Study of Fermion pair production in e+e- collisions at 130-183 GeV

TL;DR

This paper reports measurements of fermion pair production in electron-positron collisions at 130-183 GeV, confirming Standard Model predictions and setting limits on new physics scenarios like contact interactions and exotic particles.

Contribution

First detailed measurements of fermion pair production at these energies with constraints on beyond Standard Model physics.

Findings

Results agree with Standard Model predictions.

Set limits on contact interaction energy scales (2-10 TeV).

Constrain masses of R-parity violating sneutrinos to a few hundred GeV.

Abstract

The cross sections and forward-backward asymmetries of hadronic and leptonic events produced in e+e- collisions at centre-of-mass energies of 130-183 GeV are presented. Results for ee, mumu, tautau, qq, bb and cc production show no significant deviation from the Standard Model predictions. This enable constraints to be set upon physics beyond the Standard Model such as four-fermion contact interactions, leptoquarks, Z' bosons and R-parity violating squarks and sneutrinos. Limits on the energy scale Lambda of eeff contact interactions are typically in the range from 2-10 TeV. Limits on R-parity violating sneutrinos reach masses of a few hundred GeV for large values of their Yukawa couplings.