Azimuthal correlations in the structure functions of polarized dihadron semi-inclusive deep inelastic scattering

Azimuthal correlations in two hadron production in deep inelastic scattering of unpolarized leptons off a transversely polarized nucleon are discussed. Specifically, a simple approach for accessing ratios of structure functions corresponding to the Sivers effect and transversity induced single spin azimuthal asymmetries to unpolarized structure functions is presented. This approach is then applied to sample pseudodata generated by a modified version of the LEPTO Monte Carlo event generator that includes the Sivers effect. Using these data, it is shown that the azimuthal correlations in the Sivers-like structure functions and the unpolarized structure functions are significantly different. Collins-like single hadron asymmetries in a dihadron sample are also discussed, for which experimental results were recently presented by the COMPASS collaboration.

Figure 1

The leading order diagram for two hadron production in the current fragmentation region of SIDIS.

Figure 2

Left: the SL $A_{2SL}^{\sin ({\phi }_2-{\phi }_S)}(\mathrm{\Delta }\phi )$ asymmetries (filled triangles) of the negative hadron extracted directly from MC data (filled triangles) and calculated using the entanglement relations from positive hadron sine and cosine asymmetries (filled circles). The calculated asymmetries are plotted shifted on 0.05 rad. Right: the same for $A_{2SL}^{\cos ({\phi }_2-{\phi }_S)}(\mathrm{\Delta }\phi )$ asymmetry.

Figure 3

The ratios $A_{1S}(\mathrm{\Delta }\phi )$ (triangles) and $A_{2S}(\mathrm{\Delta }\phi )$ (circles) from MC data. The continuous (dashed) line is a result of a $\mathrm{\Delta }\phi$-dependent fit and dotted (dot-dashed) lines for a constant fit for a positive (negative) hadron.

Figure 4

Left: the $A_{1SL}^{\sin ({\phi }_1-{\phi }_S)}(\mathrm{\Delta }\phi )$ (triangles) and $A_{2SL}^{\sin ({\phi }_2-{\phi }_S)}(\mathrm{\Delta }\phi )$ asymmetries (circles) from MC data. The continuous (dashed) line is a result of a $\mathrm{\Delta }\phi$-dependent fit and dashed (dot-dashed) lines for a constant fit for a positive (negative) hadron. Right: the same for $A_{1SL}^{\cos ({\phi }_1-{\phi }_S)}(\mathrm{\Delta }\phi )$ and $A_{2SL}^{\cos ({\phi }_2-{\phi }_S)}(\mathrm{\Delta }\phi )$ asymmetries.