Precision Measurement of Electroweak Effects in $e^+ e^- \to \mu^+ \mu^-$ at $\sqrt{s}=29$-{GeV}

Ash, W. ; Band, H. ; Blume, H.T. ; et al.
Phys.Rev.Lett. 55 (1985) 1831, 1985.
Inspire Record 216031 DOI 10.17182/hepdata.3246

A high-statistics measurement has been made of the process e+e−→μ+μ− at s=29 GeV with the MAC detector at the SLAC storage ring PEP. The electroweak forward-backward charge asymmetry for a sample of approximately 16 000 events was measured to be Aμμ=−0.063±0.008±0.002. The ratio of the cross section to the lowest-order QED cross section was measured to be Rμμ=1.01±0.01±0.03. From these results the weak neutral axial-vector and vector couplings are determined to be gAegAμ=0.25±0.03±0.01 and gVegVμ=−0.02±0.03±0.09.

5 data tables match query

Data are fully corrected, including radiative effects.

Asymmetry determined from a two parameter fit to the angular distribution proportional to R*(1 + cos(theta)**2 + (8/3)*A*cos(theta)). R is then the total ratio relative to the lowest order QED cross section and A is the forward-backward asymmetry.

No description provided.

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Electroweak Effects in $e^+ e^- \to \mu^+ \mu^-$ at 29-{GeV}

Fernandez, E. ; Ford, William T. ; Read, Alexander L. ; et al.
Phys.Rev.Lett. 50 (1983) 1238, 1983.
Inspire Record 188749 DOI 10.17182/hepdata.20560

A measurement of the cross section for production of collinear muon pairs based upon a sample of about 3000 events observed in the MAC detector at the storage ring PEP is presented. From the angular asymmetry Aμμ=0.076±0.018 the axial-vector weak neutral coupling is found to be given by gAegAμ=0.31±0.08.

2 data tables match query

Data on non-collinearity and angular distribution.

Asymmetry measurement based on extrapolation of number of events to 4 PI acceptance.


WEAK NEUTRAL CURRENT EFFECTS IN e+ e- ---> mu+ mu- AT 29-GeV

Fernandez, E. ; Ford, William T. ; Read, Alexander L. ; et al.
SLAC-PUB-3133, 1983.
Inspire Record 190846 DOI 10.17182/hepdata.18659

None

2 data tables match query

No description provided.

Data extrapolated to full solid angle.


PROMPT MUON PRODUCTION IN e+ e- ANNIHILATIONS AT 29-GeV

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Badtke, D.H. ; et al.
Phys.Rev.D 31 (1985) 2719, 1985.
Inspire Record 213118 DOI 10.17182/hepdata.3937

We have studied the production of prompt muons in hadronic events from e+e− annihilation at a center-of-mass energy of 29 GeV with the PEP4-TPC (Time Projection Chamber) detector. The muon p and pt distributions are well described by a combination of bottom- and charm-quark decays, with fitted semimuonic branching fractions of (15.2±1.9±1.2)% and (6.9±1.1±1.1)%, respectively. The muon spectra imply hard fragmentation functions for both b and c quarks, with 〈z(b quark)〉=0.80±0.05±0.05 and 〈z(c quark)〉=0.60±0.06±0.04. We derive neutral-current axial-vector couplings of a(b quark)=-0.9±1.1±0.3 and a(c quark)=1.5±1.5±0.5 from the forward-backward asymmetries.

5 data tables match query

PT is the transverse momentum of the muon relative to the event thrust axis.

PT is the transverse momentum of the MUON relative to the event thrust axis. At this table MUON is from JET and its PT < 1 GeV/c.

PT is the transverse momentum of the MUON relative to the event thrust axis. At this table MUON is from JET and its PT > 1 GeV/c.

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