I want to know the answer to the following question:
Who is Hai Gaon thought to be referring to when he says Ashkenaz?
All the background I'm provided with is that "In the Mahzor Vitry, the kingdom of Ashkenaz is referred to chiefly in regard to the ritual of the synagogue there, but occasionally also with regard to certain other observances.". Is that enough to answer the question?
Answer: no