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Two Jet Mass Distributions at the {CERN} Proton - Anti-Proton Collider

The UA1 collaboration Albajar, C. ; Albrow, M.G. ; Allkofer, O.C. ; et al.
Phys.Lett.B 209 (1988) 127-134, 1988.
Inspire Record 261782 DOI 10.17182/hepdata.29947

Two-jet mass distributions have been measured as a function of centre-of-mass scattering angle for high-mass jet pairs produced in proton-antiproton collisions at the CERN collider operating at a centre-of-mass energy of 630 GeV. The agreement between QCD expectations and the experimental measurements has been used to place limits on the production cross section of an object X decaying into two jets. In particular we consider the existence of a massive colour octet of vector gauge bosons (axigluons). We exclude axigluons with a width Λ A < 0.4 m A and a mass m A in the range 150 < m A < 310 GeV/ c 2 (95% CL).

1 data table
Table 1

No description provided.


Direct Photon Production at the CERN Proton - anti-Proton Collider

The UA1 collaboration Albajar, C. ; Albrow, M.G. ; Allkofer, O.C. ; et al.
Phys.Lett.B 209 (1988) 385-396, 1988.
Inspire Record 261356 DOI 10.17182/hepdata.29949

Isolated photons, produced directly by a scattering process, have been observed in the UA1 experiment at the CERN p p collider at centre-of-mass energies √=546 GeV and √=630 GeV . Single and double photon differential cross sections have been determined and found to be consistent with the expectations of QCD.

6 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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rivet Analysis
Investigation of the Total Charm Pair Cross-section in Nonresonant $e^+ e^-$ Annihilations at $\sqrt{s}=10$.5-{GeV}

The CLEO collaboration Bowcock, T.J.V. ; Kinoshita, K. ; Pipkin, F.M. ; et al.
Phys.Rev.D 38 (1988) 2679, 1988.
Inspire Record 23509 DOI 10.17182/hepdata.9269

We report results from two new methods for measuring the total production of charmed particles in nonresonant e+e− annihilations at √s =10.5 GeV. The rate for detection of events containing two reconstructed charmed mesons relative to that for events containing one is used to extract information about total charm production independent of decay branching fractions. The value of ΔRcc¯, the total charm-pair cross section normalized to the pointlike μ-pair cross section, is found to be 1.13−0.13+0.17±0.09, under an assumption of limited particle correlations. In an independent analysis the inclusive cross section for e+e−→qq¯→e±X is measured to be 0.293±0.017±0.017 nb. Using measured relative production rates and semileptonic branching fractions of D0 and D+ mesons and estimates of these quantities for Ds and Λc, this is found to correspond to ΔRcc¯=2.07±0.12±0.26. These two measurements are discussed in the context of measurements made by reconstruction of exclusive hadronic decay modes and of theoretical expectations.

3 data tables
Table 1

Charm quarks production cross section (C=CQCQBQR) evaluated from tagged events.

Table 2

Results using method 1).

Table 3

Results using method 2).


Study of Multi - Hadron Events With Isolated Leptons in $e^+ e^-$ Annihilation at $50\le \sqrt{s} \le 55$-{GeV}

The VENUS collaboration Abe, K. ; Amako, K. ; Arai, Y. ; et al.
Phys.Lett.B 207 (1988) 355-360, 1988.
Inspire Record 23570 DOI 10.17182/hepdata.29946

We have studied inclusive lepton production in e + e − annihilations into multihadrons in the energy range between √ s =50 and 55 GeV using the VENUS detector at TRISTAN, KEK. Though MARK-J and JADE groups at PETRA found an excess of isolated muon events at √ s ⩾46.3 GeV, we have not observed such an anomaly in muon nor in electron production. The observed rates of isolated leptons are consistent with the production and decay of five known quarks.

4 data tables
Table 1

Observed rates for whole event sample.

Table 2

No description provided.

Table 3

No description provided.

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EXPERIMENTAL MASS LIMIT FOR A FOURTH GENERATION SEQUENTIAL LEPTON FROM e+ e- ANNIHILATIONS AT S**(1/2) = 56-GeV

The AMY collaboration Kim, G.N. ; Kim, E.J. ; Son, D. ; et al.
Phys.Rev.Lett. 61 (1988) 911, 1988.
Inspire Record 261848 DOI 10.17182/hepdata.20055

A search for pair production of fourth-generation sequential leptons in e+e− annihilation at a center-of-mass energy s=56 GeV is reported. Event topologies corresponding to the cases where one particle decays leptonically while the other decays hadronically as well as those where both particles decay hadronically were explored. We set a 95%-confidence-level lower limit of 27.6 GeV/c2 for the mass of a fourth-generation lepton.

1 data table
Table 1

No description provided.


Measurements of Transverse Quasielastic Electron Scattering From the Deuteron at High Momentum Transfers

Arnold, R.G. ; Benton, D. ; Bosted, Peter E. ; et al.
Phys.Rev.Lett. 61 (1988) 806, 1988.
Inspire Record 261496 DOI 10.17182/hepdata.20075

Cross sections for 180° inelastic electron scattering from deuterium were measured from breakup threshold to beyond the quasielastic peak for incident-beam energies of 0.843, 1.020, 1.189, and 1.281 GeV, corresponding to 0.75≤Q2≤2.57 (GeV/c)2. The data are in reasonable agreement with nonrelativistic models that include final-state interactions and meson-exchange currents. The scaling function F(y) for these data is generally in agreement with F(y) for forward-angle data at the same Q2. Values of GMn determined from the data are in good agreement with results from previous experiments.

4 data tables
Table 1

Axis error includes +- 0.0/0.0 contribution (3.9 TO 12.0////).

Table 2

Axis error includes +- 0.0/0.0 contribution (3.9 TO 12.0////).

Table 3

Axis error includes +- 0.0/0.0 contribution (3.9 TO 12.0////).

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INCLUSIVE PRODUCTION OF gamma QUANTA AND pi0 MESONS IN anti-p p INTERACTIONS AT 32-GeV/c

Bogolyubsky, M.Yu. ; Bumazhnov, V.A. ; Kiryunin, A.E. ; et al.
Sov.J.Nucl.Phys. 49 (1989) 454, 1989.
Inspire Record 265088 DOI 10.17182/hepdata.40731

None

9 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Inclusive production of pi0 mesons in p C-collisions at 4.5-GeV/c. (In Russian)

Abraamian, Kh.U. ; Arkhipov, V.V. ; Astvatsaturov, R.G. ; et al.
308-316, 1988.
Inspire Record 263949 DOI 10.17182/hepdata.38836

None

2 data tables
Table 1

No description provided.

Table 2

No description provided.


First Observation of Dielectron Production at the Bevalac

The DLS collaboration Roche, G. ; Claesson, G. ; Hendrie, D. ; et al.
Phys.Rev.Lett. 61 (1988) 1069-1072, 1988.
Inspire Record 268588 DOI 10.17182/hepdata.38105

We have begun a program to measure dielectron production in p-nucleus and nucleus-nucleus collisions at the LBL Bevalac. Results are presented for the reaction p+Be at 4.9 GeV. For the first time, direct dilepton production is observed below 10 GeV incident energy. The cross sections are discussed and compared to previous data at higher energies. The observation of a structure at a mass of about 275 MeV suggests that pion annihilation may be the dominant production mechanism in this mass range.

2 data tables
Table 1

A IS TARGET ATOMIC MASS NUMBER.

Table 2

A IS TARGET ATOMIC MASS NUMBER.


APPLICATION OF ROBUST FITTING TO DETERMINATION OF ISOBARIC CROSS-SECTIONS OF RESIDUAL NUCLEI IN RELATIVISTIC INTERACTIONS

Damdinsuren, Ts. ; Kozma, P. ; Zlokazov, V.B. ;
JINR-P1-88-312, 1988.
Inspire Record 265677 DOI 10.17182/hepdata.39436

None

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.