The phases of the O(3) σ-model for imaginary ϑ

TY - JOUR

T1 - The phases of the O(3) σ-model for imaginary ϑ

AU - Bhanot, Gyan

AU - David, Francois

PY - 1985

Y1 - 1985

N2 - The lattice O(3) σ-model in two dimensions is studied for imaginary values of the vacuum angle θ{symbol} (θ{symbol} = iθ{symbol}i) and positive β by numerical simulation. We find that the theory exhibits a line of first-order transitions starting at β = ∞, θ{symbol} = i∞ which ends in the (β, θ{symbol}i) plane in a critical endpoint. This line separates a gas phase from a liquid-like phase of topological excitations. We illustrate the physics of the phase transitions with two simple models. We also study the effect of increasing the action of small sized instantons.

AB - The lattice O(3) σ-model in two dimensions is studied for imaginary values of the vacuum angle θ{symbol} (θ{symbol} = iθ{symbol}i) and positive β by numerical simulation. We find that the theory exhibits a line of first-order transitions starting at β = ∞, θ{symbol} = i∞ which ends in the (β, θ{symbol}i) plane in a critical endpoint. This line separates a gas phase from a liquid-like phase of topological excitations. We illustrate the physics of the phase transitions with two simple models. We also study the effect of increasing the action of small sized instantons.

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U2 - 10.1016/0550-3213(85)90253-6

DO - 10.1016/0550-3213(85)90253-6

M3 - Article

SN - 0550-3213

VL - 251

SP - 127

EP - 140

JO - Nuclear Physics, Section B

JF - Nuclear Physics, Section B

IS - C

ER -