Limit on variation of fundamental constants from photoassociation in ultracold gases

ORAL

Abstract

We propose a novel approach to measure the limit on the time variation of the electron-to-proton mass ratio $\beta=m_e/m_p$. It has been shown that the scattering length, which can be obtained from ultracold scattering experiments, is extremely sensitive to $\beta$ \footnote{Cheng Chin and V. V. Flambaum, PRL 96, 230801(2006)}. We show that the photoassociation (PA) rate of ultracold atoms into molecules can also exhibit such dependence. The PA rate near a Feshbach resonance, which exhibits both a maximum at the resonance and a minimum in vicinity, allows for high sensitivity at both, while near the minimum the saturation effect is negligible. Our prediction based on a two-channel model and numerical solution indicates that the precision measurement of variation of $\beta$ of up to $10^{-14}-10^{-15}$ could be possible in a suitable system.

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Authors

  • Marco Gacesa

    University of Connecticut, Department of Physics, University of Connecticut, Storrs, CT 06269, Department of Physics, University of Connecticut

  • Robin C\^ot\'e

    Physics Department, University of Connecticut, Storrs, USA, University of Connecticut, University of Connecticut Storrs, Department of Physics, University of Connecticut, Storrs, CT 06269, Department of Physics, University of Connecticut