title: Enhanced sensitivity to fundamental constants in ultracold atomic and molecular systems near Feshbach resonances.
abstract: Scattering length, which can be measured in Bose-Einstein condensate and Feshbach molecule experiments, is extremely sensitive to the variation of fundamental constants, in particular, the electron-to-proton mass ratio (m(e)/m(p) or m(e)/Lambda(QCD), where Lambda(QCD), is the QCD scale). Based on single- and two-channel scattering models, we show how the variation of the mass ratio propagates to the scattering length. Our results suggest that variation of m(e)/m(p) on the level of 10(-11) - 10(-14) on the level of can be detected near a narrow magnetic or an optical Feshbach resonance by monitoring the scattering length on the 1% level. Derived formulas may also be used to estimate the isotopic shift of the scattering length.
authors.affiliation: James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637, USA.
authors.forename: Cheng
authors.initials: C
authors.lastname: Chin
authors.forename: V V
authors.initials: VV
authors.lastname: Flambaum