Christian, D.C.
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A Measurement of Direct Photon Production at Large P(T) at the {CERN} {ISR}

Diakonou, M. ; Kourkoumelis, C. ; Resvanis, L.K. ; et al.
Phys.Lett.B 91 (1980) 296-300, 1980.
Inspire Record 152520 DOI 10.17182/hepdata.27234

We have measured direct photon production in pp collisions at the CERN intersecting storage rings for c.m. energies 31 < √ s < 63 GeV and transverse momenta up to 9GeV/ c , using segmented lead/liquid-argon calorimeters. The ratio of direct photon to π 0 production is significantly larger than zero, starting at p T ≈ 4 GeV/ c and increasing to values of about 0.4 at 9GeV/ c . No significant √s dependence is seen.

1 data table
Table 1

No description provided.


Observation of Planar Three Jet Events in e+ e- Annihilation and Evidence for Gluon Bremsstrahlung

The JADE collaboration Bartel, W. ; Canzler, T. ; Cords, D. ; et al.
Phys.Lett.B 91 (1980) 142-147, 1980.
Inspire Record 143985 DOI 10.17182/hepdata.6339

Topological distributions of charged and neutral hadrons from the reaction e + e − → multihadrons are studied at √ s of about 30 GeV. An excess of planar events is observed at a rate which cannot be explained by statistical fluctuations in the standard two-jet process. The planar events, mostly consisting of a slim jet on one side and a broader jet on the other, are shown actually to possess three-jet structure by demonstrating that the broader jet itself consists of two collinear jets in its own rest system. Detailed agreement between data and predictions is obtained if the process e + e − →q q ̄ g is taken into account. This strongly suggests gluon bremsstrahlung as the origin of the planar three-jet events. By comparison of the data with the qq̄g-model we obtain a value for the strong coupling constant of α S ( q 2 = 0.17 ± 0.04.

2 data tables
Table 1

THRUST AND PLANARITY DISTRIBUTIONS. FINAL (BETTER) THRUST DISTRIBUTIONS WITH DETECTOR CORRECTIONS TO BE PUBLISHED LATER.

Table 2

No description provided.


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
Table 1

OMEGA DECAY TO PI0 GAMMA IS DETECTED.

Table 2

ETAPRIME DECAY TO GAMMA GAMMA IS DETECTED.


rivet Analysis
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
Table 1

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.

Table 2

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


Direct Production of High $p_T$ Single Photons at the {CERN} Intersecting Storage Rings

The Athens-Athens-Brookhaven-CERN collaboration Diakonou, M. ; Kourkoumelis, C. ; Resvanis, L.K. ; et al.
Phys.Lett.B 87 (1979) 292-296, 1979.
Inspire Record 143254 DOI 10.17182/hepdata.27293

Single photon production in pp collisions at 30 < √ s < 62 GeV has been measured with liquid-argon-lead calorimeters at the CERN ISR. This process remains approximately constant with increasing √ s . For fixed √ s , the single photon to π 0 ratio increases strongly with increase in p T . The γ π 0 ratio is about 0.2 for p T above 4.5 GeV/c.

1 data table
Table 1

No description provided.


Cross-sections for Charged Current Neutrino and Anti-neutrino Interactions in the Energy Range 10-{GeV} to 50-{GeV}

Colley, D.C. ; Jones, G.T. ; O'Neale, S. ; et al.
Z.Phys.C 2 (1979) 187, 1979.
Inspire Record 141975 DOI 10.17182/hepdata.16366

Charged-current neutrino and antineutrino interaction cross sections have been measured in the energy range 10 to 50 GeV using BEBC filled with a neon-hydrogen mixture. At these energies, σ/E was measured to be (0.73±0.08) 10−38 cm2/GeV per nucleon for neutrinos and (0.32±0.06) 10−38 cm2/GeV per nucleon for antineutrinos.

2 data tables
Table 1

Axis error includes +- 9/9 contribution (NEUTRAL CURRENT EVENTS AND NEUTRAL HADRON INDUCED REACTIONS, LOSSES OF EVENTS WITH ONLY ONE VISIBLE CHARGED PARTICLE).

Table 2

Axis error includes +- 9/9 contribution (NEUTRAL CURRENT EVENTS AND NEUTRAL HADRON INDUCED REACTIONS, LOSSES OF EVENTS WITH ONLY ONE VISIBLE CHARGED PARTICLE).


FORWARD ELECTROPRODUCTION OF CHARGED PIONS FROM DEUTERONS AT Q**2 = 1.0-GeV/c**2

Morris, J.V. ; Darvill, D.C. ; Davenport, M. ; et al.
Phys.Lett.B 86 (1979) 211-214, 1979.
Inspire Record 140702 DOI 10.17182/hepdata.27310

The ratio of π - to π + electroproduction cross sections from deuterium has been measured in the resonance region, at a four-momentum transfer squared close to −1.0 (GeV/ c ) 2 . Results in the forward direction are presented and a comparison is made with predictions based on SU(6) W and the Melosh transformation.

1 data table
Table 1

No description provided.


Inclusive $\eta$ Production at High $p_T$ at the {ISR}

Kourkoumelis, C. ; Resvanis, L.K. ; Filippas, T.A. ; et al.
Phys.Lett.B 84 (1979) 277-280, 1979.
Inspire Record 141136 DOI 10.17182/hepdata.27350

The inclusive η production cross section at the CERN ISR has been measured for p T values of up to 11 GeV/ c . We find that the η π 0 cross-section ratio has an average value of 0.55 ± 0.07 and varies little with p T .

1 data table
Table 1

No description provided.


Inclusive $\pi^0$ Production at Very Large $p_T$ at the {ISR}

Kourkoumelis, C. ; Resvanis, L.K. ; Filippas, T.A. ; et al.
Phys.Lett.B 84 (1979) 271-276, 1979.
Inspire Record 141135 DOI 10.17182/hepdata.27343

Inclusive π 0 production at 90° has been studied at the ISR at s 1 2 = 52.7 and 62.4 GeV over the p T range from 7 to 15 GeV/ c . The two photons from π 0 decay yielded overlapping electromagnetic showers in the liquid-argon-Pb plate calorimeter detector system. Any direct photon production is included in these measurements. For large values of p T , the cross section is observed to decrease with p T more slowly than the p T −8 behaviour which has been observed at lower values of p T .

1 data table
Table 1

No description provided.


Study of Resolved High {P(T)} Neutral Pions at the {CERN} {ISR}

Kourkoumelis, C. ; Resvanis, L.K. ; Voulgaris, G. ; et al.
Phys.Lett.B 83 (1979) 257-260, 1979.
Inspire Record 140588 DOI 10.17182/hepdata.27353

The inclusive production of π 0 at large values of p T in pp collisions at the ISR has been studied. In this experiment the two photons are resolved and separately measured for p T values of up to 6 GeV/ c , giving confidence that the desired signal has been separated from various backgrounds.

1 data table
Table 1

No description provided.