4 research outputs found
Light Scalar Meson and Decay Constant in SU(3) Gauge Theory with Eight Dynamical Flavors
The SU(3) gauge theory with nearly massless Dirac fermions has long
been of theoretical and phenomenological interest due to the near-conformality
arising from its proximity to the conformal window. One particularly
interesting feature is the emergence of a relatively light, stable
flavor-singlet scalar meson in contrast to the
theory QCD. In this work, we study the finite-volume dependence of the
meson correlation function computed in lattice gauge theory and
determine the meson mass and decay constant extrapolated to the
infinite-volume limit. We also determine the infinite volume mass and decay
constant of the flavor-nonsinglet scalar meson .Comment: 36 pages, 11 figures, supplementary data in zenodo
https://dx.doi.org/10.5281/zenodo.800795
Nonperturbative investigations of SU(3) gauge theory with eight dynamical flavors
We present our lattice studies of SU(3) gauge theory with = 8
degenerate fermions in the fundamental representation. Using nHYP-smeared
staggered fermions we study finite-temperature transitions on lattice volumes
as large as , and the zero-temperature
composite spectrum on lattice volumes up to . The spectrum
indirectly indicates spontaneous chiral symmetry breaking, but
finite-temperature transitions with fixed enter a strongly
coupled lattice phase as the fermion mass decreases, which prevents a direct
confirmation of spontaneous chiral symmetry breaking in the chiral limit. In
addition to the connected spectrum we focus on the lightest flavor-singlet
scalar particle. We find it to be degenerate with the pseudo-Goldstone states
down to the lightest masses reached so far by non-perturbative lattice
calculations. Using the same lattice approach, we study the behavior of the
composite spectrum when the number of light fermions is changed from eight to
four. A heavy flavor-singlet scalar in the 4-flavor theory affirms the contrast
between QCD-like dynamics and the low-energy behavior of the 8-flavor theory.Comment: 31 pages, 36 figures, 8 tables. v2: update to published versio
Light Scalar Meson and Decay Constant in SU(3) Gauge Theory with Eight Dynamical Flavors
The SU(3) gauge theory with nearly massless Dirac fermions has long
been of theoretical and phenomenological interest due to the near-conformality
arising from its proximity to the conformal window. One particularly
interesting feature is the emergence of a relatively light, stable
flavor-singlet scalar meson in contrast to the
theory QCD. In this work, we study the finite-volume dependence of the
meson correlation function computed in lattice gauge theory and
determine the meson mass and decay constant extrapolated to the
infinite-volume limit. We also determine the infinite volume mass and decay
constant of the flavor-nonsinglet scalar meson