  We obtain asymptotic bounds for the tail distribution of steady-state waiting
time in a two server queue where each server processes incoming jobs at a rate
equal to the rate of their arrivals (that is, the half-loaded regime). The job
sizes are taken to be regularly varying. When the incoming jobs have finite
variance, there are basically two types of effects that dominate the tail
asymptotics. While the quantitative distinction between these two manifests
itself only in the slowly varying components, the two effects arise from
qualitatively very different phenomena (arrival of one extremely big job (or)
two big jobs). Then there is a phase transition that occurs when the incoming
jobs have infinite variance. In that case, only one of these effects dominate
the tail asymptotics, the one involving arrival of one extremely big job.
