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Finite Temperature Momentum Distribution of a Trapped Fermi Gas

We present measurements of the temperature-dependent momentum distribution of a trapped Fermi gas consisting of $^{40}$K in the BCS-BEC crossover regime. Accompanying theoretical results based upon a simple mean-field ground state are compared to the experimental data. Non-monotonic effects associated with temperature, $T$, arise from the competition between thermal broadening and a narrowing of the distribution induced by the decrease in the excitation gap $Δ(T)$ with increasing $T$.