Abstract: | Recently, multiparticle-correlation measurements of relativistic
$p/d/^3$He$+$Au, $p$$+$Pb, and even $p$$+$$p$ collisions have shown surprising
collective signatures. Here we present beam-energy-scan measurements of 2-, 4-,
and 6-particle angular correlations in $d$$+$Au collisions at
$sqrt{s_{_{NN}}}$=200, 62.4, 39, and 19.6 GeV. We also present measurements of
2- and 4-particle angular correlations in $p$$+$Au collisions at
$sqrt{s_{_{NN}}}$=200 GeV. We find the 4-particle cumulant to be real-valued
for $d$$+$Au collisions at all four energies. We also find that the 4-particle
cumulant in $p$$+$Au has the opposite sign as that in $d$$+$Au, indicating that
the correlations are geometrical and therefore collective in origin. Further we
find that the 6-particle cumulant agrees with the 4-particle cumulant in
$d$$+$Au collisions at 200 GeV, which indicates that nonflow effects are
subdominant and provides strong evidence of collectivity. |