Influence of collective nuclear vibrations on initial state eccentricities in Pb+Pb collisions

Abstract

We study within the Monte Carlo Glauber model the influence of collective quantum effects in the Pb nucleus on the azimuthal anisotropy coefficients $\epsilon_{2,3}$ in Pb+Pb collisions at the LHC energies. To account for the quantum effects, we modify the sampling of the nucleon positions by applying suitable filters that guarantee that the colliding nuclei have the mean squared quadrupole and octupole moments consistent with the ones extracted from the experimental quadrupole and octupole strength functions for the Pb nucleus with the help of the energy weighted sum rule. Our Monte Carlo Glauber model with the modified sampling of the nucleon positions leads to $\epsilon_2\{2\}/\epsilon_3\{2\}\approx 0.8$ at centrality $\lesssim 1$\%, which allows to resolve the $v_2$-to-$v_3$ puzzle.