ZYAM and $\bf v_2$: Underestimating jet yields from dihadron azimuth correlations

Understand

Dihadron azimuth correlations can provide combinatoric access to jet structure in nuclear collisions.

• To isolate true jet yields a background must be subtracted, including a constant offset and a contribution from "elliptic flow" (azimuth quadrupole measured by $v^2_2$).
• The principle of "zero yield at minimum" (ZYAM) has been introduced to determine the constant offset.
• Independent measurements determine $v_2^2$.