Charm (and Beauty) Production at the Tevatron

We present recent results on heavy flavour production at Tevatron Run II for typically ~1/fb of analysed proton-antiproton data at a c.m. energy of 1.96 TeV. This includes results on single and correlated open charm and bottom cross sections, charm pair production kinematics, J/psi, psi(2S) and chi cross sections and polarisation measurements in J/psi, psi(2S), Upsilon(1S), and Upsilon(2S).Comment: To be published in the proceedings of CHARM07, Ithaca, NY, August 2007, eConf C07080

Black hole shadows in fourth-order conformal Weyl gravity

We calculate the characteristics of the "black hole shadow" for a rotating, neutral black hole in fourth-order conformal Weyl gravity. It is shown that the morphology is not significantly affected by the underlying framework, except for very large masses. Conformal gravity black hole shadows would also significantly differ from their general relativistic counterparts if the values of the main conformal gravity parameters, $\gamma$ and $\kappa$, were increased by several orders of magnitude. Such increased values for $\gamma$ and $\kappa$ are currently ruled out by gravitational phenomenology. Therefore, it is unlikely that these differences in black hole shadows will be detected in future observations, carried out by the Event Horizon Telescope or other such experiments.Comment: 21 pages, including 2 figures. Minor corrections and references added. Final version to appear in the Canadian Journal of Physic

Three-body effects in the Hoyle-state decay

We use a sequential $R$-matrix model to describe the breakup of the Hoyle state into three $\alpha$ particles via the ground state of $^8\mathrm{Be}$. It is shown that even in a sequential picture, features resembling a direct breakup branch appear in the phase-space distribution of the $\alpha$ particles. We construct a toy model to describe the Coulomb interaction in the three-body final state and its effects on the decay spectrum are investigated. The framework is also used to predict the phase-space distribution of the $\alpha$ particles emitted in a direct breakup of the Hoyle state and the possibility of interference between a direct and sequential branch is discussed. Our numerical results are compared to the current upper limit on the direct decay branch determined in recent experiments

Molecular and functional insights into gonadotropin hormone receptor dimerization and oligomerization

The gonadotrophin hormones, follicle stimulating hormone and luteinising hormone, are essential for reproduction. They work in concert to control multiple aspects of gonadal function to ultimately produce meiotically competent and fertilisable gametes, provide the optimal endometrial environment and support for implantation and maintain pregnancy via progesterone production throughout the first trimester of pregnancy. These complex and multidimensional functions are mediated via the gonadotrophin hormone receptors, luteinising hormone receptor (LHR) and follicle stimulating hormone receptor (FSHR), Class A G protein-coupled receptors (GPCR), which couple to multiple G protein-dependent and independent signal pathways to control these physiological processes. Over the last two decades, a plethora of experimental evidence has shown that GPCRs can associate to form dimers and oligomers. This association provides a means of mediating the diverse functional requirements of a single receptor subtype and for the gonadotrophin hormone receptors, has been shown to alter the pharmacology and signal activation profile of these receptors. This review will detail the historical and current evidence detailing the formation of gonadotrophin hormone receptor homomers and heteromers. We will discuss the functional insight gained from in vitro and in vivo studies, and the potential impact in modulating reproductive health and disease

Black hole shadows in fourth-order conformal Weyl gravity

We calculate the characteristics of the “black hole shadow” for a rotating, neutral black hole in fourth-order conformal Weyl gravity. It is shown that the morphology is not significantly affected by the underlying framework, except for very large masses. Conformal gravity black hole shadows would also significantly differ from their general relativistic counterparts if the values of the main conformal gravity parameters, γ and κ, were increased by several orders of magnitude. Such increased values for γ and κ are currently ruled out by gravitational phenomenology. Therefore, it is unlikely that these differences in black hole shadows will be detected in future observations, carried out by the Event Horizon Telescope or other such experiments

Coherent Transport through an interacting double quantum dot: Beyond sequential tunneling

Various causes for negative differential conductance in transport through an interacting double quantum dot are investigated. Particular focus is given to the interplay between the renormalization of the energy levels due to the coupling to the leads and the decoherence of the states. The calculations are performed within a basis of many-particle eigenstates and we consider the dynamics given by the von Neumann-equation taking into account also processes beyond sequential tunneling. A systematic comparison between the levels of approximation and also with different formalisms is performed. It is found that the current is qualitatively well described by sequential processes as long as the temperature is larger than the level broadening induced by the contacts.Comment: 11 pages, 5 figures included in tex

Superconducting Films for Absorber-Coupled MKID Detectors for Sub-Millimeter and Far-Infrared Astronomy

We describe measurements of the properties, at dc, gigahertz, and terahertz frequencies, of thin (10 nm) aluminum films with 10 ohm/{rm square}$ normal state sheet resistance. Such films can be applied to construct microwave kinetic inductance detector arrays for submillimeter and far-infrared astronomical applications in which incident power excites quasiparticles directly in a superconducting resonator that is configured to present a matched-impedance to the high frequency radiation being detected. For films 10 nm thick, we report normal state sheet resistance, resistance-temperature curves for the superconducting transition, quality factor and kinetic inductance fraction for microwave resonators made from patterned films, and terahertz measurements of sheet impedance measured with a Fourier Transform Spectrometer. We compare properties with similar resonators made from niobium 600 nm thick