Static Longitudinal Field Relaxation
Relaxonomy --> here
When the muon spin polarization [math]\displaystyle{ \vec{P} }[/math] is initially in the same direction as the applied magnetic field [math]\displaystyle{ \vec{B} }[/math], we call that the [math]\displaystyle{ z }[/math] direction. This is called the longitudinal field (LF) geometry. The relaxation of [math]\displaystyle{ \vec{P} }[/math] is then described by
where the lower case [math]\displaystyle{ g }[/math] is used (instead of the more general [math]\displaystyle{ G }[/math]) to designate a static relaxation function. (Dynamic cases will be treated later.)
just like in ZF. In the limit where [math]\displaystyle{ B }[/math] >> any random local magnetic fields (RLMF), this formulation is valid. (At last, a "low-bogosity" case!) However, in modest applied fields (B [math]\displaystyle{ \sim }[/math] RLMF) it is subject to the same caveats as the ZF case, which see.