Analytical calculation of the Smith lifetime Q matrix using a Magnus propagator: Applications to the study of resonances occurring in ultracold inelastic collisions with and without an applied magnetic field

作者：Guillon G^*; Stoecklin T

来源：Journal of Chemical Physics, 2009, 130(14): 144306.

DOI：10.1063/1.3111881

• atom-ion collisions
• helium
• magnetic field effects
• nitrogen
• positive ions
• resonance
• resonant states
• S-matrix theory
• wave functions

We take advantage of the simple expression of the sector adiabatic wave functions of the Magnus propagator to obtain accurate values of the energy derivative of the S matrix which, in turn, is used to get the Smith lifetime Q matrix. The procedure involves the simultaneous generation of both the R matrix and its energy derivative dR/dE which are propagated along the scattering coordinate. We present a few examples of application to the field free He-N(2)+ inelastic collisions which we previously studied. This method is then applied to the calculation of the lifetime of tuned zero energy Feshbach resonances using a magnetic field. We give and discuss the law of variation as a function of the magnetic field of the Q matrix eigenvalues across such resonance. Some examples of application are given for the He-N(2)+ collisions in a magnetic field.

• 出版日期2009-4-14