Polarized 3 parton production in inclusive DIS at small x

Abstract

Azimuthal angular correlations between produced hadrons/jets in high energy collisions are a sensitive probe of the dynamics of QCD at small x. Here we derive the triple differential cross section for inclusive production of 3 polarized partons in DIS at small x using the spinor helicity formalism. The target proton or nucleus is described using the Color Glass Condensate (CGC) formalism. The resulting expressions are used to study azimuthal angular correlations between produced partons in order to probe the gluon structure of the target hadron or nucleus. Our analytic expressions can also be used to calculate the real part of the Next to Leading Order (NLO) corrections to di-hadron production in DIS by integrating out one of the three final state partons.

Figures (2)

• Figure 1: $3$-parton production diagrams. The solid thick line represents interactions with the target (shock wave). The arrows indicate the direction of fermion charge flow. The photon momentum is incoming whereas all the final state momenta are outgoing.
• Figure 2: We fix $z_1 = z_2 = 0.2$, $|{\bm p}| = |{\bm k}| = |{\bm q}| = 2$ GeV and $Q=3$ GeV. Left: Normalized cross-section against $\Delta \theta_{\bar{q}g}$ with $\Delta_{qg} = 2 \pi/3$ for proton and gold up to linear and quadratic order in $N^{(2)}$. Right: Combined $\Delta\theta_{qg}$ and $\Delta\theta_{\bar{q}g}$ dependence of the normalized cross-section for proton and gold at quadratic order.