15min:

JINHAI CHEN, TIMOTHY C. STEIMLE, Department of Chemistry and Biochemistry, Arizona State University, Temple, AZ 85287; ZHONG WANG, TREVOR J. SEARS, Department of Chemistry, Brookhaven National Laboratory, Upton, NY 11973-5000.

The polarization signals induced by the Zeeman effect in the X⁴ F⁴ band of FeH have been proposed for use in the characterization of stellar magnetic fields. While the magnetic tuning of the low-rotational levels of the X⁴ _7/2 state has been measured by pure-rotational laser magnet resonance spectroscopy, the strength of the Zeeman effect in the upper state is unknown. Here we report on the magnetic tuning of levels in (v=1)F⁴ _7/2 state derived from the analysis of the optical Zeeman spectra of the X⁴ _7/2 F⁴ _7/2 (1,0) band system. The Zeeman broadening and splitting of the Q(3.5)( =11356.72~ cm^-1) transition were successfully modeled using a traditional effective Hamiltonian. The determined magnetic g_L-factor is 1.079(8) when the g_S-factor is constrained to 2.002. Plausible explanations for deviation of g_L from the expected value of unity will be given. The determined parameters are used to predict the magnetic tuning of the X⁴ _7/2 F⁴ _7/2 (1,0) features for fields comparable to those found in sunspots.