US actor beheaded uncertain physicist (9)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

(Werner) (h) EISENBERG [ beheaded ] Werner Heisenberg was a German physicist who worked on the German nuclear programme during the Second World War. Jesse Eisenberg is an American actor and playwright who was nomintaed for an Oscar when he played Mark Zuckerberg in The Social Network .