Based on lattice simulations using highly improved staggered quarks for twelve-flavor QCD with several bare fermion masses, we observe a flavor-singlet scalar state lighter than the pion in the correlators of fermionic interpolating operators. The same state is also investigated using correlators of gluonic interpolating operators. Combined with our previous study, that showed twelve-flavor QCD to be consistent with being in the conformal window, we infer that the lightness of the scalar state is due to infrared conformality. This result shed some light on the possibility of a light composite Higgs boson ("technidilaton") in walking technicolor theories.
@article{arxiv.1305.6006,
title = {Light composite scalar in twelve-flavor QCD on the lattice},
author = {Yasumichi Aoki and Tatsumi Aoyama and Masafumi Kurachi and Toshihide Maskawa and Kei-ichi Nagai and Hiroshi Ohki and Enrico Rinaldi and Akihiro Shibata and Koichi Yamawaki and Takeshi Yamazaki},
journal= {arXiv preprint arXiv:1305.6006},
year = {2013}
}
Comments
5 pages, 4 figures, 1 table. This version contains minor modifications and an updated Table 1. Accepted for publication in Physical Review Letters