OPT-IN:Measurements of Beam Spin Asymmetries of π± π0 dihadrons at CLAS12

[Sebastian Kuhn]

I was a bit confused about the definition for theta - "the angle θ between P1 in the dihadron center-of-
mass frame and Ph ≡P1 + P2 in the photon-target rest
frame" - why would you define it as an angle between 2 vectors in different coordinate systems? Fig. 2 doesn't clarify this (as theta doesn't seem to be visible in it). Plus, you say you are "integrating over it"? In general, try to simplify the discussion of geometry (angles) with readers in mind who are not intimately familiar with the conventions of 2-hadron SIDIS.