Shaevitz, M.H.
DN/DCOSTHETA
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Model-independent measurement of the W boson helicity in top quark decays at D0

The D0 collaboration Abazov, V.M. ; Abbott, B. ; Abolins, M. ; et al.
Phys.Rev.Lett. 100 (2008) 062004, 2008.
Inspire Record 767094 DOI 10.17182/hepdata.47072

We present the first model-independent measurement of the helicity of $W$ bosons produced in top quark decays, based on a 1 fb$^{-1}$ sample of candidate $t\bar{t}$ events in the dilepton and lepton plus jets channels collected by the D0 detector at the Fermilab Tevatron $p\bar{p}$ Collider. We reconstruct the angle $\theta^*$ between the momenta of the down-type fermion and the top quark in the $W$ boson rest frame for each top quark decay. A fit of the resulting \costheta distribution finds that the fraction of longitudinal $W$ bosons $f_0 = 0.425 \pm 0.166 \hbox{(stat.)} \pm 0.102 \hbox{(syst.)}$ and the fraction of right-handed $W$ bosons $f_+ = 0.119 \pm 0.090 \hbox{(stat.)} \pm 0.053 \hbox{(syst.)}$, which is consistent at the 30% C.L. with the standard model.

6 data tables
Table 1

COS(THETA*) distribution for leptonic W decay in lepton+jets events.. Data are read from plots and errors are statistcial (sqrt(N)).

Table 2

COS(THETA*) distribution for hadronic W decay in lepton+jets events.. Data are read from plots and errors are statistcial (sqrt(N)).

Table 3

COS(THETA*) distribution for W decay in dilepton events.. Data are read from plots and errors are statistcial (sqrt(N)).

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rivet Analysis
The Center-of-mass angular distribution of prompt photons produced in p anti-p collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Albrow, Michael G. ; Amidei, Dante E. ; et al.
Phys.Rev.Lett. 71 (1993) 679-683, 1993.
Inspire Record 354237 DOI 10.17182/hepdata.53953

Data taken with the Collider Detector at Fermilab (CDF) during the 1988–1989 run of the Tevatron are used to measure the distribution of the center-of-mass (rest frame of the initial state partons) angle between isolated prompt photons and the beam direction. The shape of the angular distribution for photon-jet events is found to be significantly different from that observed in dijet data. The QCD predictions show qualitative agreement with the observed prompt photon angular distribution.

1 data table
Table 1

Background subtracted normalised prompt photon angular distribution.


Measurement of three jet distributions sensitive to the gluon spin in e+ e- annihilations at S**(1/2) = 91-GeV

The OPAL collaboration Alexander, G. ; Allison, John ; Allport, P.P. ; et al.
Z.Phys.C 52 (1991) 543-550, 1991.
Inspire Record 317142 DOI 10.17182/hepdata.14852

None

4 data tables
Table 1

Data at Parton level.

Table 2

Ratio data/(Monte Carlo) at Parton level.

Table 3

Data at Parton level.. Distribution of Ellis-Karliner angle.

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Experimental Evidence for the Nonabelian Nature of {QCD}

The AMY collaboration Park, I.H. ; Schnetzer, S. ; Green, J. ; et al.
Phys.Rev.Lett. 62 (1989) 1713, 1989.
Inspire Record 276619 DOI 10.17182/hepdata.20045

We present evidence for the non-Abelian nature of QCD from a study of multijet events produced in e+e− annihilations from √s =50 to 57 GeV in the AMY detector at the KEK storage ring TRISTAN. A comparison of the three-jet event fraction at TRISTAN to the fraction of the DESY storage ring PETRA shows that the QCD coupling strength αs decreases with increasing Q2. In addition, measurements of the angular distributions of four-jet events show evidence for the triple-gluon vertex.

2 data tables
Table 1

No description provided.

Table 2

No description provided.