The reaction π − p → φφ n has been isolated at 16 GeV/ c and its cross section determined to be 40 ± 10 nb. The φφ mass spectrum shows a threshold enhancement between 2.1 and 2.5 GeV. A successful description of the angular content of the φφ system requires two interferingss J P = 2 + states.
No description provided.
SLOPE OF DIFFERENTIAL TP(P=3,P=2) DISTRIBUTION.
Results on inclusive K s 0 production in e + e − annihilation at mean center-of-mass energies of 9.4, 12.0 and 30 GeV are presented. The ratio R (K 0 ) = 2 σ (K s 0 )/ σ μμ rises from 3.10 ± 0.75 at √ s = 9.4 GeV to 5.6 ± 1.2 at √ s = 30 GeV, corresponding to an approximately constant K 0 /charged-particle ratio of 0.12 ± 0.02. A similar ratio for K 0 / charged particle is observed for direct hadronic decays of the ϒ.
SYSTEMATIC ERROR INCLUDED.
NUMBER OF K0 PER HADRONIC EVENT. AUTHORS ALSO USE MULTIPLICITY TO ESTIMATE NUMBER OF K0 PER CHARGED PARTICLE.
INCLUDING EARLIER DATA.
Ξ− interactions in hydrogen and deuterium are studied close to the forward direction using the CERN charged hyperon beam. The inclusive production of ∑*−(1385),Ξ−,Ξ*0(1530),Ξ*−(1700),Ξ*−(1830), and Ω− is observed, as well as an enhancement in theΞ−π+ channel at 1940 MeV/c2. The momentum distributions and the production cross sections are measured for ∑*−(1385),Ξ−,Ξ*0(1530), and Ω−.
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Inclusive coherent proton diffraction dissociation on helium has been measured in the four-momentum transfer and missing-mass region 0.04<|t|<0.40 (GeV/c)2, MX2<10 GeV2 and for incident proton beam momenta from 46 to 400 GeV/c. We find that the differential cross section d2σdtdMX2 varies slowly with energy, reveals a pronounced peak at MX2≃2 GeV2, and at large masses behaves approximately as 1MX2. The cross section falls exponentially as |t| increases, with a large slope parameter at small momentum transfers and a substantially smaller one at large |t| values, with no clear dip between the two regions as seen in elastic scattering. We compare the experimental t distributions to Glauber-model predictions and find the data provide a sensitive test of the assumptions on the details of the elementary proton diffraction-dissociation amplitudes and on the total cross sections of the diffractively produced states.
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AVERAGED DATA FOR 200 AND 259 GEV.
Charged-current neutrino interactions have been analysed in a sample of pictures from BEBC equipped with a TST. Using a method independent of both the neutrino flux and nuclear interaction corrections, the ratio R = σ n / σ p has been measured. The result is R =1.98±0.19 for the ratio of total cross sections. Bjorken x distributions for proton and neutron targets and for u and d quarks are compared.
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Data on hadron production by e + e − annihilation at c.m. energies between 12 and 36.6 GeV have been collected using the JADE detector. They have been analysed in terms of single-photon and weak neutral-current exchange assuming production of quark-antiquark pairs with only d, u, s, c and b quarks to produce values for the quark weak neutral-current couplings. A further analysis in terms of the Glashow-Salam-Weinberg theory produced the result, sin 2 θ W = 0.22 ± 0.08 . The theory has therefore been tested in a new energy domain and within the context of the neutral weak couplings of the first, second and third generation quarks.
No description provided.
WIDTH(Z) = 2.5 GEV WAS ASSUMED. CONST(N=SIN2TW) WAS DETERMINED FROM RATIO(HADRONS/MU). FIRST ORDER QCD.
The p p elastic differential cross section at 50 GeV/c has been measured in a two-arm spectrometer experiment at the CERN SPS. The | t | range covered extends from 0.7 to 5 (GeV/c. A pronounced dip-bump structure is observed with a sharp minimum at | t | = 1.5 (GeV/ c ) 2 .
No description provided.
π−p→π0n differential cross-sections have been measured in the region of small 4-momentum transfer at 40 GeV/c incident momentum. The experiment performed at the IHEP 70 GeV accelerator makes use of a hodoscope γ-spectrometer. Thet- dependence of the cross-section points to a dominance of the spin-flip amplitude.
No description provided.
Inclusive production of ϱ0,K*±(892), andf is studied in\(\bar p\)p interactions at 12 GeV/c. The inclusive cross sections for ϱ0,K*±(892), andf are found to be 6.7±0.3 mb, 1.0±0.2 mb, and 1.4±0.3 mb, respectively. The differential cross sections are presented as a function of c.m. rapidity, Feynmanx and square of the transverse momentumpT2. Comparison with the correspondingpp data shows some interesting differences which can be attributed to the\(\bar p\)p annihilation. The results are compared with the predictions of the quark fusion model.
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We have performed a high-statistics measurement of Bhabha scattering and of the production of hadrons in electron-positron annihilation at PETRA energies (12 GeV<~s<~36.7 GeV). Combining the results with measurements of μ+μ− and τ+τ− production enables us to compare our results with electroweak theory. We find sin2θw=0.27±0.08. This is in good agreement with the value obtained from neutrino experiments which were carried out in entirely different kinematic regions.
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ASYMMETRY WAS USED.
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