Properties of the top quark

Recent measurements of top-quark properties at the LHC and the Tevatron are presented. Most recent measurements of the top quark mass have been carried out by CMS using $19.7/$fb of $\sqrt{s} = 8$ TeV data including the study of the dependence on event kinematics. ATLAS uses the full Run I data at $\sqrt{s} = 7$ TeV for a "3D" measurement that significantly reduces systematic uncertainties. D0 employs the full Run II data using the matrix element method to measure the top quark mass with significantly reduced systematic uncertainties. Many different measurements of the top quark exist to date and the most precise ones per decay channel per experiment have been combined into the first world combination with a relative precision of 0.44%. Latest updates of measurements of production asymmetries include the measurement of the \ttbar production asymmetry by D0 employing the full Run II data set, by CMS and ATLAS (including the polarization of the top quark) employing both the full data set at $\sqrt{s} = 7$ TeV. CMS uses the full $\sqrt{s} = 8$ TeV data to measure the top quark polarization in single top production, the ratio ${\cal R}$ of the branching fractions ${\cal B}(t \rightarrow Wb) / {\cal B}(t \rightarrow Wq)$ and to search for flavor changing neutral currents. The results from all these measurements agree well with their respective Standard Model expectation.Comment: Large Hadron Collider Physics (LHCP) conference held at Columbia University in New York City from June 2-7, 201

Top differential cross section measurements (Tevatron)

Differential cross sections in the top quark sector measured at the Fermilab Tevatron collider are presented. CDF used 2.7 fb$^{-1}$ of data and measured the differential cross section as a function of the invariant mass of the $t\bar{t}$ system. The measurement shows good agreement with the standard model and furthermore is used to derive limits on the ratio $\kappa /M_{Pl}$ for gravitons which decay to top quarks in the Randall-Sundrum model. D0 used 1.0 fb$^{-1} of data to measure the differential cross section as a function of the transverse momentum of the top quark. The measurement shows a good agreement to the higher order perturbative QCD prediction and various predictions based on various Monte-Carlo generators.Comment: To appear in the Proceedings of TOP2011, 4th International Workshop on Top Quark Physics, Spai

Space shuttle: Basic subsonic static aerodynamic characteristics for Grumman H-33 orbiter configuration (M equals 0.17)

Results of an experimental aerodynamic investigation of the H-33 space orbiter are presented. The investigation was undertaken to determine static aerodynamic characteristics of the orbiter at a Mach number of 0.17. These data were determined by employing a 1/25 scale model of the orbiter for pitch and yaw variations of -4 degrees to 24 degrees to 15 degrees, respectively. Investigations were conducted in the 7 - by - 10 foot wind tunnel

Quantum conductance of homogeneous and inhomogeneous interacting electron systems

We obtain the conductance of a system of electrons connected to leads, within time-dependent density-functional theory, using a direct relation between the conductance and the density response function. Corrections to the non-interacting conductance appear as a consequence of the functional form of the exchange-correlation kernel at small frequencies and wavevectors. The simple adiabatic local-density approximation and non-local density-terms in the kernel both give rise to significant corrections in general. In the homogeneous electron gas, the former correction remains significant, and leads to a failure of linear-response theory for densities below a critical value.Comment: for resolution of the here published results see Phys. Rev. B 76, 125433 (2007