Direct observation of longitudinally polarized W+- bosons

The L3 collaboration Acciarri, M. ; Achard, P. ; Adriani, O. ; et al.
Phys.Lett.B 474 (2000) 194-204, 2000.
Inspire Record 509581 DOI 10.17182/hepdata.49002

The three different helicity states of W bosons, produced in the reaction e+e- -> W+W- -> l nu q q~ are studied using leptonic and hadronic W decays at sqrt{s}=183GeV and 189GeV. The W polarisation is also measured as a function of the scattering angle between the W- and the direction of the e- beam. The analysis demonstrates that W bosons are produced with all three helicities, the longitudinal and the two transverse states. Combining the results from the two center-of-mass energies and with leptonic and hadronic W decays, the fraction of longitudinally polarised W bosons is measured to be 0.261 +/- 0.051(stat.) +/- 0.016(syst.) in agreement with the expectation from the Standard Model.

1 data table

Fraction of longitudinally polarized W bosons. Combined results from 183 and 189 GeV.


Lambda, Xi and Omega production in Pb Pb collisions at 158-A-GeV/c.

The WA97 collaboration Andersen, E. ; Antinori, F. ; Armenise, N. ; et al.
Nucl.Phys.A 638 (1998) 115-124, 1998.
Inspire Record 481868 DOI 10.17182/hepdata.36351

Enhanced production of strange baryons and anti-baryons at central rapidity in S-W and S-z.sbnd;S with respect to p-A reactions has been reported by the CERN experiments WA85 and WA94. The WA97 experiment is extending such a study to Pb Pb collisions making use of the newly developed silicon pixel detectors. Results on Λ, Ξ − and Ω − production in Pb Pb collisions at 158 A GeV/ c at central rapidity are presented. Transverse mass spectra and particle ratios are presented. Hyperon yields are given as a function of the collision centrality and compared with those obtained from p-Pb collisions using the same experimental setup.

5 data tables

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WA97 results on strangeness production in lead lead collisions at 158-A-GeV/c

The WA97 collaboration Andersen, E. ; Andrighetto, A. ; Antinori, F. ; et al.
Nucl.Phys.A 610 (1996) 165C-174C, 1996.
Inspire Record 432744 DOI 10.17182/hepdata.36503

Preliminary results from WA97 measurements on Λ, Ξ and Ω production in lead-lead and proton-lead collisions are presented, along with a comparison of WA97 proton-lead data with previous WA85 proton-tungsten results. The ratio Ω gX seems to be enhanced in lead initiated reactions compared to proton initiated reactions.

4 data tables

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PRELIMINARI DATA.

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Search for higher twists in meson resonance production in hadron interactions at p(T) >= 2-GeV/c

The WA77 collaboration Bellogianni, A. ; Benayoun, Maurice ; Bloodworth, I.J. ; et al.
Z.Phys.C 69 (1996) 235-242, 1996.
Inspire Record 396807 DOI 10.17182/hepdata.48005

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3 data tables

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Strange particle production in sulphur - tungsten interactions at 200-GeV/c per nucleon

The WA85 collaboration Kinson, J.B. ; Abatzis, S. ; Antinori, F. ; et al.
Nucl.Phys.A 544 (1992) 321-334, 1992.
Inspire Record 321220 DOI 10.17182/hepdata.36664

Multi-strange baryon and anti-baryon production is expected to be a useful probe in the search for Quark-Gluon Plasma formation. We present the transverse mass distributions of negative particles, K o s, Λs, Λ s, and Ξ − s produced in sulphurtungsten interactions at 200 GeV/c per nucleon and give the corrected ratios Λ Λ, Ξ − Λ and Ξ − /Λ . We note that our ratio Ξ − / Λ appears large in comparison to that from p p interactions.

4 data tables

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