The differential cross sections and density matrix elements for the φ and ϱ 0 mesons have been measured in the reactions K − p → K − K + ( Λ , Σ 0 ) and K − p → π − π + ( Λ , Σ 0 ) at 13 GeV using a wire chamber spectrometer. The analysis shows that while the vector meson production is dominated by the natural parity exchange amplitude, some unnatural parity exchange is also required. Furthermore the φ and ϱ natural exchange cross sections are identical in shape and have the 2:1 relative strength expected in the quark model with K ∗ and K ∗∗ exchange degeneracy. The analysis of the clear peak-dip ϱ 0 − ω interference pattern observed in the π − π + data indicates that the ω production is in phase with the ϱ and of similar magnitude. Both the S ∗ and f′ meson are clearly observed in this experiment. The S ∗ data are found to be consistent with S ∗ parameters deduced from ππ scattering analyses. The f′ density matrix elements and a new limit of the f′ → π − π + branching ratio are presented.
No description provided.
CROSS SECTIONS CORRECTED FOR EVENTS OUTSIDE THE PHI MASS CUT. <T-CHANNEL>.
CROSS SECTIONS CORRECTED FOR EVENTS OUTSIDE THE PHI MASS CUT. <S-CHANNEL>.
The results of a wire chamber spectrometer experiment studying K ∗ (890) production in the reaction K − p→ K − π + n at 13 GeV are presented. Strong forward structure is observed for | t |< m 2 π in the s -channel density matrix elements and differential cross section. These features are similar to those observed in π − p→ϱ 0 n data and are characteristics of π exchange. In contrast in the intermediate, | t | ∼ 0.2 GeV 2 , and large momentum transfer regions K ∗ (890) production is demonstrated by the natural parity ϱ−A 2 exchange contribution.
No description provided.
The logarithmic slope of the differentical cross section for K ± p elastic scattering at 10 and 14 GeV, and for π ± p and p ± p at 10GeV has been measured. Rich structure is observed in the forward slope for all processes, which is well accounted for by the properties of a peripheral exchange amplitude for the nonexotic reactions, and by a peripheral component of the diffractive amplitude as clearly seen in the exotic processes, K ± p and pp.
GRAPH OF D(SIG)/DT.
SLOPE AS A FUNCTION OF T.
Differential cross sections in the t -range between 0.02 and 1.5 GeV 2 have been measured for the elastic scattering of particles and antiparticles on protons at 6.4, 10.4 and 14 GeV for K ± p and 10.4 GeV for π ± p and p ± p . Large statistics have been achieved and systematic uncertainties have been minimized. The relative systematic uncertainty between particle and antiparticle data is less than 0.5%. Accurate measurements of the position of the first crossover between particle and antiparticle differential cross sections have been performed. As the energy increases from 6.4 to 14 GeV the K ± p crossover moves to smaller values by 0.010 GeV 2 with a statistical error of 0.006 GeV 2 and a systematic uncertainty of 0.005 GeV 2 . The crossover positions at 10.4 GeV for π ± , K ± and p ± scale approximately with the interaction radii.
CROSSOVER POSITION IS -T = 0.209 +- 0.004 (DSYS = 0.003) GEV**2.
CROSSOVER POSITION IS -T = 0.209 +- 0.004 (DSYS = 0.003) GEV**2. SMALL ANGLE CROSS SECTIONS IN SMALLER T-BINS.
CROSSOVER POSITION IS -T = 0.211 +- 0.004 (DSYS = 0.0025) GEV**2.
The differential cross section for K ± p elastic scattering has been measured in the very low t region (0.003 < t < 0.2 GeV 2 ) in a wire chamber spectrometer experiment at 10.4 and 14 GeV/ c . The interference effect observed between the Coulomb and the nuclear interaction has been used to determine α, the ratio of real to imaginary part of the forward scattering amplitude. At 10.4 GeV/ c we measure α (K + p) = −0.21 ± 0.06 and α (K − p = 0.08 ± 0.04, and at 14 GeV/ c , α (K + p) = − 0.13 ± 0.03 and α (K − p) = 0.000 ± 0.04 in agreeement with the predictions of dispersion theory calculation.
No description provided.
None
No description provided.
No description provided.
No description provided.
Differential cross sections have been measured for the interactions p p → π − π + and p p → K − K + over a centre of mass angular range −0.95 ⩽ cos θ ∗ ⩽ 0.95 at 20 incident momenta between 0.79 and 2.43 GeV/ c . A magnetic spectrometer with wire spark chambers was used. Typically 2000 π − π + and 300 K − K + events were obtained at each momentum. Results are compared with those from related experiments.
No description provided.
No description provided.
No description provided.
Inclusive hadron production in muon-proton inelastic scattering has been measured for q2>0.5 (GeV/c)2 and 10<ν<135 GeV. The results are presented in the form of the transverse momentum distribution of charged hadrons and the hadron invariant structure function F(x′). Results are given for different regions of q2 and s.
No description provided.
No description provided.
No description provided.
We present measurements from a spark chamber experiment of the differential cross-sections for p p → π − π + , K − K + at 20 momenta in the range 0.8–2.4 GeV/ c (c.m. energy 2.02 to 2.57 GeV). The c.m. angular range was −0.95 < cos θ ∗ < 0.95 . There are about 2000π − π + events and about 300 K − K + events at each momentum.
ALL ANGLES.
We have made a measurement of the lepton charge asymmetry in KL0 decays. Magnetic analyses of the decay products in a spectrometer using multiwire proportional counters allowed kinematic reconstruction of the event where the particles traversed only 293 mg of matter. The leptons were differentiated from the pions only through their different transverse-momentum distributions. The asymmetry was measured to be (3.33 ± 0.50) × 10−3, in accord with the superweak description of CP nonconservation.
The asymmetry is defined as follows: ASYM = Cik/Bik, where Cik and Bik are the related to intensity of the events and depend on the particular set of transverse momenta of the leptons and pions (see text for details).
Forum