XXVII Encontro Nacional de Física de Partículas e Campos

Using data from FERMILAB E831 (FOCUS) experiment we have done the first measurement of the polarization of $\Lambda_c$'s produced in high-energy ($<E>=180$ GeV) photon-nucleon interactions. For this we have analyzed the decay mode $\Lambda_c \to \Lambda \pi$. We have measured the product $\alpha P$, where $\alpha$ is the weak decay asymmetry parameter, and, using the CP conservation hypothesis, we have gotten the polarization $P$. We have found that in photoproduction the $\Lambda_c$ is produced with a small polarization, between $8%$ and $30%$. As we have low statistics and the errors are large, the polarization is compatible with zero within $1\sigma$. The results are preliminary