STAR Collaboration2019-01-082019-01-082015STAR Collaboration. "Azimuthal Anisotropy in $\mathrm{U}+\mathrm{U}$ and $\mathrm{Au}+\mathrm{Au}$ Collisions at RHIC." <i>Physical Review Letters,</i> 115, no. 22 (2015) American Physical Society: https://doi.org/10.1103/PhysRevLett.115.222301.https://hdl.handle.net/1911/104993Collisions between prolate uranium nuclei are used to study how particle production and azimuthal anisotropies depend on initial geometry in heavy-ion collisions. We report the two- and four-particle cumulants, v2{2} and v2{4}, for charged hadrons from U+U collisions at √sNN=193 GeV and Au+Au collisions at √sNN=200 GeV. Nearly fully overlapping collisions are selected based on the energy deposited by spectators in zero degree calorimeters (ZDCs). Within this sample, the observed dependence of v2{2} on multiplicity demonstrates that ZDC information combined with multiplicity can preferentially select different overlap configurations in U+U collisions. We also show that v2 vs multiplicity can be better described by models, such as gluon saturation or quark participant models, that eliminate the dependence of the multiplicity on the number of binary nucleon-nucleon collisions.engArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.Journal articlehttps://doi.org/10.1103/PhysRevLett.115.222301