LHC limits on KK-parity non-conservation in the strong sector of universal extra-dimension models

In five-dimensional universal extra-dimensional models compactified on an S1/Z2S1/Z2 orbifold four-dimensional kinetic terms are allowed at the two fixed points. If these terms are unequal then Kaluza–Klein (KK) parity is broken. Within such a framework we consider resonant production of the n=1n=1 KK-gluon at the LHC and its subsequent decay to tt¯, where both production and decay are KK-parity non-conserving. We use, for the first time, the exclusion data for a tt¯ resonance obtained by the LHC experiments to limit the mass range of the lowest gluon excitation and, in a correlated fashion, of the n=1n=1 quark excitation of the KK-parity-violating model which are both found to be in the ballpark of 600–2000 GeV.