Identification of flow background to subtract in jet-like azimuthal correlations

We derive an analytical form for flow background to jet-like azimuthal correlations in a cluster approach. We argue that the elliptic flow parameter to use in a jet-correlation background is that from a two-particle method excluding nonflow correlation unrelated to the reaction plane, but including cross-terms between cluster correlation and cluster flow. We verify our result with Monte Carlo simulations. We discuss implications of our findings in the context of jet-like correlations from STAR and PHENIX.