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rivet Analysis
Inclusive $\phi$ Meson Production in Electron - Positron Interactions in the Energy Region of the $\Upsilon$ Resonances

The ARGUS collaboration Albrecht, H. ; Bockmann, P. ; Glaser, R. ; et al.

Z.Phys.C 41 (1989) 557, 1989.

Inspire Record 262551 DOI 10.17182/hepdata.15528

We report on a high precision measurement of ϕ-meson production in continuum events and in direct decays of the Υ(1S)- and Υ(2S)-mesons. The ratio of the total production rate of ϕ-mesons in direct Υ(1S)- and Υ(2S)-decays over that in continuum events is 1.32±0.08±0.09 and 1.07±0.13±0.11 respectively. This is compatible with the corresponding ratio obtained for lighter mesons, but is appreciably smaller than the relative baryon production rate.

6 data tables

Table 1

PHI meson cross section on the continuum.

Table 2

Differential particle density for PHI mesons in decays of upsilon(1S) and upsilon(2S).

Table 3

No description provided.

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rivet Analysis
Observation of the Charmed Baryon $\Sigma(c$) in $e^+ e^-$ Annihilations

The ARGUS collaboration Albrecht, H. ; Bockmann, P. ; Glaser, R. ; et al.

Phys.Lett.B 211 (1988) 489-492, 1988.

Inspire Record 261672 DOI 10.17182/hepdata.29913

Using the ARGUS detector at the DORIS II storage ring, we have observed the charmed baryons Σ c ++ and Σ c 0 , through their decays to Λ c + π ± . We have measured the mean Σ c −Λ c + mass difference as 167.6±0.3±1.6 MeV/ c 2 . The isospin mass splitting between the Σ c ++ and the Σ c 0 was found to be 1.2±0.7±0.3 MeV/ c 2 . The rate of Λ c + production from Σ c decays was found to be (36±12±11)% of the total rate of Λ c + production. The Σ c χ p spectrum was observed to be similar to that of the Λ c + , with a Peterson function parameter ϵ of 0.29±0.06.

1 data table

Table 1

DATA FROM UPSI(4S) WAS EXCLUDED.

Evidence for Anomalous Prompt Photons in Deep Inelastic Muon Scattering at 200-{GeV}

The European Muon collaboration Aubert, J.J. ; Bassompierre, G. ; Becks, K.H. ; et al.

Phys.Lett.B 218 (1989) 248-256, 1989.

Inspire Record 261250 DOI 10.17182/hepdata.29855

The inclusive yield of photons has been measured from deep inelastic interactions of 200 GeV muons on hydrogen. After subtracting the contributions from hadron electromagnetic decays and Bethe-Heitler muon bremsstrahlung, residual photons are observed at low p T and low z at a mean level of 0.15±0.06 per interaction. The quark Compton scattering process is unable to explain the data, thus indicating an anomalous photon production.

2 data tables

Table 1

Z distribution of anomalous direct photons.

Table 2

PT distribution of anomalous direct photons.

Observation of Inclusive $B$ Meson Decays Into $\Lambda(c$)+ Baryons

The ARGUS collaboration Albrecht, H. ; Bockmann, P. ; Glaser, R. ; et al.

Phys.Lett.B 210 (1988) 263-266, 1988.

Inspire Record 260762 DOI 10.17182/hepdata.29928

We report the first direct observation of B meson decays into Λ c + baryons using the decay channel Λ c + → pK − π + . The product of branching ratios Br(B→Λ c + X)·Br(Λ c + →pK − π + = (0.30±0.12±0.06)% is derived from an observed signal of 208±89 events. Using previous measurements of inclusive baryon rates we find a branching ratio for Λ c + → pK − π + of (4.1±2.4)%. The measured Λ c + momentum spectrum indicates that the multi-particle final states dominate the decay B→Λ c + X.

1 data table

Table 1

ACCEPTANCE CORRECTED.

Observation of the Charmed Baryon $\Lambda(c$) in $e^+ e^-$ Annihilation at 10-{GeV}

The ARGUS collaboration Albrecht, H. ; Bockmann, P. ; Glaser, R. ; et al.

Phys.Lett.B 207 (1988) 109-114, 1988.

Inspire Record 260826 DOI 10.17182/hepdata.29980

Using the ARGUS detector at DORIS II, we have studied the production of the charmed baryon Λ c in e + e − annihilation at centre-of-mass energies near 10 GeV. The Λ c + was seen in the three decay modes pK − π + , Λπ + π − π + and K̄ 0 p, with products of normalized cross section times branching ratio [ R ·Br] of (10.8±1.4±1.2)×10 −3 , 6.6±1.5±0.9)×10 −3 and (6.7±1.4±0.8)×10 −3 respectively. The measured mass for the Λ c was (2283.1±1.7±2.0) MeV/ c 2 . A limit on the decay rates to Λπ + is reported. The fragmentation function of the Λ c was measured.

2 data tables

Table 1

Data requested from authors.

Table 2

No description provided.

Comparison of the Particle Flow in $q \bar{q} \gamma$ and $q \bar{q} g$ Events From $e^+ e^-$ Annihilations at {PETRA}

The JADE collaboration Saada, F.Ould ; Allison, J. ; Ambrus, K. ; et al.

Z.Phys.C 39 (1988) 1, 1988.

Inspire Record 260834 DOI 10.17182/hepdata.15623

The particle flow distributions in the event plane of 3-jet$(e^ +e^ -\to q\bar qg)$ and of radiative 2-jet$(e^ +e^ -\to q\bar q\gamma )$ events are compared at a centre of mass energy of 35 GeV. The number of particles in the angular region opposite to the gluon in$q\bar qg$ events is found to be significantly reduced relative to the number of particles in the region opposite to the hard photon in$q\bar q\gamma $ events. This depletion is expected from the “string effect” observed in 3-jet events. It can be explained within the framework of QCD as arising from soft gluon interference.

1 data table

Table 1

Data requested from authors.

LOW-ENERGY PION YIELD AT HIGH-ENERGY ACCELERATORS AS A FUNCTION OF THE PRIMARY PROTON BEAM MOMENTUM

Bertin, A. ; Bruschi, M. ; Capponi, M. ; et al.

Nuovo Cim.A 100 (1988) 305-308, 1988.

Inspire Record 270462 DOI 10.17182/hepdata.37844

High yields of low-momentum pions were obtained from high-energy primary proton beams. The results are discussed, also with respect to the possibility of setting up cloud muon beams from the very lowmomentum poins produced by 10 GeV/c protons.

1 data table

Table 1

Data obtained with 30 cm long target.

Exclusive $\rho^0$ and $\phi$ Production in Deep Inelastic Muon Scattering

The European Muon collaboration Ashman, J. ; Badelek, B. ; Baum, G. ; et al.

Z.Phys.C 39 (1988) 169, 1988.

Inspire Record 252743 DOI 10.17182/hepdata.15619

Data are presented on exclusive ρ0 and ϕ production in deep inelastic muon scattering from a target consisting mainly of nitrogen. The ratio of the total cross sections for ρ0 and ϕ production is found to be 9∶(1.6±0.4) at 〈Q2〉=7.5 GeV2, consistent with theSU(3) prediction of 9∶2. Thet dependence for exclusive ρ0 production is found to become shallover asQ2 increases and, for largeQ2, thet dependence is typical of that for a hard scattering process. Furthermore, the ratio of the cross sections for coherent: incoherent production from nitrogen is found to decrease rapidly withQ2. Such behaviour indicates that even for exclusive vector meson production the virtual photon behaves predominantly as an electromagnetic probe.

6 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Tensor Meson Excitation in the Reaction $\gamma \gamma \to K^0_S K^0_S$

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

Z.Phys.C 37 (1988) 329, 1988.

Inspire Record 250982 DOI 10.17182/hepdata.15690

In the analysis of the reactione+e−→e+e−KS0Ks0 clear evidence for exclusive γγ→f2′ resonance production is observed. The productΓγγ ·B(f2′→K$\bar K$) is measured to be 0.10−0.03−0.02+0.04+0.03 keV independent of ana priori assumption on the helicity structure. Our data are consistent with a pure helicity 2 contribution and we derive an upper limit for the ratioΓγγ(0)/Γγγ. The absence of events in the mass region around 1.3 GeV clearly proves destructivef2−a2 interference and allows to measure the relative phases betweenf2,a2 andf2′. Upper limits on the production of the glueball candidate statesf2(1720) andX(2230) as well as theKS0KS0-continuum are given.

1 data table

Table 1

Data read from graph.

INVESTIGATION OF JET STRUCTURES IN K- P AND ANTI-P P INTERACTIONS AT INCIDENT MOMENTUM OF 32-GEV/C

The (IN RUSSIAN) SERPUKHOV-BERLIN-VIENNA-MOSCOW collaboration Babintsev, V.V. ; Bumazhnov, V.A. ; Minaenko, A.A. ; et al.

Yad.Fiz. 45 (1987) 102-109, 1987.

Inspire Record 250506 DOI 10.17182/hepdata.17429

None

10 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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rivet Analysis
Inclusive $\phi$ Meson Production in Electron - Positron Interactions in the Energy Region of the $\Upsilon$ Resonances

rivet Analysis
Observation of the Charmed Baryon $\Sigma(c$) in $e^+ e^-$ Annihilations

Evidence for Anomalous Prompt Photons in Deep Inelastic Muon Scattering at 200-{GeV}

Observation of Inclusive $B$ Meson Decays Into $\Lambda(c$)+ Baryons

Observation of the Charmed Baryon $\Lambda(c$) in $e^+ e^-$ Annihilation at 10-{GeV}

Comparison of the Particle Flow in $q \bar{q} \gamma$ and $q \bar{q} g$ Events From $e^+ e^-$ Annihilations at {PETRA}

LOW-ENERGY PION YIELD AT HIGH-ENERGY ACCELERATORS AS A FUNCTION OF THE PRIMARY PROTON BEAM MOMENTUM

Exclusive $\rho^0$ and $\phi$ Production in Deep Inelastic Muon Scattering

Tensor Meson Excitation in the Reaction $\gamma \gamma \to K^0_S K^0_S$

INVESTIGATION OF JET STRUCTURES IN K- P AND ANTI-P P INTERACTIONS AT INCIDENT MOMENTUM OF 32-GEV/C