2 research outputs found
String tensions in deformed Yang-Mills theory
We study k-strings in deformed Yang-Mills (dYM) with SU(N) gauge group in the
semiclassically calculable regime on . Their tensions
T are computed in two ways: numerically, for N
, and via an analytic approach using a re-summed perturbative expansion.
The latter serves both as a consistency check on the numerical results and as a
tool to analytically study the large-N limit. We find that dYM k-string ratios
T/T do not obey the well-known sine- or
Casimir-scaling laws. Instead, we show that the ratios
T/T are bound above by a square root of Casimir
scaling, previously found to hold for stringlike solutions of the MIT Bag
Model. The reason behind this similarity is that dYM dynamically realizes, in a
theoretically controlled setting, the main model assumptions of the Bag Model.
We also compare confining strings in dYM and in other four-dimensional theories
with abelian confinement, notably Seiberg-Witten theory, and show that the
unbroken center symmetry in dYM leads to different properties of
k-strings in the two theories; for example, a "baryon vertex" exists in dYM but
not in softly-broken Seiberg-Witten theory. Our results also indicate that, at
large values of N, k-strings in dYM do not become free.Comment: v3: To be published version, 78 pages, 7 figures, Added extended
discussion of non-commutativity of large N and large area limit