523 research outputs found
Exploring walking behavior in SU(3) gauge theory with 4 and 8 HISQ quarks
We present the report of the LatKMI collaboration on the lattice QCD
simulation for the cases of 4 and 8 flavors. The Nf=8 in particular is
interesting from the model-building point of view: The typical walking
technicolor model with the large anomalous dimension is the so-called
one-family model (Farhi-Susskind model). Thus we explore the walking behavior
in LQCD with 8 HISQ quarks by comparing with the 4-flavor case (in which the
chiral symmetry is spontaneously broken). We report preliminary results on the
spectrum, analyzed through the chiral perturbation theory and the finite-size
hyperscaling, and we discuss the availability of the Nf=8 QCD to the
phenomenology.Comment: 7 pages, Proceedings of 30th International Symposium on Lattice Field
Theory, June 24-29, 2012, Cairns, Australi
The scalar spectrum of many-flavour QCD
The LatKMI collaboration is studying systematically the dynamical properties
of N_f = 4,8,12,16 SU(3) gauge theories using lattice simulations with (HISQ)
staggered fermions. Exploring the spectrum of many-flavour QCD, and its scaling
near the chiral limit, is mandatory in order to establish if one of these
models realises the Walking Technicolor scenario. Although lattice technologies
to study the mesonic spectrum are well developed, scalar flavour-singlet states
still require extra effort to be determined. In addition, gluonic observables
usually require large-statistic simulations and powerful noise-reduction
techniques. In the following, we present useful spectroscopic methods to
investigate scalar glueballs and scalar flavour-singlet mesons, together with
the current status of the scalar spectrum in N_f = 12 QCD from the LatKMI
collaboration.Comment: 9 pages, 5 figures, 1 table. To appear in the Proceedings of SCGT 12,
KMI, Nagoya University, Dec. 4-7, 201
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