arXiv:hep-ph/0001320·v2·High Energy Physics — Phenomenology

Oblique Parameter Constraints on Large Extra Dimensions

Tao Han · Danny Marfatia · Ren-Jie Zhang

Abstract

We consider the Kaluza-Klein scenario in which gravity propagates in the $4 + n$ dimensional bulk of spacetime and the Standard Model particles are confined to a 3-brane. We calculate the gauge boson self-energy corrections arising from the exchange of virtual gravitons and present our results in the $S T U$ -formalism. We find that the new physics contributions to $S$ , $T$ and $U$ decouple in the limit that the string scale $M_{S}$ goes to infinity. The oblique parameters constrain the lower limit on $M_{S}$ . Taking the quantum gravity cutoff to be $M_{S}$ , $S$ -parameter constraints impose $M_{S} > 1.55$ TeV for $n = 2$ at the 1 $σ$ level. $T$ -parameter constraints impose $M_{S} > 1.25 (0.75)$ TeV for $n = 3 (6)$ .

Comments: Version to appear in PRD