A light composite scalar in eight-flavor QCD on the lattice
Abstract
In search for a composite Higgs boson (techni-dilaton) in the walking technicolor, we present our preliminary results on the first observation of a light flavor-singlet scalar in a candidate theory for the walking technicolor, the Nf=8 QCD, which was found in our previous paper to have spontaneous chiral symmetry breaking together with remnants of the conformality. Based on simulations with the HISQ-type action on several lattice sizes with various fermion masses, we find evidence of a flavor-singlet scalar meson with mass comparable to that of the Nambu-Goldstone pion in both the small fermion-mass region, where chiral perturbation theory works, and the intermediate fermion-mass region where the hyperscaling relation holds. We further discuss its chiral limit extrapolation in comparison with other states studied in our previous paper: the scalar has a mass much smaller than that of the vector meson, which is compared to the Nambu-Goldstone pion having a vanishing mass in that limit.
Keywords
Cite
@article{arxiv.1309.0711,
title = {A light composite scalar in eight-flavor QCD on the lattice},
author = {Yasumichi Aoki and Tatsumi Aoyama and Masafumi Kurachi and Toshihide Maskawa and Kohtaroh Miura and Kei-ichi Nagai and Hiroshi Ohki and Enrico Rinaldi and Akihiro Shibata and Koichi Yamawaki and Takeshi Yamazaki},
journal= {arXiv preprint arXiv:1309.0711},
year = {2013}
}
Comments
7 pages, 4 figures, Proceedings of 31st International Symposium on Lattice Field Theory - LATTICE 2013, July 29 - August 3, 2013, Mainz, Germany