Techni-dilaton at 125 GeV

Walking technicolor predicts a light composite scalar, techni-dilaton, arising as a pseudo-Nambu-Goldstone boson for the approximate scale symmetry spontaneously broken by techni-fermion condensation. We show that a light techni-dilaton with a mass of around 125 GeV can explain presently observed excesses particularly in the di-photon decay channel at the LHC.

Figure 1

$g_{\mathrm{TD}}/g_{h_{\mathrm{SM}}}=(3-{\gamma }_m)v_{\mathrm{EW}}/F_{\mathrm{TD}}$ with ${\gamma }_m\simeq 1$, with respect to the TD mass $M_{\mathrm{TD}}$ in a range from 110 to 600 GeV for one-family models with $N_{\mathrm{TF}}=4N_{\mathrm{TC}}$ fixed.

Figure 2

The TD LHC cross section at 7 TeV times branching ratios for $W{W}^{*}$ (top panel), $Z{Z}^{*}$ (middle panel) and di-photon (bottom panel) decay channels normalized to the corresponding quantities for the SM Higgs, in comparison with the current ATLAS (red curves) and CMS (blue curves) data [3, 4, 5] at 95% C.L. for the low Higgs mass range. The yellow band denotes the expected backgrounds within the $2\sigma$ level.