A Determination of the Properties of the Neutral Intermediate Vector Boson Z0

The L3 collaboration Adeva, B. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 231 (1989) 509, 1989.
Inspire Record 282041 DOI 10.17182/hepdata.29768

We report the results of first physics runs of the L3 detector at LEP. Based on 2538 hadron events, we determined the mass m z 0 and the width Γ z 0 of the intermediate vector boson Z 0 to be m z 0 =91.132±0.057 GeV (not including the 46 MeV LEP machine energy uncertainty) and Γ z 0 =2.588±0.137 GeV. We also determined Γ invisible =0.567±0.080 GeV, corresponding to 3.42±0.48 number of neutrino flavors. We also measured the muon pair cross section and determined the branching ratio Γ μμ = Γ h =0.056±0.006. The partial width of Z 0 →e + e − is Γ ee =88±9±7 MeV.

1 data table

No description provided.


Measurement of the Z0 Mass and Width with the OPAL Detector at LEP

The OPAL collaboration Akrawy, M.Z. ; Alexander, G. ; Allison, J. ; et al.
Phys.Lett.B 231 (1989) 530-538, 1989.
Inspire Record 282821 DOI 10.17182/hepdata.29757

We report an experimental determination of the cross section for e + e − → hadrons from a scan around the Z 0 pole. On the basis of 4350 hadronic events collected over seven energy points between 89.26 GeV and 93.26 GeV we obtain a mass of m z =91.01±0.05±0.05 GeV, and a total decay width of Γ z =2.60±0.13 GeV. In the context of the standard model t these results imply 3.1 ± 0.4 neutrino generations.

1 data table

No description provided.


Measurements of the Nucleon Structure Function in the Range 0.002-GeV**2 < x < 0.17-GeV**2 and 0.2-GeV**2 < q**2 < 8-GeV**2 in Deuterium, Carbon and Calcium

The European Muon collaboration Arneodo, M. ; Arvidson, A. ; Aubert, J.J. ; et al.
Nucl.Phys.B 333 (1990) 1-47, 1990.
Inspire Record 283347 DOI 10.17182/hepdata.33074

Small angle scattering of 280 GeV positive muons by deuterium, carbon and calcium has been measured at scattering angles down to 2 mrad. The nucleon structure function F 2 extracted from deuterium does not show a significant x dependence in the measured range of Q 2 and its Q 2 dependence is linear in log Q 2 . For calcium, a depletion of F 2 is observed at low x by 30% as compared with the values at x = 0.1 where F 2 (Ca) and F 2 (D) are not significantly different. This depletion is attributed to shadowing. The carbon structure function exhibits a similar, but less pronounced, x dependence. Such behaviour is observed to be independent of Q 2 . The data are consistent with those obtained from other charged lepton experiments both at similar and higher values of x and Q 2 and considerably extend the range of the measurements down to the low values of x to be measured in forthcoming experiments at HERA.

33 data tables

Deuterium data. Overall normalization error of 7 pct not included.

Deuterium data. Overall normalization error of 7 pct not included.

Deuterium data. Overall normalization error of 7 pct not included.

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An investigation of the spin structure of the proton in deep inelastic scattering of polarized muons on polarized protons.

The European Muon collaboration Ashman, J. ; Badelek, B. ; Baum, Guenter ; et al.
Nucl.Phys.B 328 (1989) 1, 1989.
Inspire Record 280143 DOI 10.17182/hepdata.49587

The spin asymmetry in deep inelastic scattering of longitudinally polarised muons by longitudinally polarised protons has been measured in the range 0.01<×<0.7. The spin dependent structure function g 1 ( x ) for the proton has been determined and, combining the data with earlier SLAC measurements, its integral over x found to be 0.126±0.010(stat.)±0.015(syst.), in disagreement with the Ellis-Jaffe sum rule. Assuming the validity of the Biorken sum rule, this result implies a significant negative value for the integral of g 1 for the neutron. These integrals lead to the conclusion, in the naïve quark parton model, that the total quark spin constitutes a rather small fraction of the spin of the nucleon. Results are also presented on the asymmetries in inclusive hadron production which are consistent with the above picture.

7 data tables

THE MEAN Q**2 FOR EACH OF THE 10 VALUES OF X BELOW ARE 3.5,4.5,6.0, 8.010.3,12.9,15.2,18.0,22.5,29.5.

No description provided.

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Measurements of the $u$ Valence Quark Distribution Function in the Proton and $u$ Quark Fragmentation Functions

The European Muon collaboration Arneodo, M. ; Arvidson, A. ; Aubert, J.J. ; et al.
Nucl.Phys.B 321 (1989) 541-560, 1989.
Inspire Record 276746 DOI 10.17182/hepdata.33218

A new determination of the u valence quark distribution function in the proton is obtained from the analysis of identified charged pions, kaons, protons and antiprotons produced in muon-proton and muon-deuteron scattering. The comparison with results obtained in inclusive deep inelastic lepton-nucleon scattering provides a further test of the quark-parton model. The u quark fragmentation functions into positive and negative pions, kaons, protons and antiprotons are also measured.

6 data tables

No description provided.

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Analyzing Power Measurement in Inclusive $\pi^0$ Production at High $\chi_F$

Bonner, B.E. ; Buchanan, J.A. ; Carey, D.C. ; et al.
Phys.Rev.Lett. 61 (1988) 1918, 1988.
Inspire Record 269386 DOI 10.17182/hepdata.2928

The analyzing power AN in inclusive π0 production has been measured with use of the new 185-GeV/c Fermilab polarized proton beam. We obtain the value AN=0.10±0.03 for π0's in the kinematic region 0.2<xF<0.8 and 0.3<pT<1.2 GeV/c. In certain models of particle production this suggests that the spin of the proton is carried by its valence quarks.

7 data tables

No description provided.

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Individual polarisation measurements.

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Charged Particle Production in $K^+ p$, $\pi^+ p$ and $p p$ Interactions at 250-{GeV}/$c$

The EHS/NA22 collaboration Adamus, M. ; Azhinenko, I.V. ; Ataian, M.R. ; et al.
Z.Phys.C 39 (1988) 311-329, 1988.
Inspire Record 265504 DOI 10.17182/hepdata.15620

None

6 data tables

No description provided.

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Shadowing in deep inelastic muon scattering from nuclear targets

The European Muon collaboration Arneodo, M. ; Arvidson, A. ; Aubert, J.J. ; et al.
Phys.Lett.B 211 (1988) 493-499, 1988.
Inspire Record 262246 DOI 10.17182/hepdata.29908

Results are presented on the ratio of the inelastic muon-nucleus cross section per nucleon for carbon and calcium relative to that for deuterium. The measurements were made in the kinematic range of low x (0.003–0.1) and low Q 2 (0.3–3.2 GeV 2 ) at an incident muon energy of 280 GeV. The calcium to deuterium ratio shows a significant x dependence which is interpreted as a shadowing effect. No strong Q 2 dependence is observed. This suggests that the effect is due at least partially to parton interactions within the nucleus.

4 data tables

VALUES OF Q**2 AT EACH POINT ARE:- 0.52,0.60,0.61,0.61,0.63,0.68,0.90.

VALUES OF Q**2 AT EACH POINT ARE:- 1.09,1.25,1.54,1.74,1.76,1.68,1.71, 2.29.

VALUES OF X AT EACH POINT ARE:- 0.009,0.011,0.010,0.010,0.010,0.011, 0.013,0.015.

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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

Z distribution of anomalous direct photons.

PT distribution of anomalous direct photons.


Final Results on $\mu e$ Pair Production in Neutrino Interactions With Chamber Skat Filled With Freon

Ammosov, V.V. ; Ermolaev, V.I. ; Ivanilov, A.A. ; et al.
Z.Phys.C 40 (1988) 493, 1988.
Inspire Record 263220 DOI 10.17182/hepdata.15559

We present the final results from the search for μe pairs produced in neutrino interactions using the freon filled bubble chamber SKAT. The rate of μ−e+ pairs to charged current events above the charm threshold is\(R_{\mu ^ -e^ +}= (4.8 \pm 1.1)10^{ - 3} \). Assuming charm particle production to be the origin of the positron we calculate\(R_{\Lambda _c^ +}= (6.2 \pm 3.1)10^{ - 2} \) andRD=(2.8±0.9)10−2. We observe no considerable μ−e− pair production above the background. In the regionEv>3 GeV,pμ,e>1.0 GeV/c andpμ>pe we find with a 90% confidence level the limit\(R_{\mu ^ -e^ -}< 1.7 10^{ - 4} \).

3 data tables

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