From the Physics Graduate Handbook:

"The Prelim Exam chairperson should notify the 
department chairperson in writing of the committee 
decision after the student attempts the exam."

Please include the date and the committee composition.

"After the student has passed the exam, the Preliminary 
Exam Committee should sign the Application for Admission
to Candidacy form ..." in quadruplicate.

Also, students are strongly encouraged to apply for a 
Masters (Plan II), if they have not yet received a Masters 
from our program.  All it takes is a little extra paperwork, 
since the Prelim Exam counts as the Comprehensive Exam for a 
Masters and the other requirements have been satisfied by 
this stage.