Recent BES measurements and the hadronic contribution to the QED vacuum polarization

We have updated our evaluation of the hadronic contribution to the running of the QED fine structure constant using the recent precise measurements of the e+e- annihilation at the center-of-mass (c.m.s.) energy region between 2.6 and 3.65 GeV performed by the BES collaboration. In the low energy region, around the rho resonance, we include the recent measurements from the BABAR, CDM-2, KLOE and SND collaborations. We obtain Delta alpha (5)_had (s) = 0.02750 +/- 0.00033 at s = m_Z^2.Comment: 3 pages, 1 figur

LHCb detector status and commissioning

The LHCb detector status and commissioning is presented.Comment: HCP06 proceedings for reference

Further studies on Bose-Einstein correlations in W-pair decays

Bose-Einstein correlations in W-pair decays are studied using data collected by the ALEPH detector at centre-of-mass energies up to 208 GeV. The analysis presented is based on the comparison of selected $WW \rightarrow q \bar{q}q \bar{q}$ events to "mixed" events constructed from the hadronic parts of selected $WW \rightarrow q \bar{q} \ell \nu$ events using the $\Delta \rho$ distribution. The data distribution is consistent with $\Delta \rho = 0$ predicted when the Bose-Einstein correlations are present only for pions coming from the same W. The JETSET model with the Bose-Einstein correlations between pions from di erent W's is disfavoured

LEP asymmetries and fits of the Standard Model

The lepton and quark asymmetries measured at LEP are presented. The results of the Standard Model fits to the electoweak data presented at this conference are given. The top mass obtained from the fit to the LEP data is $172^{+13+18}_{-14-20}$ GeV; it is $177^{+11+18}_{-11-19}$ when also the collider, $\nu$ and $A_{LR}$ data are included.Comment: ps file,8 pages, LAPP-EXP-94.0

Virtual effects of light gauginos and higgsinos: a precision electroweak analysis of split supersymmetry

We compute corrections to precision electroweak observables in supersymmetry in the limit that scalar superpartners are very massive and decoupled. This leaves charginos and neutralinos and a Standard Model-like Higgs boson as the only states with unknown mass substantially affecting the analysis. We give complete formulas for the chargino and neutralino contributions, derive simple analytic results for the pure gaugino and higgsino cases, and study the general case. We find that in all circumstances, the precision electroweak fit improves when the charginos and neutralinos are near the current direct limits. Larger higgsino and gaugino masses worsen the fit as the theory predictions asymptotically approach those of the Standard Model. Since the Standard Model is considered by most to be an adequate fit to the precision electroweak data, an important corollary to our analysis is that all regions of parameter space allowed by direct collider constraints are also allowed by precision electroweak constraints in split supersymmetry.Comment: 22 pages, 5 figures, v2: typos fixed and note adde

Initial-Final-State Interference in the Z line-shape

The uncertainty in the determination of the Z line-shape parameters coming from the precision of the calculation of the Initial-State Radiation and Initial--Final-State Interference is 2 10**(-4) for the total cross section sigma zero(had) at the Z peak, 0.15 MeV for the Z mass M Z, and 0.1 MeV for the Z width Gamma Z. Corrections to Initial--Final-State Interference beyond \Order{\alpha^1} are discussed.Comment: 10 pages LaTeX including 2 PostScript figure