docs: def smeft_evolve_leadinglog(C_in, scale_in, scale_out, newphys=True):
      """Solve the SMEFT RGEs in the leading log approximation.
  
      Input C_in and output C_out are dictionaries of arrays."""
      C_out = deepcopy(C_in)
      b = beta.beta(C_out, newphys=newphys)
      for k, C in C_out.items():
          C_out[k] = C + b[k] / (16 * pi**2) * log(scale_out / scale_in)
      return C_out