Update benchmark/TensorKitBenchmarks/utils/BenchUtils.jl

Co-authored-by: Jutho <Jutho@users.noreply.github.com>

Author: lkdvos

benchmark/TensorKitBenchmarks/utils/BenchUtils.jl

@@ -55,7 +55,7 @@ function generate_space(::Type{U1Irrep}, D::Int, sigma::Real=0.5)
     return U1Space((s => d for (s, d) in zip(sectors, dims))...)
 end
 function generate_space(::Type{SU2Irrep}, D::Int, sigma::Real=0.5)
-    poisson_pdf(x) = ceil(Int, D * exp(-sigma) * sigma^x / factorial(x))
+    poisson_pdf(x) = ceil(Int, D * exp(-sigma) * sigma^x / factorial(x+1))
 
     sectors = SU2Irrep[]
     dims = Int[]