Measurement of muon pair production at 50-GeV < s**(1/2) < 86-GeV at LEP

The L3 collaboration Acciarri, M. ; Adam, A. ; Adriani, O. ; et al.
Phys.Lett.B 374 (1996) 331-340, 1996.
Inspire Record 416744 DOI 10.17182/hepdata.47586

Using the data recorded with the L3 detector at LEP, we study the process e + e − → μ + μ − ( γ ) for events with hard initial-state photon radiation. The effective centre-of-mass energies of the muons range from 50 GeV to 86 GeV. The data sample corresponds to an integrated luminosity of 103.5 pb −1 and yields 293 muon-pair events with a hard photon along the beam direction. The events are used to determine the cross sections and the forward-backward charge asymmetries at centre-of-mass energies below the Z resonance.

3 data tables

Here S refers to the reduced centre-of-mass energy.

Forward-Backward Asymmetry from fit as function of the reduced centre-of-mass energy.

Background corrected Forward-Backward Asymmetry as function of the reduced centre-of-mass energy.


Measurement of charm production in two photon processes using inclusive lepton events at TRISTAN

The AMY collaboration Aso, T. ; Miyata, H. ; Sasaki, T. ; et al.
Phys.Lett.B 363 (1995) 249-258, 1995.
Inspire Record 401053 DOI 10.17182/hepdata.38520

Measurements of open charm production in photon-photon collisions made with the AMY detector at TRISTAN are reported. Charmed hadrons were identified by detecting the high momentum muons or electrons from their semileptonic decays. The data sample corresponds to an integrated luminosity of 275 pb −1 at an average center of mass energy of 58 GeV. Results are presented in the form of cross sections of inclusive leptons from charm for both muons and electrons. The measured cross section is 1.8 standard deviations higher than theoretical predictions based on the direct and photon-gluon fusion process, where the mass of charm quark is assumed to be 1.6 GeV.

3 data tables

OBSERVATION OF ANOMALOUS PRODUCTION OF MUON PAIRS IN e+ e- ANNIHILATION INTO FOUR LEPTON FINAL STATES

The AMY collaboration Ho, Y.H. ; Kurihara, Y. ; Omori, T. ; et al.
Phys.Lett.B 244 (1990) 573-579, 1990.
Inspire Record 294829 DOI 10.17182/hepdata.51362

We report results of a study of four-lepton final states produced in e + e − collisions at center-of-mass energies from 50 to 61.4 GeV using the AMY detector at the TRISTAN collider. For the cases where two or three charged tracks are produced at large angles relative to the beam direction, the cross sections agree with QED. However, we observe an excess of e + e − → e + e − μ + μ − events with four tracks at wide angles and with dimuon mass less than 1.0 GeV / c 2 .

1 data table

No description provided.