Anisotropic flow of the fireball fed by hard partons

In nuclear collisions at highest accessible Large Hadron Collider (LHC) energies, often more than one dijet pairs deposit momentum into the deconfined expanding medium. With the help of 3+1 dimensional relativistic hydrodynamic simulation we show that this leads to measurable contribution to the anisotropy of collective transverse expansion. Hard partons generate streams in plasma which merge if they come close to each other. This mechanism correlates the resulting contribution to flow anisotropy with the fireball geometry and causes an increase of the elliptic flow in noncentral collisions.

Figure 1

Parameters $v_n$ from collisions at $b=0$ for charged hadrons. Different symbols represent energy loss of hard parton ${dE/dx|}_0=4$ GeV/fm (red $-)$, 7 GeV/fm (black $\square )$, scenario with only hot spots in initial conditions (purple $\times )$, scenario with smooth initial conditions (blue $*)$.

Figure 2

Anisotropy parameters $v_n$ from centrality class 0–2.5 % for charged hadrons as functions of $p_t$. The energy loss of hard partons is given by ${dE/dx|}_0=4$ GeV/fm. Red $▵$: $v_2$; black $\circ$: $v_3$; blue $\nabla$: $v_4$.

Figure 3

Anisotropy parameters $v_n$ for charged hadrons integrated over $p_t$ for different centralities. The energy loss of hard partons is given by ${dE/dx|}_0=4$ GeV/fm.

Figure 4

Anisotropy parameters $v_2$ and $v_3$ for charged hadrons as functions of $p_t$ from collisions within centrality class 30– 40%. The energy loss of hard partons is given by ${dE/dx|}_0=4$ GeV/fm.