[Deeppwg] [EXTERNAL] SIDIS Dihadrons BSA for DIS2021

[Marco Contalbrigo]

Dear all,
below is an abstract about SIDIS di-hadron ALU study
Chris intends to submit to the DIS2021 Workshop.

Comments and suggestions are welcome before January 25.

Best regards, Marco.


Multidimensional partial wave analysis of SIDIS dihadron beam spin asymmetries
at CLAS12

Dihadron beam spin asymmetries provide a wide range of insights into nucleon
structure and hadronization. Recent measurements at CLAS12 provide the first
empirical evidence of a nonzero $G_1^\perp$, the parton helicity-dependent
dihadron fragmentation function (DiFF) encoding spin-momentum correlations in
hadronization. These measurements also allow for a point-by-point extraction of
the subleading-twist PDF $e(x)$ in a collinear framework. We observe different
behavior of the asymmetries in different invariant mass regions, motivating a
fully multidimensional study. The DiFFs also expand in terms of partial waves,
each corresponding to the interference of dihadrons of particular
polarizations. Moreover, the rapidity dependence of the asymmetry may help
distinguish between contributions from the current and target fragmentation
regions, helping shed light on the unknown fracture functions. Altogether a
fully multidimensional partial wave analysis is needed, and this presentation
will summarize the efforts and results obtained thus far.