[Clascomment] OPT-IN:Observation of azimuth-dependent suppression of hadron pairs in electron scattering off nuclei

[Sebastian Kuhn]

Nice paper, but I am confused by the dependence on AZIMUTHAL angle difference. Naively, I could understand that pairs with small angular SEPARATION (i.e., p1*p2/\p1||p2| close to 1) would see less suppression than if one particle goes in the opposite direction. However, it's not clear to me how that translates to the difference in azimuthal angle phi relative to the q-vector. For one, it really should depend also on the angle between the q vector and each particle - for instance, I can think of a case where both pions emerge nearly collinear with the q-vector but on opposite sides of it (maximum Delta-phi), yet there shouldn't be much of a difference in the material traversed if both are produced on the (far) surface of the nucleus, with q perpendicular to that surface. So the meaning of Delta-phi and how it translates into this big suppression should be explained better. (This is not - necessarily - analog to the case in heavy ion collision where you look at particles emerging at mi
 d-rapidity - here, I assume both pions tend to be in the forward direction relative to q).