Non-trivial theta-vacuum effects in the 2-d O(3) model

作者：Boegli M^*; Niedermayer F; Pepe M; Wiese U J

来源：The Journal of High Energy Physics, 2012, 2012(4): 117.

DOI：10.1007/JHEP04(2012)117

• Nonperturbative Effects
• Lattice Quantum Field Theory
• Sigma Models

We study theta-vacua in the 2-d lattice O(3) model using the standard action and an optimized constraint action with very small cut-off effects, combined with the geometric topological charge. Remarkably, dislocation lattice artifacts do not spoil the non-trivial continuum limit at theta not equal 0, and there are different continuum theories for each value 0 %26lt;= theta %26lt;= pi. A very precise Monte Carlo study of the step scaling function indirectly confirms the exact S-matrix of the 2-d O(3) model at theta = pi.

• 出版日期2012-4