Mass gap in the 2D O(3) non-linear sigma model with a theta=pi term

B. Alles; A. Papa

doi:10.1103/physrevd.77.056008

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arXiv · 0711.1496

Mass gap in the 2D O(3) non-linear sigma model with a theta=pi term

B. Alles·A. Papa

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Abstract

By analytic continuation to real theta of data obtained from numerical simulation at imaginary theta we study the Haldane conjecture and show that the O(3) non-linear sigma model with a theta term in 2 dimensions becomes massless at theta=3.10(5). A modified cluster algorithm has been introduced to simulate the model with imaginary theta. Two different definitions of the topological charge on the lattice have been used; one of them needs renormalization to match the continuum operator. Our work also offers a successful test for numerical methods based on analytic continuation.

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BibTeX RIS

B. Alles, A. Papa. 2008-02-25. Mass gap in the 2D O(3) non-linear sigma model with a theta=pi term. https://doi.org/10.1103/physrevd.77.056008

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