[pasc1878]

Why specifically in science.

PhD is the degree you usually get at that level for English, Classics, Economics, Histrory etc..

Some Universities use DPhil (Oxford) for all these but I know of no other degree at that level except for those two (MD is effectively lower and DSc is usually some form of honourary degree and I am not certain what LLD is)

[wheelinsupial]

MIT seems to offer an ScD as an alternative to the PhD in some fields.

https://oge.mit.edu/graduate-admissions/programs/doctoral-de...

[thsksbd]

Because my post was wordy enough as it was and the OP was asking about a physics degree. I was going to be more specific, but it was late, I was tiered and.... meh