Determination of the LEP Beam Energy using Radiative Fermion-pair Events

TL;DR

This paper measures the LEP beam energy using radiative fermion-pair events, confirming the standard calibration within uncertainties and providing an independent verification method.

Contribution

It introduces a novel method to determine the LEP beam energy using radiative return events, offering an independent cross-check of the standard calibration.

Findings

No significant disagreement with LEP calibration.

Beam energy measurement consistent within uncertainties.

Provides an independent validation of LEP energy calibration.

Abstract

We present a determination of the LEP beam energy using "radiative return" fermion-pair events recorded at centre-of-mass energies from 183 GeV to 209 GeV. We find no evidence of a disagreement between the OPAL data and the LEP Energy Workings Group's standard calibration. Including the energy- averaged 11 MeV uncertainty in the standard determination, the beam energy we obtain from the OPAL data is higher than that obtained from the LEP calibration by 0+-34(stat.)+-27(syst.)MeV