Evolution of the coupling constant in SU(2) lattice gauge theory with two adjoint fermions

Abstract

We measure the evolution of the coupling constant using the Schrödinger functional method in the lattice formulation of SU(2) gauge theory with two massless Dirac fermions in the adjoint representation. We observe strong evidence for an infrared fixed point, where the theory becomes conformal. We measure the β-function and the coupling constant as a function of the energy scale.

Introductory lectures to large- QCD phenomenology and lattice results

“…The other lattice study of the large-N meson spectrum [138] (see also ref. [144]), however, found incompatible results, and came to the conclusion that the mass of the ρ meson in the large-N limit would be much larger than in the theory with N = 3 colors.…”

“…It is possible that this discrepancy with the other studies may be due to uncontrolled systematic errors, related, in particular, to contamination from excited states in the momentum-space evaluation of quark propagators carried out in ref. [138].…”

“…[12,111,114,[135][136][137][138][139][140][141][142]: all of them have been carried out in pure Yang-Mills theory, or in the quenched approximation.…”

Sparameter in QCD from domain wall fermions

“…The existence of IRFPs has been investigated in theories with fundamental fermions [14][15][16][17][18][19][20] and higher representations [21][22][23][24][25][26][27][28][29][30][31]. These preliminary studies have mapped out the space of bare lattice parameters and are starting to study the spectrum of the candidate theories, and the flow of renormalized couplings.…”

Lattice studies of quantum chromodynamics-like theories with many fermionic degrees of freedom

“…Many groups (a representative list includes [48][49][50][51][52][53]) have studied N f = 2 flavours of adjoint representation fermions in SU (2). All studies to date use Wilson-type quarks.…”