Oh dear God!
I know that all the things people use like dummy owls and reflective tape don't work over time because the individual hawks get used to them - but on the theory that this is a juvenile they might work to teach it to go elsewhere as a habit.
How about you festoon the yard with reflective tape and CDs and that sort of stuff and just make generally less hospitable.
One thing I did (which you may have noticed in my photos of the Chickens in the long grass) is put a lot of stakes in the ground - I am using the step in fence stakes that
@CrazyChookChookLady and I both love for temporary fencing (I hate that we haven't heard form CCCL recently but I assume you are in contact and would tell us if anything was amiss).
Anyway, I read a lot and watched a lot of video about how hawks dive bomb their prey, and although they can be very adaptable they do prefer open ground. So I made my ground less open by creating a forest with all these stakes (about 4' high) so it requires some precision for a hawk to land and take off. The chickens navigate them just fine at ground level and they are just far enough apart for me to squeeze through (they are also easy to pull up and put back). I make some of them even more visible with reflective tape flying from the top.
For you it could only be a temporary thing because it makes it harder to move around your yard - but I am guessing it might just teach the Hawk to look elsewhere if you had them up for a month or so.
Stakes are not expensive - I bought a big batch on line but you can get them individually at TSC.