Discovering walking technirho mesons at the LHC

Abstract: We formulate a scale-invariant hidden local symmetry (HLS) as a low-energy effective theory of walking technicolor (WTC) which includes the technidilaton, technipions, and technirho mesons as the low-lying spectra. As a benchmark for LHC phenomenology, we in particular focus on the one-family model of WTC having eight technifermion flavors, which can be, at energy scales relevant to the reach of the LHC, described by the scale-invariant HLS based on the manifold $$[SU(8)<em>L \times SU(8)_R]</em>{\rm global} \times SU(8)<em>{\rm local}/SU(8)_V$$, where $SU(8)</em>{\rm local}$ is the HLS and the global $SU(8)_L \times SU(8)_R$ symmetry is partially gauged by $SU(3) \times SU(2)_L \times U(1)_Y$ of the standard model. Based on the scale-invariant HLS, we evaluate the coupling properties of the technirho mesons and place limits on the masses from the current LHC data. Then, implications for future LHC phenomenology are discussed by focusing on the technirho mesons produced through the Drell-Yan process. We find that the color-octet technirho decaying to the technidilaton along with the gluon is of interest as the discovery channel at the LHC, which would provide a characteristic signature to probe the one-family WTC.