Interactions of 40 GeV/c πp-,K− and\(\bar p\) on Li, C, S, Cu, CsI and Pb were studied with the RISK-streamer chamber spectrometer. We present multiplicities of negatively charged particles, as well as of protons, and the correlations between them. The normalized mean multiplicity of negative particles,R−, depends on\(\bar v\), the average number of inelastic collisions as\(R^ -= (0.73 \pm 0.04) + (0.34 \pm 0.02)\bar v\). The dependence of the normalized dispersion of negative particles,D−/<N−>, on the number of protons favours independent collision models and contradicts the coherent tube picture. The excess of fast positive particles behaves asA0.4 and shows, for the heavier nuclei, a clear correlation with identified protons.
AVERAGE MULTIPLICITIES OF ALL CHARGED PARTICLES.
AVERAGE MULTIPLICITIES OF ALL NEGATIVELY CHARGED PARTICLES.
The difference ΔσT=σ(↓↑)-σ(↑↑) between the proton-proton total cross sections for protons in pure transverse-spin states, was measured at incident momenta 0.8 to 2.5 GeV/c in experiments performed at the Los Alamos Clinton P. Anderson Meson Physics Facility and the Argonne Zero Gradient Synchrotron. In agreement with other data, peaks were observed at center-of-mass energies of 2.14 and 2.43 GeV/c2, where D21 and G41 dibaryon resonances have been proposed.
DATA FROM LAMPF EXPERIMENT.
DATA FROM ARGONNE EXPERIMENT.
The target asymmetry of the deuteron photodisintegration was measured at a photon energy of 550±50 MeV and at proton center-off-mass angles between 25 and 155 degrees.D-butanol andND3 were used as target material yielding a maximum deuteron polarization of 41%. Proton and neutron were detected in coincidence. The data show a structure which cannot be described by the existing analyses.
Axis error includes +- 8/8 contribution (UNCERTAINTY IN THE DETERMINATION OF THE TARGET POLARIZATION//OTHER SYSTEMATIC ERRORS ARE FROM COMPETING PROCESSES (<2 PCT) AND OTHERS (<1 PCT)).
We have studied the production of prompt muons in hadronic events from e+e− annihilation at a center-of-mass energy of 29 GeV with the PEP4-TPC (Time Projection Chamber) detector. The muon p and pt distributions are well described by a combination of bottom- and charm-quark decays, with fitted semimuonic branching fractions of (15.2±1.9±1.2)% and (6.9±1.1±1.1)%, respectively. The muon spectra imply hard fragmentation functions for both b and c quarks, with 〈z(b quark)〉=0.80±0.05±0.05 and 〈z(c quark)〉=0.60±0.06±0.04. We derive neutral-current axial-vector couplings of a(b quark)=-0.9±1.1±0.3 and a(c quark)=1.5±1.5±0.5 from the forward-backward asymmetries.
PT is the transverse momentum of the muon relative to the event thrust axis.
PT is the transverse momentum of the MUON relative to the event thrust axis. At this table MUON is from JET and its PT < 1 GeV/c.
PT is the transverse momentum of the MUON relative to the event thrust axis. At this table MUON is from JET and its PT > 1 GeV/c.
We present the results of a search for charm F mesons in 360 GeV/ c π − p interactions. Several methods have been used; all yield no evidence for the F and are interpreted as 90% confidence level cross section upper limits.
D/S+- lifetime was assumed tau = 3.2*10**-13 s.
D/S+- lifetime was assumed tau = 3.2*10**-13 s.
We present a measurement of the polarization and decay asymmetry parameters of the Ξ − inclusively produced in the forward direction in K − p interactions at 5 GeV/ c . The Ξ − decay parameters have been determined to be α Ξ = −0.405 ± 0.029 and Φ Ξ = 14.7° ± 16.0° from a sample of 20 865 events. A linear rise of the Ξ − polarization has been seen with respect to the transverse momentum of the Ξ − , reaching a maximum of 49 ± 4% at P ⊥ ∼ 0.50 GeV/ c . The value of α Ξ is consistent with the world average prior to 1975, but below the value measured by two recent experiments.
No description provided.
The inclusive production of γ's and πp0's inK−p-interactions at 32 GeV/c is studied. About 30.000 γ's coming from a Mirabelle bubble chamber experiment with a sensitivity of 6.5 ev/μb have been used for the analysis. Inclusive and topological cross sections of γ's are measured. The γ invariant differential distributions and their scaling properties are investigated. The inclusive cross section of πp0-production is determined and the πp0 invariant differential distributions are evaluated and compared to those of πp±.
No description provided.
THE CITED ERROR ON SIG( K- P --> GAMMA ANY ) TAKES INTO ACCOUNT THE UNCERTAINTIES IN THE CROSS SECTIONS CALCULATION PROCEDURE.
No description provided.
We present a study of leading protons and antiprotons inp-nucleus and\(\bar p\)-nucleus on Be, Cu, Ag, W, and U targets. The experiment was performed at the CERN-SPS at a beam energy of 120 GeV. For all targets a suppression of secondary antiprotons with respect to protons is observed. The difference between the\(\bar p\) andp spectra increases with decreasing χ-values and the effect is stronger for heavier nuclei. The features of the data are qualitatively consistent with multiple-collisions modesls. The data are analysed in terms of a dual parton model which gives a satisfactory description of leadingp and\(\bar p\) spectra.
No description provided.
The charmonium χ states are observed in both π− and p Be interactions near 200 GeV/c via their radiative decay into J/ψ. The χ(3510) and χ(3555) are produced with roughly equal cross sections in π− collisions while the χ(3555) dominates in p collisions. Simple gluon fusion can account for χ production with incident protons but additional mechanisms are needed for incident π−.
No description provided.
The masses, total widths, and leptonic widths of three triplet s-wave bb¯ states ϒ(4S), ϒ(5S), and ϒ(6S) are determined from measurements of the e+e− annihilation cross section into hadrons for 10.55<W<11.25 GeV. The resonances are identified from potential model results and their properties are obtained with the help of a simplified coupled-channels calculation. We find M(4S)=10.577 GeV, Γ(4S)=25 MeV, Γee(4S)=0.28 keV; M(5S)=10.845 GeV, Γ(5S)=110 MeV, Γee(5S)=0.37 keV; M(6S)=11.02 GeV, Γ(6S)=90 MeV, Γee(6S)=0.16 keV.
VISIBLE CROSS SECTION INTO HADRONS.
Forum