[en] The (bar B) → X_s (ell)⁺(ell)^- decay rate is known at the next-to-next-to-leading order in QCD. It is proportional to α_em(μ)² and has a ± 4% scale uncertainty before including the Ο(α_em ln(M_W²/m_b²)) electromagnetic corrections. They evaluate these corrections and confirm the earlier findings of Bobeth et al. Furthermore, they complete the calculation of logarithmically enhanced electromagnetic effects by including the previously omitted QED corrections to the matrix elements of four-fermion operators. An important feature of these matrix elements is the presence of a collinear logarithm ln(m_b²/m_#ell#_#sup 2#) that survives integration over the low dilepton invariant mass region 1 GeV² < m_#ell#_#ell#² < 6 GeV². In this region, the collinear logarithm enhances the integrated decay rate by around 6% for the electron channel. The low-m_#ell#_#ell#² integrated branching ratios yield Β(B → X_se⁺e^-) = (1.64 ± 0.11) x 10^-6 and Β(B → X_sμ⁺μ^-) = (1.58 ± 0.11) x 10^-6

[en] We present a concise review of the theoretical status of rare K → πν(bar ν) decays in the standard model (SM). Particular attention is thereby devoted to the recent calculation of the next-to-next-to-leading order (NNLO) corrections to the charm quark contribution of K⁺ → π⁺ ν(bar ν), which removes the last relevant theoretical uncertainty from the K → πν(bar ν) system

[en] Results of a search for the Flavor-Changing Neutral Current decay B_s,d⁰ → μ⁺μ^- using p(bar p) collision data at √s = 1.96 TeV collected at Fermilab Tevatron collider by the CDF and D0 detectors are presented. CDF reports upper limits on Β(B_s⁰ → μ⁺μ^-) (le) 7.5 · 10^-7 and Β(B_d⁰ → μ⁺μ^-) (le) 1.9 · 10^-7 at the 95% C.L. using 171 pb^-1. The D0 Collaboration used 240 pb^-1 to set an even more stringent limit on the branching ratio for B_s⁰ → μ⁺μ^- of 5.0 · 10^-7 at the 95% C.L.

[en] We report on irradiation studies performed on spare production silicon detector modules for the current D0 silicon detector. The lifetime expectations due to radiation damage effects of the existing silicon detector are reviewed. A new upgrade project was started with the goal of a complete replacement of the existing silicon detector. In that context, several investigations on the radiation hardness of new prototype silicon microstrip detectors were carried out. The irradiation on different detector types was performed with 10 MeV protons up to fluences of 10¹⁴ p/cm² at the J.R. Mcdonald Laboratory at Kansas State University. The flux calibration was carefully checked using different normalization techniques. As a result, we observe roughly 40-50% less radiation damage in silicon for 10 MeV p exposure than it is expected by the predicted NIEL scaling

[en] The MSSM can explain electro-weak symmetry breaking if one scalar top quark (stop) is light. In addition, in this framework, the neutralino is a good dark matter candidate and for small stop-neutralino mass differences dm_i = 30 GeV, co-annihilation plays an important role to match the results from WMAP and SDSS for the relic density in the universe. In this scenario, the stops mainly decays into charm and neutralino, making its discovery difficult at hadron colliders due to background and trigger limitations. They present results for the discovery reach of the ILC for a DM candidate as low as 0(5 GeV) based on a realistic experimental simulation. Moreover, the stop parameters could be measured with high precision

[en] Several different spare modules of the D0 experiment Silicon Microstrip Tracker (SMT) have been irradiated at the Fermilab Booster Radiation Damage Facility (RDF). The total dose received was 2.1 MRads with a proton flux of ∼3 · 10¹¹ p/cm² sec. The irradiation was carried out in steps of 0.3 or 0.6 MRad, with several days between the steps to allow for annealing and measurements. The leakage currents and depletion voltages of the devices increased with dose, as expected from bulk radiation damage. The double sided, double metal devices showed worse degradation than the less complex detectors

[en] The LHC will be a very complex environment with most of the interesting physics signals, and their backgrounds, consisting of multi-parton (and lepton/photon) final states. The ATLAS and CMS experiments will measure these final states with negligible statistical error, even in the early running, and in many cases with systematic errors smaller than those achieved by the experiments at the Tevatron (see the contribution in these proceedings from G. Dissertori). The luminosity uncertainty and the uncertainty in the parton distribution functions (PDFs) can be minimized by the normalization of the physics process of interest to certain Standard Model (SM) benchmark processes, such as W, Z, and t(bar t) production. Thus, it is important to have theoretical predictions at the same or better precision as the experimental measurements. In many cases, SM backgrounds to non-SM physics can be extrapolated from background-rich to signal-rich regions, but a definite determination of the background often requires an accurate knowledge of the background cross sections. An accurate knowledge of a cross section requires its calculation to at least next-to-leading order (NLO). There are many tools for constructing basically any complex final state at the LHC at leading order (LO). When interfaced to parton shower Monte Carlo programs, such predictions can provide a qualitative prediction of both inclusive and exclusive final states. There are several different interfaces between fixed order (both LO and NLO) matrix element and parton shower Monte Carlo programs, with a benchmark comparison reported in this workshop