Many-flavor SU(3) gauge theories with nHYP-smeared staggered fermions

Project

We perform non-perturbative lattice studies of SU(3) gauge theories with 4, 8, 12 and 16 fermions in the fundamental representation, to gain theoretical insight into these systems and assess their potential phenomenological relevance for physics beyond the standard model. We use Monte Carlo renormalization group (MCRG) techniques to explore whether or not these systems are conformal in the infrared, and also carry out wide-ranging calculations at both zero and finite temperature to study the characteristics of these systems at small fermion masses and in the chiral limit.

Participants

Publications

Software

We have modified the MIMD Lattice Computation (MILC) Collaboration software for improved staggered fermions to implement nHYP smearing (allowing an arbitrary number of smearing steps), to add an adjoint plaquette term to the gauge action, and to exploit both even and odd sublattices to simulate eight flavors. In early 2012 we finished implementing and testing an efficient Omelyan integrator accelerated by an additional heavy pseudofermion field and multiple time scales, which we now use in production. In the summer of 2012 we developed a Wilson flow application based on the MILC code, which we shared with the MILC Collaboration for incorporation into future releases of their code. In the spring of 2013 we wrote a stochastic eigenmode number calculation, also on the basis of the MILC code. Our modifications are available .

Data

We have generated many ensembles of gauge configurations with 4, 8, 12 and 16 fundamental fermions, at a large number of masses and gauge couplings. There are too many ensembles to list here, and their statistics vary widely.

Our saved configurations are available to any USQCD Collaboration member . However, through December 2013 we reserve the exclusive right to use these configurations for MCRG analyses, as well as for calculations of Wilson and Polyakov loops, the chiral condensate, the static potential, the meson spectrum and pseudoscalar decay constant, and the Dirac eigenvalue spectrum. We will also share these configurations with other members of the global lattice community wishing to collaborate or whose plans are not in direct competition to ours.

Support

(SU stands for "service unit", essentially a core-hour)

Last modified 12 November 2013

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