Best solution for your problem and probably will reduce your code is
return sessionsQuery.list();
In above problem you are iterating list using iterator and again storing into an ArrayList unnecesarry creating an object
Instead return that list what you are getting from above code.
After seeing your name Query, I found out that it will give you
List<Object[]>
because you have passed projections for select operator
Instead you can make your query as
Select sess from SESSION sess where 'your condition what you want'