https://doi.org/10.1351/goldbook.08425
Loss of magnetization in the \(xy\) plane (in the absence of \(\boldsymbol{B_{0}}\) inhomogeneities) through the interchange of energy between nuclear spins resulting in some precessing faster than the Larmor angular frequency and some slower.
Note: The resultant exponential decay of signal is characterized by the spin-spin relaxation time \(T_{2}\) (reciprocal of the rate constant of this mechanism).
See also: net dephasing time