Extended Data Fig. 4: Allowed 13S–23P transitions and their intensities.
From: Cooling positronium to ultralow velocities with a chirped laser pulse train
a, b, Magnitudes of the electric dipole moments. The subscripts x, y, and z of the variable d at the top of each figure refer to the direction of projection of the dipole moment. Numbers attached to the arrows represent the squared ratio of the projected dipole moment with respect to the constant d0 defined in the text. M refers to the projection of the total angular momentum J onto the quantisation axis. c, Summary of spontaneous emission rates. Numbers in the table cells represent the ratio of the spontaneous emission rate from the excited state with quantum numbers Je and Me to the ground state with Mg.Γsp. denotes the total spontaneous emission rate from each excited state.
