Interplay of elliptic and triangular flows in heavy-ion collisions at LHC. Consequences for higher flow harmonics and ridge.

The LHC data on azimuthal anisotropy harmonics from Pb+Pb collisions at center-of-mass energy 2.76 TeV per nucleon pair are analyzed and interpreted in the framework of HYDJET++ model (one of the official event generators of CMS collaboration). The model contains both hydrodynamic state and jets, thus allowing for study of the interplay between the soft and hard processes.
The jets are found (i) to terminate the rise of the elliptic v_2 and triangular v_3 flows with increasing transverse momentum and (ii) to be the main reason of violation of number-of-constituent-quark (NCQ) scaling for both v_2 and v_3 at LHC. The cross-talk of elliptic and triangular flow in the model generates not only even and odd harmonics of higher order, but also ridge in dihadron angular correlations.
Comparison with the experimental data shows that this mechanism is able to reproduce the p_T and centrality dependencies of quadrangular flow v_4, and also the basic trends for pentagonal v_5 and hexagonal v_6 flows.