Nobel-winning physicist Paul (5)
I believe the answer is:
dirac
'nobel-winning physicist paul' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for dirac that I've seen before include "Nobel Prize winner" , "Paul -, physicist; I'd arc (anag.)" , "English physicist" , "Scientist" , "constant originator" .)