Orbital-resolved three-body recombination across a p-wave Feshbach resonance in ultracold $^6$Li

TL;DR

This study presents high-precision, orbital-resolved measurements of three-body recombination near a p-wave Feshbach resonance in ultracold $^6$Li, enabling detailed understanding of few-body loss mechanisms and resonance properties.

Contribution

It introduces a radio-frequency gated protocol for orbital resolution and provides the first precise measurements of resonance splitting and effective-range parameters in this system.

Findings

Measured resonance splitting $oldsymbol{ ext{7.6(3) mG}}$ at lowest temperature.

Determined effective-range parameter $oldsymbol{ ext{0.151(6)} a_0^{-1}}$ in agreement with theory.

Validated the cascade-recombination model for three-body loss near p-wave resonance.

Abstract

We report precision, orbital-resolved measurements of three-body recombination near the 159~G $p$-wave Feshbach resonance in an ultracold gas of $^{6}$Li atoms prepared in their lowest hyperfine state. Using a radio-frequency gated protocol that suppresses magnetic-field transients below the milligauss level, we resolve loss features associated with the $|m_\ell|=1$ and $m_\ell=0$ orbital projections. The measured three-body loss coefficient $L_3$ is well captured by a thermally averaged cascade-recombination model, enabling extraction of the resonance splitting $\delta B$ and effective-range parameter $k_e$. At the lowest temperature, we obtain $\delta B = 7.6(3)$~mG and $k_e = 0.151(6)\,a_0^{-1}$, both in quantitative agreement with coupled-channel theory. These results establish orbital-resolved three-body spectroscopy as a precision probe of $p$-wave scattering and provide a benchmark for microscopic models of resonant few-body loss.