Experimental constraint on an exotic spin- and velocity-dependent interaction in the sub-meV range of axion mass with a SERF magnetometer

We conducted a search for an exotic spin- and velocity-dependent interaction for polarized electrons with an experimental approach based on a high-sensitivity spin-exchange relaxation-free (SERF) magnetometer, which serves as both a source of polarized electrons and a magnetic-field sensor. The experiment aims to sensitively detect magnetic-field-like effects from the exotic interaction between the polarized electrons in a SERF vapor cell and unpolarized nucleons of a closely located solid-state mass. We report experimental results on the interaction with 82 hours of data averaging, which sets an experimental limit to the interaction in the sub-meV range of axion mass within the important axion window