  We study the jamming transition in a model of elastic particles under shear
at zero temperature, with a focus on the relaxation time $\tau_1$. This
relaxation time is from two-step simulations where the first step is the
ordinary shearing simulation and the second step is the relaxation of the
energy after stopping the shearing. $\tau_1$ is determined from the final
exponential decay of the energy. Such relaxations are done with many different
starting configuration generated by a long shearing simulation in which the
shear varible $\gamma$ slowly increases. We study the correlations of both
$\tau_1$, determined from the decay, and the pressure, $p_1$, from the starting
configurations as a function of the difference in $\gamma$. We find that the
correlations of $p_1$ are more long lived than the ones of $\tau_1$ and find
that the reason for this is that the individual $\tau_1$ is controlled both by
$p_1$ of the starting configuration and a random contribution which depends on
the relaxation path length -- the average distance moved by the particles
during the relaxation. We further conclude that it is $\gammatau$, determined
from the correlations of $\tau_1$, which is the relevant one when the aim is to
generate data that may be used for determining the critical exponent that
characterizes the jamming transition.
