A map of the central campus (with workshop location and other hotel and parking information annotated) can be found here.
Here is the list of hotels that are close to the physics department:
The Inn at the Michigan League
911 N. Unoversity, Ann Arbor MI 48104
https://uunions.umich.edu/league/inn/
Please call (734) 764-3177 to make a reservation.
Bell Tower Hotel
300 S Thayer Street, Ann Arbor MI 48104
https://www.belltowerhotel.com/
Please call (734) 769-3010 to make a reservation.
The Executive and Learning Conference Center (at Ross School of Business)
710 E. University, Ann Arbor, Mi 48104
http://bookings.ihotelier.com/bookings.jsp?groupID=2104358&hotelID=76008
http://www.acc-elandconferencecenter.com/accommodations-in-michigan-en.html
Phone (734) 764-7677 for reservations
Campus Inn (Graduate Ann Arbor)
615 East Huron Street, Ann Arbor, Mi 48104
https://www.graduatehotels.com/ann-arbor/
Phone (800) 666-8693 for reservations
Please see here for alternate hotels:
Ann Arbor area Hotels and Accommodations
Hotels.com often run special rates