Searching for companions down to 2 AU from beta Pictoris using the L'-band AGPM coronagraph on VLT/NACO

Context. The orbit of the giant planet discovered around beta Pic is slightly inclined with respect to the outer parts of the debris disc, which creates a warp in the inner debris disc. This inclination might be explained by gravitational interactions with other planets. Aims. We aim to search for additional giant planets located at smaller angular separations from the star. Methods. We used the new L'-band AGPM coronagraph on VLT/NACO, which provides an exquisite inner working angle. A long observing sequence was obtained on beta Pic in pupil-tracking mode. To derive sensitivity limits, the collected images were processed using a principal-component analysis technique specifically tailored to angular differential imaging. Results. No additional planet is detected down to an angular separation of 0.2" with a sensitivity better than 5 MJup. Meaningful upper limits (< 10 MJup) are derived down to an angular separation of 0.1", which corresponds to 2 AU at the distance of beta Pic.