None
No description provided.
No description provided.
We have observed 217 (66) events of the process νp→νp (ν¯p→ν¯p) with an estimated background of 82 (28). The neutral-to-charged-current ratios are σ(νp→νp)σ(νn→μ−p)=0.11±0.02 and σ(ν¯p→ν¯p)σ(ν¯p→μ+n)=0.19±0.05 for 0.40
No description provided.
We present the results of a measurement of the cross section oof the reaction e + e − → π + π − π + π − from 890 to 1100 MeV in the center of mass, obtained with a magnetic detector at the Orsay Storage Ring ACO. With respect to previous experiments, the present one offers the possibility of reconstructing events with at least one constraint and his improved statistics. We find that our measurement of the cross section for e + e − → π + π − π + π − is compatible with quasi two-body production of π A 1 ( m A1 = 1.1 GeV, Γ A1 ∼ 0.2−0.3 GeV), through the ϱ and ϱ′(1600) intermediate states. We were able to states. We were able to determine the cross section of this reaction at the energy of the φ meson and consequently an upper limit on the branching ratio of φ → π + π − π + π − .
UPPER LIMIT FOR PHI --> 4PI.
This paper gives the results of a study of inelastic charged-current interactions of muon-type neutrinos with hydrogen and deuterium targets using the Argonne 12-foot bubble chamber. We discuss in detail the separation of the events from background. For the single-pion production reactions νp→μ−pπ+, νn→μ−nπ+, and νn→μ−pπ0, energy-dependent cross sections, differential cross sections, invariant-mass distributions, and the Δ++(1236) decay angular distribution are presented. These data are also used to study the isospin properties of the πN system. Comparisons of the data with models of single-pion production are made, and a direct test of partial conservation of the axial-vector current is discussed. Cross sections and invariant-mass distributions are given for the reactions in which more than one pion is produced. Ten events of strange-particle production were found, and the properties of these events are discussed. The energy dependence of the total νp and νn cross sections from threshold to 6 GeV was determined, and the σ(νn)σ(νp) ratio measured. This ratio and the inclusive x and y distributions rapidly approach the scaling distributions expected from the quark-parton model.
Measured charged current total cross section.
From a muon-proton scattering experiment with a streamer chamber at the Stanford Linear Accelerator we present results in the ranges 0.3
THE ABSOLUTE TOTAL CROSS SECTION IS FROM A FIT TO THE MIT-SLAC ELECTRON SCATTERING DATA BY W. ATWOOD AND S. STEIN.
No description provided.
FOR 0.6 < M(PI+ PI-) < 0.9 GEV, USING THE METHOD OF MOMENTS.
We present measurements of the differential and polarization cross sections for the reactions KL0p→Ks0p, Λπ+, Σ0π+, and Λπ+π0 made in a hydrogen bubble chamber exposed to a beam of KL0 with incident momentum 550±35 MeV/c. The quasielastic data imposes additional constraints on the partial-wave analyses of the KN and K¯N systems. Our data show no strong energy-dependent effects in the region of the reported Σ(1580), JP=32− state. The phase of the forward regeneration amplitude was found to be about - 160° independent of KL0 momentum.
SYSTEMATIC ERRORS INCLUDED.
ROUGH FIT - POSSIBLY OTHER SYSTEMATIC ERRORS.
No description provided.
An analysis of the K 0 K 0 system at threshold produced in the final states p p → K S 0 K S 0 ( n π) at 700–760 MeV/ c , is presented. A simultaneous fit to the ππ phase shifts and inelasticities and to the K S 0 K S 0 effective-mass distributions using parametrizations which take into account the analytical and unitarity properties of the I = 0 S-wave amplitudes is performed. The behaviour of the eigenphases and the unphysical Riemann sheet structure for different solutions is studied.
No description provided.
FIT TO RESONANCE PRODUCTION CHANNELS IN <KS KS PI+ PI-> FINAL STATE.
FIT TO RESONANCE PRODUCTION CHANNELS IN <KS KS PI0> FINAL STATE.
The pion form factor is measured in the reaction e + e − → π + π − for center of mass energies in the range 480–1100 MeV. Our results are first analysed in terms of the conventional Vector Meson Dominance formalism, and then taking into account the ωπ inelastic channel. The result of this later formalism is a pion form factor ( F π ) which fits quite well all the existing data on F π both in the timelike and spacelike regions, and pion mean square radius of 〈 r π 2 〉 = 0.460 ± 0.011 fm 2 or 〈r π 2 〉 1 2 = 0.678 ± 0.008 fm .
No description provided.
The production of the φ and ω mesons has been studied in the reactions p p → φ(ω)π + π − and p p → φ(ω) ϱ 0 at 0.70–0.76 GeV /c . The c.m. angular distribution of the φ meson in the reaction p p → φπ + π − is found to be consistent with isotropy. The corresponding distribution for ω is not. the ratio σ( p p → φπ + π − ) σ( p p → ωπ + π − ) is (10 ± 2.4) · 10 −3 , which leads to a value of (19 ± 5) · 10 −3 when corrected for the phase-space factor. Implications of this result for the OZI rule are discussed.
No description provided.
No description provided.
The rates for forward electroproduction of single charged pions from deutrium have been measured in the resonance region, at a virtual photon mass squared ≈−0.5( GeV/ c 2 ) 2 . Results are presented in the form of a π − to π + cross-section ratio.
No description provided.
Forum