Date

A Study of the $\Delta \pi \pi$ System in the Reaction $\pi^- p \to \pi^- p \pi^+ \pi^- \pi^0$ at 4.5-{GeV}/$c$

Sugahara, R. ; Suzuki, A. ; Fukawa, M. ; et al.
Nuovo Cim.A 52 (1979) 373, 1979.
Inspire Record 142331 DOI 10.17182/hepdata.37520

Two (Δ(1238)ππ) enhancements at 1.93 and 2.12 GeV have been observed in an analysis of the invariant-mass spectra of Δ++(1238)π-π0 and Δ++(1238)π-π- from π-p→π-pπ+π-π0 events in 4.5 GeV/c π-p interactions. An enhancement at 2.2 GeV is also seen with a dominant branching to the Δ(1238)ρ system. The 1.93 and 2.12 enhancements seem to be produced mainly through a ρ-meson exchange process. The 2.2 GeV enhancement seems to be produced diffractively and is considered to correspond to theG17(2190) state.

2 data tables

No description provided.

EXPONENTIAL FITS TO T-DISTRIBUTIONS.


Study of Electron - Positron Collisions at the Center-of-mass Energies of 27.4-{GeV} and 27.7-{GeV} at {PETRA}

Barber, D.P. ; Becker, U. ; Benda, H. ; et al.
Phys.Rev.Lett. 43 (1979) 901, 1979.
Inspire Record 141542 DOI 10.17182/hepdata.20739

This paper reports on the first results of the study of e+e− collisions at s=27.4 GeV and s=27.7 GeV at PETRA, using the 4π-sr electromagnetic and calorimetric detector MARK-J. We obtain an average R=σ(e+e−→hadrons)σ(e+e−→μ+μ−)=3.8±0.3 (statistical)±0.6 (systematic) and a relative R=1.0±0.2 between the two energies. The R values, the measured thrust distribution, and average spherocity show no evidence for the production of new quark flavors.

2 data tables

THE RELATIVE VALUE OF R BETWEEN THESE TWO ENERGIES IS 1.0 +- 0.2.

THRUST DISTRIBUTION (1/N)*DN/DTHRUST AT 13, 17 AND 27 GEV. THESE DATA ARE RATHER DETECTOR DEPENDENT.


Spin Spin Forces in 6-{GeV}/$c$ Neutron - Proton Elastic Scattering

Crabb, D.G. ; Hansen, P.H. ; Krisch, A.D. ; et al.
Phys.Rev.Lett. 43 (1979) 983, 1979.
Inspire Record 141922 DOI 10.17182/hepdata.20753

Measurement was made of dσdt for n↑+p↑→n+p at P⊥2=0.8 and 1.0 (GeV/c)2 at 6 GeV/c. The 6-GeV/c 53%-polarized neutrons from the 12-GeV/c polarized deuteron beam at the Argonne zero-gradient synchroton were scattered from our 75%-polarized proton target. Both spins were oriented perpendicular to the scattering plane. We found large unexpected spin-spin effects in n−p elastic scattering which are quite different from the p−p spin-spin effects.

1 data table

No description provided.


D MESON PRODUCTION IN e+ e- ANNIHILATION

Rapidis, Petros A. ;
PhD Thesis, 1979.
Inspire Record 141598 DOI 10.17182/hepdata.18894
4 data tables

THESE TABULATED VALUES OF THE TOTAL CROSS SECTION RATIO R ARE INCLUDED IN THE RECORD OF P. A. RAPIDIS ET AL., PRL 39, 526 (1977) AND PRL 39, 974 (1977) (ERRATUM).

THE D MESON INCLUSIVE PRODUCTION CROSS SECTIONS AND DECAY BRANCHING FRACTIONS AT THE PSI(3772)0 RESONANCE ARE PUBLISHED IN I. PERUZZI ET AL., PRL 39, 1301 (1977).

THESE D AND K MESON INCLUSIVE PRODUCTION CROSS SECTIONS ARE PUBLISHED IN M. PICCOLO ET AL., PL 86B, 220 (1979).

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Study of the Reaction $e^+ e^- \to p \bar{p}$ in the Total Energy Range 1925-{MeV} - 2180-{MeV}

Delcourt, B. ; Derado, I. ; Bertrand, J.L. ; et al.
Phys.Lett.B 86 (1979) 395-398, 1979.
Inspire Record 141565 DOI 10.17182/hepdata.27308

The e + e − → p p cross section has been measured between 1925 and 2180 MeV. About 50 p p events were detected. The total cross section decreases from 1.31 ± 0.4 nb near 1937 MeV to 0.55 ± 0.2 nb near 2135 MeV. The proton form factors | G E | 2 and | G M | 2 , assumed identical, decrease from 0.15 ± 0.05 to 0.043 ± 0.015. They are an order of magnitude higher than predicted by the well-known dipole fit. The energy range has been scanned in steps of about 2 MeV. No significant structure was found in this p p sample.

1 data table

TOTAL CROSS SECTION ASSUMING ISOTROPIC PRODUCTION. RADIATIVE CORRECTIONS CALCULATED USING PEAKING APPROXIMATION (ABOUT 20 PCT). AUTHORS ALSO QUOTE RESULTS FOR LIMITED (COSMIC RAY FREE) ACCEPTANCE AS A CHECK. FORM FACTOR DERIVED ASSUMING ELECTRIC AND MAGNETIC FORM FACTORS EQUAL IN MAGNITUDE.


Reaction $\pi^- p \to \omega n$ in the 15-{GeV}/$c$ - 40-{GeV}/$c$ Momentum Range

The Serpukhov-CERN collaboration Apel, W.D. ; Augenstein, K.H. ; Krüger, M. ; et al.
Lett.Nuovo Cim. 25 (1979) 493, 1979.
Inspire Record 142561 DOI 10.17182/hepdata.37383

None

7 data tables

DATA OBTAINED IN ASSUMPTION THAT RHO(MM=00,P=3,XYZ=SH)=1-2*RHO(MM=1-1,P=3,XYZ=SH).

INTEGRATED CROSS SECTION, INCLUDING SYSTEMATIC UNCERTAINTY IN ERRORS Axis error includes +- 15/15 contribution (DECAY-BR(BRN=OMEGA --> PI0 GAMMA,BR=0.088 +- 0.005)).

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Measurements of the Double Polarization Parameters $G$ and $H$ in Neutral Pion Photoproduction

Bussey, P.J. ; Rutherglen, J.G. ; Booth, P.S.L. ; et al.
Nucl.Phys.B 159 (1979) 383-396, 1979.
Inspire Record 141663 DOI 10.17182/hepdata.34624

Measurements have been made of the double polarisation parameters G and H in the photoproduction of neutral pions from protons, for incident photon energies between 1300 MeV and 2300 MeV and for pion c.m. angles between 50δ and 80δ. The results are compared with predictions from a recent comprehensive analysis of earlier photoproduction data.

11 data tables

No description provided.

No description provided.

No description provided.

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Cross-sections and Multiplicity Distributions for $K^+ p$ Interactions at 70-{GeV}/$c$

Barth, M. ; De Clercq, C. ; De Wolf, E. ; et al.
Z.Phys.C 2 (1979) 285, 1979.
Inspire Record 141693 DOI 10.17182/hepdata.2107

Cross sections and charged multiplicity distributions forK+p interactions at 70 GeV/c are presented and compared withK+p data at other energies. Comparisons are also made with available π+p,pp, andK−p data.

2 data tables

No description provided.

No description provided.


The Investigation of the $\pi^- p \to \pi^0 \pi^0 n$ Reaction Near the Threshold

Belkov, A.A. ; Bunyatov, S.A. ; Zalikhanov, B.Zh. ; et al.
Sov.J.Nucl.Phys. 31 (1980) 96, 1980.
Inspire Record 142916 DOI 10.17182/hepdata.18169

None

2 data tables

FIRST VARIANT OF INSTALLATION.

SECOND VARIANT OF INSTALLATION.


The Contribution of $q \bar{q}$ Annihilations to Dimuon Production in $\pi N$ Interactions

Reece, C. ; LeBritton, J. ; McCal, D. ; et al.
Phys.Lett.B 85 (1979) 427-431, 1979.
Inspire Record 7886 DOI 10.17182/hepdata.27323

We present data on dimuon production by 16 GeV π + and π − beams on a Cu target. From the data we evaluate, for π − N collisions, the fraction of dimuon events that originate from the annihilation process q q ̄ → μ + μ − . Using this information the experimentally determined cross section for the process q q ̄ → μ + μ − is observed to be in agreement with the Drell-Yan model over a wide range of incident energies. The observed deviations from exact scaling are of the order predicted by QCD calculations for the Q 2 -dependence of the nucleon and the pion structure function.

2 data tables

CROSS SECTIONS ARE PER COPPER NUCLEUS.

CROSS SECTIONS ARE PER COPPER NUCLEUS.