Helicity correlation of neighboring dihadron

TL;DR

This paper explores the helicity correlation between neighboring hadrons produced from the same parton, offering insights into hadronization mechanisms and spin transfer in high-energy collisions.

Contribution

It introduces the interference dihadron fragmentation function as a tool to study helicity correlations and their relation to spin transfer, expanding understanding beyond polarized beam experiments.

Findings

Helicity correlation arises from both nonperturbative physics and QCD evolution.

The dihadron fragmentation function is sensitive to longitudinal spin transfer.

This approach provides a new method to study spin dynamics in hadronization.

Abstract

The spin correlation of final-state hadrons provides a novel platform to explore the hadronization mechanism of polarized partons in unpolarized high-energy collisions. In this work, we investigate the helicity correlation of two hadrons originating from the same single parton. The production of such a dihadron system is formally described by the interference dihadron fragmentation function, in which the helicity correlation between the two hadrons arise from both the long-distance nonperturbative physics and the perturbative QCD evolution. Beyond the extraction of the dihadron fragmentation function, we demonstrate that it is also a sensitive observable to the longitudinal spin transfer, characterized by the single hadron fragmentation function $G_{1L}$. This intriguing connection opens up new opportunities for understanding the spin dynamics of hadronization and provides a complementary approach to corresponding studies using polarized beams and targets.