# Holographic Techni-dilaton - High Energy Physics - Phenomenology

Holographic Techni-dilaton - High Energy Physics - Phenomenology - Download this document for free, or read online. Document in PDF available to download.

Abstract: Techni-dilaton, a pseudo-Nambu-Goldstone boson of scale symmetry, waspredicted long ago in the Scale-invariant-Walking-Conformal TechnicolorSWC-TC as a remnant of the approximate scale symmetry associated with theconformal fixed point, based on the conformal gauge dynamics of ladderSchwinger-Dyson SD equation with non-running coupling. We study thetechni-dilaton as a flavor-singlet bound state of techni-fermions by includingthe techni-gluon condensate tGC effect into the previous bottom-upholographic approach to the SWC-TC, a deformation of the holographic QCD with$\gamma m \simeq 0$ by large anomalous dimension $\gamma m \simeq 1$. Withincluding a bulk scalar field corresponding to the gluon condensate, we firstimprove the Operator Product Expansion of the current correlators so as toreproduce gluonic $1-Q^4$ term both in QCD and SWC-TC. We find in QCD about$10\%$ negative contribution of gluon condensate to the $ ho$ meson mass. Wealso calculate the oblique electroweak $S$-parameter in the presence of theeffect of the tGC and find that for the fixed value of $S$ the tGC effectsdramatically reduce the flavor-singlet scalar techni-dilaton mass $M { mTD}$ in the unit of $F \pi$, while the vector and axial-vector masses$M ho$ and $M {a 1}$ are rather insensitive to the tGC, where $F \pi$ is thedecay constant of the techni-pion. If we use the range of values of tGC impliedby the ladder SD analysis of the non-perturbative scale anomaly in the large$N f$ QCD near the conformal window, the phenomenological constraint $S \simeq0.1$ predicts the techni-dilaton mass $M { m TD} \sim 600$ GeV which is withinreach of LHC discovery.

Author: ** Kazumoto Haba, Shinya Matsuzaki, Koichi Yamawaki**

Source: https://arxiv.org/