Barate, R.
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Study of neutral-current four-fermion and Z Z production in e+ e- collisions at s**(1/2) = 183-GeV.

The L3 collaboration Acciarri, M. ; Achard, P. ; Adriani, O. ; et al.
Phys.Lett.B 450 (1999) 281-293, 1999.
Inspire Record 482477 DOI 10.17182/hepdata.49310

A study of neutral-current four-fermion processes is performed using a data sample corresponding to 55.3 pb −1 of integrated luminosity collected by the L3 detector at LEP at an average centre-of-mass energy of 183 GeV. The neutral-current four-fermion cross sections for final states with a pair of charged leptons plus jets and with four charged leptons are measured to be consistent with the Standard Model predictions. Events with fermion pair masses close to the Z boson mass are selected in all observable final states and the ZZ production cross section is measured to be σ ZZ =0.30 +0.22 +0.07 −0.16 −0.03 pb, in agreement with the Standard Model expectation. No evidence for the existence of anomalous triple gauge boson ZZZ and ZZ γ couplings is found and limits on these couplings are set.

1 data table
Table 1

No description provided.


Anti-p d annihilation at rest into pi+ pi- pi- p(spectator).

The Crystal Barrel collaboration Abele, A. ; Adomeit, J. ; Amsler, C. ; et al.
Phys.Lett.B 450 (1999) 275-280, 1999.
Inspire Record 500218 DOI 10.17182/hepdata.28089

A study of antiproton annihilation in liquid deuterium into π + π − π − and a spectator proton is presented. For a long time this reaction resisted a description by final state interactions which is surprising (and disturbing) given the success of the final state interaction model in other annihilation reactions. It is shown that the introduction of ρ (1450) is essential to get a reasonable description of the measured Dalitz plot. This resonance was never tried in previous attempts to understand this data. A possible isospin-2- ππ S-wave contribution was tested, but no evidence was found for such a contribution.

1 data table
Table 1

No description provided.


Evidence for a pi eta P-wave in anti-p p annihilations at rest into pi0 pi0 eta.

The Crystal Barrel collaboration Abele, A. ; Adomeit, J. ; Amsler, C. ; et al.
Phys.Lett.B 446 (1999) 349-355, 1999.
Inspire Record 498113 DOI 10.17182/hepdata.28121

A partial wave analysis is presented of two high-statistics data samples of protonium annihilation into π 0 π 0 η in liquid and 12 atm gaseous hydrogen. The contributions from the 1 S 0 , 3 P 1 and 3 P 2 initial atomic fine structure states to the two data sets are different. The change of their fractional contributions when going from liquid to gaseous H 2 as calculated in a cascade model is imposed in fitting the data. Thus the uncertainty in the fraction of S-state and P-state capture is minimized. Both data sets allow a description with a common set of resonances and resonance parameters. The inclusion of a π η P-wave in the fit gives supportive evidence for the ρ ̂ (1405) , with parameters compatible with previous findings.

1 data table
Table 1

No description provided.


Enhancement of strange and multi-strange baryons and anti-baryons in S W interactions at 200-GeV/c.

The WA85 collaboration Antinori, F. ; Barnes, R.P. ; Bayes, A.C. ; et al.
Phys.Lett.B 447 (1999) 178-182, 1999.
Inspire Record 500180 DOI 10.17182/hepdata.28123

Strange and multistrange baryon production is expected to be enhanced in heavy ion interactions if a phase transition from hadronic matter to a Quark-Gluon Plasma takes place. The production yields of Λ s, Λ s, Ξ − s, and Ξ + s relative to the production of negative particles are presented for sulphur-tungsten interactions at 200 GeV/ c per nucleon. These production yields are compared to those produced in proton-tungsten interactions and the enhancements of strange and multistrange baryons and antibaryons are presented.

3 data tables
Table 1

Hyperon to negative production ratios with sulphur beam.

Table 2

Hyperon to negative production ratios with proton beam.

Table 3

Strange and multistrange baryon enhancements.


Neutron production in coincidence with fragments from the 40Ca + H reaction at Elab = 357A and 565A MeV

Tuve, C. ; Albergo, S. ; Boemi, D. ; et al.
Phys.Rev.C 59 (1999) 233-238, 1999.
Inspire Record 493470 DOI 10.17182/hepdata.25641

Neutron production, in coincidence with fragments emitted in the 40Ca+H reaction at Elab=357A and 565A MeV, has been measured using a 3-module version of the multifunctional neutron spectrometer MUFFINS. The mean neutron multiplicities for neutrons detected in the angular range covered by MUFFINS (0°−3.2°) have been estimated from the comparison between the neutron cross sections, in coincidence with the fragments, and the elemental cross sections. We have found evidence for a preequilibrium emission of prompt neutrons in superposition to a “slower” deexcitation of the equilibrated remnant by emission of nucleons and fragments, as already seen in inclusive rapidity distributions. The energy dependence of the inclusive neutron production cross sections, measured in a previous work, is here interpreted as due to the stronger neutron focusing in the forward direction at the higher energy. Comparison with a BNV+phase space coalescence model is discussed.

1 data table
Table 1

No description provided.


Pion proton integral cross sections at T(pi) = 40-MeV to 284-MeV.

Kriss, B.J. ; Hoibraten, S. ; Holcomb, M.D. ; et al.
Phys.Rev.C 59 (1999) 1480-1487, 1999.
Inspire Record 500165 DOI 10.17182/hepdata.25638

Integral cross sections for the scattering of pions by protons into angles greater than 30° (lab) have been measured at a wide range of energies spanning the delta resonance using liquid hydrogen targets. Cross sections were measured for π+p scattering at 40 energies from 39.8 to 283.9 MeV and for π−p at 15 energies from 80.0 to 283.9 MeV. Comparisons with phase shift predictions from the Karlsruhe group show good agreement on resonance but significant deviations below 100 MeV.

2 data tables
Table 1

The uncertainties shown include statistical and systematic contributions.

Table 2

The uncertainties shown include statistical and systematic contributions.


Measurement of the proton and deuteron spin structure functions g2 and asymmetry A(2).

The E155 collaboration Anthony, P.L. ; Arnold, R.G. ; Averett, T. ; et al.
Phys.Lett.B 458 (1999) 529-535, 1999.
Inspire Record 493768 DOI 10.17182/hepdata.27072

We have measured the spin structure functions g2p and g2d and the virtual photon asymmetries A2p and A2d over the kinematic range 0.02 < x < 0.8 and 1.0 < Q^2 < 30(GeV/c)^2 by scattering 38.8 GeV longitudinally polarized electrons from transversely polarized NH3 and 6LiD targets.The absolute value of A2 is significantly smaller than the sqrt{R} positivity limit over the measured range, while g2 is consistent with the twist-2 Wandzura-Wilczek calculation. We obtain results for the twist-3 reduced matrix elements d2p, d2d and d2n. The Burkhardt-Cottingham sum rule integral - int(g2(x)dx) is reported for the range 0.02 < x < 0.8.

4 data tables
Table 1

2.75 degree spectrometer data.

Table 2

5.5 degree spectrometer data.

Table 3

10.5 degree spectrometer data.

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Measurement of gamma p --> K0 Sigma+ at photon energies up to 1.55-GeV.

The SAPHIR collaboration Goers, S ; Barth, J ; Bennhold, C ; et al.
Phys.Lett.B 464 (1999) 331-338, 1999.
Inspire Record 512574 DOI 10.17182/hepdata.27045

The reaction γp → K 0 Σ + has been measured with the SAPHIR detector at the electron stretcher ring ELSA. The total cross section rises up to a peak value of 1.1 μ b at a photon energy of 1.4 GeV. The differential cross sections dσ/dΩ are consistent with being flat throughout the measured energy range. The first measurement of the Σ + polarization in photon induced reactions was obtained.

3 data tables
Table 1

Total cross section for the reaction GAMMA P --> K0 SIGMA+. Errors include statistics and the uncertainty on the acceptance calculation and photon flux.

Table 2

Differential cross section for the reaction GAMMA P --> K0 SIGMA+. Errors are dominated by statistical uncertainties.

Table 3

Measure of SIGMA+ polarization in the reaction GAMMA P --> K0 SIGMA+.


Measurement and interpretation of fermion pair production at LEP energies from 130-GeV to 172-GeV

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Eur.Phys.J.C 11 (1999) 383-407, 1999.
Inspire Record 495462 DOI 10.17182/hepdata.34520

None

9 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Angular dependence of the pp elastic-scattering analyzing power between 0.8 and 2.8 GeV. II. Results for higher energies

Allgower, C.E. ; Ball, J. ; Beddo, M.E. ; et al.
Phys.Rev.C 60 (1999) 054002, 1999.
Inspire Record 508562 DOI 10.17182/hepdata.25565

Measurements at 18 beam kinetic energies between 1975 and 2795 MeV and at 795 MeV are reported for the pp elastic-scattering single spin parameter Aooon=Aoono=AN=P. The c.m. angular range is typically 60–100°. These results are compared to previous data from Saturne II and other accelerators. A search for energy-dependent structure at fixed c.m. angles is performed, but no rapid changes are observed.

20 data tables
Table 1

Measured values of the P P analysing power at kinetic energy 0.795 GeV. Therelative and additive systematic errors are +- 0.018 and 0.0007.

Table 2

Measured values of the P P analysing power at kinetic energy 1.975 GeV. Therelative and additive systematic errors are +- 0.045 and 0.002.

Table 3

Measured values of the P P analysing power at kinetic energy 2.035 GeV fromrun I. The relative and additive systematic errors are +- 0.044 and 0.002.

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