Date

Total Cross-Section for Hadron Production by e+ e- Annihilation at PETRA Energies

The JADE collaboration Bartel, W. ; Canzler, T. ; Cords, D. ; et al.
Phys.Lett.B 88 (1979) 171-176, 1979.
Inspire Record 142874 DOI 10.17182/hepdata.27277

The cross section for the process e + e − → multihadrons has been measured at the highest PETRA energies. We measure R (the total cross section in units of the point-like e + e - → μ + μ - cross section) to be 2.9 ± 0.7, 4.0 ± 0.5, 4.6 ± 0.4 and 4.2 ± 0.6 at s of 22, 27.7, 30 and 31.6 GeV, respectively. The observed average multiplicity, together with existing low energy data, indicate a rapid increase in multiplicity with increasing energy.

2 data tables

STATISTICAL ERRORS ONLY. RADIATIVE CORRECTIONS APPLIED AND TAU HEAVY LEPTON CONTRIBUTION SUBTRACTED. AVERAGE VALUE OF R FOR ALL THESE DATA IS 4.14 +- 0.26.

AVERAGE CHARGE MULTIPLICITY. ADDITIONAL, SYSTEMATIC ERROR IS ABOUT 1.5.


Measurement of High-energy Direct Photons in $\psi$ Decays

Abrams, G.S. ; Alam, M.S. ; Blocker, C.A. ; et al.
Phys.Rev.Lett. 44 (1980) 114, 1980.
Inspire Record 142835 DOI 10.17182/hepdata.20729

The inclusive γ and π0 momentum distributions at the ψ have been measured. Using these data and estimates of η production, it is found that (4.1 ± 0.8)% of ψ decays contain a direct photon with energy greater than 60% of the beam energy. The expected momentum distribution for direct photons calculated to lowest order in quantum chromodynamics is qualitatively different from that observed in the data.

1 data table

INCLUSIVE PHOTON AND PI0 MOMENTUM DISTRIBUTION.


Evidence for Direct $\gamma$ Production at Large $x$ in $\psi$ (3100) Decay

Ronan, M.T. ; Trippe, T.G. ; Barbaro-Galtieri, A. ; et al.
Phys.Rev.Lett. 44 (1980) 367, 1980.
Inspire Record 142946 DOI 10.17182/hepdata.20700

The inclusive γ and π0 momentum spectra from ψ(3100) decay have been measured in e+e− annihilation at SPEAR. When the γ spectrum is compared with that expected from π0 decay, an excess of high-momentum γ's is observed. This excess is compared with that predicted by quantum chromodynamics for the decay of the ψ into a γ and two gluons.

4 data tables

THE STATISTICAL AND SYSTEMATIC ERRORS ARE GIVEN SEPARATELY AS WELL AS COMBINED IN QUADRATURE FOR THE QUOTED TOTAL ERROR.

THE STATISTICAL AND SYSTEMATIC ERRORS ARE GIVEN SEPARATELY AS WELL AS COMBINED IN QUADRATURE FOR THE QUOTED TOTAL ERROR. SYSTEMATIC ERROR IS 17 PCT.

QUOTED ERRORS ARE STATISTICAL. SYSTEMATIC ERROR IS 20 PCT. ONLY HALF THE SUM OF THE PI+ AND PI- CROSS SECTIONS IS PLOTTED IN THE FIGURE IN THE JOURNAL.

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Measurement of the Parameters of the $\psi^{\prime\prime}$(3770) Resonance

Abrams, G.S. ; Alam, M.S. ; Blocker, C.A. ; et al.
Phys.Rev.D 21 (1980) 2716, 1980.
Inspire Record 142644 DOI 10.17182/hepdata.24185

We present a measurement of the cross section for hadron production by e+e− annihilation in the vicinity of the previously observed resonance near 3.77 GeV. The data are used to determine the parameters of the ψ(3770) resonance. The values found are: mass, 3764±5 MeV/c2, total width, 23.5±5 MeV, and partial width to electron pairs, 276±50 eV.

3 data tables

THESE RESULTS ARE ALSO IN THE THESIS OF R. H. SCHINDLER, SLAC-219 (1979), THE RECORD OF WHICH CONTAINS THE TABULATED CROSS SECTIONS.

BREIT-WIGNER RESONANCE PLUS BACKGROUND FIT TO RADIATIVELY CORRECTED DATA YIELDS RESONANCE MASS OF 3764 +- 5 MEV, TOTAL WIDTH OF 23.5 +- 5 MEV AND PARTIAL WIDTH TO ELECTRON PAIRS OF 276 +- 50 EV.

PEAK CROSS SECTION FOR D MESON PAIR PRODUCTION AT PSI(3770) RESONANCE. J/PSI, PSI(3684) AND CONTINUUM BACKGROUND (R=2.5) SUBTRACTED.


Study of the Reaction $\bar{\nu} p \to \mu^+ p \pi^-$

Barish, S.J. ; Brock, R. ; Engler, A. ; et al.
Phys.Lett.B 91 (1980) 161, 1980.
Inspire Record 8430 DOI 10.17182/hepdata.51335

We present data on the reaction ν p → μ + pπ − from an exposure of the Fermilab 15 ft hydrogen bubble chamber. The channel cross section for 5 GeV < E ν < 70 GeV and M( p π − ) < 1.9 GeV is σ = (27 ± 5) × 10 −40 cm 2 . This cross section is dominated by the I = 1 2 production amplitude.

1 data table

No description provided.


Charmed Multiplicities in $K^- p$ Interactions at 110-{GeV}/$c$

The Aachen-Berlin-CERN-Cracow-London-Vienna-Warsaw collaboration Ransone, G. ; Sixel, P. ; Kaufmann, H.H. ; et al.
Nucl.Phys.B 167 (1980) 285-291, 1980.
Inspire Record 144124 DOI 10.17182/hepdata.34553

The charged multiplicity distribution is presented for K − p interactions produced in the hydrogen bubble chamber, BEBC, using an r.f. separated, tagged K − beam of 110 GeV/ c momentum. A comparison with K + p, πp and pp data at lower energies shows that the main features of the multiplicity distributions depend on energy and charge of the incident particles, but not on their strangeness. At high energies, only the energy is important.

3 data tables

No description provided.

No description provided.

No description provided.


Rapid Growth of Charged Particle Multiplicity in High-Energy e+ e- Annihilations

The TASSO collaboration Brandelik, R. ; Braunschweig, W. ; Gather, K. ; et al.
Phys.Lett.B 89 (1980) 418-422, 1980.
Inspire Record 143691 DOI 10.17182/hepdata.27273

Hadron production by e + e − annihilation has been studied for c.m. energies W between 13 and 31.6 GeV. As a function of 1n W the charged particle multiplicity grows faster at high energy than at lower energies. This is correlated with a rise in the plateau of the rapidity distribution. The cross section s d σ /d x is found to scale within ±30% for x > 0.2 and 5 ⩽ W ⩽ 31.6 GeV.

7 data tables

CHARGED PARTICLE MULTIPLICITIES.

RAPIDITY DISTRIBUTION.

RAPIDITY DISTRIBUTION.

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MEASUREMENT OF J / psi PRODUCTION IN 280-GeV/c mu+ IRON INTERACTIONS

The European Muon collaboration Aubert, J.J. ; Bassompierre, G. ; Becks, K.H. ; et al.
Phys.Lett.B 89 (1980) 267-270, 1980.
Inspire Record 143938 DOI 10.17182/hepdata.27264

Virtual photoproduction of J/ ψ mesons has been measured for 280 GeV muon iron interactions in an iron/scintillator calorimeter target. The J/ψ's were identified by their decay into muon pairs. 315 events were observed, about half of which were elastic. The t , Q 2 and v distributions of these elastic events are presented. The v dependence is measured between 40 and 180 Mev and compared with lower energy photoproduction results. The Q 2 dependence is compared with the predictions of the vector dominance model.

4 data tables

TPRIME DISTRIBUTION OF ELASTIC J/PSI EVENTS FOR ALL Q2 AND NU WITH 280 GEV MUON BEAM.

NORMALIZED Q**2 DISTRIBUTION OF ELASTIC J/PSI EVENTS FOR ALL NU AND T WITH 280 GEV MUON BEAM.

EXTRAPOLATION OF Q**2 AND T DEPENDENCE TO CALCULATE D(SIG)/DT AT Q**2=0 AND T=0 FOR ELASTIC J/PSI PHOTOPRODUCTION PER NUCLEON.

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Inclusive High {P(T)} $\omega^0$ and $\eta{'}$ Production at the {ISR}

Diakonou, M. ; Kourkoumelis, C. ; Resvanis, L.K. ; et al.
Phys.Lett.B 89 (1980) 432-436, 1980.
Inspire Record 143931 DOI 10.17182/hepdata.27254

The inclusive production cross section of ω 0 and η′ were measured at transverse momenta of 3 to 7GeV/ c at 90° in the centre of mass. The ω 0 /π 0 and η′/π 0 production ratios were found to be 0.87 ± 0.17 and 0.9 ± 0.25, respectively, at 3.5 GeV and constant up to 7 GeV/ c . The large meson/ π 0 production ratio supports the hypothesis that high- p T mesons are the leading fragments of the basic constituent jet. The η ′/ η ratio exemplifies the SU(3) singlet nature of the η ′.

2 data tables

OMEGA DECAY TO PI0 GAMMA IS DETECTED.

ETAPRIME DECAY TO GAMMA GAMMA IS DETECTED.


Comparison of the Differential Cross-sections for $\pi^- p \to \eta^\prime n$ and $\pi^- p \to \eta n$ at 8.45-{GeV}/$c$

Stanton, N.R. ; Edwards, K.W. ; Legacey, D. ; et al.
Phys.Lett.B 92 (1980) 353-357, 1980.
Inspire Record 8522 DOI 10.17182/hepdata.27193

The ratio R of the differential cross sections for π - p→ η ′n and π - p → η n has been measured with high statistics and small systematic errors at 8.45 GeV/ c . R is generally interpreted as the relative content of nonstrange, ground-state quarks in η' and η. We find that R decreases with increasing ⋎ t ⋎; however, extrapolation to t =0 gives R (0) = 0.672 ± 0.032 (statistical) ± 0.47 (systematic) for the dominant spin flip cross sections, and R (0) = 0.500 ± 0.035 for the spin non-flip, in excellent agreement with results at higher energy. An improved value of the branching fraction ( η '→ γγ )/( η '→all) of 0.0200 ± 0.0018 is obtained.

2 data tables

No description provided.

No description provided.