P-wave resonances in positron-hydrogen scattering

P-wave resonances in positron-hydrogen scattering are investigated by using the method of complex-coordinate rotation. Elaborate Hylleraas-type wavefunctions with up to N = 1120 terms are used in the present investigation. A resonance below the hydrogen N = 2 threshold is found at E = -0.254 112 Ryd with a half width of 1/2Γ = 8.1 x 10-6 Ryd. Three resonances below the positronium N = 2 threshold are also located. The lowest member is determined to lie at E = -0.148 181 Ryd, with a half width of 1/2Γ = 0.000 297 Ryd. Error estimates for the resonance parameters are also given. (author)