14 research outputs found

    TOI-481 b and TOI-892 b: Two Long-period Hot Jupiters from the Transiting Exoplanet Survey Satellite

    Get PDF
    We present the discovery of two new 10 day period giant planets from the Transiting Exoplanet Survey Satellite mission, whose masses were precisely determined using a wide diversity of ground-based facilities. TOI-481 b and TOI-892 b have similar radii (0.99 0.01 and 1.07 0.02, respectively), and orbital periods (10.3311 days and 10.6266 days, respectively), but significantly different masses (1.53 0.03, respectively). Both planets orbit metal-rich stars ( = dex and = for TOI-481 and TOI-892, respectively) but at different evolutionary stages. TOI-481 is a = 1.14 0.02 = 1.66 0.02 G-type star (=K), that with an age of 6.7 Gyr, is in the turn-off point of the main sequence. TOI-892 on the other hand, is a F-type dwarf star (=K), which has a mass of = 1.28 0.03 and a radius of = 1.39 0.02. TOI-481 b and TOI-892 b join the scarcely populated region of transiting gas giants with orbital periods longer than 10 days, which is important to constrain theories of the formation and structure of hot Jupiters

    Environmental activation of citizens in the context of policy agenda formation and the influence of social capital

    No full text
    Public policy issues arising from climate change projections are becoming increasingly important in terms of the range and the scope of their effects. In order to effectively confront them it is important to address social, environmental and economic aspects as fully as possible in decision-making processes. In this context, social risk assessment techniques have begun to be applied to explore citizens’ risk perceptions of climate change projections. The present study aims to contribute to this area by examining the influence of four social capital parameters (social trust, institutional trust, social norms and social networks) on public risk perceptions of climate change. An empirical study was conducted for this purpose in Greece’s fourth largest city, Heraklion. Results demonstrate that social capital is a significant explanatory parameter for citizens’ risk perceptions. Specifically, individuals with lower levels of social capital tend to perceive higher risks from climate change impacts. The most important parameter explaining this result is the low level of institutional trust, revealing that Heraklion’s citizens do not believe that existing public institutions will be able to effectively manage projected climate change impacts

    The reactions ππππ\pi\pi \rightarrow \pi\pi π π → π π and γγππ\gamma\gamma \rightarrow \pi\pi γ γ → π π in χ\chi χ PT with an isosinglet scalar resonance

    No full text
    The lowest-lying resonance in the QCD spectrum is the 0++0^{++} isoscalar σ\sigma meson, also known as the f0(500)f_0(500). We augment SU(2) chiral perturbation theory (χ\chiPT) by including the σ\sigma meson as an additional explicit degree of freedom, as proposed by Soto, Talavera, and Tarr\'us and others. In this effective field theory, denoted χ\chiPTS_S, the σ\sigma meson's well-established mass and decay width are not sufficient to properly renormalize its self energy. At O(p4)\mathcal{O}(p^4) another low-energy constant appears in the dressed σ\sigma-meson propagator; we adjust it so that the isoscalar pion-pion scattering length is also reproduced. We compare the resulting amplitudes for the ππππ\pi\pi\rightarrow\pi\pi and γγππ\gamma\gamma\rightarrow\pi\pi reactions to data from threshold through the energies at which the σ\sigma-meson resonance affects observables. The leading-order (LO) ππ\pi \pi amplitude reproduces the σ\sigma-meson pole position, the isoscalar ππ\pi \pi scattering lengths and ππ\pi \pi scattering and γγππ\gamma \gamma \rightarrow \pi \pi data up to s0.5\sqrt{s} \approx 0.5 GeV. It also yields a γγππ\gamma\gamma\rightarrow\pi\pi amplitude that obeys the Ward identity. The value obtained for the π0\pi^0 polarizability is, however, only slightly larger than that obtained in standard χ\chiPT.Comment: 17 pages, 7 figures. This version, which will be published in European Physical Journal A, contains clarification and more explanation of several points, as well as additional reference

    Opportunities for Lattice QCD in quark and lepton flavor physics

    No full text
    corecore