%0 Book Section %T A Beyond Mean Field study of Bose gases in a double-well potential with a Feshbach resonance publisher American Institute of Physics (AIP) %D 2013 %U 978-0-7354-1165-4 %@ https://hdl.handle.net/20.500.14352/45631 %X The Bose-Hubbard model coupled to a Feshbach resonance is studied. Quantum phase transitions are analyzed within a beyond mean field framework in order to get finite size corrections to the simple mean field approach. Analytical results for the ground state energy and the first few energy gaps are presented. %~