The problem of roughness drag at supersonic speeds

Methods of estimating roughness drag at supersonic speed

Techniques for computing two-loop QCD corrections to b-->c transitions

We have recently presented the complete O(alpha_s^2) corrections to the semileptonic decay width of the b quark at maximal recoil. Here we discuss various technical aspects of that calculation and further applications of similar methods. In particular, we describe an expansion which facilitates the phase space integrations and the treatment of the mixed real-virtual corrections, for which Taylor expansion does not work and the so-called eikonal expansion must be employed. Several terms of the expansion are given for the O(alpha_s^2) QCD corrections to the differential semileptonic decay width of the b --quark at maximal recoil. We also demonstrate how the light quark loop corrections to the top quark decay rate can be obtained using the same methods. We briefly discuss the application of these techniques to the calculation of the O(alpha_s^2) correction to zero recoil sum rules for heavy flavor transitions.Comment: 22 pages, revte

Analysis of pressure distributions for a series of tip and trailing-edge controls on a 60 deg wing at Mach numbers of 1.61 and 2.01

Supersonic pressure distributions for tip and trailing edge controls on 60 deg delta win

Theoretical face pressure and drag characteristics of forward-facing steps in supersonic turbulent boundary layers

A theoretical investigation of the pressure distributions and drag characteristics was made for forward facing steps in turbulent flow at supersonic speeds. An approximate solution technique proposed by Uebelhack has been modified and extended to obtain a more consistent numerical procedure. A comparison of theoretical calculations with experimental data generally indicated good agreement over the experimentally available range of ratios of step height to boundary layer thickness from 7 to 0.05

Theoretical pressure distributions over arbitrarily shaped periodic waves in subsonic compressible flow and comparison with experiment

Theoretical solution for pressure distribution over arbitrarily shaped periodic waves using Fourier serie

Pressure drags due to two-dimensional fabrication-type surface roughness on an ogive cylinder at transonic speeds

Pressure drags due to two-dimensional fabrication- type surface roughness on ogive cylinder at transonic speed

Electroweak Measurements

The measurements of electroweak sector of the Standard Model are presented, including most recent results from LEP, Tevatron and HERA colliders. The robustness of the Standard Model is illustrated with the precision measurements, the electroweak fits and the comparisons to the results obtained from low energy experiments. The status of the measurements of the $W$ boson properties and rare production processes involving weak bosons at colliders is examined, together with the measurements of the electroweak parameters in $ep$ collisions.Comment: 12 pages, Proceedings of "Lepton-Photon 2005", Upsalla, Swede

Measurement by wake momentum surveys at Mach 1.61 and 2.01 of turbulent boundary-layer skin friction on five swept wings

Measurement by wake momentum surveys at Mach 1.61 and 2.01 of turbulent boundary layer skin friction on five swept wing

Three-loop QCD corrections and b-quark decays

We present three-loop (NNNLO) corrections to the heavy-to-heavy quark transitions in the limit of equal initial and final quark masses. In analogy with the previously found NNLO corrections, the bulk of the result is due to the beta_0^2 alpha_s^3 corrections. The remaining genuine three-loop effects for the semileptonic b --> c decays are estimated to increase the decay amplitude by 0.2(2)%. The perturbative series for the heavy-heavy axial current converges very well.Comment: 5 page

Calculation of the One- and Two-Loop Lamb Shift for Arbitrary Excited Hydrogenic States

General expressions for quantum electrodynamic corrections to the one-loop self-energy [of order alpha(Zalpha)^6] and for the two-loop Lamb shift [of order alpha^2(Z\alpha)^] are derived. The latter includes all diagrams with closed fermion loops. The general results are valid for arbitrary excited non-S hydrogenic states and for the normalized Lamb shift difference of S states, defined as Delta_n = n^3 DeltaE(nS) - DeltaE(1S). We present numerical results for one-loop and two-loop corrections for excited S, P and D states. In particular, the normalized Lamb shift difference of S states is calculated with an uncertainty of order 0.1 kHz.Comment: 4 pages, RevTe