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Virtual graviton exchanges at the Z-pole in large extra dimensions

Anindya Datta·Emidio Gabrielli·Barbara Mele
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Abstract

In the framework of quantum gravity propagating in large extra dimensions, the effects of virtual Kaluza-Klein gravitons on the imaginary part of the amplitude of the process e+ e- --> f f-bar are analyzed at the Z-pole. Notably, the interference of the almost-continuous spectrum of the KK gravitons with the standard model resonant amplitude is finite and predictable in terms of the fundamental D-dimensional Plank scale M_D. We find that, while the virtual-gravitons effect on total cross sections vanishes at tree-level, both angular and polarization asymmetries are modified by terms whose relative effect is at most of order 10^(-4) for M_D > 1 TeV. Possible shifts in the M_Z, due to changes in the Breit-Wigner line shape are also discussed.

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Anindya Datta, Emidio Gabrielli, Barbara Mele. 2002-12-07. Virtual graviton exchanges at the Z-pole in large extra dimensions. https://doi.org/10.1016/s0370-2693(02)03164-7

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