Signals for Low Scale Gravity in the Process $\gamma \gamma \to ZZ$

Abstract

We investigate the sensitivity of future photon-photon colliders to low scale gravity scenarios via the process $\gamma \gamma \to ZZ$ where the Kaluza-Klein boson exchange contributes only when the initial state photons have opposite helicity. We contrast this with the situation for the process $\gamma \gamma \to \gamma \gamma$ where the $t$ and $u$ channel also contribute. We include the one-loop Standard Model background whose interference with the graviton exchange determines the experimental reach in measuring any deviation from the Standard Model expectations and explore how polarization can be exploited to enhance the signal over background. We find that a 1 TeV linear collider has an experimental reach to mass scale of about 4 TeV in this channel.

20 pages, 8 figures

References in corpus (6)

• Sub-millimeter Tests of the Gravitational Inverse-square Law
• Supernova and neutron-star limits on large extra dimensions reexamined
• Helicity Formalism for Spin-2 Particles
• Graviton-induced Bremsstrahlung
• Higgs pair production in association with a vector boson at e+e- colliders in theories of higher dimensional gravity
• Weak Scale Quantum Gravity Effects for $\gamma \gamma \to ZZ$ in the TeV region

Cited by in corpus (1)

• Decays $Z\to \gamma \gamma$ and $Z\to gg$ in the Standard Model Extension