Collectivity in pp from resummed interference effects?

Abstract

Azimuthal asymmetries vn in the soft transverse momentum spectra of hadronic collisions can result as a consequence of quantum interference and color flow which translates spatial anisotropies into momentum anisotropies via multipole radiation patterns. Here, we analyze to what extent these effects result in signal strengths vn{2s} that can persist in higher order (2s) cumulants. In a simple model of soft multi-particle production with quantum interference effects in which m particles are emitted from N sources and in which interference contributions appear naturally ordered in inverse powers of the adjoint color trace, 1/(Nc2−1), we provide the first resummed calculation of all powers of m2/(Nc2−1). This allows one to determine all higher order flow cumulants vn{2s} with the same parametric accuracy. For a phenomenologically relevant range of N sources emitting m particles, we find that the even flow coefficients vn{2s} decrease very mildly with increasing cumulants. This provides a proof of principle that non-vanishing higher order cumulants vn{2s} can persist in systems that exhibit neither final state interactions nor phenomena related to high (saturated) initial parton densities.