=(-0.05\pm 0.57(\mathrm{stat})\pm 0.54(\mathrm{syst}))\%$ for the overall integrated $CP$-violation asymmetry, consistent with the standard model prediction.

This report describes a search for associated production of $W$ and Higgs bosons based on data corresponding to an integrated luminosity of $\mathcal{L}\approx 5.3\mathrm{f}{\mathrm{b}}^{-1}$ collected with the D0 detector at the Fermilab Tevatron $p\overline{p}$ Collider. Events containing a $W\to \ell \nu$ candidate (with $\ell$ corresponding to $e$ or $\mu$) are selected in association with two or three reconstructed jets. One or two of the jets are required to be consistent with having evolved from a $b$ quark. A multivariate discriminant technique is used to improve the separation of signal and backgrounds. Expected and observed upper limits are obtained for the product of the $WH$ production cross section and branching ratios and reported in terms of ratios relative to the prediction of the standard model as a function of the mass of the Higgs boson ($M_H$). The observed and expected 95% C.L. upper limits obtained for an assumed $M_H=115\mathrm{GeV}$ are, respectively, factors of 4.5 and 4.8 larger than the value predicted by the standard model.

We propose to investigate various charmonium states using their common decay channel to $p\overline{p}$ at LHC. Having the branching ratios for charmonium decaying into the $p\overline{p}$ final state measured or calculated, we propose to measure the charmonium production rate for both hadroproduction, including soft-diffraction, and inclusive production from $b$-hadron decays. We discuss the theoretical impacts in QCD of measuring different charmonium production rates and also the experimental prospects at LHCb, in particular, those for yet unmeasured ${\eta }_c$ and $h_c$.

In the framework of $SO(10)$ gauge unification and the seesaw mechanism, we show that the upper bound on the mass of the heaviest right-handed neutrino $M_{R_3}<3\times {10}^{11}\mathrm{GeV}$, given by the Pati-Salam intermediate scale of $B\mathrm{\text{−}}L$ spontaneous symmetry breaking, constrains the observables related to the left-handed light neutrino mass matrix. We assume such an upper limit on the masses of right-handed neutrinos and, as a first approximation, a Cabibbo form for the matrix $V^L$ that diagonalizes the Dirac neutrino matrix $m_D$. Using the inverse seesaw formula, we show that our hypotheses imply a triangular relation in the complex plane of the light neutrino masses with the Majorana phases. We obtain normal hierarchy with an absolute scale for the light neutrino spectrum. Two regions are allowed for the lightest neutrino mass $m_1$ and for the Majorana phases, implying predictions for the neutrino mass measured in Tritium decay and for the double beta decay effective mass $|⟨m_{ee}⟩|$.

We evaluate in detail the string scattering amplitude to compute different interactions of two massless scalars, one tachyon and one closed string Ramond-Ramond field in type II super string theory. In particular we find two scalar field and two tachyon couplings to all orders of ${\alpha }^{\prime }$ up to on-shell ambiguity. We then obtain the momentum expansion of this amplitude and apply this infinite number of couplings to actually check that the infinite number of tachyon poles of the $S$-matrix element of this amplitude for the $p=n$ case (where $p$ is the spatial dimension of a ${\mathrm{D}}_p$-brane and $n$ is the rank of a Ramond-Ramond field strength) to all orders of ${\alpha }^{\prime }$ is precisely equal to the infinite number of tachyon poles of the field theory. In addition to confirming the couplings of the closed string Ramond-Ramond field to the world-volume gauge field and scalar fields including commutators, we also propose an extension of the Wess-Zumino action which naturally reproduces these new couplings in field theory such that they could be confirmed with direct $S$-matrix computations. Finally we show that the infinite number of massless poles and contact terms of this amplitude for the $p=n+1$ case can be reproduced by Chern-Simons, higher-derivative corrections of the Wess-Zumino, and symmetrized trace tachyon DBI actions.

We study the scalar fields of the five-dimensional $\mathcal{N}=2$ hypermultiplets using the method of symplectic covariance developed in previous work. For static spherically symmetric backgrounds, we show that exactly two possibilities exist. One of them is a Bogomol’nyi-Prasad-Sommerfeld zero-brane carrying charge under the hypermultiplets. We find an explicitly symplectic solution of the fields in this background and derive the conditions required for a full spacetime understanding.

The emission of gravitational waves is studied for a system of massive objects interacting on hyperbolic orbits within the quadrupole approximation following the work of Capozziello et al. Here we focus on the derivation of an analytic formula for the energy spectrum of the emitted waves. We checked numerically that our formula is in agreement with the two limiting cases for which results were already available: for the eccentricity $\epsilon =1$, the parabolic case whose spectrum was computed by Berry and Gair, and the large $\epsilon$ limit with the formula given by Turner.

Planck scale physics may influence the evolution of cosmological fluctuations in the early stages of cosmological evolution. Because of the quasiexponential redshifting, which occurs during an inflationary period, the physical wavelengths of comoving scales that correspond to the present large-scale structure of the Universe were smaller than the Planck length in the early stages of the inflationary period. This trans-Planckian effect was studied before using toy models. The Horava-Lifshitz (HL) theory offers the chance to study this problem in a candidate UV complete theory of gravity. In this paper we study the evolution of cosmological perturbations according to HL gravity assuming that matter gives rise to an inflationary background. As is usually done in inflationary cosmology, we assume that the fluctuations originate in their minimum energy state. In the trans-Planckian region the fluctuations obey a nonlinear dispersion relation of Corley-Jacobson type. In the “healthy extension” of HL gravity there is an extra degree of freedom which plays an important role in the UV region but decouples in the IR, and which influences the cosmological perturbations. We find that in spite of these important changes compared to the usual description, the overall scale invariance of the power spectrum of cosmological perturbations is recovered. However, we obtain oscillations in the spectrum as a function of wave number with a relative amplitude of order unity and with an effective frequency which scales nonlinearly with wave number. Taking the usual inflationary parameters we find that the frequency of the oscillations is so large as to render the effect difficult to observe.

Primordial black holes (PBHs) can form in the early Universe from the collapse of large density fluctuations. Tight observational limits on their abundance constrain the amplitude of the primordial fluctuations on very small scales which cannot otherwise be constrained, with PBHs only forming from the extremely rare large fluctuations. The number of PBHs formed is therefore sensitive to small changes in the shape of the tail of the fluctuation distribution, which itself depends on the amount of non-Gaussianity present. We study, for the first time, how quadratic and cubic local non-Gaussianity of arbitrary size (parametrized by $f_{\mathrm{NL}}$ and $g_{\mathrm{NL}}$ respectively) affects the PBH abundance and the resulting constraints on the amplitude of the fluctuations on very small scales. Intriguingly we find that even nonlinearity parameters of order unity have a significant impact on the PBH abundance. The sign of the non-Gaussianity is particularly important, with the constraint on the allowed fluctuation amplitude tightening by an order of magnitude as $f_{\mathrm{NL}}$ changes from just $-0.5$ to 0.5. We find that if PBHs are observed in the future, then regardless of the amplitude of the fluctuations, non-negligible negative $f_{\mathrm{NL}}$ would be ruled out. Finally we show that $g_{\mathrm{NL}}$ can have an even larger effect on the number of PBHs formed than $f_{\mathrm{NL}}$.

A fundamental problem of cosmic ray (CR) physics is the determination of the average properties of Galactic CRs outside the Solar system. Starting from COS-B data in the 1980s, gamma-ray observations of molecular clouds in the Gould Belt above the Galactic plane have been used to deduce the Galactic CR energy spectrum. We reconsider this problem in view of the improved precision of observational data, which in turn require a more precise treatment of photon production in proton-proton scatterings. We show that the spectral shape $dN/dp\propto p^{-2.85}$ of CR protons as determined by the PAMELA Collaboration in the energy range $80\mathrm{GeV}<p\mathrm{c}<230\mathrm{GeV}$ is consistent with the photon spectra from molecular clouds observed with Fermi-LAT down to photon energies $E\sim 1–2\mathrm{GeV}$. Adding a break of the CR flux at 3 GeV, caused by a corresponding change of the diffusion coefficient, improves further the agreement in the energy range 0.2–3 GeV.

We discuss the feasibility of using solar-type main-sequence stars as probes of fundamental physics and unification. We use a simple polytropic stellar structure model and study its sensitivity to variations of the gravitational, strong and electroweak coupling constants in the context of unification scenarios. We quantify the sensitivity of the Sun’s interior temperature to these variations, finding $|\Delta \alpha /\alpha |\lesssim 1.3\times {10}^{-4}$ for a “canonical” choice of unification scenario, and discuss prospects for future improvements.

We consider the see-saw mechanism within a nonsupersymmetric SO(10) model. By assuming the SO(10) quark-lepton symmetry, and after imposing suitable conditions that ensure that the right-handed neutrino masses are at most mildly hierarchical (compact right-handed spectrum) we obtain a surprisingly predictive scenario. The absolute neutrino mass scale, the Dirac and the two Majorana phases of the neutrino mixing matrix remain determined in terms of the set of already measured low energy observables, modulo a discrete ambiguity in the signs of two neutrino mixing angles and of the Dirac phase. The right-handed neutrino mass spectrum is also predicted, as well as the size and sign of the leptogenesis $CP$ asymmetries. We compute the cosmological baryon asymmetry generated through leptogenesis and obtain the correct sign, and a size compatible with observations.

We study the nucleon and pion structure functions at the small Bjorken-$x$ region in the framework of holographic QCD with a special emphasis on the roles of anti-de Sitter (AdS) space wave functions. Using the Brower-Polchinski-Strassler-Tan kernel for the Pomeron exchange and calculating its coupling to target hadrons in the AdS space, we obtain $F_2$ structure functions at the small $x$. Results for the proton $F_2^p$ as well as the pion $F_2^{\pi }$ are consistent with experimental data of the deep inelastic scattering and the forward electroproduction of a neutron. Observed $Q^2$ dependence of the Pomeron intercept is well reproduced from soft nonperturbative $(Q^2\sim 0)$ to hard perturbative $(Q^2\gg 1{\mathrm{GeV}}^2)$ region. We find the interplay between soft and hard Pomerons is closely related with behavior of AdS wave functions of hadrons and the virtual photon.

Recent measurements by the ATLAS and CMS experiments have excluded the standard model Higgs boson in the high mass region, even if it is produced with a significantly smaller cross section than expected. The bounds are dominated by the nonobservation of a signal in the clean gold-plated mode $h\to ZZ\to 4\ell$ and, hence, are directly related to the special role of the Higgs in electroweak symmetry breaking. A smaller cross section in comparison to the standard model is expected if the Higgs is realized as an unparticle in the unHiggs scenario. With the LHC probing $\sigma /{\sigma }^{\mathrm{SM}}<1$, we can therefore reinterpret the $h\to ZZ\to 4\ell$ exclusion limits as bounds on the unHiggs’ scaling dimension. Throughout the high Higgs mass range, where we expect a large signal in the presence of the standard model Higgs for the 2011 ATLAS and CMS data sets, the observed limits translate into mild bounds on the unHiggs scaling dimension in the high mass region.

We provide a scan of the parameter space for neutralino-hadron scattering in the next-to-minimal supersymmetric standard model using an updated value for the strange quark sigma commutator. These results also take into account constraints from WMAP data on the relic density and new constraints from the Large Hadron Collider. We find that the resultant spin-independent cross sections are smaller in magnitude than those found in recent results obtained within the constrained minimal supersymmetric standard model, yet still great enough to feasibly allow for detection in the case of binolike neutralinos.

We investigate the production of highly energetic top-quark pairs at hadron colliders, focusing on the case where the invariant mass of the pair is much larger than the mass of the top quark. In particular, we set up a factorization formalism appropriate for describing the differential partonic cross section in the double soft and small-mass limit, and explain how to resum simultaneously logarithmic corrections arising from soft gluon emission and from the ratio of the pair-invariant mass to that of the top quark to next-to-next-to-leading logarithmic accuracy. We explore the implications of our results on approximate next-to-next-to-leading order formulas for the differential cross section in the soft limit, pointing out that they offer a simplified calculational procedure for determining the currently unknown delta-function terms in the limit of high invariant mass.

We have calculated the scattering lengths between the pseudoscalar meson and charmed triplet, sextet, and excited sextet baryon to the third order with the heavy baryon chiral perturbation theory. The chiral expansion of some pion and eta channels converges well.

We report STAR measurements of the longitudinal double-spin asymmetry $A_{LL}$, the transverse single-spin asymmetry $A_N$, and the transverse double-spin asymmetries $A_{\Sigma }$ and $A_{TT}$ for inclusive jet production at mid-rapidity in polarized $p+p$ collisions at a center-of-mass energy of $\sqrt{s}=200\mathrm{GeV}$. The data represent integrated luminosities of $7.6{\mathrm{pb}}^{-1}$ with longitudinal polarization and $1.8{\mathrm{pb}}^{-1}$ with transverse polarization, with 50%–55% beam polarization, and were recorded in 2005 and 2006. No evidence is found for the existence of statistically significant jet $A_N$, $A_{\Sigma }$, or $A_{TT}$ at mid-rapidity. Recent model calculations indicate the $A_N$ results may provide new limits on the gluon Sivers distribution in the proton. The asymmetry $A_{LL}$ significantly improves the knowledge of gluon polarization in the nucleon.