Production of ϱ 0 , K ∗0 , K ∗0 , and φ have been measured in proton-proton collisions at the CERN Intersecting Storage Rings (ISR) at low p T in the central region. The transverse mass spectra are well described by exp (− aμ T ), with a = −6.4±0.2 GeV −1 . The cross sections for d σ/ d y| y=0 are 6.5±0.8±1.2 mb for ϱ 0 , 1.9±0.3±0.3 mb for K ∗) , 1.9±03±03 mb for K ∗0 , and 60.±0.12±0.13 mb for φ , where the first error is statistical and the second is sytematic.
No description provided.
No description provided.
The mass and momentum transfer spectra of the charged K K system produced in the reaction π ± p→K s 0 K ± p are analyzed. The data have been collected at the CERN SPS with the Geneva-Lausanne two-arm, non-magnetic spectrometer at 30 and 50 GeV/ c incident momenta. The general features of the reactions at these energies and the results of partial-wave analyses of the two kaon system are presented. The channel is dominated by the diffractive production of even spin resonances. The spin 4 recurrence of the A 2 (1320) is clearly observed at 2040 MeV ( Γ =380 MeV. A new resonance is observed with a mass M =2450MeV and a width Γ =400 MeV; the quantum numbers of this state are found to be I G ( J PC )=1 −(6 ++ ) . The analysis also shows the decay of the decay of the meson ϱ′(1600) through the K K channel at both energies. The production amplitudes are determined both as a function of the K K effective mass and of the momentum transfer. Isoscalar natural parity exchange is dominant. The energy dependence between 10 and 50 GeV/ c is shown to be well described by a Regge pole model based on the f-dominated pomeron hypothesis. We compare the production mechanisms of the 2 + resonances A 2 (1320) and K ∗ (1430). Finally, we estimate the K K branching ratios of the spin 4 A 2 (2040) and spin 6 A 2 (2450) resonances.
No description provided.
D(SIG)/DT FOR 50 GEV IN RESONANCE REGIONS.
No description provided.
The reactions K ± p→K s 0 π ± p are studied at 30 and 50 GeV/ c . Data for these reactions were obtained using the Geneva-Lausanne spectrometer whose main characteristics are: (i) large forward acceptance; (ii) high-resolution time-of-flight for recoil proton momentum measurement; (iii) high data-taking rate and on-line pattern recognition. The K ∗ (1 − ), K ∗ (2 + ), K ∗ (3 − ) and K ∗ (4 + ) resonance parameters and production cross sections are determined. The K π production amplitudes are calculated both as a function of the K π mass and of the momentum transfer. Isoscalar natural parity exchange (NPE) is dominant. The NPE amplitudes are decomposed into pomeron- f-, ω-exchange contributions, and their energy dependence between 10 and 50 GeV/ c is shown to be well-described by a Regge pole model based on the f-dominated pomeron hypothesis.
CORRECTED TO INCLUDE BW TAILS AND THE FRACTION OF EVENTS OUTSIDE THE T-ACCEPTANCE OF THE SPECTROMETER.
FITS OF THE FORM -A*TP*EXP(BTP) ARE MADE BY THE AUTHORS AND THE VALUES OF A AND B ARE GIVEN HERE. MASS REGIONS OF THE FIT ARE:-. K*(890) 0.84 < M <0.94 GEV. K*(1430) 1.36 < M <1.5 GEV. K*(1780) 1.68 < M <1.88 GEV.
FITS OF FORM -A*TP*EXP(BTP) ARE MADE BY THE AUTHORS AND THE VALUES OF A AND B ARE GIVEN HERE. MASS REGIONS OF THE FIT ARE:-. K*(890) 0.84 < M <0.94 GEV. K*(1430) 1.36 < M <1.5 GEV. K*(1780) 1.68 < M <1.88 GEV.
The reactions π − p → p π − and π − p → p ϱ − ( ϱ − → π − π 0 ) at 10 GeV/ c with the proton in the forward direction in the c.m.s. are discussed on the basis of 953 elastic scattering events and 2240 events of the reaction π − p → p π − π 0 . The total backward cross sections are 0.52±0.10 and 1.52±0.28 μ b, respectively. In both cases the production mechanism is compatible with the dominance of the baryonic Δ δ Regge trajectory exchange. The ϱ − decay angular distributions are studied in the u -channel helicity frame and the spin density matrix elements are presented as functions of u .
No description provided.
DATA FROM PRIV COMM WITH B. GHIDINI.
DATA FROM PRIV COMM WITH B. GHIDINI.
Results are presented from the first p p colliding beam runs at the CERN ISR, using the UA5 streamer chamber detector. p p interactions at s = 53 GeV are compared with pp data taken in the same experiment. The results are in good agreement with extrapolations of low-energy p p data.
No description provided.
MOMENTS OF MULTIPLICITY DISTRIBUTIONS FOR P P AND P AP. MULT(NAME=DQ) IS <(N-<N>)**Q>**1/Q. MULT(NAME=NQ) IS <N**Q>.
Data read from plot.
None
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The elastic and inelastic\(\bar p\)p cross sections at 70 GeV/c have been determined in an experiment performed at CERN using BEBC equipped with a TST. The topological cross sections were measured and the moments of the inelastic multiplicity distribution are 〈nc〉=6.16±0.09, 〈nc〉/D=2.04±0.05 andf2cc=2.97±0.03. The average number of Dalitz pairs per inelastic event is (3.12±0.09)×10−2. Assuming that these all arise from π0 decay the average π0 multiplicity is\(\langle n_{\pi ^0 } \rangle= 2.71 \pm 0.14\). The\(\bar p\)p−pp cross section differences lead to an annihilation cross section σA = 4.42±0.41 mb and the moments of the annihilation multiplicty distribution are 〈nA〉=8.0±0.3, 〈nA〉/D=2.5±0.2 andf2A−−=−1.4±0.3. An independent check of σA was made by investigating fast forward charged and neutral secondary interactions in the TST and in the surrounding neon-hydrogen mixture, and gives a value σA = 5.0±1.6 mb. The ratio of fast\(\bar n\) to\(\bar p\) production in non-annihilation interactions at 70 GeV/c is found to be 0.45±0.11.
No description provided.
INELASTIC TOPOLOGICAL CROSS SECTIONS. NORMALIZED TO TOTAL INELASTIC CROSS SECTION OF 35.7 +- 0.5 MB (AYRES ET AL., PR D15, 3105).
No description provided.
Absolute inclusive cross sections for\(\bar pp\) interactions at 7.3 GeV/c are given. The data cover prong cross sections,V0, γ production and inclusive charged particle (p/π) production. Separation has been made into annihilation and non-annihilation components. Inclusive π+, π− production in the processes of\(\bar pp\) annihilation and non-annihilation are compared with simple quark models.
No description provided.
No description provided.
ANNIHILATION AND NON-ANNIHILATION TOPOLOGICAL CROSS SECTIONS.
We have measured, at an average centre-of-mass energy of 34.22 GeV a forward-backward charge asymmetry in the reaction e + e − → μ + μ − of value −0.161 ± 0.032. This demonstrates the existence of an axial vector neutral current with coupling strength of g e a g μ a =0.53 ± 0.10. We have also obtained a limit on the vector coupling strength of g e v g μ v <0.12. The Weinberg angle is found to be sin 2 θ W =0.29 +0.09 −0.11 . From the reaction e + e − → τ + τ − we have found g e a g τ a <0.34, g e v g τ v <0.55.
No description provided.
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An experiment using the Fermilab Single Arm Spectrometer (SAS) facility and an associated nonmagnetic vertex detector studied the reactions a+p→c+X, where a and c were π±, K±, p, or p¯. Extensive measurements were made at 100 and 175 GeV/c beam momenta with the outgoing hadrons detected in the SAS covering a kinematic range 0.12<x<1.0 and pT<1.25 GeV/c. Additional data covering a more restricted range in x were also gathered at 70 GeV/c incident momentum. In this high-statistics experiment, the identification of both the incoming and outgoing charged hadrons were made with a total of eight Čerenkov counters. New and extensive single-particle inclusive data for charged-particle production in low-pT hadronic fragmentation are presented. The average associated charged-particle multiplicity and pseudorapidity distributions are also given.
No description provided.
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