HEPData Search

The cross section for the production of π+π− or K+K− pairs in γγ interactions is measured for mππ between 1.7 and 3.5 GeV/c2 and for two intervals of γγ center-of-mass scattering angle. Results are compared with predictions of a QCD model.

2 data tables

Table 1

Data read off graph.

Table 2

Data read off graph.

Observation of a Narrow K anti-K State in J/psi Radiative Decays

The MARK-III collaboration Baltrusaitis, R.M. ; Becker, J. ; Blaylock, G. ; et al.

Phys.Rev.Lett. 56 (1986) 107, 1986.

Inspire Record 217856 DOI 10.17182/hepdata.20254

Evidence is presented for a narrow state, called ξ, in the decay modes J/ψ→γξ, ξ→K+K−, and ξ→KS0KS0. In the K+K− mode, the ξ has a mass of 2.230±0.006±0.014 GeV/c2, a width of Γ=0.026−0.016+0.020± 0.017 GeV/c2, a product branching ratio of (4.2−1.4+1.7±0.8)×10 −5, and a statistical significance of ∼4.5 standard deviations. In the KS0KS0 mode, it has a mass of 2.232±0.007±0.007 GeV/c2, a width of Γ=0.018−0.015+0.023± 0.010 GeV/c2, a product branching ratio of (3.1−1.3+1.6±0.7)×10 −5, and a statistical significance of ∼3.6 standard deviations. Limits on ξ decay to other final states are presented.

1 data table

Table 1

No description provided.

Upper Limits of the Proton Magnetic Form-factor in the Timelike Region From $\bar{p} p \to e^+ e^-$ at the {CERN} {ISR}

The Annecy(LAPP)-CERN-Genoa-Lyon-Oslo-Rome-Strasbourg-Turin collaboration Baglin, C. ; Baird, S. ; Bassompierre, G. ; et al.

Phys.Lett.B 163 (1985) 400-403, 1985.

Inspire Record 218159 DOI 10.17182/hepdata.49639

From the measurement of e + e - pairs from the reaction p̄p→e + e - at the CERN-ISR, using an antiproton beam and a hydrogen jet target, we derived upper limits for the proton magnetic form factor in the time-like region at Q 2 ⋍8.9( GeV c ) 2 and Q 2 ⋍12.5( GeV c ) 2 .

1 data table

Table 1

No description provided.

Evidence for Pomeron Single Quark Interactions in Proton Diffraction at the {ISR}

The R608 collaboration Smith, A.M. ; Meritet, L. ; Reyrolle, M. ; et al.

Phys.Lett.B 163 (1985) 267-272, 1985.

Inspire Record 216801 DOI 10.17182/hepdata.30332

Measurements are presented of two exclusive diffractive reactions, pp → (Λ 0 φ 0 K + ) p and pp → (Λ 0 Λ 0 p)p , at √ s = 63 GeV . Pronounced correlations with the beam direction are observed (in the rest frame of the forward-going bracketed system) for those outgoing particles which contain the beam valence quarks. In each case there is a forward-Λ 0 in correlation with a backward K + or p, respectively. No such behavior is seen for the particles which do not contain beam valence quarks (φ 0 and Λ 0 , respectively) . Interpreted as examples of pomeron-proton scattering, these results constitute evidence that, for these final states, the pomeron interacts with a single valence quark and apparently back-scatters it. The subsequent hadronization leads to a longitudinal event structure.

3 data tables

Table 1

Cross sections for forward LAMBDA signal counting both arms of the p p interaction.

Table 2

Cross sections for forward LAMBDA signal counting both arms of the p p interaction.

Table 3

No description provided.

A Measurement of Nuclear Effects in Deep Inelastic Muon Scattering on Deuterium, Nitrogen and Iron Targets

The BCDMS collaboration Bari, G. ; Benvenuti, A.C. ; Bollini, D. ; et al.

Phys.Lett.B 163 (1985) 282, 1985.

Inspire Record 216817 DOI 10.17182/hepdata.30331

New data is presented on the ratios of structure functions F 2 ( x , Q 2 ) measured in deep inelastic muon scattering with deuterium, nitrogen, and iron targets. The existence of nuclear effects at large Q 2 is confirmed with improved systematic accuracy. The ratio F 2 Fe ( x ) F 2 D 2 ( x ) covers the range 0.20 ⩽ x ⩽ 0.70 and is in agreement with earlier measurements. The ratio F 2 N 2 ( x )/ F 2 D 2 ( x ) is measured over the range 0.08 ⩽ x ⩽ 0.70 and is compatible with unity below x = 0.3.

2 data tables

Table 1

VALUES OF Q2 CORRESPONDING TO THE X-BINS IN THIS TABLE ARE:- 46-106,46-106,53-150,53-200,70-200,80-200 RESPECTIVELY.

Table 2

VALUES OF Q2 CORRESPONDING TO THE X-BINS IN THIS TABLE ARE:- 26-40,26-61,30-80,30-106,30-106,30-150,30-200,35-200,46-200.

rivet Analysis
Inclusive Charged Particle Distribution in Nearly Threefold Symmetric Three Jet Events at $e$({CM}) = 29-{GeV}

Petersen, A. ; Abrams, G.S. ; Amidei, D. ; et al.

Phys.Rev.Lett. 55 (1985) 1954, 1985.

Inspire Record 216850 DOI 10.17182/hepdata.20285

We report a measurement of the inclusive charged-particle distribution for gluon jets derived from nearly threefold-symmetric three-jet events taken at center-of-mass energy of 29 GeV in e+e− annihilation. The charged-particle spectrum for these jets is observed to fall off more rapidly than those of quark jets of the same energy.

1 data table

Table 1

Errors include both statistics and the uncertainty in correction factors. X is defined at the energy of the individual particle divided by the total energy of the jet to which it is assigned.

Study of the Reaction $\gamma \gamma \to 2 \pi^+ 2 \pi^- \pi^0$ and Upper Limits on the Production of $\gamma \gamma \to \omega \omega$ and $\gamma \gamma \to \rho^0 \omega$

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Lackas, W. ; et al.

Z.Phys.C 29 (1985) 183, 1985.

Inspire Record 220911 DOI 10.17182/hepdata.15911

A search for the reactionsγγ→ωω andγγ→ρ0ω has been carried out at an averagee+e− CM energy of 34.6 GeV with an integrated luminosity of 45 pb−1. Upper limits are set for these two channels over the γγ CM Energy range of 1.6 to 2.5 GeV. The cross section is determined for the exclusive channelγγ→π+2π−π0.

3 data tables

Table 1

Data read from graph.

Table 2

Data read from graph.

Table 3

Data read from graph.

Search for Two Photon Production of Resonances Decaying Into $K \bar{K}$ and $K \bar{K} \pi$

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Kirschfink, F.J. ; et al.

Z.Phys.C 29 (1985) 189, 1985.

Inspire Record 220941 DOI 10.17182/hepdata.16018

An analysis of the production ofKS0KS0 andK±Ks0π∓ by two quasi-real photons is presented. The cross section forγγ→K0$\overline {K^0 } $, which is given for the γγ invariant mass range fromK$\bar K$ threshold to 2.5 GeV, is dominated by thef′(1525) resonance and an enhancement near theK$\bar K$ threshold. Upper limits on the product of the two-photon width times the branching ratio intoK$\bar K$ pairs are given forΘ(1700),h(2030), and ξ(2220). For exclusive two-photon production ofK±Ks0π∓ no significant signal was observed. Upper limits are given on the cross section ofγγ→K+$\overline {K^0 } $π− orK−K0π+ between 1.4 and 3.2 GeV and on the product of the γγ width times the branching ratio into theK$\bar K$π final states for theηc(2980) and the ι(1440), yieldingΓ(γγ)→i(1440))·BR(i(1440)→K$\bar K$π<2.2 keV at 95% C.L.

2 data tables

Table 1

Data read from graph.. Corrected for the angular distribution, which is assumed to be sin(theta)**4 for W > 1.14 GeV and isotropic in the first bin.

Table 2

Data read from graph.

EVIDENCE FOR IOTA PRODUCTION IN HIGH-ENERGY e+ e- ANNIHILATION

The JADE collaboration Bartel, W. ; Becker, L. ; Cords, D. ; et al.

DESY-85-081, 1985.

Inspire Record 220907 DOI 10.17182/hepdata.45208

None

1 data table

Table 1

Background subtracted.

Date

Collaboration

Subject_areas

Phrases

Reactions

Observables

CM Energies (GeV)

Authors Reset

MEAN CHARACTERISTICS OF SECONDARY PARTICLES IN CUMULATIVE pi- C INTERACTIONS AT 40-GeV/c

rivet Analysis
Charged Meson Pair Production in $\gamma \gamma$ Interactions

Observation of a Narrow K anti-K State in J/psi Radiative Decays

Upper Limits of the Proton Magnetic Form-factor in the Timelike Region From $\bar{p} p \to e^+ e^-$ at the {CERN} {ISR}

Evidence for Pomeron Single Quark Interactions in Proton Diffraction at the {ISR}

A Measurement of Nuclear Effects in Deep Inelastic Muon Scattering on Deuterium, Nitrogen and Iron Targets

rivet Analysis
Inclusive Charged Particle Distribution in Nearly Threefold Symmetric Three Jet Events at $e$({CM}) = 29-{GeV}

Study of the Reaction $\gamma \gamma \to 2 \pi^+ 2 \pi^- \pi^0$ and Upper Limits on the Production of $\gamma \gamma \to \omega \omega$ and $\gamma \gamma \to \rho^0 \omega$

Search for Two Photon Production of Resonances Decaying Into $K \bar{K}$ and $K \bar{K} \pi$

EVIDENCE FOR IOTA PRODUCTION IN HIGH-ENERGY e+ e- ANNIHILATION