Transverse spin correlation of back-to-back dihadron in unpolarized collisions

TL;DR

This paper explores the transverse spin correlation of back-to-back dihadron production in unpolarized collisions, proposing it as a new way to probe the chiral-odd fragmentation function and understand transversely polarized quark hadronization.

Contribution

It introduces the transverse spin correlation as a novel observable in unpolarized collisions and computes its theoretical behavior at the partonic level, linking it to helicity amplitudes.

Findings

Establishes a theoretical framework for transverse spin correlation in unpolarized collisions.

Connects the observable to the chiral-odd fragmentation function $H_{1T}(z)$.

Suggests future experimental measurements can reveal details of transversely polarized quark hadronization.

Abstract

The spin correlation of back-to-back dihadron emerges in unpolarized high-energy collision, empowering unpolarized experiments to shed light on the spin-dependent fragmentation functions. This work investigates the transverse spin correlation of back-to-back dihadron in unpolarized $e^+e^-$, $pp$, and $\gamma p$ collisions, which serves as a novel probe of the chiral-odd fragmentation function $H_{1T}(z)$. We compute the transverse spin correlation at the partonic level and establish a connection with helicity amplitudes. Measuring this observable in future experiments can reveal valuable information on the hadronization of transversely polarized quarks.