Investigating a multiparticle cumulant method for measuring fluctuations in energy loss at high transverse momentum in heavy-ion collisions

Jets are often used to probe the QGP produced in heavy-ion collisions, due to their interactions with the medium at various length scales resulting in energy loss. The Fourier harmonics for anisotropies in the high p_T particle yield v_n(p_T) are useful for measuring energy loss, because they are sensitive to the path length for jets traveling through the QGP, and are thus sensitive to the angular dependence of energy loss. These quantities and their fluctuations can be measured experimentally by differential multiparticle cumulant estimates v_n{2k}(p_T), that correlate the angular yield of high p_T particles with the net angular yield of particles. The average value for energy loss can be measured accurately, but those measurements are not sensitive to event by event fluctuations in energy loss, which could be caused by the QGP’s changing geometry, parton shower, or other variables. To measure fluctuations in v_n(p_T), we present a set of experimental observables to estimate the difference between central moments of cumulant estimates for reference and differential flow. We show these quantities are sensitive to differences in the central moments for various distributions of v_n(p_T) with a Monte Carlo simulation.