We have measured the polarization for elastic scattering in the reaction π−p→π−p at 2.93 and 3.25 GeV/c using a polarized proton target and multiwire proportional chambers (MWPC's) with emphasis on large-angle scattering. Events were selected by fast scintillation-counter logic. Beam trajectories were measured with four MWPC's and the scattered-particle angles were measured with one or two MWPC's; elastic events were determined by coplanarity and angle-angle correlations. The polarization is in agreement with previous measurements below |t|=2.0 (GeV/c)2, and crosses from negative to positive near the secondary dip in the differential cross section dσdt. In the backward region, an energy dependence appears with the polarization being large and negative at 2.93 GeV/c and consistent with zero at 3.25 GeV/c.
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A detailed account is given of observations of parity nonconservation in the 6P122−7P122 transition in Tl81203,205. Absorption of circularly polarized 293-nm photons by 6P122 atoms in an E field results in polarization of the 7P122 state through interference of the Stark E1 amplitude with M1 and parity-nonconserving E1 amplitudes. This polarization is detected by selective excitation of mF=±1 components of the 7P122 state to the 8S122 state and observation of the ensuing decay fluorescence at 323 nm. Systematic corrections due to imperfect circular polarization, misaligned E fields, and residual magnetic fields are determined precisely by a series of auxiliary experiments. The result is expressed in terms of the circular dichroism δexpt=+(2.8−0.9+1.0)×10−3, to be compared with estimates based on the Weinberg-Salam model for sin2θw=0.23:δtheo=+(2.1±0.7)×10−3.
Used 99.999% pure thallium metal with natural isotopic abundances (29.5% Tl203, 70.5% Tl205). SIG(C=+),SIG(C=-) are the cross sections for absorption of 293-nm photons with +- helicity, respectively. Spin of the Tl nucleus is 1/2.
Results on kaon, pion, and proton production in muon-proton scattering are presented for 1<Q2<80 GeV2 with an average Bjorken x of 0.033. The measured particle fractions for z>0.2(z=Phadν) are fπ=0.764±0.028, fK=0.187±0.042, and fp=0.049±0.013. The K±π± ratios as a function of z and pT2 are presented: The ratios increase with z, and with pT2 for z<0.3.
No description provided.
Results of measurements of the polarization parameter in K+p elastic scattering at 650, 700, 845, and 940 MeV/c are presented. Details of the measurements are described and results are compared with previous measurements and partial-wave parametrizations of the data. The implication of the existence of Z* resonances in light of these results is discussed.
No description provided.
Data from the ANL 12-foot bubble chamber have been used to study the K¯0π− system in the reaction K−p→K¯0pπ− at 6.5 GeV/c. Signals for the production of K*(892), K*(1430), and K*(1780) were observed with cross sections of 181±22, 41.2±6, and 8.4±2.9 ≥b, respectively. The partial waves contributing to the production of the K¯0π− system from threshold up to 1.7 GeV were studied. The principal conclusions are: (i) K*(892) and K*(1430) production is dominated by natural-parity exchange, (ii) the ratio of unnatural- to natural-parity exchange increases with the resonance mass, consistent with the predictions of a triple-Regge model, (iii) there is evidence for a broad 0+ s-wave enhancement, with considerable s−d and s−p interference, centered at 1.2 GeV, and (iv) the m=2 amplitudes are negligible.
<AK0 PI-> EFFECTIVE-MASS DISTRIBUTION FITTED WITH BREIT-WIGNER FUNCTIONS AND CUBIC POLYNOMIAL BACKGROUND. FITTED MASS OF KN(1800)- IS 1762 +- 9 MEV.
THE LARGE BACKGROUND UNDER THE K*(1420)- IS SUBTRACTED USING A LINEAR FIT.
NOT CORRECTED FOR PRESENCE OF BACKGROUND.
This paper reports the results of an experiment measuring the parameters of various electroproduction reactions for a range in the electroproduction variables 0.7<Q2<4 GeV2 and 2<W2<16 GeV2. This report is limited to nondiffractive exclusive channels, with detailed results regarding the πΔ final states, statistically limited results for KΛ final states, and upper limits on the production of a number of event topologies containing a single unseen neutral particle.
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We report differential cross sections for h+p→X+p (h=π±,K±,p±) at 100 and 200 GeV/c in the region 0.025<|t|<0.095 (GeV/c)2 and MX2s<0.1.
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We have made, for the first time, a direct reconstruction of the pp elastic-scattering matrix at 579 MeV from a series of experiments performed at the Schweizerisches Institut für Nuklearforschung polarized-beam line. Fifteen observables consisting of the polarization, two-spin correlation and transfer parameters, and three-spin parameters were measured at seven angles between 66° and 90° (c. m.). The experimental results and reconstructed amplitudes are presented and compared to phase shift analysis.
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VALUES OF PRECESSION ANGLE O. OBSERVABLES ARE RELATED BY THE FORMULA, (OABC) = (S'ABC)*COS(O) + (K'ABC)*SIN(O).
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UNNORMALIZED MULTIHADRON TOTAL CROSS SECTION ENERGY SCAN.
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CROSS SECTIONS FOR POSITIVE AND NEGATIVE G-PARITY FINAL STATES (EVEN AND ODD NUMBERS OF PIONS).
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