Anisotropic Flow Measurements from the NA61/SHINE and NA49 Beam Momentum Scan Programs at CERN SPS

The NA61/SHINE experiment at the CERN SPS has recently extended its program for the energy scan with Pb ions. In the past, the NA49 experiment, which preceded the NA61/SHINE, has also recorded data for Pb–Pb collisions at different energies. Together, the two experiments cover wide range of collision energies in the beam momentum range of 13–150A GeV/$c$ provided by CERN SPS, which has a significant overlap with the ongoing second phase of the beam energy scan program (BES-II) at RHIC. The directed and elliptic flow relative to the projectile spectator plane are measured with the new NA61/SHINE data for Pb–Pb collisions at 13 and 30A GeV/$c$ and revised existing NA49 data at 40A GeV. New results extend the existing world data available from the previous NA49 measurements and ongoing BES-II and fixed-target programs at STAR. The developed analysis techniques are also relevant for measurements at the future CBM experiment at FAIR and the MPD experiment at NICA.