17-24 July 2013
KTH and Stockholm University Campus
Europe/Stockholm timezone

Spectrum of the open QCD flux tube in d=2+1 and its effective string description

20 Jul 2013, 12:32
F3 (KTH Campus)


KTH Campus

Talk presentation Non-perturbative QFT and String Theory Non-perturbative QFT and String Theory


Bastian Brandt (U)


Simulations in lattice gauge theory suggest that the formation of a flux tube between a quark and antiquark leads to quark confinement. It is conjectured that the infrared behaviour of the flux tube is governed by an effective string theory and simulations show good agreement between lattice data and its predictions. To next-to leading order (R^{-3}) in the inverse \bar{q}q separation (R) the effective string theory is equivalent to Nambu-Goto string theory. For the open flux tube in three dimensions corrections to Nambu-Goto appear at order R^{-4}. They correspond to boundary terms in the worldsheet field theory. These corrections are presumably small for the ground state, but significantly larger for the excited states and lift the degeneracies of the free theory. We compare these predictions to measurements of the excitation spectrum of the flux tube in 3d SU(2) and SU(3) pure gauge theory and extract the coefficient of the leading order boundary term in the effective action.

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