Azimuthal Dependence of the Fractional Parton Energy Loss in Cu + Au Collisions at {{s₍₍}} = 200 GeV

The properties of the quark-gluon medium formed in Cu + Au collisions at an energy of {{s₍₍}} = 200 GeV can be investigated using information on the energy loss of high-energy partons ({pₓ} { {ₐ₂₃}}). One of the quantities that can be estimated experimentally is the fractional parton energy loss {S{₋₎ₒₒ}}. On the basis of the data on the elliptic flow {v₂} of { ^0} mesons at high {pₓ}, azimuthal dependences of the fractional parton energy loss {S{₋₎ₒₒ}} () are obtained, and dependences of the energy loss on the effective parton path length {S{₋₎ₒₒ}} ({L{₄₅₅}}) are constructed by considering the azimuthal distribution of the color charge density. Estimates of the effective medium stopping power as a function of the azimuthal angle of { ^0} -meson emission relative to the reaction plane { E / {{ E {{{L{₄₅₅}} () }}}. -0em} {{L{₄₅₅}} () }} are also presented.