Subleading conformal dimensions at the O(4) Wilson-Fisher fixed point
In this work we focus on computing the conformal dimensions D(jL,jR) of local fields that transform in an irreducible representation of SU(2)×SU(2) labeled with (jL,jR) at the O(4) Wilson-Fisher fixed point using the Monte Carlo method. In the large charge expansion, among the sectors with a fixed large value of j=max(jL,jR), the leading sector has |jL-jR|=0 and the subleading one has |jL-jR|=1. Since Monte Carlo calculations at large j become challenging in the traditional lattice formulation of the O(4) model, a qubit regularized O(4) lattice model was used recently to compute D(j,j). Here we extend those calculations to the subleading sector. Our Monte Carlo results in the range 2≤j≤20 fit well to the expected large j expansion D(j,j-1)-D(j,j)∼λ0+λ1/2/j+λ1/j+λ3/2/j3/2, but we have to assume that at least one of the purely quantum mechanical contributions λ0 or λ1 is nonzero. Assuming λ0=0 as conjectured recently, we find λ1/2≈2.1(1), λ1≈2.3(2), and λ3/2≈1.2(2).
