Measurements of elliptic and triangular flow in high-multiplicity $^{3}$He$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV

Understand

We present the first measurement of elliptic ($v_2$) and triangular ($v_3$) flow in high-multiplicity $^{3}$He$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV.

• Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in $^{3}$He$+$Au and in $p$$+$$p$ collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the $^{3}$He$+$Au system.
• The collective behavior is quantified in terms of elliptic $v_2$ and triangular $v_3$ anisotropy coefficients measured with respect to their corresponding event planes.
• The $v_2$ values are comparable to those previously measured in $d$$+$Au collisions at the same nucleon-nucleon center-of-mass energy.