For the first time, the line reversed reactions π + p→K + Σ + and K − p→ π − Σ + have been studied in the same apparatus. We present the differential cross sections and polarizations over a large t range and at two momenta, 7.0 and 10.1 GeV/ c . The differential cross sections as a function of t are shown for the first time to cross over. Going from the lower to the higher momentum, the differences in cross section between the two reactions diminish at low | t | by about a factor 2. We find large polarizations of opposite sign for the two reactions. The momentum dependence, presented in the form of α eff ( t ) for the t range 0 to −2 (GeV/ c ) 2 , is compared with the expectations from the K ∗ −K ∗∗ trajectory.
-TMIN = 0.0100 GEV**2.
-TMIN = -0.0087 GEV**2.
-TMIN = 0.0067 GEV**2.
The charged-current cross sections for neutrinos and antineutrinos on nucleons in the energy range 20–200 GeV are given. Taken in conjunction with the previous Gargamelle results, they show that σ E is almost constant with energy for antineutrinos, and falls with energy for neutrinos. The value of 〈q 2 〉 E decreases with energy for both neutrinos and antineutrinos, and these deviations from exact Bjorken scaling are consistent with those observed in electron and muon inelastic scattering. We find no evidence for new heavy quark states with right-handed coupling.
Measured charged current total cross section.
Measured charged current total cross section.
Proton elastic scattering off a polarized proton target has been measured at 150 GeV/ c , in the |; t |-range 0.2–3.0 GeV 2 . The results on polarization and differential cross section are presented.
No description provided.
No description provided.
We perform an amplitude analysis of 10 GeV/ c π − p → K − K S 0 p data as a function of K − K 0 mass from threshold up to 2 GeV. We find that the A 2 and g resonances are produced dominantly by natural and unnatural parity exchange, respectively, and we determine their resonance parameters. We present further evidence for the I = 1, 4 + state A 2 ∗ (1900), in particular by isolating interference effects. The structure of S-wave K − K 0 production suggests an I = 1, 0 + state just below 1300 MeV of width about 250 MeV.
CROSS SECTIONS FROM FITTING MASS SPECTRUM. THE RESONANT AMPLITUDE CONTRIBUTIONS ALSO GIVEN IN PAPER.
Decay modes of the charmed mesons, D 0 and D + , are studied in e + e − annihilation data at 4.03 and 4.41 GeV c.m. energy. The products of cross section times branching ratio are measured for the K − π + , K − π + π + π − , K S π + π − and K − π + π + final states. Upper limits are established for the Cabibbo forbidden decays via π + π − , K + K − , K + K − π + , K + π + π − and π + π − π + . The K − π + π + π − final state is shown to be dominated by K − π + ρ 0 .
THESE PARTIAL CROSS SECTIONS ARE CONVERTED TO TOTAL D INCLUSIVE CROSS SECTIONS USING KNOWN BRANCHING RATIOS AND TABULATED IN M. PICCOLO ET AL., PL 86B, 220 (1979).
We report on the analysis of inclusive neutral current events produced in neutrino and antineutrino narrow band beams. We find for incident neutrino energies in the range 12–200 GeV and for hadron energies above 12 GeV a neutral to charged current cross-section ratio of R v = 0.293 ± 0.010 for incident neutrinos, and R v = 0.35 ± 0.03 for antineutrinos. These ratios are consistent with the Weinberg-Salam model, with sin 2 θ w = 0.24 ± 0.02.
No description provided.
No description provided.
We report on measurements of inclusive π 0 production at c.m. energies of 53 and 63 GeV, θ ≅90°, from p-p collisions at the CERN ISR. In the range 0.2< x t <0.45 the data can be described by a form: Ed 3 σ d p 3 ∝p − (6.6±0.8) t (1−x t ) (9.6±1.0) .
No description provided.
No description provided.
The production of enutral kaons in e + e − annihilation has been measured for c.m. energies between 3.4 GeV and 7.6 GeV. Near 4 GeV the inclusive K S cross section shows an increase and structure similar to total hadron production. Roughly 40–45% of all hadronic final states contain kaons, except at 4.028 GeV and 4.415 GeV, where a significantly larger kaon fraction is observed.
No description provided.
THIS IS TWICE THE MEASURED KS CROSS SECTION. THE ERRORS ARE STATISTICAL ONLY. THERE IS 15 PCT ABSOLUTE NORMALIZATION ERROR, PLUS POSSIBLY SOME ENERGY DEPENDENT ERROR. THE DATA ARE NOT EQUALLY SPACED IN THE ENERGY INTERVALS.
We compare production of the low mass K π -resonances by K + and K − beams in the non-charge-exchange reactions K ± p → K 0 s π ± p at 10 GeV/ c . High statistics data, obtained with the same apparatus, allow extraction of the K ∗ (890) and K ∗ (1420) production amplitudes corresponding to unnatural and natural parity exchange in the t -channel. The NPE-part dominates in both charge states. Its t -dependence shows a strong crossover at t ≈ −0.3 (GeV/ c ) 2 for the K ∗ (1420). For the K ∗ (890) the crossover is weaker but it occurs at the same value of t . This behaviour can be explained by pomeron, f and ω Regge exchange contributions to the NPE amplitude. The UPE amplitudes agree, both in normalisation and t -dependence, with the expectations of π and B exchange as isolated from data for the charge exchange reaction K − p → (K − π + )n.
No description provided.
Annihilation of e + e − into final states with a single electron has been studied with the PLUTO detector at the DORIS storage ring at CMS energies from 3.6 to 5 GeV. In the sample of 4-prong events without any detected photon we observe 21 events which we assign to the reaction e + e − → τ + τ − → νν e + νϱ 0 π . We obtain a branching ratio for τ + → νϱ 0 π + of 0.050 ± 0.015 with an overall systematic uncertainty of 30%. The data are consistent with the ϱπ coming from an A 1 meson.
No description provided.
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