HEPData Search

We have measured the partial width and forward-backward charge asymmetry for the reaction e + e - →Z 0 →μ + μ - (γ). We obtain a partial width Γ μμ of 83.3±1.3(stat)±0.9(sys) MeV and the following values for the vector and axial vector couplings: g v =−0.062 −0.015 +0.020 and g A =−0.497 −0.005 +0.005 . From our measurement of the partial width and the mass of the Z 0 boson we determine the effective electroweak mixing angle, sin 2 θ w =0.232±0.005, and the neutral current coupling strength parameter, ϱ =0.998±0.016.

4 data tables

Table 1

No description provided.

Table 2

Forward backward charge asymmetry.

Table 3

No description provided.

More…

A MEASUREMENT OF THE Z0 LEPTONIC PARTIAL WIDTHS AND THE FORWARD - BACKWARD ASYMMETRY

The L3 collaboration Adeva, B. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.

L3-005, 1990.

Inspire Record 294576 DOI 10.17182/hepdata.29691

None

4 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

A STUDY OF DELTA++ AND DELTA0 ISOBAR INCLUSIVE PRODUCTION IN K- p INTERACTIONS AT 32-GeV/c

Babintsev, V.V. ; Bogolyubsky, M.Yu. ; Bumazhnov, V.A. ; et al.

Sov.J.Nucl.Phys. 39 (1984) 414, 1984.

Inspire Record 190556 DOI 10.17182/hepdata.41019

22 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

EVENTS WITH IDENTIFIED PROTONS.

More…

A Study of $K^+ p$ Elastic Scattering and the Reaction $K^+ p \to K^+ p \pi^+ \pi^-$ at 70-{GeV}/$c$

The Brussels-Genoa-Mons-Nijmegen-Serpukhov-CERN collaboration Barth, M. ; Wolf, A.E. De ; Johnson, D.P. ; et al.

Z.Phys.C 16 (1982) 111, 1982.

Inspire Record 181354 DOI 10.17182/hepdata.41205

Results are presented onK+p elastic scattering and on the reactionK+p→K+pπ+π− at 70 GeV/c. For the

9 data tables

Table 1

Table 2

Table 3

More…

A Study of the reaction e+ e- ---> mu+ mu- around the Z0 pole

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adami, F. ; et al.

Phys.Lett.B 260 (1991) 240-248, 1991.

Inspire Record 314619 DOI 10.17182/hepdata.29420

Measurements of the cross section and forward-backward asymmetry for the reaction e + e − → μ + μ − using the DELPHI detector at LEP are presented. The data come from a scan around the Z 0 peak at seven centre of mass energies, giving a sample of 3858 events in the polar angle region 22° < θ < 158°. From a fit to the cross section for 43° < θ < 137°, a polar angle region for which the absolute efficiency has been determined, the square root of the product of the Z 0 → e + e − and Z 0 → μ + μ − partial widths is determined to be (Γ e Γ μ ) 1 2 = 85.0 ± 0.9( stat. ) ± 0.8( syst. ) MeV . From this measurement of the partial width, the value of the effective weak mixing angle is determined to be sin 2 ( θ w ) = 0.2267 ± 0.0037 . The ratio of the hadronic to muon pair partial widths is found to be Γ h / Γ μ = 19.89 ± 0.40(stat.) ± 0.19(syst.). The forward-backward asymmetry at the resonance peak energy E CMS = 91.22 GeV is found to be A FB = 0.028 ± 0.020(stat.) ± 0.005(syst.). From a combined fit to the cross section and forward-backward asymmetry data, the products of the electron and muon vector and axial-vector coupling constants are determined to be V e V μ = 0.0024 ± 0.0015(stat.) ± 0.0004(syst.) and A e A μ = 0.253 ± 0.003(stat.) ± 0.003 (syst.). The results are in good agreement with the expectations of the minimal standard model.

3 data tables

Table 1

Fully corrected cross sections.

Table 2

Forward-backward asymmetries corrected to full solid angle, but not for cuts on momenta and acollinearity.

Table 3

Effective weak mixing angle.

A new measurement of the Collins and Sivers asymmetries on a transversely polarised deuteron target

The COMPASS collaboration Ageev, E.S. ; Alexakhin, V.Yu. ; Alexandrov, Yu. ; et al.

Nucl.Phys.B 765 (2007) 31-70, 2007.

Inspire Record 729695 DOI 10.17182/hepdata.48535

New high precision measurements of the Collins and Sivers asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarised 6LiD target are presented. The data were taken in 2003 and 2004 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. Both the Collins and Sivers asymmetries turn out to be compatible with zero, within the present statistical errors, which are more than a factor of 2 smaller than those of the published COMPASS results from the 2002 data. The final results from the 2002, 2003 and 2004 runs are compared with naive expectations and with existing model calculations.

24 data tables

Table 1

Collins asymmetry against PT for all negative hadrons.

Table 2

Collins asymmetry against Bjorken X for all negative hadrons.

Table 3

Collins asymmetry against Z for all negative hadrons.