Classical and quantum radiation reaction for linear acceleration

We investigate the effect of radiation reaction on the motion of a wave packet of a charged scalar particle linearly accelerated in quantum electrodynamics. We give the details of the calculations for the case where the particle is accelerated by a static potential that were outlined in Phys.Rev. D 70 (2004) 081701(R) and present similar results in the case of a time-dependent but space-independent potential. In particular, we calculate the expectation value of the position of the charged particle after the acceleration, to first order in the fine structure constant in the $\hbar \to 0$ limit, and find that the change in the expectation value of the position (the position shift) due to radiation reaction agrees exactly with the result obtained using the Lorentz-Dirac force in classical electrodynamics for both potentials. We also point out that the one-loop correction to the potential may contribute to the position change in this limit.