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K~-p interactions at 2.24 BeV/c were studied in several exposures of the Brookhavan National Laboratory 20-in. hydrogen bubble chamber at the alternating-gradient synchrotron. We give an account of all aspects of the experiment, including: experimental procedures, scanning and measuring techniques, data-reduction methods, and experimental results and their consistency with the current theories of strong and weak inter actions. The experimental results are grouped as follows: meson and baryon resonance spectroscopy; other two-body and three-body reactions; the S hyperon; and total cross sections. For completeness, we include information published elsewhere but add important details not previously given. In addition, we report a considerable range of new results.

This Letter presents measurements of the polarization of the top quark in top-antitop quark pair events, using 4.7  fb(-1) of proton-proton collision data recorded with the ATLAS detector at the Large Hadron Collider at √s=7  TeV. Final states containing one or two isolated leptons (electrons or muons) and jets are considered. Two measurements of α(ℓ)P, the product of the leptonic spin-analyzing power and the top quark polarization, are performed assuming that the polarization is introduced by either a CP conserving or a maximally CP violating production process. The measurements obtained, α(ℓ)P(CPC)=-0.035±0.014(stat)±0.037(syst) and α(ℓ)P(CPV)=0.020±0.016(stat)(-0.017)(+0.013)(syst), are in good agreement with the standard model prediction of negligible top quark polarization.

The purpose of this note is to report the existence of marked departures from phase space in the effective-mass distributions for the H7i and KK states. We present evidence that, in about 25% of the events observed, the HTT state results from the decay of a resonant state (H ) with a mass of 1535 MeV and a full width of <35 MeV. The observed anomaly in the KK effectivemass distribution is possibly open to different interpretations. If we assume it to be due to the decay of a resonant state K*, we find that M# * = 1020 MeV, and that it has a full width of 20 MeV. However, it may also be possible to explain the effect as due to S-wave KK scattering. These results, as well as preliminary evidence concerning the properties of the E and K , are discussed below.The data for this experiment were obtained in an exposure of the BNL 20-in. hydrogen bubble chamber at the Brookhaven AGS. Details of the exposure and beam have been previously discussed. 1 Data were obtained both at 2.24 and 2.5 BeV/c. The sample reported on here consists of 79 HTT and 37 KK combinations from the following production modes:All events were measured and analyzed using the BNL TRED-KECK system. Except for Reaction (Id), 2 we believe the contamination from other topologically similar event types to be negligible. H°+7TH°+77