Abstract
We address the question of whether the large-N expansion in pure SU(N) gauge theories requires that k-string tensions must have a power series expansion in 1/N2, as in the sine law, or whether 1/N contributions are also allowable, as in Casimir scaling. We find that k-string tensions may, in fact, have 1/N corrections, and consistency with the large-N expansion in the open string sector depends crucially on an exact cancellation, which we will prove, among terms involving odd powers of 1/N in particular combinations of Wilson loops. It is shown how these cancellations are fulfilled, and consistency with the large-N expansion achieved, in a concrete example, namely, strong coupling lattice gauge theory with the heat-kernel action. This is a model which has both a 1/N2 expansion and Casimir scaling of the k-string tensions. Analysis of the closed string channel in this model confirms our conclusions, and provides further insights into the large-N dependence of energy eigenstates and eigenvalues.
Original language | English |
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Journal | Physical Review D (Particles, Fields, Gravitation and Cosmology) |
Volume | 83 |
Issue number | 12 |
Pages (from-to) | 125019 |
ISSN | 1550-7998 |
DOIs | |
Publication status | Published - 17 Jun 2011 |