Kaonic nitrogen X-ray transition yields in a gaseous target

The first measurement of the yields of three kaonic nitrogen X-ray transitions, using the DEAR (DAPhiNE Exotic Atom Research) setup at the DAPhiNE collider of Frascati, is reported. The yields are 41.5 +/- 8.7(stat.) 4.1(sys.)% for the n = 7 --> 6 transition, 55.0 +/- 3.9(stat.) +/-5.5(sys.)% for the n = 6 --> 5 transition and 57.4 +/- 15.2(stat.) +/- 5.7(sys.)% for the n = 5 --> 4 transition at a density rho = 3.4rho(NTP). By using the experimental yields in an atomic cascade calculation, a 1 to 3% K-shell electron population in the n = 6 level was deduced. (C) 2004 Elsevier B.V. All rights reserved.