Meyer, H.O.
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Dependence of p(pol.) p(pol.) --> p p pi0 near threshold on the spin of the colliding nucleons.

Meyer, H.O. ; Balewski, J.T. ; Dzemidzic, M. ; et al.
Phys.Rev.Lett. 81 (1998) 3096-3099, 1998.
Inspire Record 472992 DOI 10.17182/hepdata.39971

A polarized internal atomic hydrogen target and a stored, polarized beam are used to measure the spin-dependent total cross section Delta_sigma_T/sigma_tot, as well as the polar integrals of the spin correlation coefficient combination A_xx-A_yy, and the analyzing power A_y for pp-> pp pi0 at four bombarding energies between 325 and 400 MeV. This experiment is made possible by the use of a cooled beam in a storage ring. The polarization observables are used to study the contribution from individual partial waves.

1 data table match query
Table 1

SIG(C=DEL_T) defined as the cross section with the spins of the colliding protons antiparallel, minus the cross section with spins parallel, using transversely polarized beam and target.


Total cross-section for p + p ---> p + p + pi0 near threshold measured with the Indiana cooler

Meyer, H.O. ; Ross, M.A. ; Pollock, R.E. ; et al.
Phys.Rev.Lett. 65 (1990) 2846-2849, 1990.
Inspire Record 305682 DOI 10.17182/hepdata.19936

The total cross section for the reaction pp→ppπ0 was measured at nine center-of-mass energies from 1.5 to 23 MeV above threshold. The experiment was carried out with the Indiana Cooler, a recently constructed storage ring. The experimental advantages of an electron-cooled proton beam were utilized. The data cover an energy range where only the lowest possible angular momentum state contributes in the exit channel. The measured energy dependence of the total cross section is not compatible with that predicted by models of s-wave pion production and rescattering.

1 data table match query
Table 1

No description provided.


Measurement of partial-wave contributions in p p --> p p pi0.

Meyer, H.O. ; Balewski, J.T. ; Doskow, J. ; et al.
Phys.Rev.Lett. 83 (1999) 5439-5442, 1999.
Inspire Record 504512 DOI 10.17182/hepdata.31354

We report a measurement of the spin-dependent total cross section ratios delta_sigma_T/sigma_tot and delta_sigma_L/sigma_tot of the pp --> pp pi^0 reaction between 325 MeV and 400 MeV. The experiment was carried out with a polarized internal target in a storage ring. Non-vertical beam polarization was obtained by the use of solenoidal spin rotators. Near threshold, the knowledge of both spin-dependent total cross sections is sufficient to deduce the strength of certain participating partial waves, free of any model.

2 data tables match query
Table 1

SIG(C=T1-1) and SIG(C=T11) means opposite and parallel transverse beam and target polarizations. The same is for longitudunal (L) polarizations. SIG(C=TOT)is unpolarized total cross section.

Table 2

SIG(C=L1-1) and SIG(L=11) means opposite and parallel longitudinal beam andtarget polarizations. SIG(C=TOT) is unpolarized total cross section.


Total cross-section for p + d ---> p + d + pi0 close to threshold

Rohdjess, H. ; Scobel, W. ; Meyer, H.O. ; et al.
Phys.Rev.Lett. 70 (1993) 2864-2867, 1993.
Inspire Record 362060 DOI 10.17182/hepdata.2867

The total cross section for pion production in the reaction pd→pdπ0 has been measured for bombarding energies from Tp=208.4 MeV to 294.6 MeV. This corresponds to maximum pion momenta η=pπ,c.m./mπc between 0.099 and 0.96. The experiment was performed using an electron-cooled proton beam and an internal deuterium gas jet target. The resulting σtot changes by almost four orders of magnitude over the covered energy range. The results are compared to a model which assumes quasi-free production via the pn→dπ0 elementary process.

3 data tables match query
Table 1

Geometry 1.

Table 2

Geometry 2.

Table 3

No description provided.


QCD studies with e+ e- annihilation data at 130-GeV and 136-GeV.

The OPAL collaboration Alexander, G. ; Allison, John ; Altekamp, N. ; et al.
Z.Phys.C 72 (1996) 191-206, 1996.
Inspire Record 418007 DOI 10.17182/hepdata.47564

We have studied hadronic events produced at LEP at centre-of-mass energies of 130 and 136 GeV. Distributions of event shape observables, jet rates, momentum spectra and multiplicities are presented and compared to the predictions of several Monte Carlo models and analytic QCD calculations. From fits of event shape and jet rate distributions to\({\mathcal{O}}(\alpha _s^2 ) + NLLA\) QCD calculations, we determineαs(133 GeV)=0.110±0.005(stat.)±0.009(syst.). We measure the mean charged particle multiplicity 〈nch〉=23.40±0.45(stat.) ±0.47(syst.) and the position ζ0 of the peak in the ζp = ln(1/xp) distribution ζ0=3.94±0.05(stat.)±0.11(syst.). These results are compared to lower energy data and to analytic QCD or Monte Carlo predictions for their energy evolution.

23 data tables match query
Table 1

Determination of alpha_s.

Table 2

Multiplicity and high moments.

Table 3

Tmajor distribution.

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Version 2
rivet Analysis
Measurement of differential cross sections and $W^+/W^-$ cross-section ratios for $W$ boson production in association with jets at $\sqrt{s}=8$ TeV with the ATLAS detector

The ATLAS collaboration Aaboud, Morad ; Aad, Georges ; Abbott, Brad ; et al.
JHEP 05 (2018) 077, 2018.
Inspire Record 1635273 DOI 10.17182/hepdata.80076

This paper presents a measurement of the $W$ boson production cross section and the $W^{+}/W^{-}$ cross-section ratio, both in association with jets, in proton--proton collisions at $\sqrt{s}=8$ TeV with the ATLAS experiment at the Large Hadron Collider. The measurement is performed in final states containing one electron and missing transverse momentum using data corresponding to an integrated luminosity of 20.2 fb$^{-1}$. Differential cross sections for events with one or two jets are presented for a range of observables, including jet transverse momenta and rapidities, the scalar sum of transverse momenta of the visible particles and the missing transverse momentum in the event, and the transverse momentum of the $W$ boson. For a subset of the observables, the differential cross sections of positively and negatively charged $W$ bosons are measured separately. In the cross-section ratio of $W^{+}/W^{-}$ the dominant systematic uncertainties cancel out, improving the measurement precision by up to a factor of nine. The observables and ratios selected for this paper provide valuable input for the up quark, down quark, and gluon parton distribution functions of the proton.

86 data tables match query
Table 1

Cross section for the production of W bosons for different inclusive jet multiplicities.

Table 2

Statistical correlation between bins in data for the cross section for the production of W bosons for different inclusive jet multiplicities.

Table 3

Differential cross sections for the production of W<sup>+</sup> bosons, W<sup>-</sup> bosons and the W<sup>+</sup>/W<sup>-</sup> cross section ratio as a function of the inclusive jet multiplicity.

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Measurement of W boson polarizations and CP violating triple gauge couplings from W+ W- production at LEP

The OPAL collaboration Abbiendi, G. ; Ackerstaff, K. ; Ainsley, C. ; et al.
Eur.Phys.J.C 19 (2001) 229-240, 2001.
Inspire Record 533112 DOI 10.17182/hepdata.49856

Measurements are presented of the polarisation of W+W- boson pairs produced in e+e- collisions, and of CP-violating WWZ and WWGamma trilinear gauge couplings. The data were recorded by the OPAL experiment at LEP during 1998, where a total integrated luminosity of 183 pb^-1 was obtained at a centre-of-mass energy of 189 GeV. The measurements are performed through a spin density matrix analysis of the W boson decay products. The fraction of W bosons produced with longitudinal polarisation was found to be sigma_L/sigma_total = (21.0 +- 3.3 +- 1.6)% where the first error is statistical and the second systematic. The joint W boson pair production fractions were found to be sigma_TT/sigma_total = (78.1 +- 9.0 +- 3.2) %, sigma_LL/sigma_total = (20.1 +- 7.2 +- 1.8) % and sigma_TL/sigma_total = (1.8 +- 14.7 +- 3.8) %. In the CP-violating trilinear gauge coupling sector we find kappa_z = -0.20 +0.10 -0.07, g^z_4 = -0.02 +0.32 -0.33 and lambda_z = -0.18 +0.24 -0.16, where errors include both statistical and systematic uncertainties. In each case the coupling is determined with all other couplings set to their Standard Model values except those related to the measured coupling via SU(2)_LxU(1)_Y symmetry. These results are consistent with Standard Model expectations.

4 data tables match query
Table 1

Individual W-boson transverse polarised cross-sections.

Table 2

Individual W-boson longitudinal polarised cross-sections.

Table 3

W pair polarized cross-sections. (C=TT), (C=LL), and (C=TL) stand for both W transversely polarised, for both W longitudinally polarised, and for transversely and longitudinally polarisedW-bosons, respectively.

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Search for trilinear neutral gauge boson couplings in Z-gamma production at S**(1/2) = 189-GeV at LEP

The OPAL collaboration Abbiendi, G. ; Ackerstaff, K. ; Ainsley, C. ; et al.
Eur.Phys.J.C 17 (2000) 553-566, 2000.
Inspire Record 529897 DOI 10.17182/hepdata.49934

The data recorded at a centre-of-mass energy of 189GeV by the OPAL detector at LEP are used to search for trilinear couplings of the neutral gauge bosons in the process e+e- --> Z-gamma. The cross-sections are measured for multihadronic events with an energetic isolated photon and for events with a high energy photon accompanied by missing energy. These cross-sections and the photon energy, polar angle and isolation angle distributions are compared to the Standard Model predictions and to the theoretical expectations of a model allowing for Z-gamma-Z and Z-gamma-gamma vertices. Since no significant deviations with respect to the Standard Model expectations are found, constraints are derived on the strength of neutral trilinear gauge couplings.

2 data tables match query
Table 1

Total sysytematic error for Q Qbar (NU NUbar) channel is 0.154 (0.048) pb.

Table 2

See text for Z(GAMMA) anomalous coupling definitions. Statistical and systematic errors are combined in quadrature.


W+ W- production cross section and W branching fractions in e+ e- collisions at 189-GeV.

The OPAL collaboration Abbiendi, G. ; Ackerstaff, K. ; Ainsley, C. ; et al.
Phys.Lett.B 493 (2000) 249-265, 2000.
Inspire Record 533110 DOI 10.17182/hepdata.49910

From a data sample of 183 pb^-1 recorded at a center-of-mass energy of roots = 189 GeV with the OPAL detector at LEP, 3068 W-pair candidate events are selected. Assuming Standard Model W boson decay branching fractions, the W-pair production cross section is measured to be sigmaWW = 16.30 +- 0.34(stat.) +- 0.18(syst.) pb. When combined with previous OPAL measurements, the W boson branching fraction to hadrons is determined to be 68.32 +- 0.61(stat.) +- 0.28(syst.) % assuming lepton universality. These results are consistent with Standard Model expectations.

2 data tables match query
Table 1

Total W+ W- pair production cross section.

Table 2

Cross sections for the individual decay modes of the W+ W-.


Measurement of the average b baryon lifetime and the product branching ratio f (b --> Lambda(b)) x BR (Lambda(b) --> Lambda lepton- anti-neutrino X)

The OPAL collaboration Akers, R. ; Alexander, G. ; Allison, John ; et al.
Z.Phys.C 69 (1996) 195-214, 1996.
Inspire Record 397395 DOI 10.17182/hepdata.51966

None

1 data table match query
Table 1

Charged conjugate state is assumed.