Measurements of the strong-interaction widths of the kaonic (3)He and (4)He 2p levels.

ABSTRACT

The kaonic (3)He and (4)He X-rays emitted in the [Formula see text] transitions were measured in the SIDDHARTA experiment. The widths of the kaonic (3)He and (4)He 2p states were determined to be [Formula see text], and [Formula see text], respectively. Both results are consistent with the theoretical predictions. The width of kaonic (4)He is much smaller than the value of [Formula see text] determined by the experiments performed in the 70's and 80's, while the width of kaonic (3)He was determined for the first time.