[Deeppwg] SIDIS di-hadron abstract for DIS19 by Christopher Dilks

[Marco Contalbrigo]

Dear all,
below is a SIDIS di-hadron abstract Christopher intends to submit to
DIS19 (in two days). If you have suggestions, they are welcome.
Best regards, Marco.


Presentation title: "Probing Dihadron Fragmentation Functions and Twist-3 Parton Distribution Functions at CLAS12"


Dihadron production in Semi-Inclusive Deep Inelastic Scattering (SIDIS) represents a novel probe for
nucleon structure, as well as for spin-orbit correlations in hadronization.  Measurements of the beam
spin asymmetry from dihadron production provide access to the twist-3 PDF $e(x)$, which can be related to
the transverse polarization dependence of the transverse force experienced by a struck quark in an
unpolarized nucleon. This asymmetry also provides access to the transverse momentum dependent Dihadron
Fragmentation Function (DiFF), $G_1^{perp}$, which describes the azimuthal dependence of the final state
hadrons on the helicity of the parent quark, and can thought of as the DiFF analog of the wormgear PDF.
The CLAS12 experiment recently took data with longitudinally polarized 12 GeV electrons scattering off an
unpolarized proton target, and is currently taking data using a deuterium target.  Recent
results from CLAS12 will be discussed, along with prospects for upcoming measurements.