The authors report the observation of B{sub s}°-{bar B}{sub s}° oscillations from a time-dependent measurement of the B{sub s}°-{bar B}{sub s}° oscillation frequency [Delta]m{sub s}. Using a data sample of 1 fb−1 of p{bar p} collisions at √s = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron, they find signals of 5600 fully reconstructed hadronic B{sub s} decays, 3100 partially reconstructed hadronic B{sub s} decays, and 61,500 partially reconstructed semileptonic B{sub s} decays. They measure the probability as a function of proper decay time that the B{sub s} decays with the same, or opposite, flavor as the flavor at production, and they find a signal for B{sub s}°-{bar B}{sub s}° oscillations. The probability that random fluctuations could produce a comparable signal is 8 x 10−8, which exceeds 5[sigma] significance. They measure [Delta]m{sub s} = 17.77 ± 0.10(stat) ± 0.07(syst) ps−1 and extract.

The search for flavor oscillations in the neutral Bs - B meson system constitutes a flagship analysis of the Tevatron proton-anti-proton collider physics program and an important probe for effects due to new physics beyond the Standard Model of particles and interactions. In particular, the precise measurement of a process such as Boscillations sets a strong constraint on the parameters of quark-flavor mixing in the Standard Model. This dissertation reports the analysis which, for the first time, observed B- Bs oscillations, using data collected with the CDF detector. The sub-percent precision of the measurement is also noteworthy. The data sample used for this analysis includes fully and partially reconstructed Bdecays: ... The focus of this thesis is the algorithm of same-side-kaon tagging which provides _-0 a large fraction of the flavor-tagging power available to this analysis of B- B8 oscillations. Flavor tagging consists in assessing whether a B, meson is creates as a B_--0 or a B, state, and constitutes an important ingredient in the analysis presented in this document. The algorithm which is here described combines particle identification information and kinematic characteristics of the Bevent in an artificial neural network to provide improved tagging power E'2 of about 4.0 - 4.8%, depending on the data sample to which the algorithm is applied. The search for B1 oscillations is performed using an amplitude method based on a frequency scanning procedure. Applying a neural network-based combination of lepton, kaon and jet charge opposite-side tagging algorithms, with a total tagging power of ED2 = 1.8%, and the same-side-kaon tagging algorithm to a data sample of 1 fb-1, a signal of B- B_ oscillations with a significance greater than 5 standard deviations is found ...

We report a search for B{sub s}° - {bar B}{sub s}° oscillations using a sample of 400,000 hadronic Z° decays collected by the SLD experiment. The analysis takes advantage of the electron beam polarization as well as information from the hemisphere opposite that of the reconstructed B decay to tag the B production flavor. The excellent resolution provided by the pixel CCD vertex detector is exploited to cleanly reconstruct both B and cascade D decay vertices, and tag the B decay flavor from the charge difference between them. We exclude the following values of the B{sub s}° - {bar B}{sub s}° oscillation frequency: [Delta]m{sub s}

D. O. GOUGH Institute of Astronomy. Madingley Road. Cambridge. U. K. IAU Colloquium 66 on 'Problems of Solar and Stellar Oscillations' was held at the Crimean Astrophysical Observatory, U. S. S. R. , on 1-5 September, 1981. The principal purpose of the colloquium was to study the low-amplitude oscillations of the Sun and, to a lesser extent, to consider similar oscillations of other stars. Much of the emphasis of the discussions was on the diagnostic value of the oscilla tions. In the last few years we have become aware that the frequencies of the five-minute modes of high degree, which constitute the major component of the oscillations discovered twenty years ago by Evans and Michaud, can be used to put quite tight bounds on the stratification of the solar convection zone. These permit a calibration of solar models computed from so-called standard evolution theory. Modes of low degree penetrate beneath the convection zone to the core of the Sun, and can in principle test the evolution theory. Therefore there was considerable interest in the reports of the latest observations of such modes. Broadly speaking, those observations confirm the cali bration by the high-degree modes, but there remain some systematic discrepancies that demand some revision of the theory. Besides the gross aspects of evolution theory, there are also more intricate details to be understood.

The authors report the observation of B{sub s}{sup 0} - {bar B}{sub s}{sup 0} oscillations using 1 fb{sup -1} of data from p{bar p} collisions with the CDF II detector at the Fermilab Tevatron. They measure the probability, as a function of proper decay time, that the B{sub s}{sup 0} decays with the same, or opposite, flavor as its flavor at production, which is determined using opposite-side and same-side flavor identification methods. They find a signal consistent with B{sub s}{sup 0} - {bar B}{sub s}{sup 0} oscillations, with a significance greater than 5{sigma}. They measure {Delta}m{sub s} = 17.77 {+-} 0.10(stat) {+-} 0.07(syst) ps{sup -1}.

The authors review new studies of the time dependence of B[sub s][sup 0]-[bar B][sub s][sup 0] mixing by the ALEPH, DELPHI and SLD Collaborations, with an emphasis on the different analysis methods used. Combining all available results yields a preliminary lower limit on the oscillation frequency of [Delta]m[sub s] & gt; 14.4 ps[sup -1] at the 95% C.L.