Search for Low Scale Gravity Effects in e+e- Collisions at LEP

TL;DR

This paper searches for signs of low-scale quantum gravity effects at LEP energies by analyzing various particle collision processes, finding no evidence but setting limits near 1 TeV on the gravity scale.

Contribution

It provides the first experimental constraints on low-scale gravity effects in e+e- collisions at LEP energies, exploring both real and virtual graviton contributions.

Findings

No evidence for low-scale gravity effects was observed.

Limits near 1 TeV were set on the quantum gravity scale.

Constraints apply to both graviton production and virtual exchange processes.

Abstract

Recent theories propose that quantum gravity effects may be observable at LEP energies via gravitons that couple to Standard Model particles and propagate into extra spatial dimensions. The associated production of a graviton and a photon is searched for as well as the effects of virtual graviton exchange in the processes: e+e- -> gamma gamma, ZZ, WW, mu mu, tau tau, qq and ee No evidence for this new interaction is found in the data sample collected by the L3 detector at LEP at centre-of-mass energies up to 183 GeV. Limits close to 1 TeV on the scale of this new scenario of quantum gravity are set.