{bar p}p annihilation at rest into K{sub L}K{sup {plus_minus}}{pi}{sup {minus_plus}}

We present a measurement and partial wave analysis of the final state K{sub L}K{sup {plus_minus}}{pi}{sup {minus_plus}} of {bar p}p annihilation at rest in liquid hydrogen. This reaction is important for the study of the {bar K}K decay mode of scalar resonances, in particular, the isovectors a{sub 0}(980) and a{sub 0}(1450). The determination of the a{sub 0}(1450) production also fixes the {bar K}K coupling of the isoscalar f{sub 0}(1500) which is discussed as a glueball. We find B{bold (}{bar p}p{r_arrow}a{sub 0}(1450){pi};a{sub 0}(1450){r_arrow}{bar K}K{bold )}=(8.88{plus_minus}1.68){times}10{sup {minus}4} and hence B{bold (}{bar p}p{r_arrow}f{sub 0}(1500){pi};f{sub 0}(1500){r_arrow}{bar K}K{bold )}=(4.52{plus_minus}0.36){times}10{sup {minus}4}. The mass and width of a{sub 0}(1450) are m=1480{plus_minus}30MeV/c{sup 2} and {Gamma}=265{plus_minus}15MeV/c{sup 2}, respectively. For a{sub 0}(980) we determine the relative ratio B({bar p}p{r_arrow}a{sub 0}{pi};a{sub 0}{r_arrow}{bar K}K)/B({bar p}p{r_arrow}a{sub 0}{pi};a{sub 0}{r_arrow}{pi}{eta}) =0.23{plus_minus}0.05 and its relative coupling, {bar K}K to {pi}{eta}, is 1.03{plus_minus}0.14. {copyright} {ital 1998} {ital The American Physical Society}