HEPData Search

In order to determine the ηNN coupling constant we have measured the two reactions K − p→ Λη and K − p→ Λπ 0 with a magnetic wire chamber spectrometer which contained a gamma counter for the γγ decays of π 0 and η. The Λ polarization and the differential cross sections are given. The latter have quite different u dependences. Their ratio is interpreted, in terms of a nucleon-Regge exchange model, as the effect of a small ηNN coupling constant for which we obtain G η NN 2 = G π NN 2 · (0.26 ± 0.10) as allowed by SU(3). The large value given by Heisenberg's non-linear field theory, G η NN 2 = G π NN 2 · 0.9, is excluded by this measurement if the characteristic u dependence of the Λπ 0 channel is attributed to N α Regge exchange.

4 data tables

Table 1

Axis error includes +- 10/10 contribution.

Table 2

No description provided.

Table 3

Axis error includes +- 10/10 contribution.

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Neutron-Proton Forward Angle Elastic Cross-Sections at 790-MeV

Carlini, R. ; Dieterle, B. ; Donahue, J. ; et al.

Phys.Rev.Lett. 41 (1978) 1341-1344, 1978.

Inspire Record 136558 DOI 10.17182/hepdata.20861

High-statistics measurements of the absolute differential cross section for n−p scattering have been made over neutron c.m.-system scattering angles 9.5°<θ*<64.5°. The statistical error is 1.7 to 3.3% for 2°-wide angular bins, and the systematic error is 2.7 to 3.3%. The cross section is fitted by dσdΩ*=A exp(bt), with A=10.27±0.36 mb/sr, b=5.00±0.05, and 0.01<−t<0.39 (GeV/c)2. For the ratio of the real to the imaginary part of the forward-scattering amplitude we obtained αn>~−0.43±0.04, consistent with other less precise determinations of αn.

1 data table

Table 1

EXPONENTIAL FIT TO D(SIG)/DOMEGA OVER -T = 0.01 TO 0.39 GEV**2 (THETA = 9.5 TO 64.5 DEG).

Search for Narrow Resonances in $e^+ e^-$ Annihilation at c.m. Energies Between 29.90-{GeV} and 31.46-{GeV}

The JADE collaboration Bartel, W. ; Cords, D. ; Dittmann, P. ; et al.

Phys.Lett.B 91 (1980) 152-154, 1980.

Inspire Record 152290 DOI 10.17182/hepdata.27258

A search for narrow resonances in e + e − annihilation at c.m. energies between 29.90 and 31.46 GeV provides no evidence for the existence of such states. The 90% confidence upper limit on the integrated resonance cross section is 38 nb MeV, significantly below the value expected for the lowest (t,t̄) bound state.

1 data table

Table 1

No description provided.

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

Table 1

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

Table 2

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

Table 3

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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A Study of anti-N p Annihilations Around 0.65-GeV/c

The Bombay-CERN-Neuchatel-Tokyo collaboration Hamatsu, R. ; Kitamura, S. ; Yamagata, T. ; et al.

Nucl.Phys.B 137 (1978) 283, 1978.

Inspire Record 121760 DOI 10.17182/hepdata.35091

n p annihilations with ⩾ 3 prongs with an incident antineutron momentum between 0.5 and 0.8 GeV/ c are analysed. We present the topological branching ratios and cross sections, the resonance production rates and possible ϱ-ω interference effects.

1 data table

Table 1

CHANNEL FRACTIONS IN <2PI+ PI- PI0> FINAL STATE.

Multiplicity of Secondary Charged Particles in One Nucleon and Multi - Nucleon Interactions of $\pi$ Mesons With Carbon Nucleons at $p=40$-{GeV}/$c$

Grishin, V.G. ; Jenik, L. ; Kanarek, T. ; et al.

Sov.J.Nucl.Phys. 31 (1980) 772, 1980.

Inspire Record 145721 DOI 10.17182/hepdata.18202

None

20 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Rho0 Production in 205-GeV/c p p Interactions

Singer, R. ; Fields, T.H. ; Hyman, L.G. ; et al.

Phys.Lett.B 60 (1976) 385-388, 1976.

Inspire Record 2818 DOI 10.17182/hepdata.6484

Inclusive and semi-inclusive ρ 0 production are studied in 205 GeV/ c pp interactions. The number of ρ 0 per inelastic event is 0.33 ± 0.06, so that (13 ± 2)% of the π − are products of ϱ 0 decay. The ρ 0 are found to be produced mainly near y = 0 and tend to have larger average transverse momentum than do pions.

6 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Observation of Charmed Baryon Production in e+ e- Annihilation

Abrams, G.S. ; Alam, M.S. ; Blocker, C.A. ; et al.

Phys.Rev.Lett. 44 (1980) 10, 1980.

Inspire Record 142743 DOI 10.17182/hepdata.20754

A peak in the pK−π+ and p¯K+π− invariant-mass spectra at 2.285±0.006 GeV/c2 is observed, which is associated with the lowest-lying charmed baryon (Λc). A cross section times branching ratio of 0.037±0.012 nb at Ec.m.=5.2 GeV is measured with a substantial fraction of the events produced with an equal recoiling mass. New measurements of inclusive p and Λ cross sections are also presented, allowing an estimate of the branching ratio B(Λc→pK−π+)=0.022±0.010.

3 data tables

Table 1

THE TOTAL INCLUSIVE CHARMED LAMBDA CROSS SECTION IS DERIVED FROM THE OBSERVED PRODUCTION RATE VIA THE <P K- PI+> CHANNEL USING THE STEP IN INCLUSIVE PROTON PRODUCTION AT THE CHARMED-BARYON THRESHOLD AND REASONABLE ASSUMPTIONS. THE BRANCHING RATIO (LAMBDA/C+ --> P K- PI+) IS THEN 2.2 +- 1.0 PCT.

Table 2

ACTUALLY TWICE THE INCLUSIVE ANTI-PROTON CROSS SECTION (EACH BARYON PAIR IS COUNTED TWICE).

Table 3

EACH BARYON PAIR PRODUCED IS OF COURSE COUNTED TWICE IN THIS CROSS SECTION.

Date

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Reactions

Observables

CM Energies (GeV)

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Study of Dimensions of Radiation Region of Secondary Negative Pions in $\pi^- p$, $\pi^- n$ and $\pi^-$ C Interactions at 40-{GeV}/$c$

MULTIPLICITY OF NEGATIVE PIONS PRODUCED IN CENTRAL COLLISIONS OF RELATIVISTIC NUCLEI

Measurement of the Baryon Exchange Reactions $K^- p \to \Lambda \eta$, $K^- p \to \Lambda \pi^0$ at 6-{GeV}/$c$ and the Value of the $\eta N N$ Coupling Constant

Neutron-Proton Forward Angle Elastic Cross-Sections at 790-MeV

Search for Narrow Resonances in $e^+ e^-$ Annihilation at c.m. Energies Between 29.90-{GeV} and 31.46-{GeV}

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

A Study of anti-N p Annihilations Around 0.65-GeV/c

Multiplicity of Secondary Charged Particles in One Nucleon and Multi - Nucleon Interactions of $\pi$ Mesons With Carbon Nucleons at $p=40$-{GeV}/$c$

Rho0 Production in 205-GeV/c p p Interactions

Observation of Charmed Baryon Production in e+ e- Annihilation