Title: A KiDS weak lensing analysis of assembly bias in GAMA galaxy groups,
Abstract: We investigate possible signatures of halo assembly bias for
spectroscopically selected galaxy groups from the GAMA survey using weak
lensing measurements from the spatially overlapping regions of the deeper,
high-imaging-quality photometric KiDS survey. We use GAMA groups with an
apparent richness larger than 4 to identify samples with comparable mean host
halo masses but with a different radial distribution of satellite galaxies,
which is a proxy for the formation time of the haloes. We measure the weak
lensing signal for groups with a steeper than average and with a shallower than
average satellite distribution and find no sign of halo assembly bias, with the
bias ratio of $0.85^{+0.37}_{-0.25}$, which is consistent with the $\Lambda$CDM
prediction. Our galaxy groups have typical masses of $10^{13} M_{\odot}/h$,
naturally complementing previous studies of halo assembly bias on galaxy
cluster scales.